JPS59105926A - Three valve type internal-combustion engine - Google Patents

Abstract

PURPOSE:To equalize the air-fuel ratio of a mixture accelerating the rising up combustion as well as to improve the high speed output performance reducing fuel consumption by a method wherein a swirl guide is protruded beyond the ceiling of a combustion chamber so that the swirling guide may be inserted between a suction valve port and an exhaust valve port facing to each other. CONSTITUTION:When a suction stroke is started, the first suction valve 181 is opened firstly, therefore the mixture flowing from the first suction valve port 91 to a combustion chamber 6 is led by the first branch port 131 directing to the second suction valve port 92 side and a steep first guide surface 8a of a swirl guide 8 to produce swirl and when the mixture reaches a gentle slope second guide surface 8b, the swirling direction of the mixture is deflected downward of the combustion chamber 6 led by the guide surface 8b to spiral. Next when the second suction valve 182 is opened, the mixture flowing from the second suction valve port 92 to the combustion chamber 6 is led by the second branch port 132 directing to an ignition plug 12 side to produce swirl and the air-fuel ratio of the other mixture in the combustion chamber 6 is equalized by intensifying the swirl while flowing together with the mixture preliminarily flowing from the first suction valve port 91. Through these procedures, the fuel consumption may be reduced improving the output performance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a three-valve internal combustion engine having two intake valve ports and one exhaust valve port opening into a combustion chamber.

This type of internal combustion engine generally has a sufficiently large overall effective area of the intake valve port on the ceiling surface of the narrow combustion chamber, so it is possible to increase the charging efficiency, and moreover, the total effective area of the intake valve port can be increased sufficiently. Since the effective area is relatively small, the diameter of the intake valves that open and close the intake valves can be made smaller to reduce their inertial weight and improve the ability of each intake valve to follow the valve train during high-speed engine operation. Therefore, it has the advantage of exhibiting excellent high-speed output performance.

In this type of engine, the present invention prevents the air-fuel mixture from flowing into the combustion chamber by protruding a swirl guide from the ceiling surface of the combustion chamber so as to intervene between an intake valve port and an exhaust valve port that face each other. The purpose of this invention is to generate a swirl at times, to equalize the air-fuel ratio of the air-fuel mixture, and to promote the start of combustion, thereby promoting the above-mentioned advantages and reducing fuel consumption.

An embodiment of the present invention will be described below with reference to the drawings.

The illustrated internal combustion engine is a cross-flow type four-cycle gasoline engine, and the engine main body IC is a cylinder block 1.
and a cylinder head 2 which is overlappingly bonded to the upper surface of the cylinder head 2 through a gasket 3. A piston 5 is slidably fitted into a cylinder 4 formed in the cylinder block 1. A combustion chamber 6 is recessed in the bottom surface of the cylinder head 2 at a portion facing the top surface of the piston 5, and the ceiling surface 7 of this combustion chamber 6 is
Roughly central ridge? Two ceiling slopes descending from fML to both sides7. ．． It consists of 72.

On one ceiling slope T, there is a pair of first. Second intake valve port 91. 92 are opened in parallel along the ridge line LKG, and on the other ceiling slope 72, one exhaust valve port 10 is connected to the first intake valve port 9. The electrode of the ignition plug 12 screwed onto the cylinder head 2 is deviated toward the side opposite to the second intake valve port 92 and is opened.

In addition, a swirl guide 8 is provided on the ceiling surface 7 of the combustion chamber 6.
It protrudes from the periphery so as to intervene between the first intake valve port 91 and the exhaust valve port 10. This swirl kite 8 is the first
A first valve whose side surface along the periphery of the intake valve port 91 stands up in the form of a precipice.
The side surface formed on the guide surface 8a and located on the periphery of the exhaust valve port 10 is formed as a relatively gently inclined second guide surface 8b, and the second side surface is formed on a skin surface 8C at the same height as the bottom surface of the cylinder head 2. is formed.

The cylinder head 2 has an intake boat 13 and an exhaust port 1.
4 is formed, and the intake boat 13 has a first . The first branch boat is divided into second branch boats 131 and 132. The outer end thereof is connected to a second intake valve port 91, 92, and the outer end thereof is opened to one side of the cylinder head 2, and the opening is provided with an intake pipe 1 connected to a fractional supply device, for example, a carburetor (not shown).
5 are connected. By branching the intake boat 13 within the cylinder head 2 in this manner, the structure of the intake pipe 150 passage can be simplified. Further, the intake port 3 is formed so as to be oriented generally in a substantially tangential direction of the periphery of the combustion chamber 6 .

On the other hand, the exhaust port 14 has an inner end connected to the exhaust valve port 10, an outer end that opens on the other side of the cylinder head 2, and an exhaust pipe (not shown) connected to the opening.

1st. Second intake valve port9. ．． 92 and the exhaust valve port 10,
Valve guide 16 to cylinder head 2. ．． The first. Second intake valve 1B,,1
8□ and exhaust valve 19, and these valves 18, . A valve mechanism AI for opening and closing the valve 182.19 is disposed above the seven-ring head 2.

The valve mechanism M includes the valve 18. , 18□ and 19, respectively, and springs the valve springs 20+ in the closing direction.
, 202, 21 and the valve 18. , 18□.

19 and rocker arm 22. ．． 222. 23 respectively, the valves 181, 182, 19 are connected to each valve spring 20. ．． 202. 21, and a common camshaft 24 that can open against the elastic force of the valves 181=182.

19 is given opening/closing timing as shown in FIG.

That is, the opening timing of the second intake valve 182 facing the spark plug 12 is delayed relative to the opening timing of the first intake valve 18° facing the exhaust valve 19, and the closing timing of both intake valves IL and i82 is delayed. The valve timing should be the same. In this way, the swirl of the air-fuel mixture that occurs during the intake stroke is strengthened, and the pulsating effect of the intake air acting on the combustion chamber 6 from each intake valve port 92 does not interfere with or diminish.

Further, the exhaust valve 19 and the first. Second intake valve 181.

182, there is a predetermined non-polymerization period 1 between each opening/closing timing.
．． , 12 are provided. In this way, exhaust gas backflow during low-speed operation can be minimized while scavenging can be effectively performed using exhaust inertia during high-speed operation, contributing to improved performance in terms of both fuel efficiency and output.

Furthermore, the opening curves of both intake valves 181 and 182 are made substantially parallel, thereby making the opening lift amount of the second intake valve 18□ smaller than that of the first intake square 181. In connection with this, the valve spring 202 of the second intake valve 18□, which has a small valve opening lift amount, is set to have a weaker spring force than the other valve spring 201. By doing this, the spring force of the valve spring 202 is set to be weaker than the other valve spring 201. The valve opening torque of the camshaft 24 is reduced by that amount, and the internal power loss is reduced by 4μ.

Next, the operation of this embodiment will be explained.

When the engine is operated and the intake stroke begins, first the first intake valve 181 opens, so the first intake valve 181 opens through the first branch port 9. The air-fuel mixture flowing into the combustion chamber 6 from the first branch port 13. which is directed toward the second intake valve port 92 side. The air-fuel mixture is guided by the precipitous first guide surface 8a of the swirl guide 8 to cause a swirl in the direction of the arrow in FIG. Since the downward spiral direction of the chamber 6 is deflected, the swirl progresses in a spiral manner.

Next, when the second intake valve 182 opens, the second branch port 13
The air-fuel mixture that flows into the combustion chamber 6 via the second intake valve port 92 through the second intake valve port 92 is guided to the second branch port 13□ facing the ignition plug 12 side, causing a swirl in the direction of the arrow in FIG.
Strengthen the swirl while merging with the air-fuel mixture that first flowed in from the first intake valve port 9 degrees. As a result, the air-fuel ratio of the air-fuel mixture in the combustion chamber 6 is made uniform.

During the compression stroke of the engine, the swirl guide 8 cooperates with the upper surface of the piston 5 to give squish to the air-fuel mixture in the combustion chamber 6, which contributes to increasing the compression ratio and strengthening the flow of the air-fuel mixture.

Near the end of the compression stroke, the ignition plug 12 is operated, and the spark discharge ignites the air-fuel mixture, or the air-fuel mixture flows through the first intake port 91, the second intake valve port 9□, and the ignition plug, as described above. 1
2. Since the swirl direction is taken in the direction of the exhaust valve port 10, immediately after being ignited by the ignition plug 12, it passes around the exhaust valve 19, which is already in a high temperature state due to the influence of exhaust heat. This accelerates the rise of combustion around that area.

As described above, according to the present invention, the ceiling surface of the combustion chamber is constituted by two ceiling slopes descending from the ridgeline of the medium-heat section toward both sides, and one ceiling slope has a first slope. A pair of first intake valves are opened and closed by a second intake valve. The second intake valve ports are opened in parallel along the ridgeline, and on the other ceiling slope, there is a four-hole (air valve port) that is opened and closed by the exhaust valve at a position opposite to the first intake valve port of No. 111. Since the ignition plug is opened at the same time as the ignition plug is disposed at a position opposite to the second intake valve port, a wide space for arranging the ignition plug can be obtained, and this area is not obstructed by three valves. The desired ignition performance can be obtained without any problems (the layout can be freely arranged). Also, on the ceiling surface, a river is provided from the periphery of the combustion chamber. A protruding swirl guide extending from the air-fuel ratio is provided, and this swirl guide causes the air-fuel mixture flowing in from each intake valve port to swirl in the direction from the ignition plug to the exhaust valve port, so that the air-fuel mixture has an air-fuel ratio. In addition to achieving uniformity, the fuel is forced to pass around the high temperature exhaust valve immediately after ignition.
The start-up of combustion is promoted, and as a result, combustion time is shortened, anti-knocking properties are improved, and overall combustion is significantly improved, resulting in reduced fuel consumption and improved output performance.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a bottom view of the cylinder head, and FIGS. 1A and 1B are A of FIG. 1.
-A and BB line sectional views, Figures 2 and 3 are longitudinal sectional views of the internal combustion engine along lines IJ-II and +II-UJ in Figure 1, respectively, and Figure 4 shows the intake, (Diagram of exhaust valve opening/closing timing diagram). L...Ridge line, M...Valve mechanism, 2...Cylinder head, 4...Cylinder, 5...
Piston, 6... Combustion chamber, 7... Ceiling surface, 77,7
□...Ceiling slope, 8...Swirl guide, 8a...
・First guide surface, 8b...Second guide surface, 9. ．． 92
...First. Second intake valve port, 10...Exhaust valve port, 12.
・Spark plug, 18,. 18. , ... 19th second intake valve,
19... Exhaust valve patent applicant Book] Yogiken Kogyo Co., Ltd. Figure 3 M Figure 2 Procedural Amendment (Radio) 1982 I April -511 - Commissioner of the Japan Patent Office 1, Indication of the case 1982 Patent Application No. 215325 2, Name of the invention 3-valve internal combustion engine 3, Relationship with the case of the person making the amendment Patent applicant name (532) IB Giken Kogyo Co., Ltd. 4, representative
Attorney Address: 105 Address: 4-4-5 Shinbashi, Minato-ku, Tokyo Second/Murabiru Name (7187) Patent Attorney: Ken Ochiai Telephone: Tokyo 434-4151 5 Date of amended order

Claims (1)

[Scope of Claims] (1) The ceiling surface of the combustion chamber formed in the engine body is composed of two ceiling slopes descending from a ridgeline in the approximate center toward both sides, and one ceiling slope has a first slope. A pair of first intake valves are opened and closed by a second intake valve. Second intake valve ports are opened in parallel along the ridgeline, and one exhaust valve port is opened and closed by an exhaust valve at a position opposite to the first intake valve port on the other ceiling slope. An ignition plug is disposed at a position opposite to the second intake valve, and a swirl guide is further provided on the ceiling surface to extend from the periphery of the combustion chamber so as to intervene between the first intake valve port and the exhaust valve port. Then, the side surface of the swirl guide that has healed around the first intake valve port is turned into a first guide surface that stands up like a precipice,
Further, in the three-valve internal combustion engine, the side surfaces along the periphery of the exhaust valve port are respectively formed as gently inclined second guide surfaces. (2. In the item described in claim (1),
Said 1st. The second intake valve port is the first intake valve port that is separated from the middle of one intake boat that opens on one side of the engine body. Three-valve internal combustion engine connected to each second branch port. (3) In what is stated in claim (1),
A three-valve internal combustion engine, wherein the opening timing of the second intake valve is delayed from the opening timing of the first intake valve.