JP4583668B2 - Exhaust pipe fittings - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe joint between a first pipe and a second pipe in the course of an exhaust pipe.
[0002]
[Prior art]
As shown in FIG. 10, the conventional pipes are joined to each other in the course of the exhaust pipe by fixing the flanges 3 and 4 to the pipes 1 and 2 by welding and sandwiching the gasket 5 between them with bolts and nuts. Tightening and fixing structures were common.
[0003]
In recent years, joints in which flange welding has been abolished have also been proposed in JP-A-5-33890, JP-A-8-93977, JP-A-9-189386, and the like. The part is parallel to the direction perpendicular to the axis, and even if the joint is tightened with a band, the sealing performance is poor. Therefore, in order to ensure sealing performance, a ring-shaped or spiral-shaped gasket is used in combination. In addition, since there is a gap between the pipes, the durability is weak against repetition in the bending direction (direction perpendicular to the axis). Therefore, the plate thickness had to be increased.
[0004]
[Problems to be solved by the invention]
In the case of a structure in which a flange is fixed to each pipe by welding and a gasket is sandwiched between the pipes and tightened with bolts and nuts, the welding work requires labor, time and skill. Also, the assembly work is complicated and inefficient. Further, when a gasket is used in combination with the overlapping portion of the exhaust pipe joint as in JP-A-5-33890, JP-A-8-93977, JP-A-9-189386, etc., the number of members increases. Also, the labor at the time of manufacture increases. Furthermore, there is a concern that abnormal noise such as chatter noise may occur in the joint. Accordingly, the present inventor has studied to provide a pipe joint that has no need for welding, has a high sealing performance without using a gasket, and has excellent durability.
[0005]
[Means for Solving the Problems]
As a result of examining the above problems, the diameter-expanding taper portion formed at the pipe end of the first pipe, the diameter-decreasing taper portion formed at the pipe end of the second pipe to be joined, and a band for tightening the outer periphery of these joining portions. It was set as the exhaust pipe fitting. The diameter-expanded taper portion referred to here is a taper portion whose diameter increases toward the pipe end of the first pipe. On the contrary, the diameter-reduced taper portion is a taper portion whose diameter becomes smaller toward the tube end. The outer diameter of the reduced diameter taper portion is substantially equal to the inner diameter of the enlarged taper portion, and is a structure that adheres when superposed.
[0006]
More specifically, the following three aspects can be presented. First, in the vicinity of the transition portion to the enlarged diameter locking portion formed at the end of the enlarged diameter tapered portion formed at the pipe end of the first pipe and the reduced diameter tapered portion formed at the pipe end of the second pipe to be joined. This is a pipe joint for an exhaust pipe in which the formed ring-shaped flange is brought into close contact with each other with a taper portion being brought into contact with each other at a joining portion, and an outer periphery of the contacting portion is covered with a mountain band and tightened. The chevron band here refers to a structure that has a chevron-shaped cross section and can be tightened around a tube. A structure in which both ends are united at a portion around the tube and fastened with bolts and nuts is preferable.
[0007]
In addition, the inner diameter formed by extending the end of the diameter-expanded taper section formed at the pipe end of the first pipe is formed at the clamping pipe section close to the outer diameter of the second pipe and the pipe end of the second pipe to be joined. This is a pipe joint of an exhaust pipe formed by fastening a step formed in the vicinity of the transition part to the reduced diameter tapered part with a band on the outer periphery of the fastening pipe part of the first pipe.
[0008]
Furthermore, in the vicinity of the transition portion to the enlarged diameter locking portion formed at the end of the enlarged diameter taper portion formed at the pipe end of the first pipe and the reduced diameter tapered portion formed at the pipe end of the second pipe of the joining partner. The formed chevron ring part is abutted at the joining part, and the exhaust pipe pipe joint is formed by covering and tightening the chevron band on the outer periphery of the abutting part. In any case, the enlarged diameter taper portion and the reduced diameter taper portion that is in close contact with the inside have a feature that is superior in sealing performance with a larger contact area than the gasket.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. 1 (a) to (c) are cross-sectional views of the pipe joint of the present invention before joining, FIG. 2 is a cross-sectional view of the pipe joint of the present invention after joining, and FIG. 3 (a) is a side view before tightening the angle band. Figure (b) is a side view of the mountain band after tightening. An enlarged taper portion 11 is formed at the pipe end of the first pipe 1, and the end of the enlarged taper portion is curled and formed with an enlarged locking portion 12. The second pipe 2 to be joined has a reduced diameter tapered portion 13 at the pipe end. A ring-shaped flange 14 is formed in the vicinity of the transition portion of the second pipe 2 to the reduced-diameter tapered portion 13, and the tapered portions 11, 13 are brought into close contact with each other and abutted at the joint portion. Is covered and tightened to form an exhaust pipe fitting. As shown in FIGS. 3 (a) and 3 (b), the angle band 15 is fastened and fixed with bolts and nuts on one side surface of the joining portion. Since a gap is provided between the enlarged diameter locking portion 12 and the ring-shaped flange 14 and then tightened in a state where the angle band 15 is covered, by tightening the angle band 15, The second pipe 2 is pulled close to obtain an adhesive force between the tapered portions 11 and 13 and can be firmly attached. Since there is no clearance between the tapered portions 11 and 13, the pipe has excellent durability against stress applied in the direction perpendicular to the axis. In addition, the anti-separation effect is great, and the taper portions 11 and 13 are kept in close contact with each other over a wide area, so that the sealing performance is very good. The chevron band 15 has an angled cross section 15a that corresponds to the enlarged-diameter engaging portion 12 on one side, and an angled cross-sectional shape that forms a vertical surface 15b (an engaging surface) that corresponds to the ring-shaped flange 14 on the other side. In addition, the angle band 15 includes pressing portions 15c at both ends of the convex portion.
[0010]
Figure 4 (a) ~ (c) is a sectional view of the pipe joint of the present invention before bonding, FIG. 5 is a sectional view of the pipe joint of the present invention after bonding, FIGS. 6 (a) is a side view before clamping band (B) is a side view of the band after tightening. In this example, the end of the enlarged taper portion 11 formed at the tube end of the first pipe 1 is further extended to form a tightening tube portion 16 whose inner diameter is close to the outer diameter of the second pipe 2. Further, a step 17 is formed in the vicinity of the transition portion to the reduced diameter taper portion 13 formed at the pipe end of the second pipe 2 to be joined. The diameter-reduced taper portion 13 bulges once at the step 17 portion and is reduced in diameter in the joining direction at the tip. The diameter-reduced taper part 13 formed at the pipe end of the second pipe 2 is inserted into the diameter-expanded taper part 11 formed at the pipe end of the first pipe 1, and after the taper parts 11, 13 are joined together, the first pipe 1 is tightened. It is tightened with a band 18 on the outer periphery of the pipe part 16. In the band 18, two inwardly protruding ridges 18a are formed in order to enhance the tightening effect. As shown in FIG. 6B, tightening is performed by bolts and nuts on one side surface of the joining portion.
[0011]
FIGS. 7 to 9 show another embodiment corresponding to claim 2 of the present invention. FIGS. 7A to 7C are sectional views of the pipe joint of the present invention before joining, and FIG. 9A is a cross-sectional view of the pipe joint of the present invention, FIG. 9A is a side view before tightening the angle band, and FIG. 9B is a side view of the angle band after tightening. Also in this example, an enlarged taper portion 11 is formed at the pipe end of the first pipe 1, the end of the enlarged taper portion 11 is curled, and an enlarged locking portion 12 is formed. The second pipe 2 to be joined has a reduced diameter tapered portion 13 at the pipe end. A chevron ridge 19 is formed in the vicinity of the transition portion of the second pipe 2 to the reduced diameter taper portion 13, the taper portions 11 and 13 are brought into close contact with each other and abutted at the joining portion, and a chevron band 20 is formed around the abutting portion. Is covered and tightened to form an exhaust pipe fitting. A gap is provided between the enlarged diameter locking portion 12 and the chevron ridge 19, and then the first pipe 1 and the second pipe 2 are drawn together by tightening the chevron band 20, and the enlarged taper portion 11 and An adhesion force of the reduced diameter taper portion 13 is obtained. The angle band 20 is fastened and fixed with bolts and nuts on one side of the joining portion as shown in FIG. In this example as well, the enlarged locking portion 12 and the chevron ridge 19 are tightened in a state where the chevron band 20 covers, so that the taper parts 11 and 13 are firmly adhered to each other, and the action of preventing detachment is great, The taper parts 11 and 13 are kept in close contact with each other over a wide area and have a very good sealing performance. The taper parts 11 and 13 have no pipe clearance, so they have excellent durability against stresses perpendicular to the axis. Yes. The angle band 20 has an angled section 20a on one side corresponding to the enlarged diameter locking portion 12, and the angled section 20b ( locking surface) corresponding to the angled protrusion 19 on the other side. In addition, the angle band 20 includes pressing portions 20c at both ends of the convex portion.
[0012]
【The invention's effect】
Since the pipe joint of the exhaust pipe of the present invention is a joint with a tapered portion having a long joining portion, a tight contact state is maintained over a wide area. The contact area is larger than that using a gasket and the sealing performance is very good. In addition, since there is no need for welding and no gasket is used in combination, effects such as a reduction in the number of parts and a reduction in the number of assembly steps can be achieved.
[Brief description of the drawings]
FIGS. 1A to 1C are cross-sectional views of a pipe joint of the present invention before joining.
FIG. 2 is a cross-sectional view of the pipe joint of the present invention after joining.
3A is a side view of the angle band before tightening, and FIG. 3B is a side view of the angle band after tightening.
4A to 4C are cross-sectional views of the pipe joint of the present invention before joining. FIG.
FIG. 5 is a cross-sectional view of the pipe joint of the present invention after joining.
6A is a side view of the band before tightening, and FIG. 6B is a side view of the band after tightening.
7 (a) to (c) are cross-sectional views of the pipe joint of the present invention before joining.
FIG. 8 is a cross-sectional view of the pipe joint of the present invention after joining.
9A is a side view of the angle band before tightening, and FIG. 9B is a side view of the angle band after tightening.
FIG. 10 is an exploded perspective view of a conventional pipe joint of an exhaust pipe.
[Explanation of symbols]
1 First pipe 2 Second pipe
11 Expanded taper
12 Enlarged locking part
13 Reduced diameter taper
14 Ring-shaped flange
15 Yamagata Band
15a slope
15b Vertical surface (locking surface)
15c Pushing part
16 Clamping pipe
17 steps
18 bands
19 Yamagata ridge
20 Yamagata Band
20a slope
20b Slope (locking surface)
20c Pushing part

Claims (3)

It is formed in the vicinity of the transition part to the enlarged diameter locking part formed at the end of the enlarged diameter taper part formed at the pipe end of the first pipe and the reduced diameter taper part formed at the pipe end of the second pipe to be joined. a ring-shaped flange, a pipe joint and Yamagata band which butt in junction in close contact with the tapered portion together tighten covers the outer peripheral portion abutting said, consists of the exhaust pipe,
In the state where the diameter-reduced taper portion and the diameter-expanded taper portion are in contact with each other, a clearance is provided between the diameter-enlarged locking portion and the ring-shaped flange to serve as a tightening margin for the angle band. Pipe fittings. It is formed in the vicinity of the transition part to the enlarged diameter locking part formed at the end of the enlarged diameter tapered part formed at the pipe end of the first pipe and the reduced diameter tapered part formed at the pipe end of the second pipe to be joined. and a chevron ring portion, a pipe joint and Yamagata band which butt in junction in close contact with the tapered portion together tighten covers the outer peripheral portion abutting said, consists of the exhaust pipe,
In the state where the diameter-reduced taper portion and the diameter-expanded taper portion are in contact with each other, a clearance is provided between the diameter-enlarged locking portion and the angle-shaped ring portion to serve as a tightening margin for the angle band. Pipe fittings. The chevron band is an annular member having a convex portion with a convex cross section and a pressing portion extending from the convex portion in the circumferential direction, and one of the inner walls of the convex portion is a slope that is in sliding contact with the enlarged-diameter locking portion during fastening. The exhaust pipe pipe joint according to claim 1 or 2, wherein the other is configured as a locking surface that stops a diameter with a ring-shaped flange or a mountain-shaped ring portion.

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