JPS63266122A - Intake device for internal combustion engine - Google Patents

Abstract

PURPOSE:To secure a proper suction flow by tilting a control valve, having a notch and opening or closing a suction passage by rotation of a valve stem, in a specific direction, while setting up a central position of the notch in a part corresponding to a specific circular arc in the control valve. CONSTITUTION:A suction port 3 formed in a cylinder head 1 is opened or closed by a swirl control valve 23, having a notch 21, with the rotation of a valve stem 25. In this case, the control valve 23 is tilted forward as far as the specified angle to the side of an intake valve to a perpendicular with a center line 28 of a suction passage 14 at time of its full close. A first circular arc l1 is set to a quadrisection part 29 at the cylinder outer circumferential side, while a second circular arc l3 is set up to an intersection point C equal to length of the first circular arc l1 along the circumference of the control valve 23 from an intersection point A distant from a cylinder center line 18 perpendicular with the cylinder bank direction. A central position of the notch 21 is set onto an areal part of the control valve 23 corresponding to the second circular arc l3.

Description

[Detailed description of the invention]

[Industrial Application Field] This invention is! The object of the present invention is to provide an intake system for an internal combustion engine that controls the intake flow and improves combustion by providing an IJ 611 valve. [Prior art] In general, internal combustion engines generate a strong swirl in the combustion chamber to cause intake air turbulence in the low load range shown in the separate figure to improve combustion efficiency, while in the high load range the swirl is suppressed to improve intake air filling. It is necessary to increase efficiency and improve output. For this reason, in the past, a swirl control valve having a notch was provided in the intake passage downstream of the throttle valve, and this control valve was fully opened in the low load range to introduce intake air from the notch to generate a strong swirl. A proposal has been made to improve filling efficiency by fully opening the iNI control valve in the area. For example, in Japanese Patent Application Laid-Open No. 61-112732, when a control valve equipped with a notch is fully closed, when the engine is cold, the notch is located on the lower wall side of the intake port to prevent fuel from adhering to the spark plug. While preventing so-called fogging, the control valve is reversed from this state to fully open during warm-up, and the notch is positioned on the upward side of the intake port to avoid generating a stronger swirl. -L In both the cold and warm conditions mentioned above, the control valve is not perpendicular to the intake port, but is inclined; when the engine is cold, it is tilted forward toward the intake valve side, and the hole portion is on the lower wall side of the intake port. -7'l When warmed up, it is tilted backward with respect to the intake valve, and the notch is located on the upper wall side of the intake port. [Problems to be Solved by the Invention] The conventional intake system described above has problems with the inclination toward the intake port when the control valve is fully closed, especially from the viewpoint of swirl.
i; tilb, and no particular consideration is given to the position of the notch in the circumferential direction of the control valve, so the actual situation is that it is difficult to achieve proper intake air flow and stable combustion is not achieved. This invention was made in view of the above-mentioned circumstances.

[Means for solving the problems] In order to solve the above problems, In this invention, a control valve having a notch and opening and closing the intake passage by rotation of a control valve shaft is provided in the intake passage downstream of the throttle valve, and when the IIII control valve is fully closed, the center line of the intake passage is At the same time, the circular arc of the approximately quarter-divided portion on the cylinder outer circumferential side of the two-divided portion on the side opposite to the intake port side at the combustion chamber side mouth portion of the intake port is , and the control on the soil wall surface side of the intake passage from the intersection located at least farther from the cylinder center line perpendicular to the cylinder row direction behind the two intersections of the outer periphery of the control valve and the control valve shaft. A second circular arc approximately equal in length to the first circular arc along the outer periphery of the valve is set, and a center of gravity position of the notch is set on an area portion of the t, II On valve corresponding to the second circular arc. Further, the present invention provides a sub-control valve downstream of the control valve, which has a guide hole portion having an area smaller than the area of the control valve guide hole portion and is perpendicular to the center line of the intake passage when fully closed. [Operation] When the control valve is fully closed, the control valve is tilted forward toward the intake valve side with respect to the intake passage, so that the intake air is guided by the control valve and flows out from the notch at the tip of the forward tilt side. , flows smoothly into the combustion chamber along the intake passage.This provides optimal intake flow,
1q of stable combustion will be achieved. [Embodiment] The present invention will be described in detail below based on the drawings. 1 to 11 relate to a first embodiment, in which FIG. 1 is a plan sectional view of the intake device, and FIG. 3 is a longitudinal sectional view thereof. An intake port 3 and an exhaust port 5 are formed in the cylinder head 1, and each port 3.5 has an intake valve 7. Exhaust valve 9
are provided for each. Intake port 3 is combustion chamber 11
It gradually curves toward the upstream side from the opening 13 at the top of the cylinder, forming a portion 19 that is substantially orthogonal to the cylinder center axis 17 near the intake manifold 15. In this part 19,
A swirl control valve 23 having a notch 21 is connected to the control valve shaft 2.
The intake port 3 is provided so as to be openable and closable while being supported by the intake port 5. Intake manifold 15 and cylinder head 1
The intake port 3 forms an intake passage 14. Note that the reference numeral 22 is a spark plug. The swirl control valve 23 is tilted forward by α° U toward the intake valve 7 with respect to a plane 30 perpendicular to the center line 28 of the intake passage 14 when fully closed. In addition, the combustion chamber 11 side opening portion 1 of the intake port 3
Of the semicircular two-part parts on the side opposite to the intake port 3 in 3, the first part of the approximately four-part part 29 on the cylinder outer circumferential side
The length of the arc of is defined as love 1, while the intersection points A and B between the outer periphery of the swirl control valve 23 and the center axis 26 of the control valve shaft 25 are perpendicular to the cylinder row direction (vertical direction in FIG. 1). From the cylinder center line 18) to the intersection point, along the outer periphery of the swirl control valve 23 on the upper wall surface 16 side of the intake passage 14, a point that is approximately equal to the length of the first circular arc IL+ is set as a point C, and the intersection point is Area portion 31 of the swirl control valve 23 shown in FIG. 2 corresponding to the second circular arc formed by A and point C
The center of gravity of the notch 21 is located at the top. That is, the length 3 of the second arc formed by the first arc length 1 of the two 4-divided parts, the arc length J2 of the area part 31, and the points A and C of the swirl control valve 23. are approximately equal to each other. Note that 27 indicates a line connecting a point C on the area portion 31 with a portion on the side farthest from the intake port 1-3 side of the four-divided portion 29. Specific examples of the notch portion 21 are not shown in FIGS. 4 to 7. The center of gravity of each notch 21 is indicated by G. This center of gravity G is located on the area portion 31 in each case. With this configuration, when the fully closed intake valve 7 of the swirl control valve 23 opens, the intake air flowing through the intake manifold 15 passes through the notch 21 of the swirl control valve 23 and flows toward the combustion chamber 11. At this time, swirl control valve 2
3 is α on the intake valve 7 side. Since the intake port 3 is tilted forward, the intake air on the lower wall side of the intake port 3 flows along the slope of the swirl control valve 23 toward the upper wall surface 16 side where the notch 21 is provided, reaches the notch 21, and the intake air is Along with the intake air flowing on the upper wall surface 16 side of the port 3, the notch 2
1 to the combustion chamber 11 side, it does not collide with the inner wall of the intake port 3, and since the center of gravity of the notch 21 is at the position described above, the main flow of the intake air that has passed through the notch 21 is After flowing along the intake port 3, the combustion chamber 11 flows from the four-division part 29 of the intake port 3 opening 13.
flows into the deepest part of Therefore, a school with uniform swirl ratio changes is generated in the combustion chamber 11, making it possible to keep swirl attenuation to a minimum until the latter half of the compression stroke, and flame propagation is stable during the combustion stroke without being inhibited. This progresses and significantly improves combustion, resulting in significant improvements in fuel efficiency, emissions, and drivability. Then, at full load, the swirl control valve 23 is fully opened, improving the intake air filling efficiency. Figure 8 shows Isoseki rotational speed N = 1400 rpm, average effective pressure P+ = 0.31 MPa, air-fuel ratio A/F-2
2, 5. Under the condition that the ignition advance angle is MBT, the swirl control valve 32 in Fig. 9 corresponds to the view from the direction of arrow ◯ in Fig. 3.
The variation rate of the indicated mean effective pressure depending on the position of the notch 34 (expressed as θ°) is shown for each state in which α, which is the inclination angle of , is Oo, 5°, 15°, and 30°. Notch 3
The position of 4 is the upper side of the center line 33 on the horizontal side plus (
+), and the lower side is negative (-), and each inclination angle surface is also shown as a solid line when it is on the right side (<■ side) from the center line 35 on the vertical side, and when it is on the left o+q <■ side) The time is also indicated by a broken line. In addition, in the experiment, as shown in Fig. 9, the swirl control valve 3
2 has an elliptical shape, and the angle of the notch position θ is the long axis of the ellipse (
The center point is set at a position 16 mm from the peripheral edge of the control valve 32, which intersects with the horizontal center Fi133). Further, the cutout portion 34 has an arc shape cut out by a circle with a diameter of 2611111111. Furthermore, the diameter of the combustion chamber side opening of the intake manifold is 32mlIl. As is clear from FIG. 8 mentioned above, the fluctuation rate of the indicated mean effective pressure is low and combustion is stable when α = 15°, and regardless of the inclination angle α, the position of the notch 34 is The condition is that θ=O″ to 90′. Therefore, as shown in FIGS. 1 and 2 showing the first embodiment, the center of gravity of the notch 21 is set to Approximately 4 on the cylinder outer circumferential side of the semicircular two-divided portion on the side opposite to the intake port 3 in the combustion chamber 11 side opening 13 of No. 3.
While the length of the first arc of the divided portion 29 is set to 1, the outer circumference of the swirl fi, IJ tit valve 23 and the control valve shaft 25 are
Of the intersections A and B with the central axis 26 of the cylinder row direction (
The length of the first circular arc is further 1 along the outer periphery of the swirl control valve 23 on the upper wall surface 16 side of the intake passage 14 from the intersection A that is far from the cylinder center line 18 perpendicular to the vertical direction (in FIG. 1).
By setting a point substantially equal to point C on the area portion 31 of the swirl control valve 23 shown in FIG.
1 is located in the range of 0-0° to 90° above the center line 33 on the horizontal side and to the right of the center line 35 on the vertical side in Fig. 9 according to the experiment, and stable combustion can be obtained. become. In Fig. 10, engine speed N = 140 Orpm, indicated mean effective pressure P* = 0.31 MPa, and ignition advance angle is MBT.
Based on the conditions, the indicated fuel consumption due to changes in the air-fuel ratio A/F! The fluctuation rate of the yen rate and the indicated average effective pressure are set at the inclination angle α-15° of the swirl control valve 32 in FIG. 9 and the position of the notch 34 at 0=6
0" (solid line shown), α - 0° and α = 60° (dotted chain line shown), and α - 15° and θ - -20° (dashed line shown). As shown in FIG. 10, the swirl control valve 32 is tilted forward by 15 degrees ul and the position of the notch 34 is θ-60', which is the first embodiment. The positions shown in Figures 1 and 2 are good, and in this case both stability and fuel efficiency are greatly improved.The data shown in Figures 8 and 10 above are based on the swirl control valve 32 and the intake port. The experiment was conducted with the gap between the wall and the wall constant, and the swirl control 0a valve was in the upright position at low loads.
In a system where the gap with the intake port is kept constant and the opening of the swirl control valve is increased as the load increases, the gap with the intake port becomes large, making it impossible to obtain a directional and uniform swirl, resulting in a stable It was found that it was not possible to obtain the desired combustion. Figure 11 shows the gas flow characteristics in the combustion chamber using a Leigh (Adopler flowmeter) when α = 15° and 0 = 60°, based on the conditions of engine rotation speed N = 140 Orpm and charging efficiency ηC = 40%. When α=O° and θ=60°, and when α=15°, θ
This shows three cases when = -20°. In addition, the solid line in the figure is 60 degrees before top dead center when the intake valve starts to open.
(BTDC), the dashed line is 30' (BTDC)
, the broken line indicates 0' (BTDC). According to Fig. 11 above, α=15° and α-6 as in Fig. 10.
The 0° condition is good, and there is no intersection of streamlines in the compression stroke that occurs under other conditions, and a uniform swirl ratio of 19 is achieved from the ignition timing to the initial combustion engine. FIGS. 12 and 13 show a second embodiment. This embodiment is a modification of the first embodiment, in which the intake valve 7 is
In one example, the openings 13a, 1 of the intake ports 3a, 3b to the combustion chamber 11 are set to have a Niamize-type intake port shape.
3b is formed. In this case as well, the swirl control valve 23 is tilted forward as in the first embodiment, and the center of gravity of the notch 21 is also located at the opening 13a of the intake port 3 on the combustion chamber 11 side, as in the first embodiment. Among the semicircular two-part parts on the opposite side to the intake port 3 side, the length of the first circular arc of the approximately four-part part 29a on the cylinder outer circumferential side is 1, while the outer circumference of the swirl control valve 23 and Of the intersections A and B with the center axis 26 of the control valve shaft 25, from the intersection A farther from the cylinder centerline 18 perpendicular to the cylinder row direction (vertical direction in FIG. 1), the upper wall surface 16 side of the intake passage 14 Since the swirl control valve 23 is provided on the product part 31 along the outer periphery of the swirl control valve 23, which is approximately equal to the length 11 of the first circular arc, when the swirl control valve 23 is closed, the intake air flows through the notch 2.
1, a uniform swirl similar to that of the first embodiment is obtained, and combustion is significantly improved. Then, at full load, the swirl control valve 23 is fully opened and the intake air flows into the combustion chamber 11 through the two intake ports 3a and 3b, so that the intake air filling efficiency is further improved. In the second embodiment, the cutout 21 may be provided on the lower side of the intake port 3b in the drawing. This is shown by the dashed line. Needless to say, the center of gravity of this notch 21 is located at the corresponding portions of the four-division portion 29a of the frontage portion 13a and the four-division portion 29b of the opening 13b, which corresponds to the symmetrical position in the vertical direction in the figure. . Further, a dual port type may be used instead of the Siamese type, and in this case as well, a swirl control valve having a notch formed at a predetermined position may be provided in one of the intake ports. Furthermore, the second embodiment may be applied to an engine having two exhaust valves. Also, 1st. In each of the second embodiments, the swirl ffill control valve 23 may be provided in the intake manifold 15. FIGS. 14 and 15 show a third embodiment. This embodiment is based on the first example described above. A swirl control valve 23 having a notch 21 similar to that of the second embodiment is provided in the intake manifold 15, and the cylinder head 1 downstream thereof
A sub-control valve 41 having a notch 39 fixed to a valve shaft 37 is rotatably provided in the internal intake port 3 . The swirl control valve 23 is tilted forward by α° as in the first embodiment, and the center of gravity of the notch 21 is also provided at the same position as in the first embodiment. On the other hand, when the sub-control valve 41 is fully closed, it is not inclined and is substantially perpendicular to the center line 28 of the intake passage 14. The notch 39 of the sub-control valve 41 is the same as the notch 21 of the swirl control valve 23 and the opening 13 of the intake port 3.
The area is smaller than the area of the notch 21 of the swirl control valve 23. In this case, both the swirl control valve 23 and the sub-control valve 41 are fully open in the extremely low load range including the idle link, and the sub-control valve 41 is perpendicular to the intake port 3 at this time. On the other hand, as shown in Fig. 16, the engine speed N=700r
pm, indicated mean effective pressure Pi =, 0.08 MPa,
Under extremely low load conditions including an idle link with an air-fuel ratio A/F = 15 (the experimental equipment is the same as in Figures 8 to 11), the tilt angle α of the swirl control valve in Figure 9 is large. As this increases, the rate of variation in the indicated mean effective pressure increases regardless of the position of the notch. Note that although the data shown here is when the notch is on the right side (■ side) of the center line 35 on the vertical side in Fig. 9, the same tendency is shown on the opposite side (■ side). . This is because gas flow measurements have shown that when the control valve is upright (α = 0°), the flow line in the intake port collides with the intake port wall and is disturbed, which increases the turbulence in the gas flow in the combustion chamber and improves combustion. Depends on the reason. Therefore, as mentioned above, the combustion chamber 11
By setting the side sub-control valve 41 in the upright state, the intake air flowing from upstream of the intake manifold 5 first passes through the notch 21 of the swirl control valve 23 in the same manner as in the first embodiment, and then returns to the upright state. (α=06) flows toward the notch 39 of the sub-control valve 41 and flows out to the combustion chamber 11 side. At this time, the area of the notch 39 of the sub-control valve 41 is smaller than that of the notch 21 of the swirl control valve 23, and since the sub-control valve 41 is in an upright state, the intake air flowing out from the notch 39 is transferred to the intake air as described above. It partially collides with the inner wall of the port 3, causing strong turbulence, and flows into the combustion v11 from the frontage part 13. As a result, turbulence and cycle fluctuations in the gas flow within the combustion chamber 11 increase, the combustion speed increases, and combustion is significantly improved. Next, when the load increases and reaches the partial load range, the sub control valve 4
1 is open, and the intake air is connected to the notch 21 of the swirl control valve 23.
It flows out to the intake port 3 through the. The subsequent flow of intake air is substantially the same as in the first embodiment, and therefore, in this case, a uniform swirl with little turbulence and small cycle fluctuations, which is suitable for the partial load region, is generated, resulting in a significant improvement in combustion. In the full load range, both the swirl control valve 23 and the sub-control valve 41 are fully opened, improving the intake air filling efficiency. As described above, in this embodiment, by providing two control valves, more detailed swirl control corresponding to the load state can be performed. FIGS. 17 and 18 show a fourth embodiment. This embodiment is a modification of the third embodiment, and is an example in which there are two intake valves like the second embodiment, and the intake port shape is Siamese type, and the openings 13a of the intake ports 3a and 3b to the combustion chamber 11 are used. , 13b are avoided. In this case as well, the swirl control valve 23 is tilted forward as in the third embodiment, and the position of the center of gravity of the notch 21 is also the same as in the second embodiment. On the other hand, similarly to the third embodiment, the ]1 control valve 41 is not inclined when fully closed, and the area of its notch 39 is also smaller than the area of the notch 21 of the swirl 1b11 control valve 23. . Therefore, even in the intake device configured in this way, the third
Similar to the embodiment, significant combustion improvement can be achieved in the extremely low load range and partial load range. Further, in this case, both the swirl control valve 23 and the sub-control valve 41 are fully opened in the full load range, and the intake air passes through the two intake ports 3a and 3b, so that the intake air filling rate is further improved. In addition, in the fourth embodiment, the notches 21 and 39 of the swirl control valve 23 and the sub-control valve 41 may be provided on the lower intake port 3b side in the figure, and the intake ports may have independent shapes. It may be a dual port type, with two exhaust valves.
It may be applied to a certain palace. 19 to 21 respectively show fifth to seventh embodiments, in which the diameter of the combustion chamber side opening 13 of the intake port 3 and the diameter of the swirl control valve 23 are approximately the same. Therefore, in each of the fifth to seventh embodiments, in the plan sectional view of the intake device as shown in FIGS. 19 and 20, the center line 28 of the intake passage 14 The line 27 connecting point C with the part on the side farthest from the intake port 3 side of 29 overlaps with the line 27 that connects point C. In the fifth embodiment shown in FIG. They extend in directions facing each other with respect to the chamber 11, and both are located on the cylinder center line 18 perpendicular to the cylinder row direction.Therefore, in this case, the center axis FA26 of the control valve shaft 25 and the swirl control valve 23 are aligned. The intersection points A and B with the outer periphery are located at substantially equal distances from the cylinder center line 18. Therefore, of the two divided parts of the combustion chamber side opening 13 on the side opposite to the intake port 3 side, the intersection points A and B on the cylinder outer periphery side There are two approximately four-division parts 29, and two notches 21 are formed corresponding to each four-division part 29. In the sixth embodiment shown in FIG. 20, the intake port 3 and the exhaust port 5 are the same. This figure shows an application of this invention to a so-called counterflow engine in which the combustion chamber side openings 13 of each port 3.5 are arranged in the cylinder row direction. This embodiment shows an application of this invention to an engine in which the intake passage 14 near the joint between the intake port 3 and the intake manifold 15 is inclined to introduce intake air from diagonally above. In each of the seventh embodiments, when the swirl control valve 23 is fully closed, the intake air smoothly flows out to the combustion chamber 11 side through the notch 21, and the same effect as the first embodiment is obtained. [Effects] As described above, according to the present invention, (1) of the two-divided portion on the side opposite to the intake port side at the opening of the intake port on the combustion chamber side, the circular arc of the approximately quarter-divided portion on the cylinder outer circumferential side is The length of the first circular arc along the outer periphery of the control valve on the upper wall surface side of the intake passage from the intersection point of the outer periphery of the control valve and the control valve shaft that is at least farther from the cylinder center line perpendicular to the cylinder row direction. By setting a second circular arc that is approximately equal to flame propagation progresses stably and combustion is significantly improved, fuel efficiency and
Emissions and drivability can be greatly improved. In addition, (2) a sub-control valve is provided downstream of the control valve, which has a notch area smaller than the area of the notch part of the control valve, and is perpendicular to the center line of the intake passage when fully closed, resulting in a low load. Due to the occurrence of intake holes in the region, and the sub-control valve opens in the partial load region due to uniform swirl with little cycle fluctuation.
Both can significantly improve combustion.

[Brief explanation of drawings]

1 to 11 relate to the first embodiment of the present invention, in which FIG. 1 is a plan sectional view of the intake device, FIG. 2 is a view taken in the direction of the ■ arrow in FIG. 1, and FIG. Figures 4 to 7 are explanatory diagrams showing specific examples of the notch of the control valve, Figure 8 is an explanatory diagram of the partial experimental device according to the position of the notch, and Figure 10 is the indicated fuel efficiency according to the air-fuel ratio. 11 is a gas flow characteristic diagram measured by a laser Doppler flowmeter, FIG. 12 is a cross-sectional plan view of the intake device of the second embodiment, and FIG. 13 is a diagram showing the fluctuation rate of the indicated mean effective pressure. The same longitudinal sectional view of the embodiment, 1st =
Figure 1 is a plan sectional view of the intake system of the third embodiment, Figure 15 is a longitudinal sectional view of the same, and Figure 16 is a diagram of the indicated mean effective pressure in the low load range depending on the position of the notch. An explanatory diagram showing the fluctuation rate, FIG. 17 is a plan sectional view of the intake device of the fourth embodiment, FIG. 18 is a longitudinal sectional view of the same of the fourth embodiment, and FIG. 19 is the same of the fifth embodiment. 20 is a plan sectional view of the sixth embodiment, and FIG. 21 is an m sectional view of the seventh embodiment. 3... Intake port 7... Intake valve 11...
Combustion chamber 13... Opening 14... Intake passage 16... Earth wall surface 18... Cylinder center line 21... Notch 23... Swirl control valve
25... Control valve shaft 28... Center line of intake passage 29
...four-division part 30...perpendicular 37.
... Area part 11 ... Length of the first arc 13 ... Length of the second arc A, B ... Intersection agent Patent attorney Yasuo Miyoshi Figure 3 Figure 4 Figure 5 ■ Figure 6 Figure 7 Figure 9 A/F Figure 10 Average flow velocity Figure 14 Figure 15 Figure 17 Figure 1^ Figure 18 Figure 20

Claims (2)

[Claims] (1) A control valve that has a notch and opens and closes the intake passage by rotating the control valve shaft is provided in the intake passage downstream of the throttle valve, and when the control valve is fully closed, the control valve is perpendicular to the center line of the intake passage. It is tilted forward toward the intake valve side with respect to the surface, and among the two divided parts on the side opposite to the intake port side at the opening of the intake port on the combustion chamber side, the circular arc of the approximately four-divided part on the cylinder outer circumferential side is the first circular arc. On the other hand, along the outer periphery of the control valve on the upper wall surface side of the intake passage from the intersection that is at least farther from the cylinder center line perpendicular to the cylinder row direction among the two intersections between the outer periphery of the control valve and the control valve shaft. A second arc is set substantially equal to the length of the first arc, and the center of gravity of the notch is located on an area of the control valve corresponding to the second arc. Intake system for internal combustion engines. (2) An internal combustion engine characterized in that an auxiliary control valve is provided downstream of the control valve, the sub-control valve having a notch having an area smaller than the area of the notch of the control valve and being perpendicular to the center line of the intake passage when fully closed. intake device.