JPH10318457A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joint with the small number of parts only required. SOLUTION: In a pipe 2, a brim-shaped intermediate flange 3 and an insertion part 4 are formed, in a pipe 5, an end part flange 6 and a receiving part 7 are provided. The insertion part 4 is fitted into the receiving part 7, the flange 3, 6 is gotten butted against each other, a pair of semi-circular U-shaped sectional fastener 10 are fitted into the flange 3, 6, to be tightened by a bolt 15 and a nut 16, a seal part is brought into press contact. In a fitting part of the insertion part 4 and the receiving part 7, bending of the pipe 2, 5 is prevented, the flange 3, 6 is prevented from being pried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint used for a pipe through which a high-temperature gas passes, for example, an exhaust pipe of an engine.

[0002]

2. Description of the Related Art In a joint used for a pipe through which a high-temperature gas such as an exhaust gas of an engine passes, airtightness and heat resistance are important. For this reason, there is a joint in which a heat-resistant gasket is interposed. Japanese Utility Model Publication No. 6-36273)
The use of gaskets increases costs. In addition, there is a joint in which the airtightness between the flanges provided at the ends of the two pipes is held by a pair of metal sealing members (Japanese Patent Laid-Open No. 8-1).
No. 21160), however, in this joint, since the metal sealing member has two sealing portions, one for each pipe, the airtightness is likely to be reduced, and the inner peripheral portion of the metal sealing member is also reduced. In addition, since the collar portion attached to the projection protrudes into the pipeline, there is a disadvantage that the flow of gas is obstructed, and the number of parts is large and the cost is high.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pipe joint having high airtightness and mechanical strength and requiring a small number of parts.

[0004]

According to a first aspect of the present invention, a flange is provided at each end portion of a pair of pipes, and the two flanges are abutted with each other. In a pipe joint to be joined together, an intermediate flange near the end of one of the pipes is formed with a flange formed by expanding the pipe into a flange shape, and a pipe portion from the intermediate flange to the end is used as an insertion portion, and At the end of the tube, the end is widened to form an end flange, and a receiving portion is provided following the end flange so that the insertion portion is closely fitted, and the insertion portion of the one tube is received by the other tube. The two flanges are fastened to each other by fitting the intermediate flange and the end flange to each other with a U-shaped fastener having an inner surface pressed against the outer surfaces of the two flanges.

According to this means, the insertion portion of one tube is closely fitted to the receiving portion of the other tube, so that both tubes are held in a straight tube shape to prevent rattling or bending. When the flanges are fastened with a fastener having a U-shaped cross section, the butting surfaces of the intermediate flange and the end flange come into close contact.

According to a second aspect of the present invention, in the first aspect, the end flange of the other pipe is bent rearward and inward by enlarging the end of the pipe. It is characterized by being bent.

[0007] According to this means, since the end flange is formed to be bent, the strength is large, and no distortion occurs in the contact surface between the two flanges even when the clamp is strongly pressed.

According to a third aspect of the present invention, in the first aspect, the end flange of the other pipe is bent forward and inward by bending the end of the pipe so that the end of the pipe is enlarged. It is characterized by having a shape.

According to this means, the smooth portion of the tube surface becomes the contact surface of the end flange, and the contact surfaces of both flanges are easily brought into close contact.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1, 2 and 3, 1 is a pipe joint of the present invention, 2 is one pipe, and a flange-shaped intermediate flange 3 is formed at an intermediate position near an end of the pipe 2. And, from the intermediate flange 3 to the end, an insertion portion 4 fitted to the other pipe 5 is formed. At the end of the other tube 5,
A back-flexing end flange 6 is formed by expanding the pipe end and bending backward and inward. If the pipe 5 is a welded pipe, the weld appearing on the end face of the end flange 6 is processed smoothly.

A receiving portion 7 is formed from the end flange 6 so as to receive the insertion portion 4 therein.
The outer diameter and the inner diameter of the receiving portion 7 are such that both portions 4 and 7 are tightly fitted and do not move.

As shown in FIG. 2, two fasteners 10 for fastening the intermediate flange 3 and the end flange 6 are used for each joint, and have a semicircular portion 11 and ear portions 12 at both ends thereof.
The semicircular portion 11 has a U-shaped cross section, the inner width of which is slightly wider than the width of the overlapped flanges 3 and 6, and presses the outer surfaces of the flanges 3 and 6 with both inner surfaces. A hem portion 13 is continuously provided on the edge portion, and a bolt hole 14 is formed in the ear portion 12, and the ear portion 12 is fastened with a bolt 15 and a nut 16.

In the joint 1, one pipe 2 is, for example, an outlet pipe of an exhaust converter, and the other pipe 5 is an exhaust pipe.

As described above, the insertion portion 4 of one tube 2 and the receiving portion 7 of the other tube 5 are fitted to each other, and the fasteners 10 and 10 are fitted to the flanges 3 and 6 so that the hem 13 contacts the tube surface. To the flanges 3 and 6
Are in close contact to form a seal portion 17, and the two tubes 2, 5 are held in a straight tube at the fitting portion between the insertion portion 4 and the receiving portion 7. Therefore, even if a bending load is applied to the fitting portion due to vibration or the like, the bending is prevented, and the prying action is prevented from occurring on the flanges 3 and 6, and the airtightness of the seal portion 17 is not impaired.

FIG. 4 shows another embodiment, in which an intermediate flange 3a provided on the pipe 2 is formed to be slightly wider, and an end flange 6a provided on the pipe 5 has a flange formed by expanding the pipe end in front and rear. It is formed in a forward bending type bent inward. The fastener 10a has a taper whose inner circumferential side is widened, but a pair is fastened with a bolt and a nut like the fastener 10 described above. Normally, an electric resistance welded pipe is used for the pipe 5, but the electric resistance welded pipe is not smooth because the surface of the welded portion is smooth, but the weld material protrudes from the inner surface. However, by making the end flange 6a forward bent, a smooth portion of the pipe surface can be used as the seal portion 17a, and the smoothing process need not be performed.

FIG. 5 shows an improved example of the apparatus shown in FIG. 3, in which the amount of bending in the vicinity of the seal portion 17 of the end flange 6 is increased to form a line contact, thereby improving the sealing performance. FIG. 6 also shows an improved example of the apparatus shown in FIG. 4, in which the amount of bending near the sealing portion 17a of the end flange 6a is increased to form a line contact, thereby improving the sealing performance.

In each of the above embodiments, the two types of fasteners 10 and 10a may be of any type as long as the dimensions are adapted, such as the contact pressure required for the seal portion, the bending of the flange, and the like. Should be considered.

[0018]

As is apparent from the above description, according to the first aspect, the insertion portion of one tube is fitted into the receiving portion of the other tube, and both tubes are held in a straight tube. Therefore, the fitting portion is prevented from being bent, and no prying or excessive load is applied to the seal portions of both flanges, and airtightness is maintained. In addition, the parts used in the pipe joint other than the pipe are only one kind of fasteners, bolts, and nuts, so that the cost is low, the assembly is easy, and the pipes protrude from the inner surface of the pipe. There is no effect on the flow of gas because there is no air flow.

According to the second aspect of the present invention, since the end flange is formed to be bent, the strength is large, and the contact surface between the two flanges is not distorted even if the clamp is strongly pressed. is there.

According to the means of claim 3, there is an advantage that the smooth portion of the tube surface becomes the contact surface of the end flange, and the contact surfaces of both flanges are easily brought into close contact.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 1;

FIG. 4 is a longitudinal sectional view of a main part of another embodiment.

FIG. 5 is a longitudinal sectional view of an embodiment in which a part of the embodiment of FIGS.

FIG. 6 is a longitudinal sectional view of an embodiment in which a part of the embodiment of FIG. 4 is improved;

[Explanation of symbols]

2,5 pipe 3,3a intermediate flange 4 insertion part 6,6a end flange 7 receiving part 10,10a fastening tool 17,17a sealing part

Claims (3)

[Claims] 1. An intermediate flange in which a flange is provided at each end of a pair of pipes, and the two pipes are joined by abutting the flanges. Is formed, and the pipe portion from the intermediate flange to the end portion is used as an insertion portion, and the end portion is expanded at the end portion of the other tube to form an end flange, and the insertion portion follows the end flange. A cross-section U having an inner surface that is provided with a receiving portion that fits closely, the insertion portion of one of the tubes is fitted into the receiving portion of the other tube, the intermediate flange and the end flange abut, and the outer surfaces of both flanges are pressed against each other. A pipe joint characterized in that both flanges are fastened with a U-shaped fastener. 2. The pipe joint according to claim 1, wherein an end flange of the other pipe is a back-flexing type formed by expanding the end of the pipe and bending the pipe backward and inward. 3. The pipe joint according to claim 1, wherein an end flange of the other pipe is a forward bending type in which an end of the pipe is enlarged and bent forward and inward.