JPH0318624A - Intake multiple valve - Google Patents

Abstract

PURPOSE:To improve the scavenging performance of valve at the intake side by extending a combustion chamber to the outer radial direction rather than a cylinder bore, at the position corresponding to intake ports at both ends in the sequentially arranged direction. CONSTITUTION:An intake port 33 which is positioned near the center in the sequentially arranged direction is connected to an auxiliary intake passage 16, and the intake ports 31, 32 are connected to a main intake passage 15, respectively, in a three-intake valve engine 1 which has three intake ports 31 to 33 are arranged at one side in the planar direction of a combustion chamber 2, and exhaust ports 41, 42 at the other side. Rich mixed air is supplied to the auxiliary intake passage 16, and only air is supplied to a main intake passage 15. The combustion chamber 2 is extended to the outer radial direction rather than a cylinder bore 34, at the position corresponding to the intake ports 31, 32. Consequently, the air which is introduced from the intake ports 31, 32 is blowed off to not only the part of the combustion chamber 2 near the center also to the side of a chamber wall face 2a. The peripheral part of the combustion chamber 2 is fully blowed thereby and also the mixing of fuel and air from the intake ports 33 is facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an intake multi-valve engine having a plurality of intake valves in one combustion chamber.

(Prior art) In recent years, in automobile engines, the number of intake valves has been increased from the viewpoint of increasing the intake bottom area and increasing the intake air filling efficiency. For example, JP-A-61-215
As disclosed in Japanese Patent No. 422, there is a three-valve intake engine in which one combustion chamber is provided with three intake valves. In such an intake multi-valve engine, multiple intake valves and exhaust valves are provided within the combustion chamber in a limited space, so sufficient consideration must be given to the location of these valves and the selection of the fuel supply port. Become.

(Problem to be Solved by the Invention) By the way, in the above-mentioned known example, fuel is supplied from the central intake port among the three intake ports, and air is supplied from the intake ports at both ends. However, in this case, since all three intake ports are housed within a circular cylinder bore, the intake ports at both ends are close to the periphery of the combustion chamber.

In addition, in order to obtain high intake air filling efficiency in such a configuration, it is necessary to increase the opening area of the intake ports at both ends where air is introduced, and as a result, one The intake port will be located at the periphery of the combustion chamber.

Therefore, in the above-mentioned known example, fuel is supplied to the peripheral edge of the combustion chamber on the intake side where the wall surface temperature of the combustion chamber is low, and air introduced from the intake holes on both sides of the combustion chamber is supplied to the peripheral edge of the combustion chamber. Since the structure makes it difficult for gas to flow, the peripheral edge on the intake side becomes an end gas zone, increasing the amount of HC generated and making it more likely that knocking will occur.

SUMMARY OF THE INVENTION The present invention aims to improve exhaust emissions by improving the scavenging performance on the intake side in an intake multi-valve engine, and also to improve the knock resistance of the engine.

(Means for Solving the Problems) In the present invention, as a specific means for solving the problems, a plurality of intake ports are provided on one side in the plane direction of the combustion chamber, and an exhaust port is provided on the other side in the plane direction. In the intake multi-valve engine, among the above-mentioned intake ports, the intake port located near the center in the arrangement direction is connected to the auxiliary intake passage, and the other intake ports are connected to the main intake passage, and the intake ports of each intake passage are connected to the main intake passage. A rich mixture is supplied to the inner and auxiliary intake passages, and a lean mixture or only air is supplied to the main intake passage, while the combustion chamber corresponds to the intake ports at both ends of the intake ports in the arrangement direction. It is characterized by expanding radially outward from the cylinder bore at each position.

(Function) In the present invention, with such a configuration, the air or lean mixture introduced from the intake ports at both ends expands laterally in the radial direction at the position where the combustion chamber corresponds to the intake ports. As a result, the fuel is blown not only toward the center of the combustion chamber but also toward the periphery, thereby sufficiently scavenging the periphery and promoting mixing of fuel supplied from the center intake port with air.

(Effects of the Invention) Therefore, in the intake multi-valve engine of the present invention, the periphery of the combustion chamber on the intake side is sufficiently scavenged by the air or lean mixture introduced from the intake ports on both ends, and air is supplied from the intake port on the center side. Even if the central intake port is located at the periphery of the combustion chamber, the formation of an end gas zone on the intake side is reliably prevented, and exhaust emission is reduced by reducing HC. This is intended to improve the knock resistance of the engine.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

First Embodiment FIG. 1 shows the first embodiment of the present invention. A sectional view of the main parts of the automobile engine 1 according to the embodiment is shown, and FIG. 2 shows its combustion chamber 20.
A schematic plan view of the peripheral portion (corresponding to the view in the direction of arrows 1 and 2 in FIG. 1) is shown.

This engine 1 is a multi-valve engine with 3 intake valves and 2 exhaust valves, and as shown in FIGS. A large-diameter first intake port 3 is provided on one side in the planar direction of 2.
A first intake valve 5 and a second intake valve 6 that open and close the first and second intake ports 32, respectively, and the first and second intake ports 586.
Three intake valves, a third intake valve 7 which opens and closes a third intake port 33 which is located between them and has a smaller diameter than these, are arranged, and two exhaust valves 8.9 are arranged on the other side.

Of these three intake ports 31, 32, and 33, the first intake port 3l and the second intake port 32 located at both ends straddle the cylinder bore 34 (shown by chain lines in FIG. 2) and extend to the outside thereof. There is. Therefore, as shown in FIGS. 2 and 3, the combustion chamber 2 has intake bows at both ends.
A portion of the cylinder bore 34 is located at a position corresponding to 32.
In this expanded portion, a relatively large arc shape is formed between the combustion chamber wall surface 2a and the first intake valve 5 and the second intake valve 6 attached to each intake bow. passage portions 35 and 35 are formed respectively. still,
In this case, as shown in FIG. 2, at a position corresponding to the passage 35, the peripheral edge of the gasket 53 interposed between the cylinder block 5l and the cylinder head 52 also follows the shape of the passage 35. It is cut out in an arc shape.

On the other hand, among the intake ports 31, 32.33, the first and second intake ports 31.32 located at both ends merge on the upstream side and are connected to the main intake passage 15 provided with the throttle valve l1. There is. On the other hand, the third
The intake port 33 is connected to the first and second intake bows}31.32.
It is formed on the lower side of the main intake passage 15, and is connected to a sub-intake passage 16 branched from the main intake passage 15 on the upstream side of the above-mentioned main intake passage 15. An injector 12 is provided in this sub-intake passage l6. Therefore, only air is introduced from the first intake port 3l and the second intake port 32 located at both ends of the intake boats 31, 32, and 33, and fuel is introduced from the third intake boat 33 in the center. It will be introduced.

On the other hand, each of the exhaust ports 41 and 42 joins together on the downstream side thereof and is connected to the exhaust passage 40.

In the engine l configured in this way, during the intake stroke, the first and second intake bows }31 with respect to the combustion chamber 2 are
．． Only air is introduced from the third intake port 32, and rich mixture is introduced from the third intake port 33.

In this case, even if the rich air-fuel mixture is introduced through the third intake valve 7, which is relatively far from the spark plug IO and located at a position where the intake air velocity between the intake valves 5.6 at both ends is relatively slow and is likely to become an end gas zone, As shown in FIGS. 2 and 3, a large amount of air is introduced from the intake valves 5 and 6 at both ends, and as shown in FIGS. Since the air is blown out forcefully to the periphery of the combustion chamber through the passage portion 35, 35, the air flowing around the periphery of the combustion chamber efficiently scavenges the area near the third intake valve 7, and the airflow also sweeps the vicinity of the third intake valve 7. Mixing of the rich air-fuel mixture introduced from 33 with air is promoted, and due to their synergistic effect, formation of an end gas zone in the vicinity of the third intake valve 7 is prevented as much as possible. Therefore, H.C.
This effectively suppresses the occurrence of engine exhaust emissions, improves engine exhaust emissions, and improves the knock resistance of the engine.

In addition, as in this embodiment, the intake ports 31 and 32 at both ends
When a part of the combustion chamber is expanded radially outward at a portion corresponding to The opening area of the l1 second intake port 31, 32 can be increased while maintaining this, and this can contribute to an improvement in engine output.

Second Embodiment FIG. 2 is a schematic diagram of a multi-valve intake engine according to a second embodiment of the present invention. In this embodiment, whereas in the first embodiment, the third intake port 33 for supplying fuel was opened between the intake ports 31 and 32 at both ends and toward the cylinder bore side. 3. The intake port 33 is opened approximately at the center of the combustion chamber 2. Correspondingly, two ignition plugs 10 are provided, and these are arranged near the peripheral edge of the combustion chamber 2 so as to face each other across the center of the combustion chamber 2.

Furthermore, in this embodiment, the opening timing of the third intake valve 7 is set to be later than that of the first intake valve 5 and the second intake valve 6. Note that the first intake valve 5 and the second intake valve at both ends
This embodiment is similar to the first embodiment in that a portion of the combustion chamber 2 is expanded radially outward at a position corresponding to the intake valve 6 to form a passage portion 35.

In such a configuration, first the intake valves 5.
6, the air introduced through the combustion chamber 2 sufficiently circulates around the peripheral edge of the combustion chamber 2, and its scavenging action prevents the peripheral edge on the intake side from becoming an end gas zone, and the intake ports 31 and 32 at both ends are connected to the combustion chamber. As in the case of the first embodiment, the opening area of each intake port 3l, 32 can be enlarged (that is, the engine output can be improved) by moving the intake ports 3l and 32 all the way toward the peripheral edge of the intake port 2.

Furthermore, in this embodiment, since the third intake port 33 for supplying fuel opens almost at the center of the combustion chamber 2, adhesion of fuel to the peripheral edge of the combustion chamber 2 is prevented as much as possible. At the same time, the mixing of the fuel with air is improved, and as a result, the knock resistance and exhaust emissions of the engine can be improved.

Furthermore, in this embodiment, the opening timing of the third intake valve 7 among the intake valves 5.6.7 is delayed from that of the other intake valves 5.6, so that the rich mixture The time during which the intake valves come into contact with the high-temperature residual gas is shorter than, for example, when the three intake valves 5, 6.7 are opened at the same time. As a result, the generation of force-bonding deposits is suppressed, and the temperature of the air-fuel mixture is also suppressed, thereby improving the knock resistance of the engine.

FIG. 5 is a schematic plan view of a multi-valve intake engine according to a third embodiment of the present invention. This embodiment differs from the above embodiments in that it is a 4-valve engine with four intake valves, but its basic configuration is a combination of the first and second embodiments. It becomes. That is, the fact that the third intake port 33 through which fuel is introduced is opened at the center of the combustion chamber 2 and the two spark plugs 10 and 10 are provided at positions facing each other across the center of the combustion chamber is the second feature. This is the configuration of the first embodiment, and it is the configuration of the first embodiment that the combustion chamber 2 is expanded radially outward at the portions corresponding to the first intake valve 5 and the second intake valve 6 at both ends. This example has a fourth structure on top of these configurations.
An intake port 36 and a fourth intake valve 13 for opening and closing the intake port 36 are added. This fourth intake port 36 is
Like the first and second intake valves 5.6, they are connected to the main intake passage l5, and air is also introduced from the fourth intake port 36.

By adopting such a configuration, it goes without saying that the same effects as in the first and second embodiments can be obtained, but in addition, the opening area of the fourth intake port 36 is reduced by the intake port 36. The overall passage area increases, and the engine output can be improved accordingly.

In addition, in this third embodiment, the third intake port. However, in another embodiment of the present invention, both the third intake port 33 and the fourth intake port 36 are connected to the auxiliary intake passage l6, and these two intake ports It is also possible to supply fuel via ports 33,36.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of main parts of an intake multi-valve engine according to a first embodiment of the present invention, FIG. 2 is a view taken along arrow U-■ in FIG.
The figure is a vertical sectional view of FIG. 2, FIG. 4 is a schematic plan view of a multi-intake valve engine according to a second embodiment of the present invention, and FIG. 5 is a multi-intake valve according to a third embodiment of the present invention. A schematic diagram of the engine 1-●●●●● Engine 2... Combustion chambers 5 to 7, l3... Intake valve 8. 9・・・・−! 0 ・ ・ ・ ・ l!・ ・ ・ ・ l 2 ・ ・ ・ ・ 1 5 ・ ・ ・ ・ l 6 ・ ・ ・ ・ 3l ~ 33, 36

Claims (1)

[Claims] 1. An intake multi-valve engine equipped with a plurality of intake ports on one side of the combustion chamber in the plane direction and an exhaust port on the other side, and among the above-mentioned intake ports, the intake ports are located near the center in the arrangement direction. The intake port is connected to the auxiliary intake passage, and the other intake ports are connected to the main intake passage, and among the intake passages, the auxiliary intake passage is connected to a rich mixture, and the main intake passage is connected to a lean mixture or An intake multi-valve, characterized in that, while supplying only air, the combustion chamber is expanded radially outward from the cylinder bore at a position corresponding to the intake ports at both ends in the arrangement direction among the intake ports. engine.