JPH07280157A - Installing structure of duct - Google Patents

Abstract

PURPOSE:To ease attaching/detaching work of a duct to an opening by providing a plurality of engaging claws to an end part of a duct at equally-divided positions of the circumference and providing a plurality of chamfered, inclined surfaces to a periphery of an inside surface of an opening in a vessel wall at equally divided positions of the periphery in such a manner that a total of the circumferential length of the chamfered, inclined surface is greater than that of the engaging claws and moreover it is smaller than a quantity of 'the entire circumferential length minus the total of the circumferential length of the engaging claws' together with setting the radial length (radius) of a large diameter part greater than that of the engaging claw. CONSTITUTION:Engaging claws 3 are provided to a duct 1 at equally divided positions of a circumference of the duct 1, while chamfered, inclined surfaces 9 are provided to an opening 5 of a body 4. The number of engaging claws 3 is the same as that of the chamfered, inclined surfaces 9, while the length of the engaging claws 3 in the circumferential direction is smaller than that of the chamfered, inclined surfaces 9. The radius of the engaging claw 3 is smaller than the radius of the large diameter part of the chamfered, inclined surface 9. Accordingly, despite a firm state of attachment of the duct 1 to the opening 5, attaching/detaching (especially detaching) work of the duct 1 can easily be conducted because the engaging claw 3 is guided by the chamfered, inclined surface 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for attaching a duct having a circular cross section to a container wall.

[0002]

2. Description of the Related Art Conventionally, as a structure for attaching a duct to a wall surface of a container, a duct end portion is fitted into an opening of the container wall, and an engaging claw provided at a tip end of the duct end is locked to an inner surface side of the container wall. It is known and disclosed, for example, in Japanese Utility Model Publication No. 63-73517.

As shown in FIG. 3, in the conventional duct mounting structure, a plurality of engaging claws 2 are provided at the tip of a duct 20 made of synthetic resin.
1, which are distributed on the circumference and are inserted into an opening 23 provided in a container wall of a container 22 (for example, a casing of an air cleaner) to lock a plurality of engaging claws 21 on an inner side surface 24 of the opening 23. Met. A guide cylinder 25 is provided so as to project from the peripheral edge of the opening 23, and the tip thereof abuts on the flange portion 26 of the duct 20 to serve as a stopper. A slit 27 is cut in the axial direction from the end of the duct with an appropriate length.

[0004]

After the duct 20 and the container 22 are once attached, it is necessary to remove them for replacement and cleaning. Slit 2
Numeral 7 is provided for the convenience of its removal, and the slit 27 bends the tip of the pipe 20 to engage the engaging claw 2.
Needed to unlock 1 If the engagement is released, the guide cylinder 25 can be moved back and forth only by elastically bending the engaging claw 21 portion, and therefore the slit 27 is not necessarily required when the duct 20 is inserted.

Thus, the slit 2 is mainly used for removal.
7 is provided, the tightened state of the distal end portion of the duct 20 is loosened, the attachment is easily detached due to external force such as vibration, and the duct 20 is easily detached, and air leakage occurs from the slit 27 portion.

[0006]

Means for Solving the Problems A plurality of engaging claws having an equal circumferential length projecting outward on the circumference of an end surface of a duct having a circular cross section are provided at equal circumferential positions and at a circumferential length. The total number of chamfers is 1/2 or less of the length in the circumferential direction, and the same number of chamfered inclined surfaces as the number of engaging claws are arranged at equal circumferential positions on the inner peripheral edge of the container wall opening. The chamfered chamfers shall have a total length in the circumferential direction of each chamfered inclined surface that is 1/2 or more of the circumference and smaller than "total circumference length-total length in the circumferential direction of engaging claws". The radius of the large diameter portion of the inclined surface is larger than the projection radius of the engaging claw, and the end of the opening duct is inserted to lock the engaging claw at a portion of the edge on the inner surface side of the opening without the chamfering inclined surface.

[0007]

When the duct is inserted into the container wall opening of the container, it is pushed in by the bending of the engaging claws to be fitted therein, and the bending is restored at the point where the engaging claws cross the inner surface side of the opening, and the duct is locked. In this case, the engaging claw is rotated so as to match the position without the chamfered inclined surface. In this state, since there is no conventional structure for softening the duct such as the slit, the vibration resistance is excellent and there is no leakage from the connecting portion.

When the duct is removed, the duct is rotated to align the engaging claw with the chamfered inclined surface and pull out, and the engaging claw is accommodated within the length of the chamfered inclined surface and has a small radius. Therefore, it can be pulled out by being guided to the chamfered inclined surface and bent toward the axial center.

[0009]

EXAMPLE FIG. 1 shows an example. Duct made of synthetic resin 1
Is an air suction pipe attached to the air cleaner 2. Engaging claws 3 projecting outward are provided at positions where the circumference of the end of the duct 1 is divided into four equal parts. The circumferential length d of the engaging claw 3 is slightly smaller than 1/8 of the total circumferential length. An opening 5 is provided in a body 4 of the air cleaner 2, and a fitting tube 6 is provided in a tubular shape from the opening 5, and a tip thereof is brought into contact with a flange portion 7 of the duct 1 to form a stopper. The radially projecting portion of the engaging claw 3 is locked to the inner side surface 8 of the body 4 at the inner peripheral edge of the opening 5.

As shown in FIG. 2, the body 4 is formed with a chamfered inclined surface 9 that widens toward the inner side surface 8 at the inner peripheral edge of the opening 5. The chamfered inclined surface 9 is provided at a position that divides the circumference into four equal parts, and the length D in the circumferential direction is greater than ⅛ of the length of the circumference (circumferential length-4d). The radius R of the large diameter portion of the chamfered inclined surface 9 is larger than the radius r of the engaging claw 3.

When the duct 1 is pulled out from the body 4, the duct 1 is rotated about 45 ° so that the engaging claw 3 and the chamfered inclined surface 9 are formed.
And the radial protruding end of the engaging claw 3 is aligned with the inner surface 8
Since it is guided to the chamfered inclined surface 9 and bends, it can be pulled out as it is.

[0012]

As described above, according to the present invention, engaging claws and chamfered inclined surfaces are formed at equal positions on the circumference of the duct end portion and the peripheral edge of the inner side surface of the opening of the container wall, respectively, and their circumferential lengths are set. Since the engaging claws are made smaller, and the radius of each large diameter part is also smaller, the engaging claws are easy to install and remove without providing slits in the duct. There is no slack, falling off, or leakage from the slit.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment, (a) is a mounted state,
(B) shows the end surface of the duct (arrow A direction).

FIG. 2 is a view showing an air cleaner body of the embodiment,
(A) is a sectional view, (b) is a plan view of the opening (direction of arrow B), and (c) is an opening sectional view of arrow C.

FIG. 3 is a sectional view showing a conventional duct mounting structure.

[Explanation of symbols]

 1 Duct 3 Engaging Claw 4 Body (Container) 5 Opening 9 Chamfered Slope

Claims (1)

[Claims] 1. A plurality of engaging claws protruding outward are provided on the circumference of an end surface of a duct having a circular cross section, and the end of the duct is fitted into an opening provided in the container wall of the container to form an inner surface side of the container wall. In the duct mounting structure that locks the engaging claws, the locking claws are arranged at equal positions on the circumference of the end face, the circumferential lengths of the respective locking claws are made equal, and the total length is calculated as It is less than 1/2 of the circumferential length, and the same number of chamfered inclined surfaces as the number of engaging pawls are provided on the peripheral edge on the inner surface side of the opening of the container wall, and each chamfered inclined surface is equidistant on the circumference at equal positions. Arranged so that the length in the circumferential direction is greater than the length in the circumferential direction of the engaging claws, and the total length is smaller than "total circumference length-total length in the circumferential direction of the engaging claws". A duct mounting structure characterized in that the radius of the large diameter portion of the inclined surface is made larger than the projection radius of the engaging claw.