JP2008057550A - Connection part structure of pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve workability in connecting a pipe with a C-type clamp. <P>SOLUTION: An inner pipe 1 having a chevron bead 11 bulging to an outer side of a diameter direction in a periphery of an end part is inserted in an outer pipe 2 with a flare 23, which is formed on the end part and abuts on an end part side tapered surface 11a of the chevron bead 11 formed by enlarging to the outer side of the diameter direction. The tapered surface 11a and the flare 23 are clamped by the C-type clamp having a chevron shape in cross section to connect the inner pipe 1 and the outer pipe 2. A tip end part of a tongue piece 46 for fixation extended to a direction of the outer pipe 2 from one side of the C-type clamp 4 is previously welded and fixed with respect to a position deviating from a first large diameter part 22 of the outer pipe 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pipe connection structure, and more particularly to a pipe connection structure that is optimal for connection of pipes constituting an exhaust system for a vehicle.

  Conventionally, as a pipe connection structure, an inner pipe in which a chevron-shaped bead bulging radially outward is formed in the vicinity of the end, and the end of the chevron bead is widened radially outward at the end. C-shaped clamp with a cross-sectional chevron shape that is inserted into an outer pipe formed with a flare that abuts the taper surface, abuts the flare against the taper surface on the end of the chevron bead, and has a taper surface and a flare provided with fastening bolts from the outside There is known a structure in which the inner pipe and the outer pipe are connected by tightening with (see, for example, Patent Document 1).

  However, in the above-described conventional example, after inserting the inner pipe into the outer pipe, to attach the C-type clamp and fasten it with the fastening bolt, hold the C-type clamp with one hand and the other hand. Therefore, since it is necessary to insert the fastening bolt into the fastening bolt insertion hole of the C-type clamp with a tool such as an air screwdriver and to perform screwing and fastening, the workability is poor and the work is very tired.

Therefore, as a solution to the above-mentioned problem, it is conceivable to fix in advance a fixing tongue piece extending from the C-shaped clamp in the direction of the outer pipe to the outer pipe.
JP-A-9-189386

  However, in the above-described solution, if the tongue of the C-shaped clamp is welded to the outer pipe, the weld bead may swell toward the inner surface of the outer pipe. There is a problem that it cannot be done. This is particularly a problem when the pipe is thinned to reduce the weight of the exhaust system.

  The problem to be solved by the present invention is to provide a pipe connection structure that can improve workability when connecting pipes with a C-shaped clamp.

  In order to solve the above-mentioned problem, the pipe connecting portion structure according to claim 1 is configured such that an inner pipe in which an angled bead that bulges radially outward is formed in the vicinity of the end portion and is expanded radially outward at the end portion. A pipe that is inserted into an outer pipe formed with a flare that comes into contact with the tapered surface on the end side of the angled bead and the inner surface and the outer pipe are connected by tightening the tapered surface and the flare with a C-shaped clamp having a cross-sectional angle. It is a connection part structure, Comprising: The front-end | tip part of the fixing tongue piece extended toward the outer pipe direction from the one side of the said C type clamp was fixed by welding beforehand at the position opposite to the front-end | tip part of the said outer pipe, Means characterized in that a notch portion is formed at the end opening edge of the inner pipe facing the inner surface of the portion of the outer pipe where the fixing tongue is welded. .

  The pipe connecting portion structure according to claim 2, wherein an inner pipe in which a chevron-shaped bead bulging radially outward is formed in the vicinity of the end, and the end of the chevron bead is widened radially outward at the end. A pipe connecting portion structure in which the inner pipe and the outer pipe are connected by inserting the outer pipe formed with a flare in contact with the taper surface on the side, and tightening the taper surface and the flare with a C-shaped clamp having a mountain-shaped cross section. A second large diameter portion larger than the diameter of the outer pipe is formed in a portion of the inner pipe where a tip portion of the pipe is inserted from the chevron-shaped bead excluding a part of the non-expanded diameter portion; A fixing tongue piece formed with a first large-diameter portion having a larger diameter than the second large-diameter portion on the base side of the flare side in the large-diameter portion, and extending from one side of the C-shaped clamp toward the outer pipe. The tip of The front end opening edge of the inner pipe that is welded and fixed in advance to the non-expanded diameter portion of the second large diameter portion of the outer pipe and faces the inner surface of the outer pipe where the fixing tongue is welded A cutout portion that engages with the non-expanded diameter portion is formed in the portion.

  In the pipe connecting portion structure according to the present invention, as described above, the distal end portion of the fixing tongue extended from one side of the C-shaped clamp toward the outer pipe is more distal than the first large-diameter portion of the outer pipe. When connecting the pipe with the C-type clamp, it is not necessary to hold the C-type clamp with one hand, and the fastening bolt can be set with a tool such as an air screwdriver. Since both hands can be used for the operation of inserting into the fastening bolt insertion hole of the mold clamp and screwing and fastening, an effect of improving workability can be obtained.

  In addition, since the notch portion is formed at the edge of the opening of the inner pipe facing the portion where the fixing tongue piece of the outer pipe is welded, the weld bead of the outer pipe is welded by the fixing tongue piece. Even if it swells to the inner surface side, the inner pipe cannot be inserted into the outer pipe.

  In the pipe connecting portion structure according to the second aspect of the present invention, as described above, the second large diameter portion having a larger diameter than the other portion is integrated into the portion where the tip portion of the inner pipe is inserted from the angled bead. A first large-diameter portion larger than the second large-diameter portion is formed on the flare-side base side of the second large-diameter portion, and is formed on one side of the C-shaped clamp. The tip of the fixing tongue extending from the outer pipe toward the outer pipe is welded and fixed in advance to the non-expanded portion of the second large diameter portion of the outer pipe, and the fixing tongue of the outer pipe is welded. Since the notch portion that engages with the non-expanded diameter portion is formed at the edge of the opening of the inner pipe facing the inner surface of the portion, the C is clamped with one hand when connecting the pipe with a C-shaped clamp. No need to have a mold clamp, air driver etc. Since both hands can be used to work for fastening screwed plug the fastening bolt with a tool to fastening bolt insertion holes of the C-shaped clamp, the effect is obtained that it is possible to improve the workability.

  In addition, as described above, the notch portion that engages with the non-expanded diameter portion is formed at the end opening edge of the inner pipe facing the portion to which the fixing tongue piece of the outer pipe is welded. The non-expanded diameter portion and the cutout portion can also serve to prevent the inner pipe from rotating relative to the outer pipe.

  Embodiments of the present invention will be described below with reference to the drawings.

  The pipe connecting portion structure of the first embodiment corresponds to the invention described in claims 1 to 3.

  First, the pipe connecting portion structure of the first embodiment will be described with reference to the drawings.

  1 is a plan view of a connection state showing a pipe connection structure of the first embodiment, FIG. 2 is a right side view thereof, FIG. 3 is a longitudinal sectional view taken along line AA of FIG. 1, and FIG. It is a longitudinal cross-sectional view which shows a state.

  This pipe connecting portion structure includes an inner pipe 1, an outer pipe 2, a gasket 3, and a C-type clamp (C-type clamp) 4.

  More specifically, as shown in FIG. 3, the inner pipe 1 is formed with a chevron-shaped bead 11 that bulges radially outward near its end.

  The outer pipe 2 has a second large-diameter portion 21 having a diameter larger than the original diameter of the outer pipe 2 at a portion where the pipe tip portion 1a at the tip of the inner pipe 1 is inserted from the angled bead 11. It is formed excluding the non-expanded diameter portion 21a, and has a diameter larger than the outer diameter of the distal end portion of the pipe at the distal end of the second large diameter portion 21 and the angled bead 11 in the inner pipe 1 on the base side of the second large diameter portion 21. The first large-diameter portion 22 is formed, and further, the end portion of the first large-diameter portion 22 is expanded radially outward to the end-side tapered surface 11a of the mountain-shaped bead 11 in the inner pipe 1. A contact flare 23 is formed.

The gasket 3 is interposed between the first large-diameter portion 22 of the outer pipe 2 and the pipe tip portion 1a of the inner pipe 1, so that the connection portion between the inner pipe 1 and the outer pipe 2 is securely sealed. To be done.
In addition, since sealing is performed also by the support part side taper surface 11a of the angle bead 11, and the flare 23, it is also possible to omit the gasket 3 as needed.

  As shown in FIG. 2, the C-type clamp 4 has a body portion 41 formed in a substantially circular shape with a part of the cutout, and a fastening flange 42 extending substantially parallel to the outside at the cutout both ends. 42, and both the fastening flanges 42 and 43 are fastened by fastening bolts 44 and nuts 45. The fastening flanges 42 and 43 are formed with fastening bolt insertion holes 42 a and 43 a, and the nut 45 is fixed to the outside of the flange 43 by welding in advance.

  Further, the body portion 41 is formed with a clamp bead 41a having a mountain-shaped cross section whose central portion bulges outward in the radial direction.

  And the front-end | tip part of the tongue piece 46 for fixation extended toward the outer pipe 1 direction from the one side of the said main-body part 41 with respect to the part of the non-expanded diameter part 21a in the 2nd large diameter part 21 of the said outer pipe 1 A notch 12 that engages with the non-expanded diameter portion 21a is formed at the edge of the opening of the inner pipe 1 facing the inner surface of the portion of the outer pipe 1 where the fixing tongue piece 46 is welded. .

  In addition, it is good also as a concave groove shape instead of the notch part 12, In this case, it can process comparatively easily only by pushing with a press die, without cut | disconnecting.

  Further, a bent portion 46 a that is bent in a U shape is formed in the middle of the fixing tongue 46 in the C-shaped clamp 4.

  Next, the operation of the first embodiment will be described.

  Since the pipe connection portion structure of the first embodiment is configured as described above, first, the gasket 3 is attached to the outer periphery of the pipe tip portion 1a of the inner pipe 1, and the notch 12 and the outer pipe 2 of the inner pipe 1 are attached. By inserting the pipe tip portion 1a of the inner pipe 1 into the first large diameter portion 22 and the second large diameter portion 21 of the outer pipe 2 in a state where the circumferential position of the non-expanded diameter portion 21a is aligned, 1 The gasket 3 is press-fitted between the large diameter portion 22 and the pipe tip portion 1a, the non-expanded diameter portion 21a engages with the notch portion 12, and the flare 23 of the outer pipe 2 The state is in contact with the tapered surface 11 a on the end side of the angled bead 11 of the pipe 1.

  Therefore, by fastening both fastening flanges 42 and 43 with fastening bolts 44 and nuts 45, both tapered surfaces of the angle-shaped clamp beads 41 a are connected to the tapered surface 11 b on the base side of the angle-shaped beads 11 in the inner pipe 1 and the outer pipe 2. The outer pipe 2 and the inner pipe 1 are connected in a state where the outer pipe 2 and the inner pipe 1 are prevented from coming off.

  Next, the effect of the first embodiment will be described.

  In the pipe connection portion structure of the first embodiment, as described above, the distal end portion of the fixing tongue piece 46 extending from one side of the C-shaped clamp 4 toward the outer pipe 2 is the first portion of the outer pipe 2. By adopting a configuration in which the inner pipe 1 and the outer pipe 2 are connected with the C-type clamp 4 by using a configuration in which the inner pipe 1 and the outer pipe 2 are connected to each other at a position opposite to the end portion of the large diameter portion 22 in the axial direction. There is no need to have the mold clamp 4, and both hands can be used for the work of inserting the fastening bolt into the fastening bolt insertion holes 42a, 43a of the C-type clamp 4 and screwing and fastening to the nut 45 with a tool such as an air screwdriver. The effect that it becomes possible to raise is acquired.

  Further, since the notch 12 is formed at the edge of the opening of the inner pipe 1 facing the portion of the outer pipe 2 where the fixing tongue 46 is welded, welding is performed by welding the fixing tongue 46. Even if the bead swells to the inner surface side of the outer pipe 2, the inner pipe 1 cannot be inserted into the outer pipe 2.

  In addition, since the weld bead portion can be easily and securely fastened without being processed again by polishing or the like even with a relatively thin pipe joint, the exhaust system can be reduced in weight.

  Further, a non-expanded diameter portion 21 a is formed in the second large diameter portion 21 of the outer pipe 2, and a notch portion 12 that engages with the non-expanded diameter portion 21 a is formed in the pipe tip portion 1 a of the inner pipe 1. As a result, the non-expanded diameter portion 21a and the cutout portion 12 can also serve to prevent the inner pipe 1 from rotating relative to the outer pipe 2.

  Further, a bent portion 46 a that is bent in a U shape is formed in the middle of the fixing tongue piece 46 of the C-shaped clamp 4, so that the mountain-shaped bead 11 in the inner pipe 1 and the mountain-shaped bead 4 a in the C-shaped clamp 4 are formed. Can be corrected by expansion and contraction of the bent portion 46a.

  Next, another embodiment will be described. In the description of the other embodiments, the same components as those of the first embodiment are not shown, or the same reference numerals are given and the description thereof is omitted, and only the differences are described.

The apparatus of the second embodiment corresponds to the invention described in claims 1 to 4.
This embodiment 2 shows a modification of the apparatus in the above embodiment 1, and as shown in the plan view of FIG. 5, of the both fastening flanges 42 and 43 formed in the notch portion of the C-type clamp 4, A nut is fixed to the outside of the fastening bolt insertion hole 43a of the fastening flange 43,

  The point that the fixing tongue 46 is provided in the vicinity of the fastening flange 43 on the side where the nut 45 of the C-shaped clamp 4 is fixed is different from the first embodiment.

  Therefore, in the second embodiment, the same effect as in the first embodiment can be obtained, and the fastening flange 43 on the side to which the nut 45 is fixed is supported by the fixing tongue piece 46 and the movement is restricted. It is possible to perform a fastening operation simply by inserting the fastening bolt 44 into the fastening bolt insertion holes 42a, 43a from the side of the one fastening flange 42 with a tool such as an air screwdriver and screwing the nut 45 into the nut 45. An effect is obtained.

  Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and design changes and the like within the scope not departing from the gist of the present invention are included in the present invention.

  For example, in the embodiment, a non-expanded diameter portion 21a is formed in the second large diameter portion 21 of the outer pipe 2, and a notch portion 12 that engages with the non-expanded diameter portion 21a is formed in the pipe tip portion 1a of the inner pipe 1. However, the non-expanded diameter portion 21a may not be provided.

It is a top view of the connection state which shows the connection part structure of the pipe of Example 1. FIG. It is a right view of the connection state which shows the connection part structure of the pipe of Example 1. It is a longitudinal cross-sectional view in the AA line of FIG. It is a longitudinal cross-sectional view which shows the state before the connection which shows the connection part structure of the pipe of Example 1. FIG. It is a top view of the connection state which shows the connection part structure of the pipe of Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner pipe 1a Pipe front-end | tip part 11 Angle-shaped bead 11a Tapered surface 11b End side taper surface 11b Base side taper surface 12 Notch 2 Outer pipe 21 2nd large diameter part 21a Non-expanded diameter part 22 1st large diameter part 23 Flare 3 Gasket 4 C-type clamp 41 Body portion 41a Clamp bead 42 Fastening flange 42a Fastening bolt insertion hole 43 Fastening flange 43a Fastening bolt insertion hole 44 Fastening bolt 45 Nut 46 Fixing tongue 46a Bent portion

Claims (4)

An inner pipe in which a chevron-shaped bead bulging radially outward is formed in the vicinity of the end portion, and a flare is formed in the end portion so as to contact the end side taper surface of the chevron bead by expanding radially outward. A pipe connecting portion structure that is inserted into an outer pipe and the tapered surface and the flare are tightened with a C-shaped clamp having a mountain-shaped cross section to connect the inner pipe and the outer pipe,
The tip of the fixing tongue extended from one side of the C-shaped clamp toward the outer pipe is welded and fixed in advance to a position opposite to the tip of the outer pipe,
A pipe connecting portion structure, wherein a notch portion is formed at a tip opening edge portion of the inner pipe facing an inner surface of a portion of the outer pipe to which the fixing tongue piece is welded. An inner pipe in which a chevron-shaped bead bulging radially outward is formed in the vicinity of the end portion, and a flare is formed in the end portion so as to contact the end side taper surface of the chevron bead by expanding radially outward. A pipe connecting portion structure that is inserted into an outer pipe and the tapered surface and the flare are tightened with a C-shaped clamp having a mountain-shaped cross section to connect the inner pipe and the outer pipe,
A second large-diameter portion having a diameter larger than that of the outer pipe is formed in a circularly cut-out circular shape, leaving a non-expanded diameter portion in a portion of the inner pipe at a portion into which the tip portion of the pipe is inserted from the angled bead.
A first large-diameter portion having a diameter larger than that of the second large-diameter portion is formed on the base side of the flare side of the second large-diameter portion;
The tip of the fixing tongue extended from one side of the C-shaped clamp toward the outer pipe is welded and fixed in advance to the non-expanded portion of the second large diameter portion of the outer pipe,
A pipe having a notch that engages with the non-expanded-diameter portion formed at a tip opening edge of the inner pipe facing an inner surface of a portion of the outer pipe where the fixing tongue is welded. Connection structure.   The pipe connection part structure according to claim 1 or 2, wherein a bent part is formed in the middle of the fixing tongue in the C-shaped clamp. The connection part structure of the pipe according to any one of claims 1 to 3, wherein a fastening bolt insertion hole is formed in each of the fastening flanges formed in the cutout part of the C-type clamp, A nut is fixed to the outside of one of the fastening bolt insertion holes,
A pipe connecting portion structure, wherein the fixing tongue piece is provided in the vicinity of a fastening flange on a side to which a nut in the C-type clamp is fixed.

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