JP2005105946A - Intake device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake device for an engine capable of reinforcing a tumble flow in a low rotational speed and less intake amount area while suppressing over-tumble in an area of high rotational speed and much intake amount area in the intake device having a tumble control valve with an opening part on the upper wall side of an intake port when it is fully closed. <P>SOLUTION: In this intake device for an engine, the tumble control valve 20 opened on the upper side when it is closed is installed on the upstream side of the intake port in the cross section of the intake port at an axis CL10 when the intake port 10 is viewed in a direction incident from a diagonal upper side relative to a cylinder bore 50. An extension part 12 moving apart gradually from the opening edge of a valve seat upper end 16 after moving close to a valve axis CL40 is formed on the lower wall of the intake port immediately on the upstream side of a throat part 14. The cross sectional area of the intake port section d-d at a position with the extension part 12 is smallest excluding the opening area at the valve seat upper end 16. Also, an intake port upper wall 13 is formed of an approximately straight smooth wall surface starting at the upstream side of the intake port to near the lower end part of a valve guide boss 41. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention provides an intake device for an engine, in particular, an intake port that is obliquely incident on a cylinder bore, an intake valve in which the valve axis is inclined with respect to the cylinder axis, and a valve that supports the intake valve The present invention relates to an engine intake device in which a part of a guide boss and a tumble control valve are arranged.

  In addition to the intake air amount control throttle valve that adjusts the intake air amount of the engine in the engine intake system, a tumble control valve that enhances the tumble flow in the cylinder in the low speed range including when idling is improved. An intake device to be provided has been proposed.

  For example, in Patent Document 1, when the tumble control valve is fully opened, a notch is provided on the lower wall surface side of the intake port that is obliquely incident on the cylinder bore to inject the intake air to enhance the tumble flow in the cylinder. An air intake device has been proposed.

  Patent Document 2 proposes an intake device that intensifies a tumble flow by inclining an inner peripheral surface of a valve seat in a direction along an intake port that is incident on the cylinder bore obliquely from above.

  Also, Patent Document 3 proposes an intake device that enhances the tumble flow by providing a rectification unit that adjusts the intake flow in order to prevent a drop in the tumble flow caused by a vortex generated by an injector hole upstream of the intake port. Has been.

Further, in Patent Document 4, a movable plate with a variable protrusion length that protrudes from the throat portion is provided on the lower side wall surface of the intake port that is obliquely incident on the cylinder bore, and the tumble flow is strengthened in a low rotation range. Therefore, an intake control device has been proposed that obtains a high output in a high rotation range.
JP-A-11-107764 JP2001-173513 JP 2001-140715 A Japanese Patent Laid-Open No. 06-058153

  However, the conventional intake device provided with the tumble control valve has the following problems.

  FIG. 7 is a diagram illustrating a configuration example of an intake device provided with a conventional tumble control valve 20 and a state in which the tumble control valve 20 is fully opened, that is, in a high rotation range. In FIG. 7A, 30 is an injector hole, 40 is an intake valve, and 41 is a valve guide boss of the intake valve. FIG. 7B is a d1-d1 sectional view of the section of the intake port at the lower end portion of the valve guide boss of FIG. 7A as viewed from the downstream side. It can be seen that the valve guide boss 41 protrudes into the intake port.

  In the high rotation range of FIG. 7A, a large amount of intake air flows through the entire intake port at high speed. In the high rotation region, in order to obtain a high output, the overtumble flow is suppressed and the combustibility is improved. In order to suppress the overtumble flow, it is necessary to perform intake into the cylinder as evenly as possible from the entire circumference of the valve seat portion. However, as shown in FIG. 7 (a), the high-speed intake flow is separated from the lower wall of the intake port in the valve seat upstream region A of the intake port, and the intake main flow is in the front end side of the intake port axis line ( 7), and the intake air flow around the cylinder bore outer periphery shown by the broken arrow in FIG. 7A is weakened, and the bubble seat part is shifted toward the cylinder bore center side in the entire periphery of the bubble seat. Inhaled. As a result, the intake resistance of the valve seat portion is increased, the intake charging efficiency is lowered, and fuel is unevenly distributed in the cylinder, so that high output is hindered.

  On the other hand, when the tumble control valve 20 shown in FIG. 8 is fully closed, that is, in a low rotation region such as idle, the intake port upper wall resistance, particularly the resistance due to the protrusion of the valve guide boss as shown in FIG. The intake flow flowing along the upper wall of the port (the air flow that should strengthen the tumble flow) becomes weak or peels off from the upper wall, and the tumble flow in the cylinder is not strengthened. As can be seen from FIG. 8B in plan view, it is difficult to strengthen the tumble flow because the intake flow wraps around the valve guide boss as indicated by B.

  That is, the intake port that is incident on the cylinder bore from obliquely above has a problem of overtumble due to separation of the intake air flow from the lower wall of the intake port in a high rotation range. Even in an intake device equipped with a tumble control valve having a tumble flow, there was a problem of a decrease in tumble flow due to the influence of the upper wall of the intake port and the valve guide boss in the low rotation range.

  In view of such a problem, the present invention provides an intake device including a tumble control valve that is an intake port that is obliquely incident on a cylinder bore and has an opening on the upper wall side of the intake port when fully closed. Provided is an engine intake device that suppresses overtumble in a region where there is a large amount of intake air while enhancing the tumble flow in a region where the amount of intake air in a low rotation region is small.

  In order to solve such a problem, an intake device for an engine according to the present invention is provided with an intake port that is obliquely incident on a cylinder bore, and an intake valve in which a valve axis is inclined with respect to the cylinder axis. In an engine intake device in which a part of a valve guide boss that supports the intake valve and a tumble control valve are arranged, an intake port shaft when the intake port is viewed in a direction obliquely incident on a cylinder bore It has a tumble control valve on the upstream side of the intake port on the upstream side of the intake port, and is gradually opened from the opening edge of the upper end of the valve seat toward the upstream side of the intake port. It has a protruding part that moves away after approaching the valve axis, and the cross-sectional area of the cross section of the intake port at the position where the protruding part is located is upstream of the upper end of the valve seat Characterized in that it is a narrowest in the intake port.

  Here, on the upstream side of the intake port cross section near the lower end of the valve guide boss, the lower wall of the intake port is inclined with respect to the upper wall so that the height of the inner cross section of the intake port increases upstream. .

  In addition, the intake port axial center is a cross-section of the intake port when the intake port is seen obliquely incident on the cylinder bore, and the upper wall of the intake port is substantially straight from the upstream side of the intake port to the vicinity of the lower end of the valve guide boss. The wall is smooth. Moreover, it has an embed | buried part which protrudes in an intake port inward in the left-right upper wall of the said valve guide boss in the cross section of the intake port near the said valve guide boss lower end part. Also, an injector hole is provided downstream of the tumble control valve, and the upper and lower intake port upper wall surfaces sandwiching the injector hole are formed to be substantially straight. The shape of the intake port cross section perpendicular to the intake port center line gradually changes from the upstream rectangle to the downstream circle upstream and downstream of the intake port cross section near the lower end of the valve guide boss.

  The intake port axis is substantially straight from the tumble control valve position to the intake port cross section near the lower end of the valve guide boss.

  According to the present invention, in an intake device having a tumble control valve having an opening on the upper wall side (upper side) of the intake port when the valve is closed, the intake port is incident obliquely from above on the cylinder bore. It is possible to provide an engine intake device that suppresses over-tumble in a region where the amount is large and increases the strength of the tumble flow in a region where the intake amount in a low rotation region is small.

  That is, fuel efficiency and output performance can be improved by improving combustibility in the low speed range and charging efficiency in the high speed range.

  Specifically, while keeping the position of the valve guide low, intake air is smoothly throttled by the upper and lower walls of the intake port, and the minimum cross-sectional area of the intake port is formed by the overhanging portion of the lower wall of the intake port As a result, in the high engine speed range, separation of the intake air flow from the lower wall of the intake port is suppressed, and the intake air flow from the cylinder bore outer periphery to the combustion chamber is sufficiently achieved on the entire periphery of the valve seat portion (this region By strengthening the intake air flow), an increase in intake air resistance is suppressed and generation of overtumble is suppressed in an operation region where the intake air amount is large. In addition, in the low speed range, the intake flow that has been energized by the tumble control valve is smoothly guided in the intake port so that the tumble flow is strengthened. It can be secured. And since these effects are played in a state where the valve guide position is low, it can be achieved while making a compact engine in which the overall height of the engine is suppressed.

  In addition, by setting the buried portion of the upper wall of the intake port, it is easy to form a rectangle upstream of the intake port, and a drift along the wall surface can be formed to strengthen the tumble flow.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an engine intake device of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiment, only the intake port from the valve seat to the tumble control valve, which is the main part of the present invention, is illustrated and described, but the intake apparatus of the present invention is located upstream of the tumble control valve. The configuration is also included.

<Configuration Example of Engine Intake Device of Present Embodiment>
FIG. 1A is a diagram illustrating a configuration example of an engine intake device of the present embodiment. The intake port of this embodiment is shown by a solid line, and the conventional example shown in FIGS. 7 and 8 is shown by a broken line. Improvements in the intake port 10 of FIG. 1 from the conventional example of FIGS. 7 and 8 are indicated by arrows 11a, 30a, 42a, and 43a. Further, the tumble control valve of the present embodiment is illustrated in a shape having a valve shaft at substantially the center of the intake port, but the present invention may be applied to other shapes such as a shape in which the valve shaft is on the intake port wall surface. It does not change the gist.

  CL10 indicates the port axis of the intake port 10, and 11 indicates the lower wall of the intake port. Conventionally, as indicated by a broken line, the valve seat is connected in a shape substantially parallel to the upper wall of the intake port, and the lower wall does not approach the axis of the intake valve within the throat diameter. On the other hand, in this embodiment, the lower wall 11 of the intake port is formed so as to approach the valve axis CL40 of the intake valve 40 from the upper end 16 of the valve seat 15 toward the upstream side of the intake port 10 and then away from it. The overhanging portion 12 is formed immediately upstream of the throat portion 14, and the cross section of the intake port is narrowed by an arrow 11a. For example, according to experimental results, when the throat diameter is 31.5 mm, the approach of the intake port lower wall 11 to the valve axis CL40 is preferably 1 mm or more. Further, an arbitrary position of the intake port lower wall 11 related to the overhanging portion 12 and a position A that is 2/3 (21.0 mm) of the throat diameter from the valve axis CL40 is the throat diameter from the valve seat lower end 17. The result that it is preferable that it exists in 3/4 (24.0 mm) or more has come out. However, it is not necessarily limited to this value.

  Reference numeral 20 denotes a tumble control valve formed with an opening (notch) that opens upward (intake port upper wall 13 side) when the valve is closed. Reference numeral 30 denotes an injector hole facing the injector tip. 40 is an intake valve, 41 is a valve guide boss of the intake valve 40, 42 is an embedded portion for reducing the influence of protrusions of the valve guide boss 41 on the intake flow upstream of the valve guide boss 41, and 43 is a valve guide boss 41. It is a buried part downstream. An arrow 42a indicates a change direction of the embedded portion 42 from the conventional example, and an arrow 43a indicates a change direction of the embedded portion 43 from the conventional example. Reference numeral 50 denotes an engine cylinder (cylinder bore), and CL50 denotes a cylinder axis.

  FIG. 1B is a diagram showing a cross-sectional area of the intake port 10 from the opening of the valve seat 15 of FIG. 1 to the tumble control valve 20. As shown in the drawing, when the opening of the valve seat 15 and the position of the tumble control valve 20 are excluded, the d1-d1 cross section (d2) is obtained by the overhanging portion 12 and the embedded portions 42 and 43 of the intake port lower wall 11 of this embodiment. It can be seen that the cross-sectional area (same as -d2 cross section) is reduced to the minimum.

  2 is a cross-sectional view taken along d1-d1, d2-d2, and ee of the intake port 10 of FIG. 2A is a d1-d1 cross-sectional view of the cross section of the intake port 10 at the lower end of the valve guide boss 41 of FIG. 1 as viewed from the downstream side. FIG. 2B is a d2-d2 cross-sectional view of the cross section of the intake port 10 at the lower end of the valve guide boss 41 of FIG. 1 as viewed from the upstream side, and is the same cross section as the d1-d1 cross-sectional view. FIG. 2C is an ee cross-sectional view of the cross section of the valve seat upper end 16 portion of FIG. 1 viewed from the upstream side.

  In FIG. 2, each reference number and change arrow correspond to FIG. 1. As shown in FIGS. 2A and 2B, the intake port 10 has a rectangular shape with reduced protrusions at the lower end and upstream of the valve guide boss 41 due to the overhang portion 12 and the embedded portions 42 and 43. And as shown in (c) of Drawing 2, the section of valve seat upper end 16 portion is circular. Although not shown here, it can be seen that the valve guide boss 41 protrudes into the intake port 10. From the lower end of the valve guide boss 41 toward the valve seat 15, the cross section of the intake port is formed so that the shape gradually changes from a rectangle to a circle.

<Operation Example of Engine Intake Device of Present Embodiment>
(Operation example at high speed range (tumble control valve fully open))
FIG. 3 is a diagram showing an intake state in the high rotation range (the tumble control valve is fully opened) of the intake device of the present embodiment. FIG. 4 is a diagram showing a cross-section at each cutting plane of FIG. The reference numerals in FIGS. 3 and 4 correspond to the same elements in FIGS.

  An arrow in the intake port 10 indicates a schematic flow of the intake flow in the high rotation range. As shown in the figure, the tumble control valve 20 is fully open in the high speed range, and the intake flow along the intake port upper wall 13 causes a tumble flow in the cylinder (cylinder bore) 50, while the intake port lower wall 11 moves along the intake port lower wall 11. Since the intake air flows into the cylinder bore 50 without being separated from the intake port lower wall 11 even in the area A upstream of the valve seat 15, the strong tumble flow along the upper wall is suppressed and the outer periphery of the cylinder bore is circulated. Increases airflow and enables high output.

  4A is a d1-d1 cross-sectional view of the cross section of the intake port 10 at the lower end of the valve guide boss 41 of FIG. 3 as viewed from the downstream side. FIG. 4B is a cross-sectional view taken along the line cc when the cross section of the position changing from the end of the injector hole 30 to the start of the embedded portion 42 in FIG. 3 is viewed from the upstream side.

  As shown in FIGS. 4 (a) and 4 (b), the opening shape of the intake port 10 is substantially rectangular, only the cross-sectional area is different and no vortex is generated, and as shown in FIG. In addition, it can be seen that the intake port 10 is formed so that the intake flow divided in the vertical direction by the tumble control valve 20 is smoothly guided to the throat portion 14.

(Operation example at low rotation range (tumble control valve fully closed))
FIG. 5 is a diagram illustrating an intake state in the low rotation range (the tumble control valve is fully closed) of the intake device of the present embodiment. FIG. 6 is a view of the intake port 10 as viewed from above in FIG. The reference numerals in FIGS. 5 and 6 correspond to the same elements in FIGS.

  An arrow in the intake port 10 indicates a schematic flow of the intake flow in the low rotation range. As shown in the figure, the tumble control valve 20 is fully closed in the low rotation range, but an opening is left on the intake port upper wall 13 side. The intake flow that is blocked by the tumble control valve 20 and injected from the opening is the intake port 10 in which the resistance of the valve guide boss 41 or the like or the wraparound as shown in FIG. Without separating from the upper wall 13 along the port upper wall 13, it flows into the cylinder bore 50 as shown in the region B (see FIGS. 5 and 6), and a maximum tumble flow is generated in the cylinder bore 50. Such tumble flow can improve the combustibility in the low rotation range.

  FIG. 6 further clearly shows the state of the intake air flow along the intake port upper wall 13 in which the resistance of the valve guide boss 41 and the like in the present embodiment or the wraparound as shown in FIG. 8B is reduced. ing.

  The specific example shown in this embodiment is only an example, and the gist of the present invention is that the valve guide boss is embedded in the overhanging portion of the lower wall of the intake port and the upper wall of the intake port, and the intake air near the lower end of the valve guide boss. It is the minimization of the port cross-sectional area, and the use of other shapes of intake ports and other shapes of tumble control valves that realize these are also included in the technical idea of the present invention.

It is a figure which shows the structural example of the intake port which comprises the engine intake device of this embodiment. FIG. 2 is a cross-sectional view of an intake passage viewed from each cross section of the intake port of FIG. It is a figure which shows the operation example in the high rotation area of the intake port of this embodiment. FIG. 4 is a cross-sectional view of an intake passage viewed from each cross section of the intake port of FIG. It is a figure which shows the operation example in the low rotation area of the intake port of this embodiment. FIG. 6 is a diagram showing a schematic flow of the intake air flow when the intake port of FIG. 5 is viewed from above. It is a figure which shows the operation example in the high rotation area of the intake port which comprises the conventional engine intake device. It is a figure which shows the operation example in the low rotation area of the intake port which comprises the conventional engine intake device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Intake port CL10 Intake port axial center 11 Intake port lower wall 12 Overhang | projection part 13 Intake port upper wall 14 Throat part 15 Valve seat 16 Valve seat upper end 20 Tumble control valve 30 Injector hole 40 Intake valve CL40 Valve axis 41 Valve guide boss 42, 43 Buried part 50 Cylinder bore CL50 Cylinder axis

Claims (7)

An intake port that is obliquely incident on the cylinder bore is provided, an intake valve in which the valve axis is inclined with respect to the cylinder axis, a part of a valve guide boss that supports the intake valve, and a tumble control valve In the intake system of the engine where
In the cross-section of the intake port axis when the intake port is viewed in an obliquely incident direction with respect to the cylinder bore,
It has a tumble control valve that opens on the upper side when the valve is closed on the upstream side of the intake port,
On the lower wall of the intake port immediately upstream of the throat portion, there is a projecting portion that gradually moves away from the opening edge of the valve seat upper end toward the upstream side of the intake port after approaching the valve axis.
An intake device for an engine, characterized in that a cross-sectional area of a cross section of the intake port at a position having the projecting portion is narrowest in the intake port upstream from the upper end of the valve seat.   The lower wall of the intake port is inclined with respect to the upper wall so that the height of the inner cross section of the intake port increases upstream from the intake port cross section near the lower end of the valve guide boss. The engine intake system according to claim 1.   In the cross section of the intake port axial center when the intake port is viewed in a direction obliquely incident on the cylinder bore, the upper wall of the intake port is substantially straight from the upstream side of the intake port to the vicinity of the lower end of the valve guide boss. 2. The engine intake device according to claim 1, wherein the intake device is a smooth wall surface.   4. The engine intake device according to claim 3, further comprising a buried portion projecting inward of the intake port on the left and right upper walls of the valve guide boss in a cross section of the intake port near the lower end of the valve guide boss.   4. The engine intake system according to claim 3, wherein an injector hole is provided downstream of the tumble control valve, and the upper and lower intake port upper wall surfaces sandwiching the injector hole are substantially straight. .   The shape of the intake port cross section perpendicular to the intake port center line is gradually changed from the upstream rectangle to the downstream circle in the upstream and downstream of the intake port cross section near the lower end of the valve guide boss. The engine intake device according to claim 3.   4. The engine intake device according to claim 1, wherein the intake port axis is substantially straight from the tumble control valve position to an intake port cross section near a lower end portion of a valve guide boss. 5. .

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