JPS59194030A - Fluid passage structure - Google Patents

Abstract

PURPOSE:To make the opening adjustment of an on-off valve performable in an easy manner, by expanding or contracting the on-off valve itself with pressure inside a fluid passage, in case of a device installing the on-off valve inside the fluid passage. CONSTITUTION:A suction pipe 1 carrying a suction passage 1A inside is connected to a suction port 3 of a cylinder head 2, and an inlet part of the suction port 3 is connected to a cylinder 5 via a suction valve 4. In addition, an exhaust port 6 is connected to the cylinder 5 via an exhaust valve 7. And, an on-off valve 8 is set up in a boundary part between the suction pipe 1 and the suction port 3 with its holder 8A interposingly held between a tip flange 1B of the suction pipe 1 and an inlet part peripheral edge of the suction port 3. In this case, the on-off valve 8 is constituted in a way of sealing a gaseous body such as air or the like inside a hollow body in baglike form composed of an elastic material. With this constitution, the on-off valve 8 itself is expanded or contracted accord- ing to pressure inside the suction passage 1A whereby its opening adjustment is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid passage structure applied to, for example, an intake passage of an internal combustion engine.

An intake passage of an internal combustion engine is provided with an on-off valve for adjusting the amount of intake air depending on the load of the internal combustion engine. In other words, when the internal combustion engine is under high load, the opening of the on-off valve is increased in order to increase the amount of intake air accordingly and ensure high output.
When the load is low, the opening of the on-off valve is reduced in order to reduce the amount of intake air accordingly and achieve complete combustion of the fuel. Conventionally, this type of on-off valve uses a throttle box or flap valve, and the opening is adjusted accordingly. detects the pressure inside the intake passage, the opening of the intake throttle valve of the carburetor or throttle body, or the position or displacement of a member belonging to the adjustment mechanism that adjusts the opening of the intake throttle valve, and uses the detected value. This was done by inputting the information to the opening adjustment means of the on-off valve. .

However, such a conventional opening/closing valve opening adjustment mechanism has a complicated structure and a large number of parts, resulting in high costs, poor productivity, and complicated maintenance.

An object of the present invention is to solve the above-mentioned drawbacks and provide an on-off valve that has a simple structure and can adjust the opening degree, and the main feature of the present invention is to expand or contract the on-off valve itself by the pressure within the fluid passage. .

The invention will be explained in more detail below by means of embodiments shown in the figures.

FIG. 1 shows 11i: the first embodiment. In the figure, an intake pipe (1) having an intake passage (1) A therein communicates with an intake port (3) of a cylinder head (2). The outlet 1 of the intake boat (8) communicates with the cylinder (5) via an intake valve (4). Note that (6) is an exhaust boat that communicates with the cylinder (5) via the exhaust valve (7), and OQ is a spark plug. The on-off valve (8) is made by holding a spacer-shaped holder (8) A between the suction pipe (1) tip 7 flange (1) B and the periphery of the intake port (3) of the cylinder (5), and tightening it with bolts, etc. By fixing it, it is attached to the boundary between the intake pipe (1) and the intake port (3) in the intake passage (1) A. Further, a guide (9) for regulating the expansion of the on-off valve (8) is installed in the intake passage (1) A opposite to the on-off valve (8). The guide (9) is not essential to the present invention. The shape of the guide (9) may be arbitrarily selected, such as a flat plate or a semi-cylindrical shape, as shown in FIGS. 2 and 3.

The on-off valve (8) is a bag-shaped or elastic bellows-shaped hollow body made of a stretchable material such as rubber, elastomer, or soft plastic, and a gas such as air is sealed inside.

In the above configuration, when the internal combustion engine is under high load, that is, when the throttle is fully opened or when accelerating, the pressure in the intake passage (1) A increases to atmospheric pressure, and when the internal combustion engine is under low load, that is, when idling or decelerating, etc. The pressure in the intake passage (1) A decreases.Therefore, the gas sealed in the on-off valve (8) changes to the poi-rushal shown in equation (1) according to the pressure in the intake passage (]) A. The volume is made smaller by the law of

In response to the change in the volume of the gas, the opening/closing valve (8) also changes in volume, and its opening degree is increased by 11IiI. For example, P1=0.87 atm (660rrrnH
Let the volume of air when air is sealed in g) be Vl, and the relationship between intake pressure (P) and volume ratio (vt/v, ) is (1
) and plotted for each temperature as shown in Figure 4. In the figure, the 10 mode ranges are indicated by xj, the range when decelerating is Xl, the range when idling is X2, and the range when traveling at 401 m/h is X3. The range when accelerating is shown as X4, and the range when the throttle is fully open is shown as X5. Thus, as shown in FIG. 5, the on-off valve (8) is in the state indicated by the solid line v1 when the inside of the intake passage (1) A is at atmospheric pressure, but when the load is high, the volume is indicated by the dotted line V2.
When the load is low, the volume expands to the dotted line v3. Thus, the opening degree of the on-off valve (8) increases when the load is high and decreases when the load is low. And the kite (9) is in the intake passage (
1) A is prevented from being completely closed by the on-off valve (8).

A second embodiment is shown in FIG. In this embodiment, the inside of the on-off valve (8) is communicated with the atmosphere through a communication passageway (8)B. In such a configuration, the amount of air in the on-off valve (8) is not limited to a certain level, so the degree of expansion and contraction of the on-off valve (8) is large, and therefore, the on-off valve (8) responds to pressure changes in the intake passage (1) A. ) has the advantage of increasing the volume change.

When applying the fluid passage of the present invention to a 4-valve internal combustion engine,
For example, as shown in FIG. 7, a pair of intake passages (1)A,
(1) An on-off valve (8) may be provided only on either side of A. As mentioned above, the on-off valve (8) may have any shape as long as it expands and contracts in accordance with the expansion and contraction of the gas contained therein, such as bag-like, bellows-like, etc. The shape may be changed to create a strong vortex in the intake air. It goes without saying that the fluid passage of the present invention can be applied not only to the intake passage of an internal combustion engine but also to passages for supplying gas or liquid to chemical equipment or the like.

As described above, the on-off valve provided in the passage expands or contracts depending on the pressure inside the passage, so the present invention provides direct or indirect detection means for the pressure inside the passage, and opening and closing of the on-off valve linked to the detection means. It does not require any complicated mechanism such as a temperature adjustment means and has an extremely simple structure, so it can be provided at low cost, has good productivity, and is easy to maintain.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG.
2 and 3 are sectional views taken along the line A-A' in FIG. 1, and FIG.
This is a graph showing the relationship between Vi/V+) and intake pressure P. --- is 30°C1o-o is 40°C, x-x is 80°C
Fig. 5 is an explanatory diagram of the operation of the on-off valve;
The figure is a cross-sectional view of the second embodiment, and FIG. 7 is a cross-sectional view when applied to a four-valve internal combustion engine. In the diagram, (1)...Suction pipe, (1)A...Intake passage, (3)...Intake boat, (8)...Open/close valve Patent applicant Aichi Machine Industry Co., Ltd. company

Claims (1)

[Claims] A fluid passage structure characterized in that, in a fluid passage provided with an on-off valve in the passage, the on-off valve itself expands or contracts depending on the pressure within the passage.