JPH01321A - 4-stroke internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a four-stroke internal combustion engine, and particularly to an engine having a supercharging function.

(Prior art and its problems) Conventional two-stroke internal combustion engines have the disadvantages of poor fuel efficiency, large oil consumption, and large amounts of unburned hydrocarbon emissions, making it difficult to implement exhaust gas countermeasures. , the structure is simple because a valve mechanism is not required, and the output per unit weight (specific output) is greater than that of a four-cycle engine.

The advantage of such a two-stroke engine is that the air-fuel mixture is introduced into the crank chamber at the bottom of the cylinder, and when the piston descends during the expansion stroke, the air-fuel mixture in the crank chamber is compressed, and this compressed fresh air is released into the cylinder (combustion chamber). This is due to the fact that it has a structure in which it is sprayed and supplied.

The present invention takes advantage of the structural features of the two-stroke engine, and also reduces the fuel consumption by four strokes compared to the conventional four-stroke engine.
A 4-stroke internal combustion engine that can achieve a specific output equal to or higher than a 2-stroke engine without making any major structural changes to controls, etc., and that can achieve performance equivalent to a 4-stroke engine in terms of exhaust gas characteristics and other characteristics. The purpose is to provide.

(Means for Solving the Problems) In order to achieve the above-mentioned object, according to the present invention, an intake port defined by a cylinder and a piston and provided with an intake valve and an exhaust valve are provided. A supercharging chamber is provided at the bottom of the cylinder of an internal combustion engine having a combustion chamber equipped with an exhaust port, on the opposite side of the combustion chamber with the piston in between, and the supercharging chamber is provided with an intake port and a discharge port, an air passageway having one end connected to the discharge port and the other end connected to at least the intake port of the combustion chamber of the cylinder;
A first valve means that allows air to flow only in the direction of flowing into the supercharging chamber is provided in the suction port, and a first valve means is provided in the discharge bow Hζ.
is provided with a second valve means that allows the air to flow only in the direction outflowing from the supercharging chamber, and the piston compresses the air in the supercharging chamber during the suction stroke and the expansion stroke to A four-stroke internal combustion engine is provided, characterized in that compressed air is discharged into a passage, and compressed air discharged into the air passage is drawn into the combustion chamber during an intake stroke.

(Function) When the piston descends toward the supercharging chamber during the suction stroke and expansion stroke of the four strokes of a four-stroke engine, it compresses the air in the supercharging chamber and discharges it into the air passage. In other words, the volume of compressed air discharged from the supercharging chamber into the air passage is approximately twice the volume of intake air drawn into the combustion chamber of the engine during the intake stroke, and the air in the air passage is pressurized by this amount. , pressurized air will be supplied to the combustion chamber, resulting in a significant increase in power output.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a conceptual diagram of the configuration of a two-cylinder four-stroke gasoline engine when the present invention is applied to the engine.For convenience of explanation, the engine shown in FIG. It is expanded and shown.

That is, the engine 1 has two #1 cylinders 2a and #2 cylinders 2b bored in the cylinder block 1a,
Pistons 3a and 3b are fitted into each cylinder 2a and 2b, respectively, so as to be slidable in the vertical direction and to reciprocate in an airtight manner. Each cylinder 2a (2b) has a combustion chamber 4 between the upper wall of the piston 3a (3b) and the cylinder head lb installed on the cylinder block la.
a (4b) is defined, and the cylinder head 1b has an intake port 5a (5b) that opens facing each combustion chamber 4a (4b).
) and an exhaust port 6a (6b). An intake valve 7a (7b) is provided at the intake port 5a (5b), and an exhaust valve 8a (8b) is provided at the exhaust port 6a (6b). An exhaust manifold 9 is connected to each exhaust valve 8a (8b).

At the bottom of each cylinder 2a (2b) is a crank chamber 1c.
A partition wall 1d (ld') is formed to separate the corner from the cylinder 2a (2b), and a supercharging chamber 10a (10b) is defined between the lower wall of the piston 3a (3b) of the cylinder 2a (2b) and the partition wall 1d (ld'). . Therefore, each cylinder 2a (2b) has a combustion chamber 4a (4b) above the piston 3a (3b) with the piston 3a (3b) in between, and a supercharging chamber 10a (10
b) will be defined respectively. Combustion chamber 4a (4b)
and the piston 3a fitted between the supercharging chamber 10a (10b).
(3b) A rod 31a (31b) is installed at the center of the lower wall surface.
One end is fixed integrally with the piston 3a (3b), the rod 31a (31b) extends vertically downward, and the other end 32
a' (32b) extends into the crank chamber 1c through a through hole le (1g') bored at the center of the partition wall 1d (ld'). A sealing member is fitted between the rod 31a (31b) and the through hole 1e (le'), and the supercharging chamber 1
0a (10b) is kept airtight. Rod 31a (3
The other end 32a (32b) of lb) is connected to the crankshaft 12 via a connecting rod 33a (33b).

Each supercharging chamber 10a (10b) has a suction port lla (l).
lb) and a discharge port 13a (13b) are formed, and each intake port 11a (llb) is connected to an intake pipe in which a throttle valve is disposed via an intake manifold (not shown). On the other hand, each discharge port 13a (13b)
is the upstream branch pipe 21a of the manifold 20 as an air passage.
(21b), and the downstream branch pipes 22a (22b) of the manifold 20 are connected to the intake ports 5a (5b) of the combustion chamber 4a (4b), respectively. That is, the discharge port 13a of the supercharging chamber 10a of the #1 cylinder 2a communicates with the intake port 5a of the combustion chamber 4a of the cylinder 2a through the manifold 20, and also communicates with the intake port 5a of the combustion chamber 4b of the #2 cylinder 2b. It also communicates with port 5b. and,
The discharge port 13b of the supercharging chamber 10b of the #2 cylinder 2b is connected to the combustion chamber 4b of the cylinder 2b via the manifold 20.
It communicates with the intake port 5b of the #1 cylinder 2a, and also communicates with the intake port 5a of the combustion chamber 4a of the #1 cylinder 2a.

Suction port 1la (1l) of each supercharging chamber 10a (10b)
b) is provided with a reed valve 12a (12b). This reed valve 12a (12b) is the supercharging chamber 10a.
(10b) allows air to flow only in the direction of inflow into the supercharging chamber 10a (lob) through this reed valve! 2a (12b) cannot flow back to the intake manifold side. - side, each supercharging chamber 10a
A reed valve 14a (14b) is also provided at the discharge port 13a (13b) of (10b). This reed valve 14
a (14b) allows air to flow only in the direction outflowing from the supercharging chamber 10a (10b), and air flows from the manifold 20 side to the supercharging chamber 10a (10b) via this reed valve 14a (14b). cannot flow backwards.

A fuel injection valve 1 is installed in each downstream branch pipe 22a (22b) near the intake port 5a (5b) of the manifold 20.
8a (1'8b) are arranged facing the intake valves 7a (7b), respectively, and these fuel injection valves 18a (18b)
A required amount of fuel is injected and supplied to each combustion chamber 4a (4b) via the intake air amount.

Next, the effect will be explained.

The pistons 3a (3b) fitted in the #1 and #2 cylinders 2a, 2b are shifted by a 360° crank angle and reciprocate up and down in the same phase. That is, #1 cylinder 2
Each cylinder 2a is based on the suction stroke top dead center (TDC) of a.
. The compression stroke is the exhaust stroke of #2 cylinder 2b, the expansion stroke of #1 cylinder 2a is the suction stroke of #2 cylinder 2b, and the exhaust stroke of #1 cylinder 2a is #2.
This will proceed simultaneously with the compression stroke of the cylinder 2b.

As the piston 3a of #1 cylinder 2a moves downward during the suction stroke, it compresses the air in the supercharging chamber 10a, and the air in the supercharging chamber 10a is pushed out to the manifold 20 via the reed valve 14a, and the air in the supercharging chamber 10a is pushed out to the manifold 20 through the reed valve 14a. Opening intake valve 7
a into the combustion chamber 4a of the #l cylinder 2a. On the other hand, as the piston 3b of the #2 cylinder 2b moves downward during the expansion stroke, it compresses the air in the supercharging chamber 10b, and the air in the supercharging chamber 10b is pushed out to the manifold 20 via the door valve 14b. Open intake valve 7
a into the combustion chamber 4a of the #1 cylinder 2a. Thus, in the suction stroke of #1 cylinder 2a, #
The combustion chamber 4a of the first cylinder 2a is supplied with air discharged from the supercharging chamber 10a of the #1 cylinder 2a and air discharged from the supercharging chamber tab of the #2 cylinder 2b (see Fig. 1). The arrows shown indicate the flow of air taken into the combustion chamber 4a during the intake stroke of the #1 cylinder 2a).

While the piston 3a (3b) strokes from top dead center to bottom dead center, the volume of the combustion chamber 4a (4b) increases and the volume of the supercharging chamber 10a (10b) decreases (the volume from which air is discharged) is: There is only a difference in the volume bone occupied by the rod 31a (31b), and both are substantially equal. Therefore, compared to a conventional engine with the same displacement, the amount of intake air is approximately twice as much at maximum, and the specific output of the engine 1 can be significantly increased.

In the compression stroke of the #1 cylinder 2a in which the piston 3a (3b) rises, and in the exhaust stroke of the #2 cylinder 2b, each reed valve 12a (12b) is opened and the supercharging chamber 10a (10
In b), fresh air is taken in from the intake pipe through the intake port 11a (llb).

Then, the air sucked into the supercharging chamber 10a (10b) is compressed by the piston 3a (3b) during the next expansion stroke of the #1 cylinder 2a and the suction stroke of the #2 cylinder 2b, and the air is sucked into the supercharging chamber 10a (10b). The fuel is discharged from the engine and is sucked into the combustion chamber 4b of the #2 cylinder 2b via the manifold 20 and the open intake valve 7b. Thus, #2
# is also present in the combustion chamber 4b of the cylinder 2b during its suction stroke.
Compressed air from the supercharging chamber 10a of the #1 cylinder 2a and compressed air from the supercharging chamber tab of the #2 cylinder 2b are supplied.

Furthermore, during the exhaust stroke of the #1 cylinder 2a and the compression stroke of the #2 cylinder 2b, each reed valve 12a (12b) is opened, and the intake port 1-11a (llb) is opened from the intake pipe to the supercharging chamber 10a (10b). ), and the suction stroke and subsequent steps of the #1 cylinder 2a are sequentially repeated again in the same manner as described above.

Although the above-mentioned embodiment applies the present invention to a two-cylinder engine, the present invention is not limited thereto, and the same effects can be obtained even when applied to a single-cylinder engine, three or more cylinder engines. When applying the present invention to a single cylinder etc., the air passage (manifold)
What is necessary is to increase the capacity of the tank and give it the role of a surge tank.

Further, the combustion supply system of the four-stroke internal combustion engine of the present invention is shown in Fig. 1, in which fuel injection valves are disposed near the intake ports of each cylinder, and fuel is injected and supplied from these fuel injection valves to each cylinder. , it may be of the so-called MPI method,
It may be of the so-called TBI (also referred to as SPI or CFI) type, in which one fuel injection valve is commonly disposed for each cylinder upstream of the throttle valve, or even of the carburetor type.
Fuel supply systems conventionally applied to four-stroke internal combustion engines can be widely applied.

Furthermore, various modifications of the above-mentioned embodiment have been considered. For example, a bypass passage connecting the manifold 20 shown in FIG. 1 and the intake pipe is provided, and the air inside the manifold 20 is Part of the air is transferred to the supercharging chamber 1OA
It is also possible to return the fuel to the intake pipe upstream of the intake port 11a (llb) in (10b) to prevent dilution of the air-fuel mixture and improve fuel efficiency.

Furthermore, the present invention is not limited to gasoline engines, but is also applicable to diesel engines.

(Effects of the Invention) As detailed above, according to the four-cycle internal combustion engine of the present invention, a supercharging chamber is provided at the bottom of the engine cylinder on the opposite side of the combustion chamber with the piston in between, and the suction a port and a discharge port, one end is connected to the discharge port,
The other end of the air passage is connected to at least the intake port of the combustion chamber of the cylinder, and the intake port has a first valve means that allows air to flow only in the direction of flowing into the supercharging chamber. is provided with a second valve means that allows the air to flow only in the direction outflowing from the supercharging chamber, and the piston compresses the air in the supercharging chamber and discharges it into the air passage during the suction stroke and the expansion stroke. The compressed air discharged into the air passage is drawn into the combustion chamber during the intake stroke, so although it is a 4-stroke engine, it has the advantages of a 2-stroke engine, and is structurally superior to conventional engines. Without making any major changes, the structure is simple, and the output per unit weight of the engine is as high as or higher than that of a 2-stroke engine.Moreover, because the structure is not significantly changed, it is similar to a conventional 4-stroke engine. Exhaust gas countermeasures can be applied, and special consideration is not required for the fuel supply system.

Since the four-stroke internal combustion engine of the present invention has a simple structure, it can be easily combined with conventional supercharging systems such as turbochargers and superchargers, and has various excellent effects.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a cross-sectional developed view of a four-stroke internal combustion engine according to the present invention, with the cylinders cut off and expanded laterally, and FIG. 2 is a cross-sectional development view of the engine shown in FIG. 1. 5 is a timing chart showing the relationship between the crank angle and stroke of each cylinder. ■...Internal combustion engine, 2a, 2b...Cylinder, 3
a. 3b... Piston, 4a, 4b... Combustion chamber, 5a,
5b...Intake port, 6a, 6b...Exhaust port,
? a, 7b...Intake valve, 8a, 8b-=exhaust valve, 10
a, 10b--supercharging chamber, lla, 1lb-intake port, 12a. 12b--Reed valve (first valve means), 13a,
13b...Discharge port, 14a, 14b...Reed valve (second valve means), 20...Manifold (air passage). Applicant Mitsubishi Motors Corporation Agent Patent Attorney Kanji Nagato Figure 1 Figure 2 IW TDC

Claims (1)

[Claims] The piston is sandwiched between the piston and the combustion chamber of an internal combustion engine having a combustion chamber defined by a cylinder and a piston and having an intake port in which an intake valve is disposed and an exhaust port in which an exhaust valve is disposed. A supercharging chamber is provided on the opposite side of the combustion chamber, and the supercharging chamber is provided with an intake port and a discharge port, one end is connected to the discharge port, and the other end is connected to at least the intake port of the combustion chamber of the cylinder. The suction port is provided with a first valve means that allows air to flow only in the direction of flowing into the supercharging chamber, and the discharge port is provided with a first valve means that allows air to flow only in the direction of flowing out from the supercharging chamber. second valve means are respectively disposed to allow a flow of air, and the piston compresses the air in the supercharging chamber and discharges it into the air passage in the suction stroke and the expansion stroke, and the air is discharged into the air passage. A four-stroke internal combustion engine, characterized in that compressed air is drawn into the combustion chamber during the intake stroke.