JP2015158157A - exhaust pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust pipe capable of facilitating manufacturing process and reducing manufacturing cost without degrading the performance of a catalyst container.SOLUTION: The present invention provides an exhaust pipe 1, 1A, 1B comprising: an outer pipe 2, 21, 55 that includes an inner pipe 7, 27, 53 in which exhaust gas discharged from a vehicle internal combustion engine flows, and an outer pipe 9, 29, 55 spaced apart from the inner pipe 7, 27, 53 and arranged to cover the inner pipe 7, 27, 53; and a converter 3 arranged downstream of the outer pipe 2, 21, 55, a protrusion 19, 37, 61 being provided on at least either the outer pipe 2, 21, 55 or the converter 3, the protrusion 19, 37, 61 abutting and slidable on the outer pipe 2, 21, 55 or the converter 3.

Description

  The present invention relates to an exhaust pipe connected to an internal combustion engine for automobiles.

  As shown in FIG. 4, conventionally, an exhaust pipe 100 connected to an internal combustion engine for an automobile is disposed on an inner side of the outer pipe 101 and an outer pipe 101 composed of a first outer pipe 107 and a second outer pipe 102. The inner pipe 105 and the catalytic converter 104 disposed on the downstream side of the inner pipe 105 are configured.

  The inner tube 105 and the outer tube 101 are fixed at one end to an automobile internal combustion engine (not shown), and the other end of the inner tube 105 is a free end as shown in FIG.

  Further, the second outer tube 102 is connected to the first outer tube 107 of the outer tube 101 by a welded portion 103. The inner pipe 105 arranged in the outer pipe 101 is arranged with a certain distance from the outer pipe 101, and the exhaust gas passes through the inner pipe 105. Therefore, the inner pipe 105 is the axis of the pipe by the heat of the exhaust gas. It can be expanded and contracted in the direction.

  The second outer tube 102 includes a distal end portion 117 and an enlarged diameter portion 115 that expands toward the distal end portion 117, and the distal end portion 117 and the inner peripheral surface 111 of the first outer tube 107 come into contact with each other. A distal end 113 of the first outer tube 107 and a distal end portion 117 of the second outer tube 102 are fixed by the welded portion 103.

  A catalyst container 104 formed in a honeycomb shape is accommodated in a second outer pipe 102 fixed downstream of the outer pipe 101, and exhaust gas sent from an internal combustion engine (not shown) is decomposed.

  However, in the exhaust pipe 100 shown in FIG. 4, since there is a gap between the inner pipe 105 and the first outer pipe 107, dust contained in the exhaust gas accumulates in this gap and solidifies, and solidified dust etc. Enters the honeycomb shape of the catalyst container 104 on the downstream side of the exhaust gas, and the exhaust gas cannot be completely decomposed in the catalyst container 104.

  In addition, it is conceivable that the gap between the inner tube 105 and the first outer tube 107 is closed by fixing the space between the inner tube 105 and the first outer tube 107. Since the inner tube 105 thermally expands through the passage, it is difficult to fix the inner tube 105 and the first outer tube 107.

  Therefore, in the exhaust pipe 100A described in Patent Document 1 (FIG. 5), the buffer material 202 is fixed by spot welding between the outer peripheral surface 209 of the inner pipe 205 and the inner peripheral surface 211 of the internal combustion side outer pipe 207. What has been proposed.

  In Patent Document 1, the shock absorbing material 202 disposed between the inner pipe 205 and the internal combustion side outer pipe 207 is made of a mesh material, thereby allowing thermal expansion of the inner pipe 205, and the inner pipe 205 is thermally expanded by exhaust gas. Even so, sliding between the inner pipe 205 and the internal combustion side outer pipe 207 is enabled by contraction of the buffer material 202.

  Further, in Patent Document 1, a flange portion 213 is provided on the internal combustion side outer pipe 207, and a flange portion 227 is provided at the tip of the converter side outer pipe 201, and the flange portion 213 of the internal combustion side outer pipe 207 and the converter side outer pipe are provided. A configuration in which the internal combustion side outer pipe 207 and the converter side outer pipe 201 are connected by fixing the flange portion 227 of 201 with a bolt or the like is described.

JP-A-6-336921

  However, in the configuration shown in Patent Document 1, since the buffer material 202 is used, welding or the like for fixing the buffer material 202 between the inner tube 205 and the internal combustion side outer tube 207 must be performed. However, there is a problem that the manufacturing cost of parts and the like becomes high.

  Therefore, an object of the present invention is to provide an exhaust pipe that can reduce the manufacturing cost while facilitating the manufacturing process without reducing the performance of the catalyst container.

  In order to solve the above-described problems, in the present invention, the outer pipes 2, 21, 55 having one end connected to the exhaust port of the internal combustion engine and the catalyst container 5 disposed therein, the exhaust port of the internal combustion engine, Exhaust pipes 1, 1A, 1B having inner pipes 7, 27, 53 disposed inside the outer pipes 2, 21, 55 between the upstream positions of the catalyst container 5, and the outer pipe 2 , 21 and 55 are provided at the upstream position of the catalyst container 5 with projections 19, 37 and 61 projecting toward the inner pipes 7, 27 and 53, and the projections 19, 37 and 61 are provided in the inner pipe. The inner pipes 7, 27, 53 are slidably supported by the protrusions 19, 37, 61 in contact with the outer peripheral surfaces 11, 31, 53 a of the 7, 27, 53. Further, the protrusions 19, 37, 61 are characterized in that they are created in the process of creating the outer tubes 2, 21, 55. Furthermore, the protrusions 19, 37, 61 are characterized by being created by spinning. In addition, the outer tube 55 also serves as an outer tube of the catalyst container 5, and the outer tube 55 and the outer tube of the catalyst container 5 are integrally formed.

  According to the present invention, the projecting portions 19, 37, 61 projecting toward the inner tubes 7, 27, 53 are provided at the upstream positions of the catalyst containers 5 of the outer tubes 2, 21, 55. 61 is in contact with the outer peripheral surfaces 11, 31, 53a of the inner pipes 7, 27, 53, and the inner pipes 7, 27, 53 are slidably supported by the projecting portions 19, 37, 61. Keeping the space between the inner tube 7, 27, 53 and the outer tube 9, 29, 55 without arranging a buffering material or the like between the inner tube 7, 27, 53 and the outer tube 9, 29, 55. Can do.

  Further, since the projecting portions 19, 37, 61 abut on the outer peripheral surfaces 11, 31, 53 a of the inner tubes 7, 27, 53, dust particles are placed between the inner tubes 7, 27, 53 and the outer tubes 9, 29, 55. Even if it accumulates, etc., it is possible to prevent dust and the like from entering the catalyst container 5 by the protrusions 19, 37, 61.

  Furthermore, since the protrusions 19, 37, 61 are slidable with the outer peripheral surfaces 11, 31, 53a of the inner pipes 7, 27, 53, the inner pipes 7, 27, 53 are hot exhaust gas from the internal combustion engine. Even if it is a case where it thermally expands by, the thermal expansion of the inner pipes 7, 27, 53 can be permitted.

It is an expanded sectional view of the exhaust pipe of the present invention. It is an expanded sectional view of an exhaust pipe which shows a 2nd embodiment. It is an expanded sectional view of an exhaust pipe which shows a 3rd embodiment. It is an expanded sectional view showing the conventional exhaust pipe. It is the schematic which shows the conventional exhaust pipe.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 1, the exhaust pipe 1 of the present embodiment includes an outer pipe 2 whose upstream side is fixed to the internal combustion engine, and an inner pipe 7 disposed inside the outer pipe 2.

  An outer pipe 2 fixed at one end to an internal combustion engine (not shown) includes a first outer pipe 9 and a second outer pipe 3, and exhaust gas flows through the inner pipe 7 as indicated by arrows in the figure. A first outer tube 9 is disposed so as to cover the tube 7.

  The first outer tube 9 is disposed at a constant distance from the inner tube 7, and the second outer tube 3 is fixed to the distal end 13 of the first outer tube 9 by the welded portion 4.

  The second outer pipe 3 includes a catalyst container 5 through which the exhaust gas that has passed through the outer pipe 2 passes. The second outer pipe 3 is continuous with the diameter-expanding section 15 and the diameter-expanding section 15. A provided tip portion 17 is formed.

  On the inner peripheral surface 17a of the distal end portion 17, a protruding portion 19 that abuts on the outer peripheral surface 11 of the inner tube 7 is formed so as to protrude over the entire periphery. The protruding portion 19 is in contact with the outer peripheral surface 11 of the inner tube 7 and is in contact with the outer peripheral surface 11 of the inner tube 7 so that the inner tube 7 can slide. About the formation method of the protrusion part 19, it can select suitably from various construction methods, for example, it can form by a spinning construction method, an extrusion construction method, and a drawing construction method.

  Further, the distal end portion 17 is fixed to the outer peripheral surface 17 b of the second outer tube 3 by welding the distal end 13 of the first outer tube 9 described above with the welded portion 4.

  Next, assembly of the exhaust pipe 1 of the present embodiment will be described.

  The distal end portion 17 of the second outer pipe 3 is inserted between the inner pipe 7 and one of the first outer pipes 9 fixed at one end to an internal combustion engine (not shown).

  Then, the distal end portion 17 of the second outer tube 3 is inserted to the desired insertion position while the distal end portion 17 of the second outer tube 3 is slidably contacted between the inner tube 7 and the first outer tube 9. 9 and the outer peripheral surface 17 b of the second outer tube 3 are fixed by the welded portion 4. Thereby, fixation of the outer tube 2 and the inner tube 7 is completed.

  According to the present embodiment, the projecting portion 19 abuts on the outer peripheral surface 11 of the inner tube 7 and the inner tube 7 is slidably supported by the projecting portion 19. The space between the inner tube 7 and the outer tube 9 can be maintained without disposing a cushioning material or the like between the inner tube 7 and the number of components, and the cost can be reduced.

  Further, since the protruding portion 19 formed on the inner peripheral surface 17 a of the second outer tube 3 abuts on the outer peripheral surface 11 of the inner tube 7, dust or the like has accumulated between the inner tube 7 and the first outer tube 9. Even so, the protrusions 19 can prevent dust and the like from entering the catalyst container 5.

  Furthermore, since the protrusion 19 is slidably in contact with the outer peripheral surface 11 of the inner tube 7, even if the inner tube 7 is thermally expanded by high-temperature exhaust gas from the internal combustion engine, the protrusion 19 Slides with respect to the outer peripheral surface 11 of the inner tube 7, so that the inner tube 7 can be allowed to move due to thermal expansion of the inner tube 7.

  In addition, the protrusion part 19 of this embodiment is not restricted to the shape shown in FIG. 1, What is necessary is just the shape which contact | abuts to the inner tube | pipe 7 of the outer tube | pipe 2, and can slide.

[Second Embodiment]
A second embodiment of the present invention will be described with reference to FIG. In addition, description is abbreviate | omitted about the structure similar to 1st Embodiment.

  In the exhaust pipe 1 </ b> A of the present embodiment, a protruding portion 37 is formed on the inner peripheral surface 35 of the first outer tube 29 of the outer tube 21, and the tip 33 of the first outer tube 29 is connected to the tip 41 of the second outer tube 23. It is fixed by the weld 22.

  Further, the protruding portion 37 formed on the inner peripheral surface 35 of the first outer tube 29 abuts against the inner tube 27 and contacts the outer peripheral surface 31 of the inner tube 27 so that the inner tube 27 can slide. It touches.

  Next, assembly of the exhaust pipe 1A of the present embodiment will be described.

  The distal end portion 41 of the second outer tube 23 is inserted so as to be in sliding contact with the inner peripheral surface 35 of the first outer tube 29 whose one end is fixed to an internal combustion engine (not shown).

  Then, the distal end portion 41 of the second outer tube 23 is inserted to a desired insertion position, and the distal end 33 of the first outer tube 29 and the distal end portion 41 of the second outer tube 23 are fixed by the welded portion 22. Thereby, fixation of the outer tube 21 and the second outer tube 23 is completed.

  According to this embodiment, the same effect as that of the first embodiment can be obtained.

  In addition, the protrusion part 37 of this embodiment is not limited to the shape shown in FIG. 2 as in the first embodiment, and may be any shape that can contact and slide on the inner tube 27.

  Further, the present embodiment is not limited to the above, and may be appropriately combined with the first embodiment.

[Third Embodiment]
A third embodiment of the present invention will be described with reference to FIG. In addition, description is abbreviate | omitted about the structure similar to 1st Embodiment and 2nd Embodiment.

  In the exhaust pipe 1B of the present embodiment, the first outer pipes 9 and 55 described in the first and second embodiments and the second outer pipes 3 and 23 are integrally formed.

  As shown in FIG. 3, the exhaust pipe 1 </ b> B of the present embodiment includes an inner pipe 53 and an outer pipe 55.

  An outer tube 55 fixed at one end to an internal combustion engine (not shown) has a diameter enlarged portion 57 formed at the other end, and accommodates the catalyst container 5 inside.

  Further, a protruding portion 61 is provided between the outer tube 55 and the enlarged diameter portion 57, and this protruding portion 61 is formed by recessing the inner peripheral surface 59 of the outer tube 55 toward the inner tube 53 side. ing.

  The protrusion 61 is in contact with the inner tube 53 and is in contact with the outer peripheral surface 53a of the inner tube 53 so that the inner tube 53 is slidable.

  Also in this embodiment, the same effect as the first and second embodiments described above can be obtained.

  In addition, according to this embodiment, since the first outer tubes 9 and 55 and the second outer tubes 3 and 23 are integrally formed, the first outer tubes 9 and 55 and the second outer tubes 3 and 23 are formed. And need not be fixed by welding. Therefore, since the outer tube 55 only needs to be recessed in advance by spinning or the like on the inner tube 53 side, the manufacturing process can be facilitated.

  Furthermore, the manufacturing process can be simplified by inserting the inner tube 53 into the outer tube 55 and fixing the outer tube 55 to an internal combustion engine (not shown).

  Moreover, since the protrusion part 61 can be formed in the same process as the formation process of the outer tube | pipe 55, in addition to being able to make manufacture easier, manufacturing cost can be reduced.

  Note that the present embodiment is not limited to the above-described embodiment, and may be appropriately combined with the first and second embodiments.

1, 1A, 1B Exhaust pipe 2, 21, 51 Exhaust manifold 3 Converter 7, 23, 53 Inner pipe 9, 29, 55 Outer pipe 19, 37, 61 Projection

Claims (4)

An outer pipe (2, 21, 55) having one end connected to an exhaust port of the internal combustion engine and having a catalyst container (5) disposed therein, an upstream position of the exhaust port of the internal combustion engine and the catalyst container (5) An exhaust pipe (1, 1A, 1B) provided with an inner pipe (7, 27, 53) disposed inside the outer pipe (2, 21, 55) between,
At the upstream position of the catalyst container (5) of the outer pipe (2, 21, 55), a projecting part (19, 37, 61) projecting to the inner pipe (7, 27, 53) side is provided,
The protrusions (19, 37, 61) abut on the outer peripheral surfaces (11, 31, 53a) of the inner pipe (7, 27, 53), and the inner pipes (7, 27, 53) are in contact with the protrusions ( 19, 37, 61) and an exhaust pipe (1, 1A, 1B) characterized by being slidably supported. The exhaust pipe (1, 1A, 1B) according to claim 1,
The projecting portion (19, 37, 61) is an exhaust pipe (1, 1A, 1B) produced in the production process of the outer pipe (2, 21, 55). The exhaust pipe (1, 1A, 1B) according to claim 2,
The exhaust pipe (1, 1A, 1B) is characterized in that the protrusion (19, 37, 61) is formed by spinning. The exhaust pipe (1B) according to any one of claims 1 to 3,
The outer pipe (55) also serves as an outer pipe of the catalyst container (5), and the outer pipe (55) and the outer pipe of the catalyst container (5) are integrally formed. The exhaust pipe (1B).

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