Improved wankel-type internal combustion engine

Abstract

To improve the environmental performance of a Wankel-type internal combustion engine and improve rotation performance.SOLUTION: A rotational force is obtained by using pressure when combustion pressure is maximum, so that the combustion pressure can be received as strongly as possible in a desired direction. The pressure decreases as a combustion chamber volume increases, and the pressure decreases as a temperature decreases. Thus, in a Wankel-type internal combustion engine, a large area of a plane for receiving the combustion pressure in a normal rotation direction is achieved, and other faces are served as faces concentric about a rotor center which do not hinder the rotation. When the vicinity of an apex of a face facing a reverse rotation direction which hinders the rotation is hidden behind a rotor housing, a value of receiving the combustion pressure in the normal rotation direction becomes maximum, at which ignition is performed. Since fuel injection timing is set slightly before the ignition for the purpose of not generating HC, there is no time for mixing as a mixed gas, which allows a combustion under the presence of spots. Also, since the fuel is injected in a small volume, the ignition is facilitated even under a significant lean state.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention is a technology for improving the environmental performance and rotational performance of a Wankel internal combustion engine (hereinafter referred to as RE). [Background technology]

[0002] Conventional REs slightly shift the ignition timing of the two spark plugs when the compression ratio is at its highest to stabilize rotation. DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0003] The problem we are trying to solve is to reduce hydrocarbons (hereafter referred to as HC) and further stabilize rotation.

[0004] First of all, the cause of HC generation is that the air-fuel mixture is supplied to the working chamber, and particulate fuel adheres to the walls of the working chamber, which is then scraped off by the apex and side seals.The collected particulate fuel returns to a liquid and accumulates in a narrow groove, and when combustion begins at that time, the fuel on the surface of the groove burns, but the fuel deep inside cannot burn due to a lack of oxygen and is converted into HC by the heat.

[0005] Compared to reciprocating engines, there are far more seal grooves, and another thing that is unique to RE is that the gap between the rotor and rotor housing is very narrow, making combustion more likely to result in oxygen deficiency.

[0006] The way to prevent these two causes is to inject fuel directly into the working chamber and to change the injection location and timing.

[0007] If fuel is injected just before combustion begins, there will not be enough time for the fuel to mix into the air-fuel mixture, but combustion will begin before the seals have time to collect the fuel particles that have adhered to the wall, thereby suppressing the generation of HC.

[0008] Another issue is that the combustion pressure has the property of pushing with equal force perpendicular to the direction of all the walls that make up the combustion chamber. To improve rotational performance, the shape of the combustion chamber needs to be changed so that this property acts in the direction of rotation.

[0009] This property of pushing perpendicular to the direction of the wall is important, and in conventional combustion chambers on the rotor side, half of the combustion chamber faces in the forward direction and the other half faces in the reverse direction. Even when ignition occurs when the compression ratio is at its highest, the force that the rotor receives in the direction of rotation is plus or minus zero, and the rotor does not receive any rotational force.

[0010] For this reason, the ignition timing of the two plugs is shifted, causing a difference in combustion pressure between the forward and reverse directions, and when the surface of the rotor facing the reverse direction is hidden by the rotor housing, the pressure received in the reverse direction is reduced, resulting in the pressure in the forward direction being greater and causing the rotor to rotate.

[0011] No matter what you do, it is impossible to create a rotor surface that is angled so that it is not subjected to combustion pressure in the reverse rotation direction. Therefore, the shape of that surface remains the same, but the rotor surface that receives the forward rotation force is shaped so that it is more strongly subjected to the force in the forward rotation direction.

[0012] The recess in the rotor that forms the conventional combustion chamber has been eliminated, and the shape of the front half of the rotor in the direction of rotation has been carved into a circle concentric with the center of the rotor, with many flat surfaces pointing toward the center of the rotor.By locating these flat surfaces as far away from the center of the rotor as possible, they are located closer to the apex seal so that they can receive the combustion pressure in the forward rotation direction with greater force.

[0013] However, if left as is, the combustion chamber volume would become too large, so by providing multiple concentric surfaces and multiple flat surfaces facing the center of the rotor, the combustion chamber volume can be reduced while ensuring the area of ​​the flat surfaces that receive combustion pressure in the forward rotation direction.

[0014] If the rotor position where the working chamber volume is smallest is set to 0 degrees, fuel is injected into the new jagged combustion chamber between -5 degrees and 10 degrees, and when the rotor is between 10 degrees and 15 degrees, the number of spark plugs is increased (from 3 to 4) and ignited simultaneously by spark plugs located in a position that matches the new combustion chamber position, resulting in rapid combustion.

[0015] The part of the surface that receives the combustion pressure in the reverse rotation direction is hidden by the rotor housing between about 18 and 28 degrees, where the force hindering rotation is the least, so combustion is carried out so that the combustion pressure is at its maximum at that time, and the maximum rotational force is obtained on the flat surface that receives the combustion pressure in the forward rotation direction. [Brief explanation of the drawings] [Figure 1] This is a side view showing the rotor position when it rotates from 5 degrees to 20 degrees, with 0 degrees being the position when the compression ratio is highest.

Claims

1. A Wankel-type internal combustion engine has a combustion chamber in the front half of the three sides of the rotor in the direction of rotation, which is formed by the inner envelope of a peritrochoid, and which is composed of a curved surface concentric with the rotor central axis and a flat surface extending from the rotor central axis to just before the apex of the rotor.

2. A Wankel type internal combustion engine in which the plane of claim 1 is configured with multiple planes shifted at equal intervals forward in the direction of rotation of the rotor, and the curved surface of claim 1 is configured to match these, thereby increasing the area of ​​the planes and reducing the combustion chamber volume.

3. When the rotor position is set to 0 degrees, which is the position where the Wankel internal combustion engine has the smallest combustion chamber volume, the Wankel internal combustion engine injects fuel between -5 and 10 degrees and ignites it between 10 and 15 degrees, thereby suppressing the generation of hydrocarbons.

4. The position of the fuel injection device of claim 3 is such that it faces the new combustion chamber direction when the rotor position is between -5 degrees and 10 degrees, and the position of the spark plug is also aligned with the jagged combustion chamber when the rotor position is between 10 degrees and 15 degrees, and multiple spark plugs are arranged to ignite multiple sparks simultaneously, thereby increasing the combustion speed in a Wankel internal combustion engine.

5. Unlike the Wankel type, this internal combustion engine has a reciprocating type piston in which the valve recess is not angled to match the valve clamping angle, but is instead dug into a vertical cylindrical shape, with the increased volume piled up on the cylinder head side.

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