JPH0874688A - Suction pipe mounting structure of air cleaner - Google Patents

Abstract

PURPOSE: To allow a casing to have an excellent silencing effect by constructing a suction pipe from an insertion pipe for insertion into the inner surface of the cylindrical flange of a casing and an introducing duct fitted on the outer surface of the flange, and projecting the end of the insertion pipe into the casing, the suction pipe being mounted in an opening having the cylindrical flange; and to facilitate insertion and ensure that the insertion pipe closely adheres to the cylindrical flange by providing the insertion pipe with an axial slit. CONSTITUTION: An air cleaner casing 2 is provided with an opening 6 having a cylindrical flange 5, and an insertion pipe 22 having a slit 25 is inserted into the cylindrical flange 5 and projected inwards by a length (a). Since the insertion pipe 22 closely adheres to the cylindrical flange 5 because of the elastic force of the slit 25, these members do not require any high precision machining. An introducing duct 21 for introducing outside air is fitted on the outer surface of the cylindrical flange 5, and the introducing duct 21 and the insertion pipe 22 constitute a suction pipe 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction pipe mounting structure for an air cleaner mounted on an internal combustion engine or the like.

[0002]

2. Description of the Related Art Air cleaners mounted on internal combustion engines and the like often have a structure in which a separate suction pipe is inserted into a casing body. For example, the air cleaner 1 shown in FIG. 4 comprises a casing 2 made of synthetic resin, a body 4 having a discharge port 3 and a cover 7 having an opening 6 having a tubular flange 5, and a space between the body 4 and the cover 7. Filter element 8
It is clamped by the clip 9 and clamped. A suction pipe 10 made of synthetic resin is inserted into the opening 6 of the casing 2 and attached so as to be in close contact with the inner surface of the tubular flange 5. The insertion portion 11 is formed by projecting the end portion of the attachment base portion of the suction pipe 10 into the casing 2. The insertion portion 11 is provided because the insertion portion 11 effectively acts to attenuate the engine noise on the intake side by causing the casing 2 to act as a silencer, and the silencing effect becomes large.

[0003]

In the conventional suction pipe mounting structure as described above, it is difficult to accurately bring the outer surface of the suction pipe into close contact with the inner surface of the cylindrical flange, resulting in mounting play and air leakage. The reason is that the cylindrical flange 5 and the suction pipe 10 are
This is because when both and are molded with a synthetic resin, dimensional error and molding distortion occur during molding. Further, although the cylindrical flange 5 has a taper that is divergent on the inner surface as a draft at the time of molding, it is extremely difficult to form the same taper on the outer surface base portion of the suction pipe 10. In order to obtain a satisfactory mounting state with this structure, it is necessary to perform complicated work such as actual product matching and finishing. Further, a locking claw 12 is provided to prevent the suction pipe 10 from coming out, but since the locking claw 12 has no bending margin, the cylindrical flange 5 is scratched when it is inserted into the cylindrical flange 5, and the locking claw 12 itself. Is almost in a state of pressure loss, and the locking action is incomplete.

[0004]

A suction pipe attached to an opening having a cylindrical flange formed in a casing comprises an introduction duct and an insertion pipe, and the introduction duct is fitted on the outer surface of the cylindrical flange, and the insertion pipe is a cylinder. The flange is inserted into the inner surface and the tip is projected into the casing to form the insertion part, and the insertion tube is formed with a slit in the axial direction to insert it while narrowing the slit width and elastically cylindrical. It is a suction pipe mounting structure of an air cleaner that is closely attached to the inner surface of the flange.

[0005]

[Operation] The insertion tube comes into close contact with the inner surface of the tubular flange by the elastic force based on the restoring force, and can be easily inserted into the tubular flange. Further, since the introduction duct is a normal fitting to the outer surface of the tubular flange, it is easy to fix it tightly. That is, the outer surface of the tubular flange has a draft at the time of molding to expand the diameter toward the base, and even if the tip of the introduction duct is slightly elastic, it is pushed into the tubular flange. Follow the instructions to fit and adhere to the outer surface. If necessary, it is also possible to form an annular bead on the outer surface of the tubular flange and use it as a contact fixing means.

[0006]

EXAMPLE FIG. 1 shows a main part of an example. Air cleaner 2
0 is the opening 6 of the conventional synthetic resin casing 2 shown in FIG.
A suction pipe 23 composed of an introduction duct 21 and an insertion pipe 22 is attached to a cylindrical flange 5 provided around the.
The introduction duct 21 and the insertion tube 22 are made of synthetic resin. As shown in FIG. 2, the insertion tube 22 has a stopper flange 24 at the end and is provided with a slit 25 in the axial direction, and the side surface outer diameter D is larger than the inner diameter d of the tubular flange 5 in a free state. The width b of the slit 25 is set to be almost 0 when the outer diameter D is reduced to the inner diameter d by being inserted into the tubular flange 5 as shown in FIG. As shown in FIG. 3, the width b of the slit 25 is set at b ₁ at the tip end and b _{2 at} the end end, and b ₁ > b ₂ so that when the draft of the inner surface of the tubular flange 5 is slightly large, it is sufficient. You can also adapt to.

As shown in FIG. 1, the distal end of the insertion tube 22 projects to the inner surface of the casing 2 by a length a to form an insertion portion 26. As a result, the noise damping effect of the casing 2 is maintained as good as the conventional one shown in FIG.

The introduction duct 22 is pushed into the outer surface of the cylindrical flange 5 and fitted therein. The tubular flange 5 has a draft at the time of molding, and since the introduction duct is made of synthetic resin and has a slight elasticity, it fits well to the outer surface of the tubular flange 5 as it is pushed. If necessary, the tubular flange 5 may be provided with an annular rib 27 to improve the adhesion. With this configuration, the manufacturing accuracy of the tubular flange 5, the introduction duct 21, and the insertion tube 22 can be relaxed as compared with the conventional one to facilitate manufacturing, and the adhesion can be improved.

In the above embodiment, the length of the introduction duct 21 to the outside air intake end is not particularly limited,
Also, it may have a flexible bellows-shaped part in the middle thereof. Further, the mounting direction of the suction pipe 23, that is, the direction of the tubular flange 5 with respect to the opening 6 of the casing 2 is not necessarily the vertical direction of the tubular flange 5 with respect to the opening 6, and may be inclined. Furthermore, the shape of the casing 2 and the characteristics of the filter element 8 are not limited.

[0010]

As described above, according to the present invention, the suction pipe attached to the cylindrical flange provided in the opening of the casing is composed of two introduction ducts on the outside and the insertion pipe on the inside, and the slits are provided in the insertion pipe. Even if the manufacturing accuracy of the above is relaxed, the mounting structure has a tighter fixing property than the conventional one. Further, the fitting and assembling work is easy. Moreover, since there is an insertion portion protruding into the casing, it is possible to maintain the same silencing effect as in the conventional case.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of an embodiment.

FIG. 2 is a perspective view of the insertion tube of the embodiment.

FIG. 3 is a perspective view of another insertion tube according to the embodiment.

FIG. 4 is a sectional view of a suction pipe mounting structure of a conventional air cleaner.

[Explanation of symbols]

 2 Casing 5 Cylindrical Flange 6 Opening 21 Suction Pipe 22 Introduction Duct 23 Insertion Pipe 25 Slit 26 Insertion Part

Claims (1)

[Claims] 1. An air cleaner mounting structure in which a base portion of a separately formed suction pipe is inserted into an opening having a cylindrical flange provided in a casing, and an end portion thereof is projected into the casing to form an insertion portion, It consists of an introduction duct that fits the suction pipe to the outer surface of the cylindrical flange, and an insertion tube that is inserted into the inner surface of the cylindrical flange.The insertion tube is provided with an axial slit so that the outer surface of the insertion tube is the inner surface of the cylindrical flange. A suction pipe mounting structure for an air cleaner, which is elastically adhered to the.