JP2007154690A - Intake device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device of an internal combustion engine which can prevent interference between a swirl flow and a tangential flow in the same intake port. <P>SOLUTION: The intake device of the internal combustion engine 1 is provided with the intake port 4 and a guide plate 10. The intake port 4 includes therein an opening 4a opened toward a cylinder 2 of the internal combustion engine 1, a main flow 4b extending in the tangential direction of the cylinder 2 and led to the opening 4a, and a helical portion 4c which is adjacent to the main flow 4b and led to the opening 4a in such a manner that the helical portion 4c is curved along the periphery of the opening 4a so as to be joined with the main flow 4b at the terminal end of a curve. The guide plate 10 is arranged at a joining position where the terminal end of the curve of the helical portion 4c and the main flow 4b are joined each other and extends in the direction of a center line CL of the cylinder 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intake device for an internal combustion engine that introduces intake air into a cylinder of the internal combustion engine.

  2. Description of the Related Art An intake device for an internal combustion engine is known in which two helical ports are provided for one cylinder, and at each portion where the helical ports are close to each other, a protrusion protruding in the side direction inside the port is formed at each port. (Patent Document 1). In the portion where the two helical ports are close to each other, the intake air guided from each port flows in the opposite direction, and the flows may interfere with each other. In the device of Patent Document 1, the flow of intake air is weakened by the protrusion formed inside the port, so that interference due to the flow of intake air guided from each port in the cylinder collides with each other is reduced. In addition, a swirl control plate is provided in the helical portion of the helical port, and the suction is guided to the cylinder by changing the posture between the side approaching the cylinder and the side away from the cylinder according to the operating state of the internal combustion engine. There is an intake device for an internal combustion engine that changes the flow direction of air (Patent Document 2). In addition, there is an intake device in which the passage cross section of the helical port is formed in an L shape so that a tangential flow and a swirling flow directed in the tangential direction of the cylinder can be generated in the same port (Patent Document 3).

JP-A-8-246885 Japanese Utility Model Publication No. 7-38627 Japanese Patent Laid-Open No. 2-147830

  In the intake devices of these documents, the swirl flow generated by the helical part of the helical port and the tangential flow directed in the tangential direction of the cylinder collide with each other in the port and interfere with each other, so the component of the tangential flow is weakened. May interfere with the generation of the swirl flow. In particular, in the air intake device of Patent Document 3, the tangential flow component is relatively increased by interference with the swirl component, although the port cross-sectional shape is L-shaped to relatively increase the tangential flow component. There is a possibility that the enhanced effect cannot be fully exhibited.

  Therefore, an object of the present invention is to provide an intake device for an internal combustion engine that can suppress interference between a swirling flow and a tangential flow within the same intake port.

  An intake device for an internal combustion engine of the present invention includes an opening that opens in a cylinder of the internal combustion engine, a main flow portion that extends in a tangential direction of the cylinder and continues to the opening, is adjacent to the main flow portion, and A helical port continuing in the same port so as to merge with the main flow part at the end of the curve while curving along the circumferential direction; and an intake port having the helical part in the same port. The above-described problem is solved by providing a guide member that is disposed at a joining position where the terminal end and the main flow portion join and extends in the direction of the center line of the cylinder.

  According to this intake device, a tangential flow toward the tangential direction of the cylinder is generated by the main flow portion of the intake port, and a swirl flow is generated by the helical portion of the intake port. And since the guide member is provided in the confluence | merging position of the curvature end of a helical part and a main flow part, it is avoided that the swirl flow produced | generated by the helical part collides with the tangential flow produced | generated by the main flow part. The As a result, interference between the swirl flow and the tangential flow is suppressed in the intake port, and a desired swirl flow can be formed in the cylinder.

  The intake device of the present invention further includes a guide member drive mechanism that drives the guide member in the direction of the center line of the cylinder in conjunction with the opening / closing operation of the intake valve of the internal combustion engine disposed in the opening. (Claim 2). In this case, the guide member operates in the direction of the center line of the cylinder in conjunction with the opening / closing operation of the intake valve of the internal combustion engine. Therefore, even when the intake valve is lifted in the opening direction and a space is created between the intake valve and the opening, the space can be partitioned by the guide member. Therefore, the effect of suppressing interference between the swirling flow and the tangential flow can be maintained regardless of the valve lift amount of the intake valve.

  In this aspect, the guide member drive mechanism may be provided with a connecting means for connecting the guide member and the valve stem portion of the intake valve (claim 3). In this case, since the guide member and the valve stem portion of the intake valve are connected by the connecting means, the guide member can be operated in the direction of the center line of the cylinder in conjunction with the opening / closing operation of the intake valve. Moreover, by setting the length of the guide member in the direction of the center line of the cylinder in accordance with the stroke of the intake valve, for example, a through hole that penetrates the cylinder head in which the intake port is formed is formed, and the guide member is formed in this through hole. The guide member can be driven while easily avoiding the interference between the inner wall of the intake port and the guide member without special processing such as disposing the cylinder. Therefore, the cost required for the design and processing of the cylinder head can be reduced.

  In the intake device of the present invention, the guide member may extend in a tangential direction of the cylinder. In this case, it is possible to guide the tangential flow generated in the main flow portion toward the tangential direction of the cylinder while avoiding interference between the swirl flow and the tangential flow. Therefore, the directivity of the tangential flow can be improved, which is advantageous for forming a swirl flow.

  As described above, according to the present invention, since the guide member extending in the direction of the center line of the cylinder is arranged at the joining position where the end of the curved portion of the helical portion of the intake port and the main flow portion join, the same intake port The interference between the swirl flow and the tangential flow can be suppressed.

(First form)
FIG. 1 is a perspective view schematically showing a main part of an internal combustion engine in which an intake device of the present invention is incorporated. The internal combustion engine 1 is configured as a diesel engine, and includes two intake ports 4 and 5 for introducing intake air into the cylinder 2, and two exhaust ports 6 and 6 for discharging exhaust gas after combustion from the cylinder 2. It has. In addition, about the intake port 5 and the exhaust ports 6 and 6, the opening part was shown with the broken line and illustration of the shape was abbreviate | omitted. The intake port 5 is a well-known helical port. One intake valve 7 is disposed in each of the openings 4a and 5a of the two intake ports 4 and 5 (the illustration of the intake port 5 is omitted). In the two exhaust ports 6 and 6, one exhaust valve (not shown) is arranged in each opening.

  2 to 7 show details of the intake port 4 shown in FIG. 1, FIG. 2 is a plan view of the intake port 4 as viewed from above, and FIGS. 3 to 7 show cross sections of a to e in FIG. FIG. As shown in these drawings, the intake port 4 extends in the tangential direction t (FIG. 2) of the cylinder 2 and continues to the opening 4a, and is adjacent to the main flow portion 4b and in the circumferential direction of the opening 4a. It has a helical portion 4c that follows the opening 4a in the same port so as to join the main flow portion 4b at the end of the curve while bending along s (FIG. 2). A valve seat 9 for seating the intake valve 7 is fitted into the opening 4a. The main flow portion 4b is located closer to the cylinder 2 than the helical portion 4c (the lower side in FIGS. 3 to 7) and is adjacent to the helical portion 4c. As shown in FIGS. 5 and 6, the main flow portion 4 is formed so that the lateral width in the direction across the cylinder 2 is larger than the lateral width of the helical portion 4 c, and the cross-sectional shape of the intake port 4 is substantially L-shaped. It has a shape. As shown in FIGS. 1, 3, 6 and 7, the helical portion 4c is curved along the circumferential direction s (FIG. 2) of the opening 4a, and the center line CL (FIG. 1) of the cylinder 2 is curved. The vertical width in the direction of) is gradually reduced. Further, the helical portion 4c is formed so that the lateral width gradually decreases as it approaches the opening 4a.

  According to the intake port 4 described above, a tangential flow f1 directed in the tangential direction of the cylinder 2 is generated by the main flow portion 4b and a swirl flow f2 is generated by the helical portion 4c as shown in FIG. As a result, a swirl flow Fsw is formed in the cylinder 2 by the tangential flow f1.

  As shown in FIG. 2, in the intake device of this embodiment, the tangential flow f <b> 1 and the swirl flow f <b> 2 collide with each other and interfere at the merging position X between the end of the helical portion 4 c of the intake port 4 and the main flow portion. In order to avoid this, a guide plate 10 as a guide member is arranged. As shown in FIGS. 1 and 2, the guide plate 10 is a plate-like body configured to extend in the direction of the center line CL of the cylinder 2 and to extend in the tangential direction t of the cylinder 2. As shown in FIGS. 3 and 7, the guide plate 10 is disposed in a through hole 8 a that is formed so as to penetrate the cylinder head 8 and extends in the vertical direction of the cylinder 2. The guide plate 10 may be stationary with respect to the intake port 4. However, in the intake device of this embodiment, as shown in FIG. 8, the guide plate that drives the guide plate 10 in conjunction with the opening / closing operation of the intake valve 7. A drive mechanism 21 is provided.

  FIG. 8 is an explanatory view schematically showing the details of the guide plate drive mechanism 21. As shown in this figure, the guide plate drive mechanism 21 includes a connection member 23 coupled to a valve lifter 33 for driving the intake valve 7 to open and close, and an urging means for urging the guide plate 10 in a direction in which the guide plate 10 is pressed against the connection member 23. And a coil spring 25. As is well known, the intake valve 7 is driven to open and close by a valve mechanism 30 that uses the rotation of a crankshaft (not shown) of the internal combustion engine 1 as a drive source. The valve mechanism 30 includes a camshaft 31 driven by a crankshaft, a cam 32 provided on the camshaft 31, a valve lifter 33 that contacts the cam 32 and operates to open and close the intake valve 7, And a valve spring 34 for following the intake valve 7.

  Thus, when the cam 32 of the valve mechanism 30 rotates, the valve lifter 33 is displaced in the direction of the arrow according to the profile of the cam 32, and the intake valve 7 is driven to open and close by the displacement. Since the connection member 23 of the guide plate driving mechanism 21 is coupled to the valve lifter 33, the guide plate 10 is interlocked with the opening / closing operation of the intake valve 7 by the connection member 23, in the direction of the center line CL of the cylinder 2 (up and down in the figure). Direction). In the configuration shown in FIG. 8, the coil spring 25 can be omitted by connecting the connection member 23 and the guide plate 10.

  According to the above embodiment, the guide plate 10 operates in the direction of the center line CL of the cylinder 2 in conjunction with the opening / closing operation of the intake valve 7 of the internal combustion engine 1. Therefore, even when the intake valve 7 is lifted in the opening direction and a space is formed between the opening 4a, the space can be partitioned by the guide plate 10. Therefore, the effect of suppressing interference between the swirling flow f2 and the tangential flow f1 can be maintained regardless of the valve lift amount of the intake valve 7. Further, as shown in FIG. 2, the guide plate 10 is configured to extend in the tangential direction t of the cylinder 2, so that the interference between the swirling flow f2 and the tangential flow f1 is avoided, and at the same time, the main flow portion 4b. It is also possible to guide the tangential flow f <b> 1 generated in the above toward the tangential direction t of the cylinder 2. Therefore, the directivity of the tangential flow f1 can be improved, which is advantageous for forming a swirl flow.

(Second form)
Next, a second embodiment of the intake device of the present invention will be described with reference to FIGS. This form is the same structure as the first form except that the mechanism for driving the guide plate 10 is different from the first form. Therefore, FIGS. 1 to 7 are appropriately referred to for the configuration common to the first embodiment. FIG. 9 shows a guide plate drive mechanism 22 according to the second embodiment, and FIG. 10 shows a cross section of the intake port according to the second embodiment corresponding to FIG. 3 of the first embodiment.

  As shown in FIG. 9, in the second embodiment, as a guide plate driving mechanism 22 for driving the guide plate 10, a connecting member 24 as a connecting means for connecting the valve stem portion 7 a of the intake valve 7 and the guide plate 10 is used. Is provided. Thereby, when the valve mechanism 30 drives the intake valve 7 to open and close, the guide plate 10 is driven in the direction of the center line CL of the cylinder 2 by the connecting member 24 in conjunction with the opening and closing operation of the intake valve 7. Further, as shown in FIG. 10, the guide plate 10 according to this embodiment has a length in the direction of the center line CL of the cylinder 2 such that the clearance Cr with the inner wall of the intake port 4 is equal to or greater than the stroke St of the intake valve 7. Is set. Therefore, interference between the inner wall of the intake port 4 and the guide plate 10 is facilitated without applying special processing to the cylinder head 8 such as providing a through hole 8a (FIG. 3) penetrating the cylinder head 8 as in the first embodiment. The guide plate 10 can be driven while avoiding this. Therefore, according to the second embodiment, the cost required for designing and processing the cylinder head 8 can be reduced.

  The present invention is not limited to the above embodiment, and may be realized in various forms. The intake device of the present invention is suitable for application to a diesel engine in which it is desired to form a swirl flow in a cylinder, but does not exclude the application of the present invention to other types of internal combustion engines. For example, it can be applied to a gasoline engine.

  In addition, the present invention is not limited to a mode in which two or more intake ports are provided for one cylinder, and the intake device of the present invention can be applied to a mode in which one intake port is provided for one cylinder. When a plurality of intake ports are provided for one cylinder, the present invention may be applied to some intake ports or to all intake ports.

  As the intake port according to the present invention, as in each of the embodiments described above, the passage cross section is formed in a substantially L shape so that a tangential flow and a swirl flow directed in the tangential direction of the cylinder can be generated in the same port. However, the present invention can be applied to a known intake port having the same lateral width between the main flow portion and the helical portion.

The perspective view which showed typically the principal part of the internal combustion engine in which the intake device of this invention was integrated. The top view which looked at the intake port of FIG. 1 from upper direction. Sectional drawing along the aa line of FIG. Sectional drawing along the bb line of FIG. Sectional drawing along the cc line | wire of FIG. Sectional drawing along the dd line of FIG. Sectional drawing along the ee line of FIG. Explanatory drawing which showed the detail of the guide plate drive mechanism. Explanatory drawing which showed the detail of the guide plate drive mechanism which concerns on a 2nd form. Sectional drawing which shows the cross section of the intake port which concerns on the 2nd form corresponding to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder 4 Intake port 4a Opening part 4b Main flow part 4c Helical part 7 Intake valve 7a Valve stem part 10 Guide plate (guide member)
21, 22 Guide plate drive mechanism (guide member drive mechanism)
24 connecting member (connecting means)
t Cylindrical direction of cylinder s Circumferential direction of opening CL Centerline of cylinder X Junction position

Claims (4)

  An opening that opens in a cylinder of the internal combustion engine, a main flow portion that extends in a tangential direction of the cylinder and continues to the opening, and is curved while being curved along the circumferential direction of the opening adjacent to the main flow portion An intake port having a helical portion that continues to the opening so as to merge with the main flow portion at the end, and a merge portion where the curved flow end of the helical portion of the intake port and the main flow portion merge An intake device for an internal combustion engine, comprising: a guide member disposed at a position and extending in a direction of a center line of the cylinder.   The guide member drive mechanism according to claim 1, further comprising a guide member drive mechanism that drives the guide member in a center line direction of the cylinder in conjunction with an opening / closing operation of an intake valve of the internal combustion engine disposed in the opening. An intake device for an internal combustion engine as described.   The intake device for an internal combustion engine according to claim 2, wherein a connecting means for connecting the guide member and a valve stem portion of the intake valve is provided as the guide member driving mechanism. The intake device for an internal combustion engine according to any one of claims 1 to 3, wherein the guide member extends in a tangential direction of the cylinder.

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