JPH02163414A - Four-cycle engine - Google Patents

Abstract

PURPOSE:To increase the output by forming a chamber for allowing the combustion chambers of the contiguous cylinders to communicate each other, between these chambers, and by opening a subintake port between a main intake port and a main exhaust port which are opened in each combustion chamber, in the above-described chamber. CONSTITUTION:When main intake ports 4c,... are opened, and pistons 1 and 1 move downward, mixed gas is introduced into the combustion chambers 11 and 11 and into sleeves 3 and 3 through ports 4c,... from carburetors 5 and 5. At this time, a suction valve 9 is operated in a chamber 12, together with suction valves 6, 6,..., and a subintake port 4f opened at the part between the ports 4c,... and main exhaust ports 4d,... is opened. Therefore, mixed gas is sucked into the combustion chambers 11 and 11 and sleeves 3 and 3 also from a carburetor 8 through the port 4f and the chamber 12, and the suction efficiency for the mixed gas is improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a four-stroke engine.

(Conventional technology) Today's four-stroke engines tend to have more valves.
By increasing the frontage area of the pulse, the air-fuel mixture suction efficiency is increased, thereby improving the output.

[The problem that the defense seeks to solve]

By the way, in a 4-stroke engine equipped with a normal cylindrical piston, the maximum number of exhaust valves per cylinder is 3 exhaust valves per cylinder due to the significant complexity of IRM4, and further improvement of intake efficiency is required. It is difficult to achieve this goal.

For this reason, conventionally, a four-cycle engine has been provided in which a piston is configured in the shape of an elliptical cylinder and four intake valves are arranged in parallel in the long axis direction of the ellipse.

However, in the above-mentioned engine, the screws are shaped like elliptical cylinders, which is disadvantageous in terms of balance and thermal strain compared to cylinder-shaped screws, and also makes machining work for pistons, etc. complicated. shall be.

In view of the above-mentioned circumstances, an object of the present invention is to provide a four-stroke engine that is advantageous in terms of balance and thermal distortion, and can improve output through easy machining operations.

[Means to solve the problem]

In the four-stroke engine according to the present invention, a chamber is provided between adjacent cylinders to allow the combustion chambers of these cylinders to communicate with each other, and a main intake port and a main exhaust port opening into each combustion chamber in this chamber are provided. A sub-intake port is opened at the position, and a valve is provided in the chamber to open and close the space between the liter and the WJ Zeinke boat.

[Effect]

According to the above configuration, suction efficiency can be improved using the barbed piston.

(Example) Hereinafter, the tree defense will be explained in detail based on drawings showing examples.

1 to 4 conceptually show the main parts of a four-cycle engine according to the present invention, and exemplify a DOHC engine mounted on a motorcycle.

As shown in FIGS. 2 and 3, this engine has a pair of pistons 1,1. The pistons 1, 1 have the same cylindrical shape and are fitted into sleeves 3, 3 embedded in the cylinder block 2, respectively. The sleeves 3.3 are cylindrical and have their circumferential surfaces connected to each other, and are approximately in the shape of a figure 8 on the cylinder head 1 face 2a of the cylinder block 2. Although not clearly shown in the drawings, each of the pair of pistons 1.1 is connected to crank bins of the same phase on the crankshaft via connecting rods.

On the other hand, as shown in FIG. 1, the cylinder head 4 used in this engine has a cylinder block mounting surface 4a.
It has a pair of four parts 4b, 4b.

The recesses 4b, 4b are each formed at a portion corresponding to the piston 1.1 in the cylinder block 2, and two main intake ports 4C and two ends of the main exhaust boat 4d are communicated inside the recesses 4b, 4b, respectively. . These main intake ports 4c, 4c, 4c, 4
c and main exhaust boat 4d, 4d, 4d, 4d
The openings in each of the recesses 4b and 4b are arranged in one row along the longitudinal direction of the cylinder head 4,
Further, the other ends of each of the cylinder heads 4 are opened to opposing side walls of the cylinder head 4 . Main intake port 4c, 4c, 4
The other ends of the concave portions c and 4c are joined to each concave portion 4b and /lb, and carburetors 5 and 5 having the same diameter are connected to each of the concave portions 4b and 4c.

Furthermore, two intake valves 6 and two exhaust valves 7 are provided in each of the recesses 4b, 4b. The intake valves 6.6, 6.6 are connected to the main intake port 4c,
4c, 4c, and 4c, and are opened and closed at the same time by an intake valve camshaft (not shown) disposed in the cylinder head 4.

On the other hand, the exhaust valves 7.7, 7, 7 are the intake valves 6.6
As in ゜6.6, the above main exhaust boat 4d.

4d, 4d, and 4d, and are opened and closed at the same time by an exhaust valve camshaft (not shown).

On the other hand, the cylinder head 4 has a recess 4e in the cylinder block mounting surface 4a. This recessed portion 4e is formed at a portion located in the center between the pair of four portions 4b, 4b. b are communicated with each other. Further, one end of an intake port 4f is communicated with the recess 4e. The auxiliary intake port 4f is connected to a row of openings of the main intake ports 4c, 4c, 4c, 4c communicating with the pair of recesses 4b, 4b.
Exhaust boat 4d, 4d, 4. The frontage is located between the rows of frontages d and 4d, and the other end is
It opens between the frontages of main intake ports 4c, 4c, 4c, and 4c in the side wall of the cylinder head 4. Furthermore, as is clear from the figure, the opening in the side wall of the cylinder head 4 in this sub-intake port 4f has a diameter smaller than that of the carburetor 5.5 connected to the main intake ports 4c, 4c, 4c, 4c. A vaporizer 8 is connected.

Further, an intake valve 9 is disposed in this recess 4e. As shown in FIG. 4, the intake valve 9 is disposed at a position that closes the opening of the sub-intake port 4f, and its stem portion 9a extends along the axial direction of the pistons 1, 1. ing. This intake valve 9 is operated by an intake valve camshaft and a rocker arm (not shown) that open and close the intake valve 6°6.6.6 described above.
These intake valves 6.6.6.6 are opened and closed at the same time. Note that the reference numeral 10 in FIGS. 1 and 2 is
This is the spark plug mounting hole.

In the above-mentioned engine, as shown in FIG. 2, when the cylinder head 4 is installed on the cylinder block 2,
A combustion chamber 11.11 is defined by the recesses 4b, 4b, the inner peripheral surfaces of the sleeves 3, 3, and the upper surface of the piston 1.1 located at the top dead center, and the recess 4e and the connecting portion of the sleeves 3, 3. A chamber 12 is defined between the combustion chambers 11.11, which allows these combustion chambers 11.11 to communicate with each other.

Now, the intake valves in the combustion chambers 11, 11 are 6.6°6
．． 6 is operated by a cam (not shown) on the intake valve camshaft, and the main intake ports 4c, 4c, 4G, 4c
is opened and the screw latch 1.1 is moved downward, the main intake ports 4c, 4c, 4
The air-fuel mixture is sucked in from the vaporizer 85.5 via c and 4c.

At this time, in all 12 communicating with the combustion chamber 11.11, the intake valve 9 is operated at the same time as the intake valves 6.6 and 6.6, the sub intake port 4f is opened, and the piston 1. 1 is in a negative pressure state due to the downward movement. Therefore, the auxiliary intake port 4f enters the combustion chamber 11.11 and the sleeves 3, 3.
The air-fuel mixture is also drawn from the carburetor 8 through the chamber 12, thereby improving the air-fuel mixture suction efficiency.

In addition, in the above embodiment, the combustion chambers 11 and 11 of the two cylinders are
Although the combustion chambers of three or more cylinders are communicated with each other by the chamber 12, in the present invention, the combustion chambers of three or more cylinders may be communicated with each other.

Further, although a case is illustrated in which there is one set of cylinders communicating with the combustion chambers 11 and 11, the engine may include a plurality of sets of cylinders.

Further, although a DOHC engine mounted on a motorcycle is illustrated, the present invention is not necessarily limited to this.

Further, in the above embodiment, one sub-intake port 4f is provided in the chamber 12, and one intake valve 9 is provided in the entire section 12, but in the present invention, the sub-intake port 4f is 4r and J: There may be a plurality of intake valves 9. Further, in the chamber 12, there is a sub-index board 1.
Although only the intake valve 9 according to the present invention is provided, in the 4-cycle engine according to the present invention, only the intake valve 9 is provided. In addition, there is a secondary exhaust bow in chamber 12!・With a frontage and an exhaust valve! ! i! You may also set it.

〔Effect of the invention〕

As described above, according to the four-stroke engine according to the present invention, the suction efficiency can be improved by using a cylindrical piston, which is advantageous for balance and thermal distortion, and moreover, the output can be improved by easy machining work. can be achieved.

In addition, it is possible to reduce the pitch between the main intake port that opens the WJ intake port into each combustion chamber and the main exhaust boat cylinder, which reduces the size of the engine and reduces the pressure
It is possible to improve the ratio.

[Brief explanation of the drawing]

FIG. 1 is a bottom view conceptually showing a cylinder head section applied to a four-stroke engine according to the present invention, 7152
The figure is a cross-sectional side view conceptually showing the main parts of a four-stroke engine according to the present invention, and FIG. 3 is a perspective view conceptually showing a cylinder block section applied to the four-cycle engine according to the present invention. , FIG. 4 shows IV-I in FIG.
It is a V-line enlarged sectional view. 4C...Main intake port, 4d...Main exhaust boat, 4F...Sub-intake boat 1, 9...Valve, 1
... Combustion chamber, 2... chamber. Figure 1

Claims (1)

[Claims] A chamber is provided between adjacent cylinders that allows the combustion chambers of these cylinders to communicate with each other, and a sub intake port is opened in this chamber at a portion located between the main intake port and the main exhaust port that open to each of the combustion chambers. 4, characterized in that the chamber is further provided with a valve that opens and closes between the chamber and the sub-intake port.
cycle engine.