JP6678550B2 - Exhaust system parts - Google Patents

Description

The present invention is an exhaust equipment member having an KanTsugi hand for connecting the tubes belonging to the exhaust system in an airtight, particularly about the outlet flange integral exhaust system part products.

  2. Description of the Related Art Lean-burn engines have been used to meet the requirements for emission regulations or low fuel consumption of vehicles. Accordingly, the exhaust manifold as an exhaust system component and its peripheral members have been required to be reduced in weight. Since the exhaust gas temperature becomes high in the lean burn system, an exhaust manifold having a simple and low distortion shape capable of exhibiting sufficient strength at a high temperature is suitable.

  Generally, a plurality of members for hermetically connecting the exhaust manifold and the exhaust pipe, for example, an outlet pipe member of the exhaust manifold, a flange member for fastening between the exhaust manifold and the exhaust pipe and holding a seal member A plurality of brackets for fixing the flange member to the cover (heat insulator) are fixed one by one by welding.

  Patent Literature 1 discloses a connection structure between an exhaust manifold and an exhaust pipe, which is assembled through multiple weldings as described above. In the connection structure of Patent Literature 1, an outlet pipe member is welded to an outer peripheral surface of a collecting pipe of an exhaust manifold, and a flange member is welded to an outer peripheral surface of the outlet pipe member. A seal portion for hermetically sealing the space between the outlet pipe member and the exhaust pipe is disposed near the welding portion between the collecting pipe and the outlet pipe member on the small diameter side of the flange member.

  Patent Literature 2 discloses that, in an exhaust system, a flange-shaped bulging portion that protrudes in a radial direction is integrally formed at a downstream end portion of a first pipe body, and a downstream side surface of the bulging portion is connected to the first pipe body and the first pipe body. There is disclosed a connection structure in which two pipes are used as a sealing surface for airtight connection.

JP-A-2002-276358 JP-A-2002-276870

  The following analysis is provided by the present invention. According to the connection structure of Patent Literature 1, there are a problem that the manufacturing cost is increased due to a large number of welding locations, and a problem that the sealing surface is distorted due to welding heat, which affects the airtightness of the connection structure.

  According to the connection structure of Patent Literature 2, since the bulging portion protrudes in the radial direction, there is a problem that the case accommodating the bulging portion is enlarged. In addition, since the bulging portion comes into direct contact with the high-temperature exhaust gas, the amount of thermal expansion of the bulging portion increases, thereby deforming the sealing surface. May affect the airtightness of the airbag.

  Therefore, a pipe joint for hermetically connecting exhaust system components with a compact shape that can reduce the influence of heat generated during assembly or use, and an exhaust system component including the same are desired.

The present invention provides, in a first aspect, a fitting comprising the following elements:
A tube configured to have a distal end projecting toward the second tube;
A tubular folded portion that is turned back at least once in the axial direction of the tube portion and has one end connected to the base end of the tube portion; and a radially outward portion connected to the other end of the folded portion. And a sealing portion for hermetically sealing the space between the first tube and the second tube is formed on a small diameter side thereof, and a portion between the first tube and the second tube is formed on a large diameter side thereof. A flange part that forms a fastening part to be fastened.
A pipe joint according to the present disclosure can air-tightly connect a first pipe (a first pipe member or a first pipe section) and a second pipe (a second pipe member or a second pipe section) belonging to an exhaust system. . The first tube and the second tube may be a single part or a part of the part. A plurality of first tubes and second tubes may be provided, respectively.

The present invention provides, in a second aspect, an exhaust system component to which a pipe joint according to the first aspect is connected.
As a modification of the second viewpoint, a first pipe belonging to an exhaust system, a second pipe belonging to the exhaust system, and an airtight connection between the first pipe and the second pipe and the first pipe A pipe joint having a seal surface for hermetically sealing the space between the second tube and the second tube, a flange member fixed to an outer peripheral surface of the second tube, and interposed between the seal surface and the flange member; An annular gasket, wherein the pipe joint is configured such that a distal end portion is configured to protrude toward the second pipe side, and at least one turn in an axial direction of the pipe portion, and at one end thereof, A cylindrical folded portion connected to the base end of the tube portion, and a seal portion connected to the other end of the folded portion and extending radially outward and having the sealing surface on the small diameter side are configured. And a fastening portion for fastening between the first pipe and the second pipe is formed on the large diameter side thereof. And the pipe portion, the folded portion, and the flange portion are integrally formed with the pipe joint, and the annular gasket is an exhaust gas that comes into contact with the sealing surface, the flange member, and the pipe portion. Provide system parts.

The present invention, in a third aspect, provides a method of manufacturing a pipe fitting that includes the following elements:
(A) drawing the blank in the forward direction to form a bottomed tube shape on the small diameter side of the blank, and forming a flange portion on the large diameter side of the blank;
(B) drawing the bottomed tube shape in the opposite direction to form a cylindrical folded shape extending in the axial direction between the bottomed tube shape and the flange portion;
(C) removing the bottom of the bottomed tube shape to form a bottomless tube shape; and (d) burring the bottomless tube shape and the folded shape to form an axially extending tube portion and tube. A pipe joint having at least a folded portion and at least the flange portion extending in the radial direction is obtained.

  In a fourth aspect, the present invention provides a method of manufacturing a pipe joint according to a third aspect and a method of manufacturing an exhaust system component including welding the obtained pipe joint to the exhaust system component.

  One aspect of a pipe joint according to the present disclosure has a compact shape capable of reducing the influence of heat generated during assembly or use, and hermetically connects a plurality of exhaust system components.

It is an outline view of an exhaust manifold provided with a pipe fitting concerning one example. It is a component diagram of the pipe joint shown in FIG. FIG. 3 is a partial view for explaining an example of a connection configuration of a pipe joint shown in FIG. 2 and a cover that covers a part of an exhaust manifold. FIG. 2 is a schematic axial partial cross-sectional view illustrating a connection configuration between a pipe joint and an exhaust manifold shown in FIG. 1. FIG. 2 is a schematic partial axial sectional view illustrating a connection configuration between an exhaust manifold and an exhaust pipe via a pipe joint illustrated in FIG. 1. It is a flowchart explaining an example of the manufacturing method of the pipe joint concerning one example.

  Preferred embodiments of the pipe joint and the like according to the present disclosure will be exemplified below. The embodiments, embodiments, and examples described below are examples of aspects based on the present disclosure, and aspects based on the present disclosure are not limited thereto.

(Form 1)
(1) According to the present disclosure, a pipe joint for hermetically connecting at least a first pipe and a second pipe belonging to an exhaust system, heat is applied by welding during assembly and high-temperature exhaust gas passes during use. A cylindrical folded portion extending in the axial direction is provided between the exhaust system component and the seal portion.
Examples of the exhaust system parts include an exhaust manifold with a catalytic converter, an exhaust manifold without a catalytic converter, a catalytic converter, and an exhaust pipe, and a pipe joint is applied to an upstream portion, an intermediate portion, and a downstream portion of these components, respectively. be able to. If a fitting is used for the connection between the exhaust manifold and the exhaust pipe, the first pipe can be, for example, a shell, an outer pipe or an inner pipe of the outlet pipe (outlet pipe section) of the exhaust manifold, and the second pipe. The pipe can be an exhaust pipe.
(2) Since the folded portion is interposed in this manner, the amount of heat transmitted from the exhaust system component to the seal portion, particularly the seal surface, is reduced, and the seal portion is prevented from being distorted due to the heat, and the exhaust system component is connected. Good airtightness in the structure is maintained.
(3) In the pipe joint, the amount of heat transmitted to the folded portion itself is also reduced by disposing the pipe portion and the seal portion on the upstream side in the heat flow direction of the folded portion.
(4) The cylindrical folded portion extending in the axial direction can be formed by drawing. Further, a pipe joint in which the folded portion and other elements related to the connection of the exhaust system components are integrated can be manufactured by drawing using a general-purpose press machine.
(5) By the effects of (4), it is possible to reduce the welding location, the number of parts, the total weight, and the manufacturing cost related to the connection structure of the exhaust system components.
(6) Due to the reduction in the number of welding points, distortion of the seal portion is prevented, and the durability of the seal portion is improved.
(7) When the folded portion is integrally formed with the flange portion, the connection structure between the two can be simplified.
(8) When the folded portion and the tube portion are integrally formed, the connection structure between the both can be simplified.
(9) When the bracket for fixing the flange portion and the exhaust system component to the cover (heat insulator) is integrally formed, the connection structure between the two can be simplified.
(10) Since the folded portion extending in the axial direction can extend the dead space in the axial direction, an increase in dimension due to the provision of the folded portion can be avoided.

(Mode 2) At least one bracket attached to a cover that covers at least a part of the pipe portion, the folded portion, the flange portion, and at least a part of the exhaust system is integrally formed with the pipe joint. According to this aspect, compared with a conventional pipe joint in which various parts are fixed to the pipe joint by welding, welding locations and the number of times of welding are reduced, and as a result, distortion of the seal portion is reduced.

(Mode 3) The inner tube portion is configured to extend in the axial direction from the base end portion of the tube portion toward the first tube side, and is folded back in the axial direction from the inner tube portion. An outer cylindrical portion configured to extend toward the second pipe side. With such a double-cylinder structure, the rigidity and the heat insulation of the pipe joint and the connection structure of the exhaust system can be increased without increasing the size.

(Mode 4) The inner cylindrical portion and the outer cylindrical portion are configured to be in contact or to be in close contact with each other. According to this aspect, since the rigidity of the pipe joint is increased by the folded portion, the work when fixing the pipe joint to the exhaust system component becomes easy.

(Mode 5) A first pipe is welded to an inner peripheral edge of the folded portion. Thereby, welding quality is improved and airtightness can be easily ensured.

(Mode 6) The exhaust system component includes the first pipe as an outlet member of the exhaust system component, and a pipe joint is connected to the outlet member. For example, after connecting a pipe joint to one or more components selected from one of an exhaust system component, for example, an exhaust manifold component, a first exhaust pipe, or a catalytic converter, by welding or the like, and then connecting the other to the other via the pipe joint. The exhaust system components can be connected to one or more selected from a second pipe, for example, a component of an exhaust manifold, a second exhaust pipe, or a catalytic converter.

(Mode 7) The pipe joint is supplied through a process including forward drawing and reverse drawing in a state in which at least the pipe portion, the tubular folded portion, and the flange portion, and more preferably, at least one bracket are integrally formed. .

(Mode 8) An exhaust system part with a pipe joint can be obtained by welding a pipe joint manufactured according to mode 7 to an exhaust system component (for example, an outlet member thereof).

  Hereinafter, embodiments and the like will be exemplified as examples with reference to the drawings.

  With reference to FIG. 1, a pipe joint 1 is fixed to an outlet member 61 of an exhaust manifold 60 with a catalytic converter as an exhaust system component by, for example, welding.

Referring to FIG. 2, a pipe joint 1 is integrated with a pipe part 2, a cylindrical folded part 3, a flange part 4, and a plurality of brackets 5 shown in FIGS. 4 and 5. Through the pipe section 2, the exhaust manifold 60 is airtightly connected to an exhaust pipe 70 as shown in FIG. As shown in FIG. 5, the flange portion 4 has a seal portion 4a for sealing between the exhaust manifold 60 and the exhaust pipe 70, and a fastening portion 4b for mechanically fastening the exhaust manifold 60 and the exhaust pipe 70. Is provided. The plurality of brackets 5 are fastened to a cover (heat insulator) 62 (see FIG. 3) that covers a part of the exhaust manifold 60.
In the present embodiment, an example will be described in which the pipe joint 1 connects the outlet member 61 of the exhaust manifold 60 with the catalytic converter as the first pipe and the exhaust pipe 70 as the second pipe. Also, the present invention can be applied to a connection point relating to an exhaust manifold without a catalytic converter or a catalytic converter not attached to the exhaust manifold, or another connection point in an exhaust system.

With reference to FIGS. 4 and 5, the fitting 1 has the following elements:
A pipe 2 whose tip projects toward the exhaust pipe 70;
A cylindrical folded portion 3 which is bent at least once in the axial direction of the tube portion 2 and has one end connected to the base end portion of the tube portion 2; and a diameter connected to the other end of the folded portion 3. A sealing portion 4a is formed on the small diameter side to hermetically seal the space between the outlet member 61 of the exhaust manifold 60 and the exhaust pipe 70, and the outlet member 61 and the exhaust A flange portion 4 in which a fastening portion 4b for fastening between the pipes 70 is formed; 5 omitted).

  The pipe portion 2, the tubular folded portion 3, the flange portion 4, and the plurality of brackets 5 are connected and formed continuously, and can be integrally formed on one blank by, for example, a method described later.

  The cylindrical folded portion 3 is configured to extend in the axial direction from the base end of the pipe portion 2 toward the exhaust manifold 60, and the exhaust pipe is folded back in the axial direction from the inner cylindrical portion 31. An outer cylinder portion 32 is provided so as to extend toward the 70 side. In the folded portion 3, the outer peripheral surface of the inner cylindrical portion 31 and the inner peripheral surface of the outer cylindrical portion 32 abut, or radially oppose each other so as to be able to abut with close or slight clearance. By such contact or proximity, the rigidity of the pipe joint 1 is improved, and the pipe joint 1 is downsized in the radial direction. The outlet member 61 of the exhaust manifold 60 is welded to the inner peripheral edge 3c of the folded portion 3. The inner peripheral side edge portion 3c has a shape that makes it easy to abut, fix, and weld the pipe joint 1 to the outlet member 61.

  In the seal portion 4 a, the top surface of the protrusion protruding toward the exhaust pipe 70 is used as the seal surface 41. An annular gasket 42 is in contact with the sealing surface 41. A flange member 71 is fixed to the outer peripheral surface of the exhaust pipe 70 by, for example, welding. An annular gasket 42 is interposed between the sealing surface 41 and the flange member 71.

  A hole 43 is formed in the flange portion 4, and a hole 72 is formed in the flange member 71. A nut 44 (see FIG. 4) is provided on one side of the hole 43 in the flange portion 4. The bolt 73 (see FIG. 4) resists the elastic force of a spring (not shown) (not shown) that is compression-inserted between the back of the head of the bolt 73 and the back of the flange member 71. , 43 and screwed together with the nut 44, the exhaust manifold 60 and the exhaust pipe 70 are fastened, and the annular gasket 42 is pressed toward the sealing surface 41 to form the outlet member 61 of the exhaust manifold 60. And the exhaust pipe 70 is kept airtight.

  When the pipe joint 1 is entirely welded to the outlet member 61 of the exhaust manifold 60 at the inner peripheral edge 3c, a large amount of heat is applied to the pipe joint 1 and the heat is transferred to the seal portion 4a. However, the amount of heat transmitted to the seal portion 4a is reduced due to the heat radiation from the folded portion 3 formed between the welding portion and the seal portion 4a, and the distortion of the seal surface 41 is reduced. The same effect is exhibited during use, that is, when high-temperature exhaust gas passes through the outlet member 61. The folded portion 3 extends in the axial direction of the exhaust manifold 60 so as to use a dead space in the cover 62 (see FIG. 3). Furthermore, since the folded portion 3 extends in the axial direction, it can be formed by uniaxial molding using a general-purpose press machine.

  An example of a method for manufacturing the above-described pipe joint 1 will be described with reference to FIG. This manufacturing method is performed through the following processes (a) to (d) using a general-purpose press 80 having a blank holder 81, a lower die 82, and a punch 83.

(A) The blank BL is drawn in the forward direction to form a tube with a bottom on the small diameter side of the blank BL, and a flange portion is formed on the large diameter side of the blank BL. For the blank BL, a material having moldability capable of forming a folded portion and heat resistance to high-temperature exhaust gas is suitable. For example, a steel plate, a stainless steel plate, or the like can be used as the blank BL.

(B) The bottomed tube shape is drawn in the opposite direction to form a cylindrical folded shape extending in the axial direction between the bottomed tube shape and the flange portion.

(C) A bottomless tube shape is formed by extracting the bottom of the bottomed tube shape using a method such as laser cutting or press punching.

(D) The bottomless tube shape and the folded shape are burred to be erected, and the tube has at least a tube portion and a tubular folded portion extending in the axial direction, and a flange portion further extending in the radial direction. The joint 1 is obtained.

  The above manufacturing method can be efficiently performed using a general-purpose press, but the manufacturing method of the pipe joint is not limited to this, and can be performed using a dedicated machine. Alternatively, it can be performed using other techniques. In addition, depending on the desired shape of the pipe joint 1, the shapes and dimensions of the blank holder 81, the lower die 82, and the punch 83, and their relative relationships are adjusted, preliminary processing is performed, or each process is performed a plurality of times. By doing so, cracking during drawing can be prevented.

  By fixing the obtained pipe joint 1 to the outlet member 61 by welding or the like as shown in FIG. 5, an exhaust manifold 60 with a pipe joint is obtained as shown in FIG. Further, as shown in FIG. 5, by connecting the exhaust manifold 60 with the pipe joint to the exhaust pipe 70 (flange member 71) via the pipe joint 1, a connection structure between the exhaust manifold 60 and the exhaust pipe 70 is obtained. Can be

  The disclosure of the above patent documents is incorporated herein by reference. Modifications and adjustments of the embodiments or examples are possible within the framework of the entire disclosure (including the claims) of the present invention and based on the basic technical concept thereof. Various combinations or selections of various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) within the scope of the claims of the present invention. Is possible. That is, the present invention naturally includes various variations and modifications that can be made by those skilled in the art according to the entire disclosure including the claims and the technical idea. In particular, with respect to the numerical ranges described in this document, any numerical values or small ranges included in the ranges should be interpreted as being specifically described even if not otherwise specified.

  The pipe joint according to the present disclosure is suitably used, for example, in a place where a high temperature is generated during assembly or exposed to a high temperature during use, and is not limited to an exhaust system of an internal combustion engine, for example, an exhaust system of a vehicle. It is preferably applied.

DESCRIPTION OF SYMBOLS 1 Pipe joint, pipe joint structure 2 Pipe part 3 Cylindrical folded part 3c Inner peripheral edge part 31 Inner cylinder part 32 Outer cylinder part 4 Flange part 4a Seal part 4b Fastening part 41 Seal surface, annular seal 42 Annular gasket 43 hole 44 Nut, fixing nut 5 Bracket, stay 60 Exhaust manifold (with catalytic converter) (exhaust system parts)
61 Outlet member of exhaust manifold (first pipe)
62 cover (heat insulator)
70 Exhaust pipe (second pipe)
71 Flange member 72 Hole 73 Bolt 80 Press machine 81 Blank holder 82 Lower die 83 Punch BL Blank

Claims (6)

A first pipe belonging to an exhaust system;
A second pipe belonging to the exhaust system,
A pipe joint having a sealing surface for sealing between said second tube and said first tube in an airtight manner with connecting airtightly between the first pipe and the second pipe,
A flange member fixed to the outer peripheral surface of the second pipe;
An annular gasket interposed between the sealing surface and the flange member,
With
The pipe fitting,
A tube configured to have a distal end protruding toward the second tube;
A tubular folded portion that is turned back at least one time in the axial direction of the tube portion and is connected at one end to the base end of the tube portion,
A seal portion connected to the other end portion of the folded portion and extending radially outward has the seal surface on the small diameter side, and the first tube and the second tube on the large diameter side. A flange portion that forms a fastening portion for fastening between the;
Have a,
The pipe portion, the folded portion and the flange portion are integrally formed with the pipe joint,
The annular gasket is in contact with the sealing surface, the flange member, and the pipe portion,
An exhaust system component characterized by the above. 2. The pipe joint according to claim 1, wherein at least one bracket attached to a cover covering at least a part of the pipe portion, the folded portion, the flange portion, and the exhaust system is integrally formed with the pipe joint. 3. Exhaust system parts . An inner cylinder configured to extend in an axial direction from the base end of the pipe toward the first pipe, and an inner cylinder that is axially folded from the inner cylinder and the second cylinder; The exhaust system component according to claim 1, further comprising an outer cylinder configured to extend toward a pipe side. 4. The exhaust system component according to claim 3, wherein the inner tube portion and the outer tube portion are configured to be in contact with or close to each other in the folded portion. 5. The exhaust system component according to any one of claims 1 to 4, wherein the first pipe is welded to an inner peripheral edge of the folded portion. The first pipe is an outlet member of an exhaust system component,
The second pipe is an exhaust pipe,
The exhaust system part according to any one of claims 1 to 5 , wherein the pipe joint is connected to the outlet member.