JP2009030526A - Intake valve mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake valve structure capable of inhibiting disturbance of linear flow of air-fuel mixture entering a combustion chamber from am intake port with a simple structure. <P>SOLUTION: The intake valve structure for opening and closing an opening part 3a of an intake port 3 communicating to the combustion chamber 2 includes a valve head part 6 positioned in the combustion chamber 2 and capable of opening and closing the opening part 3a, and a stem 7 slidably supported with extending from the valve head part 6 to the intake port 3 side via the opening part 3a. The stem 7 branches to a plurality of parts at the valve head part 6 side and supports a part near an outer circumference edge part of the valve head part 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an intake valve structure that opens and closes an opening of an intake port that communicates with a combustion chamber.

  Conventionally, an intake / exhaust structure described in Patent Document 1 is known as an intake valve structure that opens and closes an opening of an intake port communicating with a combustion chamber. In this intake / exhaust structure, the intake valve has a valve umbrella portion that can open and close an opening portion of the intake port, and a pair of stems extending in parallel to each other from the valve umbrella portion. Since the pair of stems is not located near the center of the opening, the flow of the air-fuel mixture tends to concentrate near the center of the combustion chamber, and the air-fuel mixture will convect in the axial direction of the combustion chamber, An axial vortex (longitudinal vortex) is formed. Since such a longitudinal vortex is applied to the air-fuel mixture, stratified combustion in the left and right (radius) direction of the combustion chamber can be obtained. The stratified combustion and the turbulence of the mixed airflow can make it easy to achieve lean combustion.

JP-A-7-305610

  However, the intake valve structure described in Patent Document 1 makes it possible to ensure smooth movement of each stem by forming the valve head portion so that it can be divided into a plurality of valve pieces between each stem. Since it is a structure, the increase in the number of parts for forming a valve head part and the complexity of a structure become a problem. On the other hand, when the structure of the pair of stems is extended without dividing the valve head part into a plurality of valve pieces, the structure is simplified, but in order to ensure smooth operation, both stems and stems are used. It is necessary that the guides are arranged in parallel and at appropriate positions. Therefore, it is necessary to suppress the manufacturing error, and there is a possibility that the manufacturing cost increases.

  In view of the above circumstances, an object of the present invention is to provide an intake valve structure capable of suppressing the obstruction of the flow of a linear air-fuel mixture entering the fuel chamber from the intake port with a simple configuration.

Means and effects for solving the problems

The present invention relates to an intake valve structure that opens and closes an opening of an intake port that communicates with a combustion chamber.
In order to achieve the above object, the intake valve structure according to the present invention has several features as follows. That is, the intake valve structure of the present invention includes the following features alone or in combination as appropriate.

  In order to achieve the above object, a first feature of the intake valve structure according to the present invention is an intake valve structure for opening and closing an opening of an intake port that communicates with a combustion chamber. A valve umbrella part capable of opening and closing the opening part, and a stem that extends from the valve umbrella part through the opening part to the intake port side and is slidably supported. On the part side, it is branched into a plurality of parts to support the vicinity of the outer peripheral edge of the valve head part.

  According to this configuration, since the stem branches and supports the vicinity of the outer peripheral edge of the valve head portion, the vicinity of the center of the valve head portion is not supported by the stem. Therefore, for example, by arranging the stem so that the branched portion of the stem is not located at the center of the intake port, it is possible to suppress the obstruction of the flow of the linear air-fuel mixture entering the combustion chamber from the intake port. In addition, since the vicinity of the outer peripheral edge portion of the valve head portion is supported at a plurality of positions, the coupling state between the stem and the valve head portion can be stabilized. As a result, the intake valve structure can be made hard to break. Moreover, since the valve head portion is supported by one stem, the number of components is reduced and the configuration is simplified.

  A second feature of the intake valve structure according to the present invention is that the stem is bifurcated and formed on the valve umbrella side, and the branched portion is close to the inner wall of the intake port. It is arranged to do.

  According to this configuration, the branched portion of the stem is disposed away from the center of the intake port, so that the path passing through the center of the intake port can be prevented. Moreover, since the configuration is simple, the intake valve structure can be easily manufactured.

  A third feature of the intake valve structure according to the present invention is that the stem branch point is a recess formed on the inner wall of the intake port in the closed state in which the opening is closed by the valve umbrella. It is configured to be stored.

  According to this configuration, the position of the stem branch point can be kept away from the center of the intake port, so when the opening is opened, the branch point moves to the vicinity of the center of the intake port, It becomes easy to configure so as not to block the flow of the air-fuel mixture.

  A fourth feature of the intake valve structure according to the present invention is that the stem branch point is housed in the recess when the valve head portion is open from the opening. That is.

  According to this configuration, when the opening is opened, the branch point of the stem does not extend from the recess to the intake port side, so that the flow of the air-fuel mixture in the intake port is blocked by the branch point. Absent. As a result, the air-fuel mixture is more likely to pass linearly.

  A fifth feature of the intake valve structure according to the present invention is that the stem is formed in a net shape on the valve umbrella side.

  According to this configuration, since the stem is formed in a net shape on the side of the valve head, the air-fuel mixture easily passes. In addition, the valve head portion is stably supported by a stem that spreads by branching the outer peripheral edge into a net shape.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic cross-sectional view showing an intake valve structure according to a first embodiment of the present invention. 2 is a cross-sectional view of the intake valve structure shown in FIG. FIG. 3 is a perspective view showing the valve head portion shown in FIG. The intake valve structure according to the first embodiment is an application of the present invention to a reciprocating type internal combustion engine.

The intake valve structure shown in FIG. 1 includes a cylinder head 1 and an intake valve 5.
The cylinder head 1 is formed with an intake port 3 communicating with a combustion chamber 2 of the cylinder. The schematic cross-sectional view shown in FIG. 1 shows a cross section in which the cylinder head 1 is cut so as to include the radial center of the intake port 3. The opening 3a of the intake port 3 with respect to the combustion chamber 2 is formed to be substantially circular, and a valve seat 4 on which the valve head portion 6 is seated is provided around the opening 3a.

  The intake valve 5 includes a disc-shaped valve umbrella portion 6 and a stem 7 extending from the valve umbrella portion 6. The valve head portion 6 can be seated on the valve seat 4 to close the opening 3a. FIG. 1 shows a closed state in which the valve head portion 6 is seated on the valve seat 4.

  As shown in FIG. 3, the stem 7 is formed so as to be bifurcated from the main shaft portion 7 a on the valve umbrella portion 6 side. And the outer periphery part vicinity of the valve head part 6 is supported by branch part 7b * 7b. From the viewpoint of securing the strength of the intake valve 5, a surface that can contact the valve seat 4 is secured on the surface of the valve head portion 6 facing the valve seat 4, and the position closest to the outer peripheral edge portion is branched. It is desirable to support the portions 7b and 7b.

  As shown in FIG. 1, the cylinder head 1 has a through hole 1 a that opens from the outside toward the intake port 3 at a position substantially facing the opening 3 a of the intake port 3. The through hole 1a is formed at a position where the center line passes through the approximate center of the opening 3a. A cylindrical stem guide 8 is installed in the through hole 1a.

  The stem 7 is slidably attached to the cylinder head 1 via the stem guide 8. Note that the end of the stem 7 on the opposite side to the valve head portion 6 of the main shaft portion 7a is connected to a drive mechanism using a cam (not shown). By moving the stem 7 forward and backward by the drive mechanism, the valve head portion 6 can be seated or separated.

  As shown in FIG. 2, the branch portions 7 b and 7 b are formed in a symmetrical arch shape with an axis passing through the center of the main shaft portion 7 a, and the branch portions 7 b and 7 b are formed in the intake port 3. The intake valve 5 is arranged along the wall surface. That is, the intake valve 5 is disposed by restricting the rotation about the stem axis so that the virtual plane including the branch portions 7b and 7b and the virtual plane including the radial center of the intake port 3 are substantially orthogonal to each other. Is done.

Next, the intake process of the intake valve structure configured as described above will be described.
FIG. 4 is a schematic cross-sectional view showing a valve opening state in which the intake valve 5 moves so as to extend toward the combustion chamber 2 and the valve head portion 6 is separated from the intake valve structure shown in FIG. In FIG. 4, the intake valve 5 also shows a cross section cut along a virtual plane including the radial center of the intake port 3.

  When the stem 7 moves to the intake port 3 side based on the action of a drive mechanism (not shown), the valve umbrella 6 is separated from the valve seat 4 and the opening 3a leading to the combustion chamber 2 is opened as shown in FIG. At this time, the branch portions 7b and 7b of the stem 7 are not located near the center of the opening 3a. Therefore, the air-fuel mixture passing through the radial center of the intake port 3 maintains a linear flow when viewed from the axial direction of the main shaft portion 7a in the stem 7, and is formed by the arch formed by the branch portions 7b and 7b. It passes through and flows into the combustion chamber 2 (indicated by an arrow f in FIGS. 3 and 4). As a result, a strong vertical vortex can be generated in the combustion chamber 2 with a simple configuration without processing the conventionally used port shape.

  As described above, the intake valve structure according to the first embodiment is an intake valve structure for opening and closing the opening 3 a of the intake port 3 communicating with the combustion chamber 2, and is located in the combustion chamber 2. A valve head portion 6 capable of opening and closing the opening portion 3a, and a stem 7 extending from the valve head portion 6 to the intake port 3 side through the opening portion 3a and slidably supported. The stem 7 is bifurcated so as not to obstruct the path passing through the center of the intake port 3 on the side of the valve head part 6 and supports the vicinity of the outer peripheral edge of the valve head part 6. It can be suppressed that the flow of the linear air-fuel mixture entering the combustion chamber 2 from the intake port 3 is obstructed. Further, since the stem 7 is bifurcated in the middle, the vicinity of the outer peripheral edge of the valve head portion 6 is supported at two positions, so that the coupling state of the stem 7 and the valve head portion 6 can be stabilized. In addition, since the valve head portion 6 is supported by the one stem 7, the number of components is reduced and the configuration becomes simple.

  Further, since the stem 7 is disposed so that the branch portions 7 b and 7 b are close to the inner wall surface of the intake port 3, the branch portions 7 b and 7 b in the stem 7 are disposed away from the center of the intake port 3. Further, it is possible to remarkably suppress the blockage of the air-fuel mixture at the center of the intake port 3 by the branch portions 7b and 7b. Moreover, since the configuration is simple, the intake valve structure can be easily manufactured.

(Second Embodiment)
Next, an intake valve structure according to a second embodiment of the present invention will be described. FIG. 5 is a schematic sectional view showing an intake valve structure according to the second embodiment of the present invention. 6 is a cross-sectional view of the intake valve structure shown in FIG. FIG. 7 is a schematic cross-sectional view showing a valve open state of the intake valve structure shown in FIG. In addition, the same code | symbol is attached | subjected to the same member as the intake valve structure which concerns on 1st Embodiment, and description is abbreviate | omitted.

  In this intake valve structure, as shown in FIG. 5, a recess 3 b is formed in a part of the inner wall of the intake port 3. 5 and 7, the shape of the intake port 3 in a state where the recess 3 b is not formed is indicated by a two-dot chain line. The recess 3 b is formed so as to communicate with a through hole 1 a for installing the stem guide 8 formed on the inner wall of the intake port 3.

  The intake valve 10 includes a stem 11 and a valve umbrella portion 12. The stem 11 has a main shaft portion 11a and branch portions 11b and 11b bifurcated from the main shaft portion 11a at a branch point X. The valve head portion 12 is connected to the end portions of the branch portions 11b and 11b. Yes. As shown in FIG. 6, the intake valve 10 is arranged so that the branched portions 11 b and 11 b are along the inner wall surface of the recess 3 b formed in the intake port 3.

  The intake valve structure according to the second embodiment is in a closed state (see FIGS. 5 and 6) in which the valve head portion 12 is seated on the valve seat 4 and an open state (see FIG. 7) in which the valve umbrella portion 12 is separated from the valve seat 4. In any state, the intake valve 10 is arranged so that the branch point X in the stem 11 is accommodated in the recess 3b.

  Thus, in the intake valve structure according to the second embodiment, the branch point X of the stem 11 is formed in the recess 3b formed on the inner wall of the intake port 3 in both the closed state and the open state. Since it is configured to be housed, as shown in FIG. 7, when the opening 3a is opened, the branch point X of the stem 11 does not extend from the recess 3b to the intake port 3 side. Therefore, the flow of the air-fuel mixture in the intake port 3 is not blocked by the branch point X. As a result, the air-fuel mixture is more likely to pass linearly.

  In addition, as shown in 2nd Embodiment, it is not restricted to the case where it is comprised so that the branch point X may be located in the recessed part 3b in a valve-open state, but the branch point X is located in the recessed part 3b at least in a valve-closed state You may comprise. Even in this case, the position of the branch point X of the stem 11 can be maintained at a position away from the center of the intake port 3, that is, a position close to the inner wall surface of the intake port 3, so that when the opening 3a is opened. The branch point X moves to the vicinity of the center of the intake port 3 so that the flow of the air-fuel mixture is not blocked.

(Third embodiment)
Next, an intake valve structure according to a third embodiment of the present invention will be described. FIG. 8 is a perspective view showing the intake valve 20 in the intake valve structure according to the third embodiment of the present invention. 9 is a view of the intake valve 20 shown in FIG. 8 as viewed from the axial direction of the main shaft portion 21a in the stem 21 (the direction of arrow C in FIG. 8).

  In the intake valve structure according to the third embodiment, the configuration of the intake port 3 is the same as that of the first embodiment, and only the configuration of the intake valve 20 is different. Hereinafter, the configuration of the intake valve 20 will be described.

  As shown in FIG. 8, the intake valve 20 includes a stem 21 and a valve head portion 22. The stem 21 has a main shaft portion 21a and four branch portions 21b and 21c having the same shape that branch from the main shaft portion 21a. · 21d · 21e. And the valve head part 22 is connected in the edge part of the said branch parts 21b-21e.

  As shown in FIG. 9, among the branch portions 21b to 21e, the branch portions 21b and 21c branch from the main shaft portion 21a so as to be positioned symmetrically with the branch portions 21d and 21e with the main shaft portion 21a interposed therebetween, respectively. It is connected to the portion 22 and is configured such that the angle θ formed by the branch portion 21b and the branch portion 21e in FIG. 9 is an obtuse angle.

  The intake valve 20 is disposed in the intake port 3 so that the air-fuel mixture easily passes between the branch portions 21b and 21c and the branch portions 21d and 21e. Specifically, the intake valve 20 is connected to the intake port 3 so that the virtual plane including the radial center of the intake port 3 substantially equally divides the angle θ formed by the branch portion 21b and the branch portion 21e in FIG. Placed in. Thereby, the linear flow of the air-fuel mixture (indicated by arrow D in FIGS. 8 and 9) can be configured to be difficult to block. In this case, the valve head portion 22 can be stably supported by the four branch portions 21b to 21e, which is effective.

(Fourth embodiment)
Next, an intake valve structure according to a fourth embodiment of the present invention will be described. FIG. 10 is a perspective view showing the intake valve 30 in the intake valve structure according to the fourth embodiment of the present invention.

  In the intake valve structure according to the fourth embodiment, the configuration of the intake port 3 is the same as that of the first embodiment, and only the configuration of the intake valve 30 is different. Hereinafter, the configuration of the intake valve 30 will be described.

  As shown in FIG. 10, the intake valve 30 has a stem 31 and a valve head portion 32, and the stem 31 has a main shaft portion 31a and a plurality of wire members 31b branched from the main shaft portion 31a. And the valve head part 32 is connected in the edge part of the said wire member 31b. The plurality of wire members 31b are configured such that adjacent wire members 31b are connected to each other by another wire member 31c disposed substantially parallel to the surface of the valve head portion 32 so as to be net-like as a whole. Further, the plurality of wire members 31b are branched so as to have substantially equal intervals.

  The diameters of these wire members 31b and 31c are preferably smaller than the shaft diameter of the main shaft portion 31a and not more than one-tenth of the shaft diameter of the main shaft portion 31a. In addition, the distance L between the connection position of one wire member 31b and the valve head portion 32 and the connection position of another adjacent wire member 31b is at least longer than the length corresponding to the shaft diameter of the main shaft portion 31a. It is desirable to make it long.

  Thus, since the stem 31 is formed in a net shape on the side of the valve head portion 32, it is possible to suppress the mixture 31 from being blocked by the stem 31. In addition, since the plurality of wire members 31 b are branched so as to be substantially equally spaced from each other, the same effect can be obtained even when the intake valve 30 rotates around the axis of the stem 31.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

1 is a schematic cross-sectional view showing an intake valve structure according to a first embodiment of the present invention. It is an AA cross-sectional arrow view of the intake valve structure shown in FIG. It is a perspective view which shows the valve head part shown in FIG. It is a schematic sectional drawing which shows the valve opening state of the intake valve structure shown in FIG. It is a schematic sectional drawing which shows the intake valve structure which concerns on 2nd Embodiment of this invention. It is a BB cross-sectional arrow view of the intake valve structure shown in FIG. It is a schematic sectional drawing which shows the valve opening state of the intake valve structure shown in FIG. It is a perspective view which shows the intake valve in the intake valve structure which concerns on 3rd Embodiment of this invention. It is the figure which looked at the intake valve shown in FIG. 8 from the stem axial direction. It is a perspective view which shows the intake valve in the intake valve structure which concerns on 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Combustion chamber 3 Intake port 3a Opening part 4 Valve seat 5 Intake valve 6 Umbrella part 7 Stem 7a Main shaft part 7b Branch part 8 Stem guide

Claims (5)

An intake valve structure for opening and closing an opening of an intake port leading to a combustion chamber,
A valve head portion that is located in the combustion chamber and can open and close the opening;
A stem that extends from the valve head portion to the intake port side through the opening and is slidably supported;
The intake valve structure according to claim 1, wherein the stem branches into a plurality of portions on the side of the valve head portion and supports the vicinity of the outer peripheral edge portion of the valve head portion.   2. The stem according to claim 1, wherein the stem is bifurcated and formed on the side of the valve head portion, and the branched portion is disposed so as to be close to an inner wall of the intake port. Intake valve structure.   The valve branching state is configured so that a branching point of the stem is housed in a recess formed in an inner wall of the intake port when the opening is closed by the valve umbrella. The intake valve structure according to claim 1 or 2.   4. The intake valve structure according to claim 3, wherein a branching point of the stem is accommodated in the recess when the valve umbrella portion is opened from the opening. 5.   The intake valve structure according to claim 1, wherein the stem is formed in a net shape on the valve umbrella side.

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