JP2566379Y2 - Intake duct - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake duct for an internal combustion engine, and more particularly to an intake duct having a silencing side branch.

[0002]

2. Description of the Related Art It has been known that a silencing effect can be obtained by connecting a side branch made of a hollow body to an appropriate position of an intake duct of an internal combustion engine. As shown in FIGS. 4 and 5, a side branch 12 composed of a bent tube having a closed end and a joint portion 13 formed at a base end is formed in a proper position of the intake duct 11 as shown in FIGS. It is known that the fitting is made to fit into the cylinder opening 14 and the fitting joint surface is bonded with a butyl rubber adhesive 15.

In Japanese Utility Model Laid-Open Publication No. 2-63067,
As shown in FIG. 6, a concave portion 22 is formed at an appropriate position on the bottom surface of the intake duct 21, and a silencer box 23 is accommodated and mounted therein, and the silencer box 23 and the inside of the intake duct 21 are connected by a communication hole 24. A communication is disclosed.

[0004]

However, in the configuration shown in FIGS. 4 and 5, the side branch 12 is
In addition, there is a problem that the appearance is not good because it protrudes long in the near and far directions, and the vibration of the side branch 12 causes a large repetition at the connection surface between the connection port 13 of the side branch 12 and the connection cylinder port 14 of the intake duct 11. There is a problem in the durability of the bonded portion due to the action of the stress, and also in the poor sealing performance due to the bonding with the butyl rubber adhesive 15.

[0005] In the structure shown in FIG.
Although the appearance is good because 3 does not protrude from the intake duct 21 at all, the concave section 22 for accommodating the silencer box 23 is formed in the intake duct 21 so that the cross-sectional area of the flow path becomes narrow at that portion, and the air flow is reduced. And the noise reduction effect is reduced, and the length of the intake duct 21 is different depending on the type of the internal combustion engine. Therefore, when the arrangement position of the muffler box 23 is different, the type differs. There is a problem that it is necessary to manufacture an air intake duct.

The present invention has been made in view of the above-mentioned conventional problems, and has an object to provide an intake duct having a side branch, which is not bad in appearance, and has a durable and well-sealed mounting portion for the side branch. Aim.

[0007]

According to the present invention, a side branch made of a flat rectangular parallelepiped hollow body extending along the longitudinal direction of the intake duct is provided on an appropriate outer wall of the intake duct. A communication hole is formed in a portion facing one end, packing is mounted on the inner periphery thereof, and a connecting cylinder protruding from one end of the side branch is press-fitted into the communication hole, and both ends of the side branch are intake ducts. It is characterized by being screwed to the outer wall.

[0008]

According to the present invention, a flat rectangular parallelepiped side branch is disposed along the outer wall of the intake duct and does not protrude significantly from the intake duct, so that the appearance is not bad and vibration is hardly generated, and the side branch is not affected. Since both ends are screwed to the intake duct, it is durable in the mounting state.In addition, a connecting cylinder protruding from the side branch is fitted into the communication hole formed on the outer wall of the intake duct, and packing is interposed between them. High sealing performance is ensured for a long period of time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

Reference numeral 1 denotes an intake duct, and a communication hole 3 for connecting the side branch 2 is formed in an appropriate outer wall of the intake duct. A packing 4 having a substantially U-shaped cross section is attached to the inner peripheral edge of the communication hole 3.

The side branch 2 is formed of a flat rectangular parallelepiped hollow body extending along the longitudinal direction of the intake duct 1.
A connection cylinder 5 that can be inserted and fitted into the communication hole 3 is protruded from one end of the surface facing the outer wall of the intake duct.

A projecting piece 6 projects from both ends of the side branch 2 so as to overlap the outer wall of the intake duct 1. The projecting piece 6 is screwed to the outer wall of the intake duct 1 with a tapping screw 7. I have.

In the above configuration, when the side branch 2 is mounted on the intake duct 1, a communication hole 3 is formed in a predetermined portion of the intake duct 1 at the same time as other machining is performed. At this time, if the length of the intake duct differs depending on the model of the internal combustion engine, and accordingly the arrangement position of the side branch 2 differs, the perforation position of the communication hole 3 may be adjusted. Next, when assembling the side branch 2, the packing 4 is mounted on the inner peripheral edge of the mounting hole 3, and the connecting cylinder 5 of the side branch 2 is pressed into the communication hole 3 while compressing the packing 4, and the side branch 2 is pressed. Is connected to the intake duct 1, and finally, the protrusion 6 is screwed to the intake duct 1 with a tapping screw 7 to complete the mounting of the side branch 2.

In the mounted state of the side branch 2, since the side branch 2 is disposed along the outer wall of the intake duct 1, the side branch 2 does not protrude greatly from the intake duct 1,
Even if the side branch 2 is provided, the appearance does not deteriorate. Further, since the side branch 2 is disposed along the intake duct 1, vibration is hardly generated, and both ends of the side branch 2 are screwed to the intake duct 1. In addition, since the connecting cylinder 5 of the side branch 2 is fitted to the communication hole 3 of the intake duct 1 via the packing 4, high sealing performance is ensured for a long time.

[0015]

According to the intake duct of the present invention, the flat rectangular parallelepiped side branch is disposed along the outer wall of the intake duct as described above, and does not protrude greatly from the intake duct, so that the appearance is not bad and vibration is not caused. In addition, since both ends of the side branch are screwed to the intake duct, it is durable in the installed state, and a connection cylinder protruding from the side branch fits into a communication hole formed in the outer wall of the intake duct The packing is interposed between them to ensure high sealing performance over a long period of time.In addition, there are different types of intake ducts with different lengths depending on the type of internal combustion engine. By adjusting the position, it is possible to easily arrange the side branch at an arbitrary position.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of an embodiment of an intake duct of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an enlarged sectional view of a main part taken along line AA of FIG. 2;

FIG. 4 is a perspective view of a main part of a conventional intake duct.

FIG. 5 is a cross-sectional plan view of a main part of FIG. 5;

FIG. 6 is a front view of a main part of another conventional intake duct.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intake duct 2 Side branch 3 Communication hole 4 Packing 5 Connecting cylinder 7 Tapping screw

Claims (1)

(57) [Scope of request for utility model registration] 1. A side branch made of a flat rectangular parallelepiped hollow body extending along the longitudinal direction of an intake duct is disposed on an appropriate outer wall of an intake duct, and communicates with a portion of the outer wall of the intake duct facing one end of the side branch. A hole is formed, packing is mounted on the inner circumference, and a connecting cylinder protruding from one end of the side branch is press-fitted into the communication hole, and both ends of the side branch are screwed to the outer wall of the intake duct. And the intake duct.