JPS5997382A - Bellows device and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bellows device used in an automobile exhaust system, etc., and a method for manufacturing the same.

Generally, an automobile exhaust system includes a bellows device for absorbing vibration energy. In this bellows device, both ends of the bellows are fixed to a cylindrical body, and the bellows is surrounded by a protective tube.

This protective tube is flexible and protects the bellows from stones, sand, etc. thrown by the wheels.

Conventionally, both ends of the protective tube were formed with a reduced diameter, and were tightened and fixed to the outer circumferential surface of the cylindrical body using a tightening ring.

However, Tonoyo! In this configuration, both ends of the protection tube were weakly fixed, and the distance between the protection tube and the bellows was insufficient, making it impossible to reliably protect the bellows.

The present invention was made based on the above circumstances, and its purpose is to provide a bellows device that can securely fix both ends of a protection tube, and that can securely protect the bellows by separating the protection tube and the bellows sufficiently. Our goal is to provide the following.

Another object of the present invention is to provide a method for manufacturing a bellows device that can particularly firmly fix both ends of a protective tube.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view in section of the upper half of the bellows device, and FIG. 2 is a side view of the same. In the figure, reference numeral 1 indicates a bellows. The bellows 1 is constructed by forming a thin-walled tube into a spiral shape, or by winding a band plate having waves parallel to the longitudinal direction in a spiral shape while shifting the band plate by, for example, one wave. Cylindrical bodies 2, 2 are inserted into both ends of the bellows 1, and both end edges of the bellows 1 are welded to the outer peripheral surfaces of the cylindrical bodies 2, 2. Said cylinder 2.2
is in contact with, for example, an exhaust pipe (not shown). A protective tube 3 is arranged outside the bellows 1 in a spaced-apart manner from the bellows 1. For example, this protection tube 3 is @@
It is constructed by weaving a bundle of wires and has flexibility. Both ends of the protection tube 3 are fixed by ring bodies 4, 4. This ring body 4 has an S-shaped cross section,
A cylindrical fixing part 5, a caulking part 6 having a U-shaped cross section and having a diameter larger than the fixing part 5, and an intermediate part 7 extending in a direction perpendicular to the axial direction and connecting the fixing part 5 and the caulking part 6. have. The fixing portion 5 of the ring body 4 is fixed to the outer peripheral surface of the cylinder body 2 by means such as spot contact. Further, the end portion of the protection tube 3 described above is caulked to the caulking portion 6.

In the above-described configuration, both ends of the protective tube 30 are caulked to the ring body 4.4, so that they are fixed with sufficient strength.

Furthermore, since the fixing part 5 and the caulking part 6 of the ring body 4 are separated by the width of the intermediate part 7, the protection tube 3 can surround the bellows 1 while being sufficiently spaced from the bellows 1, and The bellows 1 can be reliably protected from stones and sand thrown by.

Next, a method of manufacturing the above-mentioned bellows device will be explained.

The ring body 4 is formed in advance to have the cross-sectional shape shown in FIG. Here, fixing part 5. The overhanging portion 7 has a shape after caulking (second
(see figure), but the caulking part 6 is different. The caulking part 6 includes a cylindrical inner circumferential piece part 6a parallel to the fixing part 5, a truncated can-shaped outer circumferential piece part 6b inclined with respect to the inner circumferential piece part 6a, and these inner circumferential pieces. 6a and an intermediate portion 6c that connects the outer peripheral piece portion 6b. Since the outer peripheral piece 6b has a truncated conical shape, the opening 6d of the caulked portion 6 is wide enough to allow the protection tube 3 to be inserted therein.

First, cylindrical bodies 2 are attached to both ends of the bead 1. The crystal is inserted and fixed. Next, both ends of the protection tube 3 are inserted into the caulking part 6 of each ring body 4 as shown in FIG. be done.

Next, as shown in FIG. 3, an annular pedestal 8 is inserted between the fixing part 5 of the ring body 4 and the inner peripheral piece part 6a of the caulking part 6.

Thereafter, the outer circumferential piece 6b of the caulking portion 6 is deformed under pressure by a plurality of pressure members 9 arranged radially around the ring body 4, thereby causing the protection tube 3 to be deformed by pressure. The ends are caulked and fixed. The pressure surfaces of the pressure members 9 are formed into curved surfaces along the outer peripheral surface of the protection tube 3. In addition, the pressure member 9
Since they are spaced apart from each other by a predetermined distance when crimping is completed, the excess thickness of the outer peripheral piece 6b concentrates in the gap between the pressure members 9 and bulges there. An extra wall portion 10 is formed. As a result, the outer peripheral piece 6
In b, the portion other than the excess wall portion 10 is uniformly adhered to the end of the retaining tube 3, and the caulking of the protection g3 becomes strong.

Further, by spot welding the caulked portion 6 after the caulking is completed, the fixation of the end portion of the protective tube 3 can be further strengthened.

In addition, in the above process, the order of fixing the ring body 4 to the cylinder body 2 and caulking the end portion of the protective tube 3 to the ring body 4 may be reversed.

As explained above, the device of the present invention caulks the end of the storage tube to the ring body, so this end can be fixed with sufficient strength, and the protection tube and the bellows can be sufficiently spaced to securely secure the bellows. Can be preserved.

Further, according to the manufacturing method of the present invention, the outer circumferential piece of the caulking portion of the ring body is formed in advance into a truncated conical shape, and the pressurizing members arranged radially around the circumference of the ring body are used. The outer circumferential piece is pressurized and deformed to caulk the end of the protective tube, and the excess thickness of the outer circumferential piece is concentrated in the gap between the pressurizing members during caulking, thereby strengthening the caulking. It can be made into something.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a section of the upper half of a blade device according to an embodiment of the present invention, FIG. 2 is a side view of the same, and FIG. 3 is an enlarged sectional view of a main part in a caulking process. 1...Bellows, 2...Cylinder, 3...
・・・Hokitube, 4... Ring body, 5...
Fixed part, 6... Caulked part, 6a... Inner circumference piece part, 6b... Outer circumference piece part, 9... Pressure member, 10... ...extra meat part. Applicant Sakamoto Kogyo Co., Ltd. Representative Patent Attorney Noboru Watanabe

Claims (2)

[Claims] (1), (B) a bellows; (i) a cylindrical body inserted and fixed into both ends of the bellows; (c) a flexible protective tube surrounding the bellows; and) an outer circumferential surface of the cylindrical body. A ring body integrally formed with a fixing part fixed to the fixing part and a caulking part having a larger diameter than the fixing part and having a U-shaped cross section for caulking and fixing the end of the protection tube. bellows device. (2), H) A step of inserting and fixing a cylinder into each end of the bellows, and (B) fixing a ring to the cylinder, and providing flexible protection to the ring to surround the bellows. the ring body has a cylindrical fixing part to be fixed to the inner cylinder and a caulking part having a larger diameter than the fixing part, and has a cylindrical inner circumferential piece and an outer circumferential piece having a frustoconical surface shape, and after inserting the end of the preservation tube between the inner circumferential piece and the outer circumferential piece, the annular body The end of the protection tube is caulked by pressurizing and deforming the outer circumferential piece using a plurality of pressurizing members arranged radially around the circumference of the outer circumferential piece. A method for manufacturing a bellows device, characterized in that excess meat is concentrated.