JP2000274237A - Parts for sheet metal pipe and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide parts for sheet metal pipes and manufacturing method, the number of part items of which is minimized and which can be assembled with ease. SOLUTION: A diffuser 1 comprises a first shell 2, second shell 3 and outlet flange 4 which are formed by pressing metal sheet. The first shell 2 has an S-shaped cross section and a first slit 5 at the center position of the S-shaped cross section, The second shall 3 has a nearly inverted S-shaped cross section and a second slit 12 at the center position of the nearly inverted S-shaped cross section. The first and second shells 2 and 3 are incorporated with each other with the first and second slits 5 and 12 meshed with each other, and the edges of both ends 6, 7, 13 and 14 and slits 5 and 12 are welded to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet metal pipe part used as, for example, an exhaust system part of an internal combustion engine and a method of manufacturing the same.

[0002]

2. Description of the Related Art For example, Japanese Unexamined Utility Model Publication No. 5-64418 discloses a bifurcated exhaust pipe made of sheet metal for connecting two exhaust passages to one exhaust pipe on the downstream side. This bifurcated exhaust pipe is formed by combining two sheet metal members in a so-called middle alignment manner and by welding the side edges of the two pieces together, and has two parallel pipes inside. It is configured. These pipes are independent so as to form a substantially circular shape at one end on the exhaust inlet side,
As they approach the other end, they approach each other as if they gather in one passage, and finally, at the other end, a pair of substantially semicircular conduits is formed in a substantially circular cross section. It has become so. In order to partition into such a substantially semicircular passage, the above-mentioned publication has a straightening plate made of a separate member in addition to the two sheet metal members. The current plate is sandwiched and welded between sheet metal members. That is, in this publication, 3
The two forked exhaust pipes are formed by the two sheet metal members.

[0003]

In the above-mentioned conventional construction, since the pipeline component having two parallel pipelines is constituted by three sheet metal members, the number of components is large, and the assembly thereof is difficult. The process becomes complicated.

[0004] The present invention minimizes the number of parts,
The object is to provide a sheet metal pipe part whose assembly is also easy and a method of manufacturing the same.

[0005]

According to a first aspect of the present invention, there is provided a sheet metal pipe part constituting two parallel pipes, a first member having a substantially S-shaped cross section, and the first member. And a second member having a substantially S-shaped cross-section in a direction opposite to that of the second member. The two members are engaged by engaging slits formed respectively corresponding to substantially the center of the S-shape of each member. It is characterized by being integrally joined.

[0006] Further, the invention according to claim 6 is characterized in that:
A method for manufacturing a sheet metal pipe part constituting a pipe of the present invention, wherein a first member is formed of sheet metal so as to form a substantially S-shaped cross section, and is substantially opposite to the first member. The second member is formed of sheet metal so as to form an S-shaped cross section,
In addition, slits each having a length of approximately の of the length of the conduit are formed at substantially the center of the S-shape of each member, and the two members are combined while engaging these slits. It is characterized by welding parts.

That is, the first member having a substantially S-shaped cross-sectional shape constitutes substantially half of one conduit and approximately half of the other conduit, and similarly, the second member comprises one of the conduits. It constitutes the other half of the channel and the other half of the other channel. Each member is provided with a slit having one end opened at the opposite end. Each slit has a width substantially equal to the plate thickness of each member (strictly, the plate thickness of the other member to be combined), and the two members are assembled so that the slits mesh with each other. Since the members are combined while sliding along the respective slits, the slits are basically linear, but are not strictly straight, but are combined with each other, such as gently curved arcs. Any shape is possible.

[0008] The two sheet metal members combined in this manner are integrated by welding the side edges. The slits are also welded so that fluid such as exhaust gas does not leak. It is easier to weld the slit portion from the outside, but when a gap generated in the combined portion is large, it is desirable to weld from the inside in addition to welding from the outside.

According to a second aspect of the present invention, the second member has a band-shaped flat portion substantially in the center of the S-shape, and the slit is formed in the flat portion. Have been.

If the slit is formed in the flat portion substantially at the center as described above, the two members are combined in a form orthogonal to each other at the slit portion, and a reliable connection can be made without generating an extra gap. It is possible.

[0011] The sheet metal pipe part is used, for example, as an exhaust system part of an internal combustion engine.

[0012] Claim 4 is a further embodiment of claim 3.
According to the invention, the exhaust system component has two pipes which are independent of each other in a substantially circular shape at one end, and gradually approach each other toward the other end to form a substantially circular shape. It is characterized in that it changes into a shape having two substantially semicircular conduits in the cross-sectional shape.

This is used, for example, in an exhaust manifold with a catalytic converter of an internal combustion engine, which is used at the outlet side of a pair of catalytic converters, and is connected downstream with a single exhaust pipe whose interior is partitioned into a pair of passages. .

According to the fifth aspect of the invention, at the other end, the central portion of the member having no slit at the end is extended in a tongue shape as a partition wall along the flow direction of the conduit. Is formed. The partition wall extends, for example, further into the exhaust pipe across a joint portion with the exhaust pipe on the downstream side, so that the two passages can be reliably separated.

[0015]

According to the present invention, a sheet metal pipe part having two parallel pipes suitable for an exhaust system or the like can be constituted by combining two sheet metal members. And the assembling process becomes very simple.

In particular, according to the second aspect of the present invention, two sheet metal members can be surely combined in an orthogonal shape with a slit having a minimum width, and the connection by the engagement of the slits is further strengthened. As well as ease of assembly.

According to the fifth aspect of the present invention, even when a partition extending through the joint portion is required, it can be constituted by only two sheet metal members without adding another member. It is possible to keep the pipeline separated.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 7 shows, as an example, an exhaust manifold 51 with a catalytic converter of an in-line four-cylinder internal combustion engine using the pipe line component according to the present invention. The exhaust manifold 51 is a first exhaust manifold that combines exhaust from the # 1 cylinder and the # 4 cylinder.
A manifold section 52, a second manifold section 53 for merging the exhaust of the # 2 cylinder and the # 3 cylinder, and a pair of substantially cylindrical cylinders having one ends respectively connected to the outlet sections 52a, 53a of the first and second manifold sections. Catalytic converters 54, 55
And the diffuser 1 which is a sheet metal pipe part of the present invention connected to the other ends of the pair of catalytic converters 54 and 55. The diffuser 1 constitutes two parallel pipes connected to each of the catalytic converters 54 and 55, and these two pipes gradually converge so as to form a substantially V-shape, and are not shown. One front tube is connected to the outlet side. The interior of the front tube (not shown) is also partitioned into two passages by an internal partition wall, thereby minimizing interference with the exhaust system.

FIG. 1 is a perspective view showing only the diffuser 1. The diffuser 1 includes a first shell 2 and a second shell 3 formed by press-forming a metal plate, and an outlet flange 4 provided on the outlet side and formed of a relatively thick metal plate. The main body portion of the diffuser 1 formed by combining the first shell 2 and the second shell 3 has two conduits 21 and 22 at an upstream end.
Has a substantially circular figure-shaped cross-sectional shape that is substantially independent of each other, and the two conduits 21 and 2 are directed toward the downstream end.
2 gradually approach and change so as to have a substantially circular cross-sectional shape as a whole. As shown in FIG. 6, the outlet flange 4 is a rhombus or an ellipse having a single circular opening 9 corresponding to the shape of the downstream end, and is connected to a spherical joint (not shown). The flange at the end of the front tube is swingably connected.

FIG. 2 is a perspective view showing the first shell 2 from two different directions, and FIG. 3 is a plan view showing the shape of the upstream end of the first shell 2. This first shell 2
It has a substantially S-shaped cross-section so as to form substantially half of one pipeline and approximately half of the other pipeline, and a first slit along the flow direction of the pipeline is provided at the center of the S-shape. 5 are formed. The first slit 5 has a length substantially half of the total length of the first and second shells 2 and 3, and as shown in FIG. 2, one end is opened at the upstream end. Is formed. On both side edges of the first shell 2, there are provided stepped portions 6 and 7 which are bent so as to expand one step outward. The steps 6 and 7 are located near the downstream end inserted into the opening 9 of the outlet flange 4.
Notched so as not to interfere with. A partition 8 is formed at the downstream end of the first shell 2 in a tongue shape from the center thereof. The partition 8 extends through the outlet flange 4 into the front tube downstream and is continuous with the partition in the front tube. As a result, the two exhaust passages are reliably partitioned up to the front tube. Since the front tube is connected by a spherical joint (not shown) so as to be able to swing in the direction along the surface of the partition 8, the front end 8 a of the partition 8 is connected to the front tube.
Is formed in an arc shape, and a corresponding distal end edge of the partition on the front tube side is concave in an arc shape. This allows the front tube to swing in a state where the two are abutted.

FIG. 4 is a perspective view showing the second shell 3 from two different directions, and FIG. 5 is a plan view showing the shape of the upstream end of the second shell 3. This second shell 3
Again, the cross section is substantially S-shaped so as to constitute substantially half of one pipe and substantially half of the other pipe. In particular, the cross section of the substantially S-shape which is opposite to the first shell 2 is formed. No. A band-shaped flat portion 11 is formed at the center of the S-shape, and a second slit 12 is formed at the center of the band-shaped flat portion 11 along the flow direction of the pipeline. As is apparent from FIG. 5, the band-shaped flat portion 11 has a surface along a straight line connecting both side edges. Further, the second slit 12 is provided with first and second shells 2 and 3.
As shown in FIG. 4, one end is opened at the end opposite to the first slit 5, that is, at the downstream end. Both side edges 13 and 14 of the second shell 3 remain arc-shaped in cross section.

The first shell 2 and the second shell 3 are:
The first and second slits 5 and 12 are integrally connected to each other by sliding while engaging with each other. That is, the second shell 3 is provided in the first slit 5.
The flat central part 11 of the first shell 2 fits into the second slit 12. Also, the second shell 3
Are fitted inside the step portions 6 and 7 of the side edges of the first shell 2. Then, in this combined state, the side edges 6, 7, 13, and 14 are welded to each other, and further, the central slits 5 and 12 are welded.
The welding of the slits 5 and 12 is usually performed from the outside of the diffuser 1 in view of workability.
When the gap remaining in each of the slits 5 and 12 is large,
It is desirable to also weld from inside. Further, the downstream end is inserted into the circular opening 9 of the outlet flange 4 and welded to the outlet flange 4 to complete the diffuser 1 shown in FIG.

FIGS. 8 to 11 are explanatory views showing changes in the cross-sectional shape of the diffuser 1 and showing the formation positions of the first and second slits 5 and 12 in each cross-section.
9 is a sectional view taken along line AA of FIG. 8, FIG. 10 is a sectional view taken along line BB of FIG. 8, and FIG.
It is sectional drawing along the line. As is apparent from these figures, the diffuser 1 has a configuration in which each of the conduits 21 and 22 is separated and independent in a substantially figure-eight shape on the upstream side, and has a substantially circular cross-sectional shape on the downstream end. A pair of substantially semicircular pipes 2
1 and 22 are configured. The above-mentioned partition wall 8 at the downstream end is configured in such a manner that a partition part that divides the semicircular conduits 21 and 22 shown in FIG. 11 is extended to the downstream side. Note that the two conduits 21 and 22 are basically symmetrical. 9 to 11, the slits 5 and 12 are formed along the intersection M of the diagonal lines L1 and L2 of the rectangle surrounding the cross-sectional shape.

In the diffuser 1 of the above embodiment,
Including the partition wall 8 extending to the downstream side, it can be constituted only by the pair of shells 2 and 3 and the outlet flange 4, so that the number of parts can be reduced and the assembling process becomes very simple. Further, by providing the strip-shaped flat portion 11 in the second shell 3, the two shells 2, 3 can be surely combined in an orthogonal shape, and the width of the slits 5, 12 does not need to be set too large. It is possible to engage with the slits 5 and 12 having the minimum width, so that the connection between the two can be made firmer and no extra welding is required.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a diffuser which is a pipe part according to the present invention.

FIG. 2 (A) and (B) show two different shells of the first shell.
The perspective view shown from a direction.

FIG. 3 is a plan view of an upstream end of the first shell.

FIG. 4 (A) and (B) show two different shells
The perspective view shown from a direction.

FIG. 5 is a plan view of an upstream end of the second shell.

FIG. 6 is a perspective view of an outlet flange.

FIG. 7 is a perspective view of the entire exhaust manifold with a catalytic converter in which the diffuser is used.

FIG. 8 is a front view of the diffuser for showing a sectional position.

FIG. 9 is a sectional view taken along the line AA of FIG. 8;

FIG. 10 is a sectional view taken along the line BB of FIG. 8;

FIG. 11 is a sectional view taken along the line CC of FIG. 8;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Diffuser 2 ... 1st shell 3 ... 2nd shell 4 ... Exit flange 5 ... 1st slit 8 ... Partition wall 12 ... 2nd slit

Claims (6)

[Claims] 1. A sheet metal pipe part constituting two parallel pipes, a first member having a substantially S-shaped cross-section, and a substantially S-shaped cross-section opposite to the first member. A second member comprising: a sheet metal member, wherein the two members are integrally connected by engaging slits formed respectively corresponding to the substantially central portion of the S-shape of each member. Pipeline parts. 2. The sheet metal according to claim 1, wherein the second member has a band-shaped flat portion at a substantially central portion of the S-shape, and the slit is formed in the flat portion. Pipeline parts. 3. The sheet metal pipe part according to claim 1, wherein the sheet metal pipe part is an exhaust system part of an internal combustion engine. 4. The exhaust system component has two pipes each having a substantially circular shape at one end, and the pipes gradually approach each other toward the other end to form a substantially circular shape. 4. The sheet metal pipe part according to claim 3, wherein the cross-sectional shape changes into a shape having two substantially semicircular pipes in the cross-sectional shape. 5. At the other end, a central portion of the member having no slit at the end is formed in a tongue shape as a partition wall along the flow direction of the pipeline. The sheet metal pipe part according to claim 4, characterized in that: 6. A method for manufacturing a sheet metal pipe part constituting two parallel pipes, wherein a first member is formed of a sheet metal so as to have a substantially S-shaped cross section, and the first member is formed of a sheet metal. The second member is formed of a sheet metal so as to have a substantially S-shaped cross-section opposite to that of the member. A method of manufacturing a sheet metal pipe part, comprising forming slits of two lengths, combining these members while engaging these slits, and welding side edges and slit portions.