JPS58206866A - Suction pipe for engine - Google Patents

Abstract

PURPOSE:To vary the effecitive cross-sectional area of a suction air pipe according to the loading condition of an engine, by forming a part of the suction air pipe of an elastic body. CONSTITUTION:A part of a suction air pipe 3 provided between a suction air duct 1 and the opening of each cylinder of an engine is formed of an elastic material, such as synthetic rubber, high negative pressure of the suction pipe is generated, which is compressed when a pressure difference between the inside and the outside becomes large and an effective cross-sectional area is reduced as shown by a chain line 3A with two dotts. As the higher negative pressure becomes the greater the suction pipe is compressed, a velocity of flow of air-fuel mixture flowing in the pipe 3 is increased and the air-fuel mixture is fed to the engine in a short period of time.

Description

[Detailed description of the invention] It is related to pipes.

When the engine is running with no load or under low load, the opening of the throttle valve in the intake passage is small and the flow rate of the air-fuel mixture is low, so the air-fuel mixture flowing downstream in the intake pipe has a low velocity. Therefore, it takes a considerable amount of time for the mixture to pass through the throttle ax and reach the engine cylinder inlet, and when the engine is running at high speed (compared to Even if the air-fuel mixture is controlled by the engine, it is not possible to promptly supply an appropriate air-fuel mixture in response to engine operating conditions.

The present invention was invented for the purpose of providing an intake pipe that can supply air-fuel mixture sharply even during no-load or low-load operation. It is characterized in that the effective cross-sectional area changes depending on the pressure difference.

Embodiments of the present invention will be explained below with reference to the drawings.

In FIG. 1, l is an intake passage having a throttle square 2. 3 is an intake pipe according to the present invention. 4 is the engine. 5 indicates the exhaust pipe.
The intake pipe 3 provided between the intake passage 1 and the inlet of each cylinder of the engine 4 is at least partially made of an elastic material such as synthetic rubber, and a large negative pressure is generated in the intake pipe. When the pressure difference between the inside and outside becomes large, it is compressed and the effective cross-sectional area is reduced as shown by the two-dot chain line 3A in the figure.
F fc is on.

The 2nd m is @ air passage 1 The flange 5 that connects &C and the flange 6 that connects the cylinder inlet vc are made of metal, and everything from the inlet part 7 to the part 8 corresponding to the number of cylinders is made of an elastic material. Metal prefectures 9 and 10 for preventing pressure dR are installed at bends and branching parts, and furthermore, pressure of circular cedar of Ci2 VA N is installed at appropriate places inside.
The material 11 is fixed inside.

The part made of elastic material is hardly compressed by the suction pipe negative pressure during normal engine operation, but the material is made so that it can be compressed by the high suction pipe negative pressure during no-load or low-load operation. The thickness and shape are selected, and crush prevention material 1
1, it is compressed to a diameter equal to that diameter, as shown by the work point chain @3B in Figure 3.

$4 The same is the intake pipe part 3a of the artificial part and the branch part close to this.
is made of metal, and the branch part 3b far from the inlet part is made of an elastic material. By compressing the branch part 3b, the air-fuel mixture is supplied to the distant cylinder in about the same time as to the nearby cylinder.

Although not shown in the drawings, only the bending part, the branching part, and the flange may be made of metal, and the other parts may be made of elastic material. In addition, an elastic body may be formed by forming a thin wall into a corrugated shape to give it elasticity.

As shown in E-E, the present invention provides at least a portion of the intake pipe with I.
Since it is made of S-type material, when high suction pipe negative pressure is generated, it will be compressed and the effective cross-sectional area will decrease.Moreover, the higher the negative pressure, the more it will be compressed, so the flow speed of the air-fuel mixture flowing through the pipe will increase. .

The mixture is supplied to the engine in a short time. Therefore, the effective Kv surface of the intake pipe changes depending on the engine load condition, and even when there is no load or Ilk load, the air-fuel mixture is quickly supplied depending on the engine operating condition IcρLl. It is something.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of the engine system M including the intake pipe of the present invention, Fig. 2 shows the implementation row of the fifth volume of this book. Figures 4 and 4 are plan views of this embodiment of Ryumei's duck. 3...Suction pipe, 4...1 engine, 3b
... Branch, 7 ... Entrance, 8 ...
・Branch. Agent Mutsumi Nozawa Aki

Claims (1)

[Claims] An engine intake pipe, at least a part of which is made of an elastic material, and is configured so that its effective cross-sectional area changes due to the difference in internal and external IE forces.