JP2006291880A - Intake valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent occurrence of disturbance in the vicinity of a ceiling of a combustion chamber by improving an intake valve. <P>SOLUTION: The intake valve 28 has an umbrella portion 45 for opening/closing the outlet of an intake port 26 provided in the ceiling 57 of the combustion chamber 25 of an internal combustion engine. On the radial inside of a valve seal face 45c of the umbrella portion 45 for making close contact with an intake side valve seat 41 provided on the outlet, a swollen portion 52 is formed for changing the direction of intake air flowing from the intake port 26 into the combustion chamber 25. The swollen portion 52 changes the direction of the intake air flowing from the intake port 26 into the combustion chamber 25, for example, to the vicinity of the ceiling 57 of the combustion chamber 25. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement of an intake valve.

As a conventional intake valve, there is known one in which turbulent flow is not generated in the air flow from the intake passage to the combustion chamber (see, for example, Patent Document 1).
JP 2000-161030 A

FIG. 5 of Patent Document 1 will be described with reference to FIG. 5 below. In addition, the code | symbol was reassigned.
FIG. 5 is a cross-sectional view showing an intake flow by a conventional intake valve. A valve seat 102 is provided at the outlet of the intake passage 101, and the intake passage 101 is closed by bringing the seat face surface 103 into close contact with the valve seat 102. A possible intake valve 104 is shown.

  The intake valve 104 includes a tapered bulging portion 107 extending radially from the seat face surface 103 toward the outer peripheral edge of the valve body 106. On the downstream side of the throttle intake passage 108, the cross-sectional area of the passage gradually increases, so that the intake flow flowing therethrough is not disturbed.

  In the intake valve 104, the intake air flow is substantially along the seat face surface 103 so that the intake air flow is not disturbed around the conical surface 111 and the rounded surface 112 following the seat face surface 103. In the room, it is difficult to eliminate the disturbance of the intake flow at the corner of the combustion chamber because the intake flow by the intake valve 104 is difficult to reach near the cylinder head side, which is near the valve seat 102, particularly at the end of the ceiling. . It is necessary to change the direction of the intake air flow along the ceiling of the combustion chamber.

  An object of the present invention is to prevent the generation of turbulent flow near the ceiling of a combustion chamber by improving the intake valve.

  According to a first aspect of the present invention, there is provided an intake valve that opens and closes an outlet of an intake port provided on a ceiling of a combustion chamber of an internal combustion engine with an umbrella part, and a valve seal provided on the umbrella part to closely contact a valve seat provided at the outlet. A bulging portion for changing the flow direction of the intake air flowing into the combustion chamber from the intake port is formed inside the surface in the radial direction.

  A bulging portion is formed on the radially inner side of the valve seal surface of the umbrella portion, and the flow direction of the intake air flowing into the combustion chamber from the intake port at the bulging portion is changed to, for example, the vicinity of the ceiling of the combustion chamber.

The invention according to claim 2 is characterized in that the bulging portion is formed on the side far from the central portion of the combustion chamber of the umbrella portion.
By the bulging part formed in the umbrella part far from the center part of the combustion chamber, the flow of the intake air is changed to the vicinity of the ceiling of the combustion chamber, particularly to the corner of the end of the ceiling, that is, the corner of the combustion chamber.

The invention according to claim 3 is characterized in that a recess is formed on the bottom surface of the umbrella.
The direction of the secondary flow of the air-fuel mixture toward the bottom surface of the umbrella portion in the combustion chamber is smoothly changed by the hollow portion formed on the bottom surface of the umbrella portion, and the speed reduction of the secondary flow is suppressed.

  In the invention according to claim 1, since the bulging portion is formed radially inside the valve seal surface provided in the umbrella portion, the bulging portion forms a flow of intake air along the ceiling of the combustion chamber, and It is possible to prevent the formation of turbulent flow in the vicinity of the ceiling of the engine and increase the speed of the intake air. By increasing the intake air amount, the volumetric efficiency of the intake air can be improved and the output of the internal combustion engine can be improved.

  In the invention according to claim 2, since the bulging part is formed on the side far from the central part of the combustion chamber of the umbrella part, it is possible to prevent the formation of turbulent flow at the corner on the side far from the central part of the combustion chamber. It is possible to increase the intake air flow velocity at the corner of the combustion chamber and improve the volumetric efficiency of the intake air.

  In the invention according to claim 3, since the hollow portion is formed on the bottom surface of the umbrella portion, the hollow portion generates a secondary flow having a fast mixture in the combustion chamber, and the secondary flow and the intake flow from the intake port By overlapping, the intake flow is accelerated, and the volumetric efficiency of the intake can be further improved.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a cross-sectional view of an internal combustion engine employing an intake valve according to the present invention. The internal combustion engine 10 includes a cylinder block 11, a piston 13 movably inserted into a cylinder bore 12 provided in the cylinder block 11, and A connecting rod 16 connected to the piston 13 via a piston pin 14 and a crankshaft 18 that is rotatably attached to the lower portion of the cylinder block 11 and supports the connecting rod 16 with a crankpin 17 so as to be swingable.

  The cylinder block 11 includes a cylinder part 21 provided at the upper part and a skirt part 23 provided integrally at the lower part of the cylinder part 21, and a member having a cylinder head 24 attached to the upper part via a head gasket (not shown). It is.

  The cylinder head 24 includes an intake port 26 and an exhaust port 27 communicating with the combustion chamber 25. The intake port 26 is opened and closed by an intake valve 28, and the exhaust port 27 is opened and closed by an exhaust valve 29.

  Here, 31 is a sliding bearing interposed between the large end portion 16a of the connecting rod 16 and the crank pin 17, 32 is a counterweight provided on the crankshaft 18, and 33 is a crankcase formed by the skirt portion 23. An underskirt portion 36 is attached to the lower portion of the skirt portion 23 with a plurality of bolts 34, 36 is an oil pan attached to the lower portion of the underskirt portion 33 with a plurality of bolts 38 via an undercase 37, and 41 is an intake valve 28 closed. An intake side valve seat that forms a seal surface with the intake valve 28 when the exhaust valve 29 is closed, 42 is an exhaust side valve seat that forms a seal surface with the exhaust valve 29 when the exhaust valve 29 is closed, 43 is an ignition plug, 44 is a shaft portion of the intake valve 28, and 45 is an umbrella portion of the intake valve 28.

  The shaft portion 44 is provided with a protrusion (not shown) at the upper end thereof, and the protrusion is guided in the axial direction by a groove provided on the cylinder head 24 (see FIG. 1) side. Prevent rotation.

  FIG. 2 is a cross-sectional view of the main part around the combustion chamber for explaining the intake valve according to the present invention. The intake valve 28 is a side surface 45a of the umbrella portion 45 (the surface on which the shaft portion 44 extends). A bulging portion 52 is formed on the outer periphery of the umbrella portion 45 by recessing a portion close to the shaft portion 44 to form an upper depression portion 51, and concave on the other side surface 45b facing the combustion chamber 25 at the bottom of the umbrella portion 45. A lower depression 53 having a curved surface is formed.

  A surface 45A indicated by an imaginary line drawn on the intake valve 28 is a surface located on the side of the central portion 25A of the combustion chamber 25 on the side surface 45a of the umbrella portion 45 (the portion obtained by drawing the center line 55 as the cylinder axis). 45B is a portion symmetrical to the axis of the shaft portion 44, and the amount of depression is from this surface 45A to the upper surface of the upper depression 51. Reference numeral 57 denotes a ceiling of the combustion chamber 25, 58 denotes a central portion of the ceiling 57, 59 denotes an end wall surface of the ceiling 57, and 25 B denotes a corner portion of the combustion chamber 25 adjacent to the end wall surface 59 of the ceiling 57.

  The umbrella portion 45 is formed with a valve seal surface 45c that is in close contact with and seals a valve seat seal surface 41a provided on the intake side valve seat 41, and a bulging portion 52 is formed radially inside the valve seal surface 45c. It is.

FIG. 3 is a view for explaining the intake valve according to the present invention, and is a view of the intake valve 28 as seen from the axial direction of the shaft portion 44.
The bulging portion 52 of the intake valve 28 is a cross-hatched portion in the figure, and is a portion of the umbrella portion 45 far from the central portion 25A of the combustion chamber 25 (that is, the portion through which the center line 62 passes). This is a portion formed on one side surface 45 a and in a range of approximately 180 °, and a portion between the bulging portion 52 and the shaft portion 44 becomes a recessed portion 51. Here, although the hollow part 51 and the bulging part 52 were divided with the line for convenience, each surface of these hollow part 51 and the bulging part 52 is a smoothly continuous part. Reference numeral 64 denotes an outline of the combustion chamber 25.

Next, the operation of the intake valve 28 described above will be described.
4A and 4B are operation diagrams showing the operation of the intake valve.
In the example (this embodiment) shown in (a), when the piston is lowered and the intake valve 28 is opened, intake air in the intake port 26 (here, intake air indicates intake air or intake air mixture). A part flows along the upper hollow portion 51 and the bulging portion 52 of the intake valve 28 as indicated by an arrow A, and linearly reaches the end wall surface 59 of the ceiling 57, that is, the corner portion 25 B of the combustion chamber 25. It flows so as to descend in the combustion chamber 25 along the end wall surface 59. Further, as shown by the arrow B, a part of the intake air flows so as to descend the outer peripheral part of the umbrella part 45 along the bulging part 52 and the valve seal surface 45c. As described above, the space between the valve seal surface 45c and the valve seat seal surface 41a of the umbrella portion 45 on the central portion 25A side of the combustion chamber 25 flows into the combustion chamber 25 along these.

  The intake air that flows into the combustion chamber 25 and travels from the piston side toward the intake valve 28 as indicated by the arrow D is smoothly changed to the cylinder bore 12 side by the curved lower recess 53 as indicated by the arrow E, As indicated by arrows F and G on the downstream side of the intake flow indicated by arrows A and B, the intake flow indicated by arrows A and B is used to join the intake flow indicated by arrows A and B. The intake flow is large and fast.

In the comparative example shown in FIG. 5B, the intake valve 121 is provided with a valve seal surface 131 on one side 123 of the umbrella portion 122 and the other side 132 made flat, and the cylinder head body 124 has an intake port 126. A valve seat 127 is provided at the outlet, and a valve seat seal surface 128 is provided on the valve seat 127.
The valve seal surface 131 is a portion that can be in close contact with the valve seat seal surface 128.

  When the intake valve 121 is opened, the intake air in the intake port 126 flows along the one side surface 123 of the umbrella portion 122 between the valve seat seal surface 128 and the valve seal surface 131 into the combustion chamber 134. At this time, since the intake air does not flow directly into the corner portion 138 of the combustion chamber 134 formed by the wall 137 that is depressed at the end of the ceiling 136 of the combustion chamber 134, turbulent flow is generated. Therefore, this turbulent flow becomes a resistance to the inflow of the intake air, and the intake air speed is reduced.

  From the above (a) and (b), in the embodiment, the upper hollow portion 51 and the bulging portion 52 of the intake valve 28 prevent the turbulent flow of the intake air flowing into the combustion chamber 25 from the intake port 26. The flow velocity of the intake air can be increased, whereby the volumetric efficiency of the intake air can be increased and the output of the internal combustion engine can be improved.

  As shown in FIG. 2 and FIG. 4A, the present invention firstly sets the outlet of the intake port 26 provided on the ceiling 57 of the combustion chamber 25 of the internal combustion engine 10 (see FIG. 1) to the umbrella portion 45. In the intake valve 28 that is opened and closed by the intake air, the intake air that flows into the combustion chamber 25 from the intake port 26 on the radially inner side of the valve seal surface 45c provided in the umbrella 45 in order to closely contact the intake side valve seat 41 provided at the outlet. The bulging part 52 which changes the flow direction of this is formed.

  Since the bulging portion 52 is formed on the radially inner side of the valve seal surface 45 c provided in the umbrella portion 45, the bulging portion 52 forms a flow of intake air along the ceiling 57 of the combustion chamber 25. It is possible to prevent the formation of turbulent flow in the vicinity of the ceiling 57 of the engine and increase the speed of the intake air. By increasing the intake air amount, the volumetric efficiency of the intake air can be improved and the output of the internal combustion engine 10 can be improved.

Secondly, the present invention is characterized in that the bulging portion 52 is formed on the far side from the central portion 25A of the combustion chamber 25 of the umbrella portion 45.
Since the bulging portion 52 is formed on the far side from the central portion 25A of the combustion chamber 25 of the umbrella portion 45, turbulent flow formation at the corner portion 25B of the combustion chamber 25 can be prevented, and the corner portion 25B of the combustion chamber 25 can be prevented. The intake air flow velocity can be increased and the volumetric efficiency of intake air can be improved.

Thirdly, the present invention is characterized in that a lower dent portion 53 as a dent portion is formed on the other side surface 45b as a bottom surface of the umbrella portion 45.
Since the lower dent portion 53 is formed on the other side surface 45 b of the umbrella portion 45, the lower dent portion 53 generates a secondary flow having a fast mixture in the combustion chamber 25, and this secondary flow and the intake air from the intake port 26 are generated. By overlapping with the flow, the intake flow is accelerated, and the volumetric efficiency of the intake can be further improved.

  In the present embodiment, as shown in FIG. 3, the bulging portion 52 is formed in a range of 180 ° in the circumferential direction of the umbrella portion 45. You may form in the range of 360 degrees (entire circumference) of the circumferential direction.

  The intake valve of the present invention is suitable for a high-power internal combustion engine.

It is sectional drawing of the internal combustion engine which employ | adopted the intake valve which concerns on this invention. It is principal part sectional drawing of the surroundings of a combustion chamber explaining an intake valve to this invention. It is a figure explaining the intake valve which concerns on this invention. It is an action figure which shows the effect | action of an intake valve. It is sectional drawing which shows the intake flow by the conventional intake valve.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 25 ... Combustion chamber, 26 ... Intake port, 28 ... Intake valve, 41 ... Valve seat (intake side valve seat), 45 ... Umbrella part, 45b ... Bottom face (other side) of umbrella part, 45c ... Umbrella Valve sealing surface, 52 ... bulge part, 53 ... hollow part (lower hollow part), 57 ... ceiling.

Claims (3)

In the intake valve that opens and closes the outlet of the intake port provided on the ceiling of the combustion chamber of the internal combustion engine with an umbrella,
A bulging portion for changing the flow direction of the intake air flowing into the combustion chamber from the intake port is formed on the radially inner side of the valve seal surface provided in the umbrella portion so as to closely contact the valve seat provided at the outlet. Intake valve featuring   The intake valve according to claim 1, wherein the bulging portion is formed on a side of the umbrella portion that is far from a center portion of the combustion chamber.   The intake valve according to claim 2, wherein a hollow portion is formed on a bottom surface of the umbrella portion.

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