JP2000074268A - Dual tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low cost, mass-producible dual tube with the minimum number of parts, having no regulation of the bending direction. SOLUTION: In a dual tube having two passages formed in one cylindrical tube, a first semicylindrical wall 1, an S-shaped partition wall 2 and a second semicylindrical wall 3 integrally formed from one plate material are formed into an integrated pipe structure, a first passage 4 is formed by circularly extending the first semicylindrical wall 1 from one end 2a of the S-shaped partition wall 2 to one end 2a, a second passage 5 is formed by circularly extending the second semicylindrical wall 3 from the other end 2b to one end of the S-shaped partition wall, the terminal part 1a of the first semicylindrical wall 1 and the other end 2b of the S-shaped partition wall 2 are welded to each other at a first welding part 6, and the terminal part 3a of the second semicylindrical wall 3 and one end 2a of the S-shaped partition wall 2 are welded to each other at a second welding part 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a dual tube applied as an exhaust tube of an automobile.

[0002]

2. Description of the Related Art Conventionally, as a dual tube, for example, those described in Japanese Utility Model Application Laid-Open No. 63-196425 and Japanese Utility Model Application Laid-Open No. 60-37686 are known.

In the former publication, as shown in FIG. 3, there is provided a dual tube in which an I-shaped partition is provided at a diameter position of a cylindrical tube and two flow paths having a semicircular cross section are formed by the I-shaped partition. Has been described.

In the latter publication, as shown in FIG. 4, there is described a dual tube in which an S-shaped partition is provided at a diameter position of a cylindrical tube and two flow paths are formed by the S-shaped partition. .

[0005]

However, in the case of the dual tube shown in FIG. 3, when the tube is bent in accordance with the floor shape of the vehicle when applied as an exhaust tube of the vehicle, FIG. As shown in b), I
Although bending can be performed with the direction perpendicular to the U-shaped partition as the bending direction, as shown in FIG. There is a problem that the partition walls serve as reinforcing ribs and are difficult to bend, and the bending direction is restricted. That is, although it is possible to perform two-dimensional bending in a direction perpendicular to the I-shaped partition wall,
It is difficult to perform a three-dimensional bending process in which the direction of the U-shaped partition wall is added to the bending direction. Even if the three-dimensional bending process is performed, the bending radius varies depending on the position of the I-shaped partition wall serving as a rib, and the accuracy is high. Cannot be bent.

In the dual tube shown in FIG.
At the time of manufacture, as shown in FIG.
Since a S-shaped partition is prepared, an S-shaped partition is inserted into a cylindrical tube, and the S-shaped partition is manufactured by requesting by spot welding, laser welding, or the like at a position where the S-shaped partition contacts.
There is a problem that two parts are required as the number of parts, and that the production becomes a single item, and mass production cannot be performed by applying a continuous pipe forming machine for continuously forming a pipe from a coil material. That is, the product cost as a dual tube increases.

An object of the present invention is to provide a low-cost dual tube which can be mass-produced with a minimum number of parts and has no restriction on the bending direction.

[0008]

[Means for Solving the Problems] [Solution 1] Solution 1 of the above-mentioned problem (Claim 1) is a dual tube in which two flow paths are formed in a single cylindrical tube, and a single plate material is provided. The first semi-cylindrical wall, the S-shaped partition wall, and the second semi-cylindrical wall are integrally formed from an integral pipe structure, and the first semi-cylindrical wall is formed in an arc shape from one end to the other end of the S-shaped partition. To form a first flow path, and extend the second semi-cylindrical wall in an arc shape from the other end of the S-shaped partition wall toward one end to form a second flow path. The end of the cylindrical wall and the other end of the S-shaped partition were welded by a first weld, and the end of the second semi-cylindrical wall and one end of the S-shaped partition were welded by a second weld. It is characterized by the following. (Solution 2) The solution 2 of the above-mentioned problem (Claim 2) is:
The dual tube according to claim 1, wherein the dual tube is connected to an exhaust manifold of an automobile, and is applied as an upstream exhaust tube of an automobile exhaust system in which a collection portion of each exhaust port is brought to the rear side of the vehicle.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) Embodiment 1 is a dual tube corresponding to the first and second aspects of the present invention. [Configuration of Dual Tube] FIG. 1 is a tube end view showing a dual tube according to the first embodiment, where A is a dual tube, 1 is a first semi-cylindrical wall, 1a is an end portion of the first semi-cylindrical wall 1, 2 Is an S-shaped partition, 2a is one end of the S-shaped partition 2, 2b is the other end of the S-shaped partition 2, 3 is a second semi-cylindrical wall, 3a is an end of the second semi-cylindrical wall 3, 4 Are the first flow path, 5
Denotes a second flow path, 6 denotes a first welded part, and 7 denotes a second welded part.

As shown in FIG. 1, a dual tube A according to a first embodiment in which two flow paths are formed in one cylindrical tube has a first semi-cylindrical wall 1 integrally formed from a single plate material. And an S-shaped partition wall 2 and a second semi-cylindrical wall 3 to form an integral pipe structure.

The first flow path 4 is formed by extending the first semi-cylindrical wall 1 in an arc from one end 2a of the S-shaped partition 2 toward the other end 2b.

The second flow path 5 is formed by extending the second semi-cylindrical wall 3 in an arc shape from the other end 2b of the S-shaped partition wall 2 to one end 2a.

The first welded portion 6 is a portion where the terminal portion 1a of the first semi-cylindrical wall 1 is welded to the other end 2b of the S-shaped partition wall 2, and the second welded portion 7 is a second welded portion 7. This is a portion where the terminal end 3a of the semi-cylindrical wall 3 and one end 2a of the S-shaped partition 2 are welded. [Application to Exhaust System] As a method of improving the output of an automobile engine, there is a method in which a collective portion of each exhaust port is brought to the rear of the vehicle as much as possible. However, in a car having a narrow space around the engine, it is difficult to arrange a plurality of tubes in an engine room or under the floor. Therefore, a dual tube in which one tube is divided into two tubes has been used for an exhaust system.

As shown in FIG. 2, the dual tube A according to the first embodiment is connected to an exhaust manifold 8 of an automobile, and an exhaust port upstream of an automobile exhaust system in which a collection of exhaust ports is brought to the rear of the vehicle. Applied as a tube.

Therefore, the dual tube A having no restriction on the bending direction is provided with flanges 9 and 10 at both ends, and is used as an upstream exhaust tube of an automobile exhaust system connected to the exhaust manifold 8, so that the periphery of the engine can be prevented. The output of the engine can be improved even in an automobile having a narrow space and requiring three-dimensional bending in accordance with the floor shape of the vehicle. [Regarding Tube Production and Bending Action] In producing the dual tube A, a continuous pipe forming machine or the like for continuously forming a pipe from a coil material is applied, and the first semi-cylindrical wall 1 is formed using a bending roll from the coil material. The S-shaped partition wall 2 and the second semi-cylindrical wall 3 are formed while gradually increasing the amount of bending, and finally narrowed down into a cylindrical tube to adjust the shape, and welded by two welding machines to a predetermined length. It is manufactured by cutting. In other words, the number of components is one with only one plate material, and mass production is possible by continuous molding from the coil material, so that the product cost of the dual tube A can be reduced.

Next, a bending process is performed to form a tube shape designed to be compatible with the vehicle to be applied.
Since the structure is divided into two flow paths 4 and 5 by the S-shaped partition 2, the S-shaped partition 2 does not become a reinforcing rib unlike the I-shaped partition, and can be bent in any direction. The direction is not regulated. That is, it is possible not only to perform a simple two-dimensional bending process but also to perform a high-precision bending process in which a bending radius does not vary even when a complicated three-dimensional bending process is performed.

In the case where laser welding is used for the first welded portion 6 and the second welded portion 7, compared to welding using a molten material in which a weld bead is formed, the weld bead has no bending effect, so that it is easy to bend. Become. (Other Embodiments) In the first embodiment, an example of application as an exhaust tube on the upstream side of an automobile exhaust system has been described. However, a dual tube is also used in a portion other than the exhaust system where a complicated bent shape is required. Can be applied.

[0018]

According to the first aspect of the present invention, in a dual tube in which two flow paths are formed in one cylindrical tube, the first tube integrally formed from one plate material.
The first passage is formed by extending the first semi-cylindrical wall in an arc shape from one end of the S-shaped partition toward the other end of the S-shaped partition. Is formed, and a second flow path is formed by extending the second semi-cylindrical wall in an arc shape from the other end of the S-shaped partition wall toward the one end, thereby forming the second semi-cylindrical wall in an S-shape with the terminal end of the first semi-cylindrical wall. The other end of the partition is welded by the first weld, and the end of the second semi-cylindrical wall and one end of the S-shaped partition are welded by the second weld, so mass production can be performed with a minimum number of parts. Moreover, it is possible to provide a low-cost dual tube having no restriction on the bending direction.

According to the second aspect of the present invention, a first aspect is provided.
In the dual tube described above, the exhaust tube is connected to the exhaust manifold of the vehicle, and the collective portion of each exhaust port is applied as an upstream exhaust tube of an automobile exhaust system that is brought to the rear side of the vehicle. Even in an automobile where the space around the engine is narrow and it is necessary to bend deeply in accordance with the floor shape of the vehicle, the output of the engine can be improved, and the size of the catalytic converter provided on the downstream side can be reduced. be able to.

[Brief description of the drawings]

FIG. 1 is a tube end view showing a dual tube according to a first embodiment.

FIG. 2 is a diagram showing an example in which the dual tube of the first embodiment is applied as an upstream exhaust tube of an automobile exhaust system.

FIG. 3 is a perspective view showing a dual tube of Conventional Example 1.

FIG. 4 is an exploded perspective view and a tube end view showing a dual tube of Conventional Example 2.

[Explanation of symbols]

 A Dual tube 1 First semi-cylindrical wall 1a End of first semi-cylindrical wall 1 2 S-shaped partition 2a One end of S-shaped partition 2 2b Other end of S-shaped partition 2 3 Second semi-cylindrical wall 3a End of second semi-cylindrical wall 3 4 First flow path 5 2nd flow path 6 First weld 7 Second weld 8 Exhaust manifold 9,10 Flange

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G004 AA01 DA01 DA13 FA04 GA05 GA06 3H111 AA01 BA01 CA23 CB14 CB21 DA26 DB11 DB20 EA09

Claims (2)

[Claims] A dual tube in which two flow paths are formed in one cylindrical tube, wherein a first semi-cylindrical wall (1) integrally formed from one plate material.
And an S-shaped partition wall (2) and a second semi-cylindrical wall (3) to form an integral pipe structure. The first half of the S-shaped partition wall (2) is moved from one end (2a) to the other end (2b). Cylindrical wall (1) The terminal end (1a) of the first semi-cylindrical wall (1) and the other end (2b) of the S-shaped partition (2) are welded by a first welded portion (6), 2
The end (3a) of the semi-cylindrical wall (3) and one end of the S-shaped partition (2) (2
a) is welded by a second welded portion (7). 2. The dual tube according to claim 1, wherein the dual tube is connected to an exhaust manifold (8) of an automobile, and is applied as an upstream exhaust tube of an automobile exhaust system in which a group of exhaust ports is brought to the rear side of the vehicle. A dual tube characterized by the above.