JPS6018809B2 - Intake system for single-cylinder internal combustion engines for small models - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air intake device that can improve output with a simple configuration in an internal combustion engine used in small models such as motorcycles.

In this type of internal combustion engine, a chamber with a fixed volume is formed in the cylinder head, and this chamber is passed through a pipe or a hose member to the intake passage downstream of the throttle valve to improve the filling efficiency of the air-fuel mixture during the intake stroke. Samurai Akisho No. 55-3491 has proposed a device that increases the air-fuel ratio, but although this device is useful for improving the filling efficiency of the air-fuel mixture, since the chamber is installed at the top of the cylinder head,
Connection with the intake passage requires extra parts such as pipes and hoses, and the heat of the cylinder for atomizing the air-fuel mixture in the chamber is not sufficiently utilized. It only opens into the intake passage at a downstream position, and does not contribute to the establishment of the air-fuel mixture in the combustion chamber. This invention does not require the above-mentioned extra materials, and by simply improving the cylinder head,
This is intended to increase the intake efficiency of the air-fuel mixture, as well as promote evaporation, atomization, and aggregation of the air-fuel mixture, thereby increasing output.The required volume is replenished by placing it adjacent to the cylinder in the intake passage side of the cylinder head. It is characterized in that a chasobar is provided and the replenishment chamber is connected to the air-fuel mixture passage in the vicinity of the intake valve. To explain the embodiment with reference to the drawings, in Figs. 1 and 2, 1 is a cylinder of a four-stroke engine, la is its combustion chamber, 2 is a cylinder head, and 3 is an intake hole formed in the cylinder head. aisle, 4
is also an exhaust passage, an intake valve 3a is disposed at the outlet end of the intake passage 3 to partition the combustion chamber la and the intake circuit 3, and an exhaust valve 4a is disposed at the inlet end of the exhaust vent 4. The combustion chamber la and the exhaust passage 4 are separated from each other, and these valves 3
a, 4a are rotary arms 5 provided on the cylinder head 2;
This is the same as in the normal case in that the intake valve 3a and the exhaust valve 4a are alternately opened and closed in relation to the reciprocating movement of the piston 7 via the rocker arms 6a and 6b.

By the way, in this invention, the intake passage 3 of the cylinder head 2
A replenishment chamber 8 with a required volume is provided adjacent to the cylinder 1 on the side part, and a mixture passage 8a is formed from the inner end of the replenishment chamber 8 to open into the intake passage 3 in the vicinity of the intake valve 3a. An intake pipe 10 that connects to the carburetor C is detachably attached to the outer end surface of the intake passage 3 side via a sealing material 9, and the intake passage 3 communicates with the intake pipe 1, and the outer end of the chamber 8 is connected to the intake pipe 1. It is sealed by a flange 10a of the tube 10.

This eliminates the need for a separate container or connecting pipe for the replenishment chamber, reducing the number of parts and making it easy to seal and inspect the chamber by attaching and detaching the intake pipe.

Therefore, during the intake stroke of the engine, the intake valve 3a is opened as shown in FIG. At the same time that the intake pressure becomes a predetermined negative pressure, the inside of the replenishment chamber 8 also becomes a negative pressure via the air-fuel mixture passage 8a.
Even when the compression stroke begins and the intake valve 3a is closed, negative pressure still remains in the replenishment chamber 8, so the suction action continues in the intake passage 3, and the air-fuel mixture from the carburetor C is It will flow into the replenishment chamber 8 through the passage 8a as shown by the arrow, and this will continue until the internal pressure of the intake passage 3 and the internal pressure of the replenishment chamber 8 are balanced, and a predetermined amount of air-fuel mixture will be filled into the replenishment chamber 8. be done. The air-fuel mixture filled in the chamber 8 is retained in the chamber 8 until the engine enters the next intake stroke, that is, during the three strokes of compression, expansion, and exhaust. The heat of No. 1 is efficiently absorbed, and atomization is promoted.

Thus, when the engine enters the intake stroke again, the intake valve 3a is opened, and the piston 7 descends, the air-fuel mixture flows through the intake passage 3 and enters the replenishment chamber 8, as shown in FIG. The stored warmer air-fuel mixture becomes a jet and is sucked out into the combustion chamber la, promoting the imitation of fresh air and atomization.

Figure 4 shows an example in which the above-mentioned intake system is applied to a gasoline engine of a motorcycle, where A is an air cleaner and B is an air cleaner.
is a connection pipe, C is a carburetor, F' is a body frame, E is a gasoline engine, Ea is a cylinder head equipped with the above-mentioned supply chamber, M is a transmission, and N is an exhaust muffler. As described above, in the present invention, in a single-cylinder internal combustion engine for small models equipped with an intake valve and an exhaust valve, a replenishment chamber with a required volume is provided adjacent to the cylinder in the portion of the cylinder head on the intake passage side. Since the replenishment chamber is connected to the intake passage near the intake valve, the required amount of air-fuel mixture can be stored in the replenishment chamber by residual negative pressure at the end of the intake stroke, and the heat of the cylinder head and cylinder can be stored. This can promote its evaporation and atomization, and during the next intake stroke, the stored air-fuel mixture is ejected into the combustion chamber, increasing intake efficiency accordingly, and reducing the loss of intake air and atomization. This system improves the output of the engine, and does not require a separate container or connecting pipe, making it extremely suitable for internal combustion engines for Type 4 models.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the invention. FIG. 2 is a cutaway plan view taken along the X-X line. Figure 3 A, C and C are explanatory diagrams of the operating state. FIG. 4 is a schematic side view of an example applied to a motorcycle. In the figure, 1... cylinder, la... combustion chamber, 2... cylinder head,
3... Intake passage, 3a intake valve, 4... Exhaust passage, 4
a... Exhaust valve, 7... Piston, 8... Supply chamber, 8a... Mixture passage, 10... Intake pipe, 1
0a...That flange. Figure 2 Figure 4 Figure 1 Figure 3

Claims (1)

[Claims] 1. In a single-cylinder internal combustion engine for small models equipped with an intake valve that controls the inflow of air-fuel mixture into the combustion chamber and an exhaust valve that exhausts burnt gas, a part of the cylinder head on the intake passage side is provided adjacent to the cylinder. 1. An intake device characterized in that a replenishment chamber having a required volume is provided, and the replenishment chamber is communicated with an intake passage in the vicinity of an intake valve.