JPS5849424Y2 - Internal combustion engine intake system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake device that allows backfire flames generated in the intake system of an internal combustion engine to escape.

In an internal combustion engine, when the air-fuel mixture is too rich or too lean during startup, resulting in extremely slow combustion in the cylinder, or when the ignition timing is significantly delayed even when the air-fuel mixture is normal, the air-fuel mixture may open when the intake valve opens. In some cases, gas is still burning in the cylinder and ignites and burns fresh air in the intake system, causing a backfire.

This backfire generates a very large pressure due to explosive combustion, which can cause harmful effects such as destroying the intake system or causing flames to reach the air cleaner and burn its elements. This was proposed in view of the circumstances,
To provide an intake system for an internal combustion engine which is improved so that when a backfire occurs in the intake system, the pressure and flame are immediately released to the outside of the intake system to eliminate the adverse effects caused by the backfire.

For this purpose, the device according to the present invention provides a bent part in the middle of the suction pipe leading from the air cleaner to the carburetor, and at the bent part, a relief pipe having a diameter larger than the suction pipe and equipped with a reed valve inside. The reed valve is connected in a straight line from the carburetor side suction pipe, and normally the reed valve is closed due to negative suction pressure, but when a back burn occurs, the reed valve is opened due to the increase in the internal pressure of the suction pipe to release the flame. It is characterized by leading to.

In addition, there is a prior art related to Utility Model Application Publication No. 54-156013 that eliminates the adverse effects caused by backfire, and the provision of a reed valve in the structure of the present invention is disclosed in Utility Model Application Publication No. 55-1989. Related prior art can be found in Publication No. 30999.

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

The illustrated embodiment is one in which the present invention is applied to an internal combustion engine of a rear-engine, rear-drive type vehicle. In FIG. The air taken in from the front is guided to the rear of the vehicle body on the side where the engine is mounted, and the rear side of the vehicle body is bent upward into a substantially crank shape and raised.

The high point 1a of the frame 1 is communicated with an air cleaner 3 via a conduit 2, and the air cleaner 3 is communicated with an engine body 6 via an intake conduit 4 and a carburetor 5.

Thus, according to the present invention, the relief pipe 7 extends in a straight line from the carburetor side of the suction pipe 4 to the bent portion 4a bent at a substantially right angle to the suction pipe 4, as shown in detail in FIG. It is communicated as follows.

This relief pipe 7 is bent as appropriate and connected to the other left and right frame 8 of the vehicle body, which is configured similarly to the frame 1, and has a pipe diameter larger than that of the suction pipe 4, so that the lead pulp 9 is inside. It is designed to close with negative suction pressure and open with an increase in internal pressure.

Since the present invention is constructed as described above, during normal engine operation, the reed pulp 9 closes due to suction negative pressure in the intake system, and the relief pipe 7 is separated from the suction pipe 4.
As a result, from the frame 1 to the conduit 2 as in the conventional case. Air cleaner 3. Air is taken into the carburetor 5 through the intake pipe 4, and the air-fuel mixture produced by the carburetor 5 is supplied to the engine body 6.

On the other hand, when a backfire occurs in the intake system, the relief pipe 7 extends in a straight line with respect to the carburetor side of the suction pipe 4, so that the extremely large pressure generated when a backfire occurs is transferred to the relief passage. It acts directly on the reed pulp 7 to open the reed pulp 9.

Furthermore, since the diameter of the relief pipe T is larger than that of the suction pipe 4, almost all of the flame is guided to the relief pipe 7 without going around to the air cleaner side of the suction pipe 4 when a back burn occurs. , and is discharged to the frame 8.

As described above, according to the present invention, flames generated when a backfire occurs in the intake system are guided to the relief pipe T before the air cleaner 3 and do not go to the air cleaner 3, so that danger can be prevented.

Further, as described above, the pressure and flame are immediately released by the relief pipe 7 when back 7-year occurs, thereby preventing damage to the carburetor 5 and the like.

Furthermore, since the flame is discharged into the frame 8, it is safe.

It goes without saying that the present invention is not limited to the internal combustion engine of the rear engine rear drive type vehicle of the above embodiment.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of an intake system for an internal combustion engine according to the present invention, and FIG. 2 is a sectional view of the main parts. 1.8...Frame, 1a...High place,
2...Pipe line, 3...Air cleaner, 4
...Suction pipe line, 4a...Bent part, 5.
... Carburetor, 6 ... Engine body, 7 ... Relief pipe, 9 ... Lead pulp.

Claims (1)

[Scope of utility model registration request] A bent part is provided in the middle of the suction pipe leading from the air cleaner to the carburetor, and a relief pipe branched from the bent part and having a larger diameter than the suction pipe is communicated with the carburetor side suction pipe so as to extend in a straight line; An intake system for an internal combustion engine, characterized in that a reed valve that opens in response to an increase in internal pressure when a backfire occurs is provided in the relief pipe.