JP2019194446A - Flange structure of catalyst converter - Google Patents

Abstract

To suppress increase of manufacturing costs even when the entire structure of a flange having a supporting portion of a thermal insulation cover is complicated, in a flange structure of a catalyst converter in which the flange for connection with another exhaust system component is disposed on an end portion of a converter case of the catalyst converter, and the supporting portion for supporting the thermal insulation cover for covering a part of the converter case, is disposed on the flange.SOLUTION: A flange 13A is composed of a flange main body 26A having at least a thick flat plate portion 24 having a planar seal surface and fixed to a converter case 11, and a thin auxiliary flange plate 27 overlapped to the thick flat plate portion 24 in a non-welded state while having supporting portions 19, 20, and the overlapped thick flat plate portion 24 and auxiliary flange plate 27 are fastened to an exhaust system component at a plurality of positions.SELECTED DRAWING: Figure 1

Description

  According to the present invention, a flange for connection to other exhaust system parts is provided at an end portion of a converter case included in a catalytic converter constituting a part of an exhaust system of an internal combustion engine, and covers a part of the converter case. The present invention relates to a flange structure of a catalytic converter in which a support portion that supports a heat shield cover is provided on the flange.

  Patent Document 1 discloses a flange structure in which a support portion is provided on a flange of a catalytic converter so as to support a heat shield cover that covers a part of the catalytic converter.

JP 2012-211556 A

  Incidentally, the flange of the catalytic converter that constitutes a part of the exhaust system of the internal combustion engine is formed of a heat-resistant metal such as stainless steel, and as disclosed in Patent Document 1, a heat shield cover is provided. When the flange on which the support portion is provided for supporting is a flat plate shape, the flange can be formed by press molding. However, as shown in FIG. 5, a part of the catalytic converter is covered with the first and second heat shield covers 15 and 16, and the support portions 40 and 41 that support the second heat shield cover 16 are integrated. In some cases, the flange 39 has a complicated shape due to the shape of the support portions 40 and 41. In this case, the flange 39 needs to be formed by hot forging, resulting in an increase in manufacturing cost. .

  The present invention has been made in view of such circumstances, and provides a flange structure of a catalytic converter that can suppress an increase in manufacturing cost even if the overall structure of the flange having the support portion of the heat shield cover is complicated. The purpose is to do.

  In order to achieve the above object, the present invention is provided with a flange for connection with other exhaust system parts at the end of a converter case included in a catalytic converter constituting a part of an exhaust system of an internal combustion engine, In the flange structure of the catalytic converter in which the flange is provided with a support portion that supports a heat shield cover that covers a part of the converter case, the flange is in a planar shape that abuts a gasket interposed between the exhaust system components. A flange main body that has at least a thick flat plate portion having a sealing surface and is fixed to the converter case; and a thin auxiliary flange plate that is superposed on the thick flat plate portion in a non-welded state while having the support portion. The first feature is that the stacked thick plate portion and the auxiliary flange plate are fastened to the exhaust system component by a plurality of joint fastenings.

  In the present invention, in addition to the configuration of the first feature, the flange main body is integrally provided with a cylindrical portion penetrating the auxiliary flange plate, and the cylindrical portion is welded to the converter case. Features.

  In addition to the configuration of the second feature, the third feature of the present invention is that the inner peripheral side of the cylindrical portion is welded to the converter case.

  In the present invention, in addition to the configuration of the third feature, an annular protrusion disposed on the inner circumference of the cylindrical portion on the upstream side in the exhaust flow direction from the welded portion of the cylindrical portion to the converter case. The fourth feature is that the projection is provided.

  In addition to the configuration of the second feature, the fifth feature of the present invention is that the outer peripheral side of the cylindrical portion is welded to the converter case.

  Furthermore, in addition to any one of the configurations of the first to fifth features, the present invention is such that an engaging portion that engages with the outer periphery of the thick flat plate portion is integrally provided on the outer periphery of the auxiliary flange plate. The sixth feature.

  According to the first feature of the present invention, the flange provided in the converter case has at least a thick flat plate portion having a flat sealing surface and is fixed to the converter case with the flange main body and is thick in a non-welded state. Since the auxiliary flange plate has a support portion that supports the heat shield cover, the auxiliary flange plate has a support portion that supports the heat shield cover. Even if the shape is complicated, it is possible to form both the flange main body and the auxiliary flange plate by pressing, and it is possible to reduce the cost while ensuring the strength and sealability with the flange main body. Since it is stacked on the thick flat plate in a non-welded state, heat distortion can be suppressed and heat conduction from the flange to the heat shield cover can be suppressed. Furthermore even if the mounting position of the heat shielding cover is changed only need replacing auxiliary flange plate can be applied to a catalytic converter of a plurality of models to suppress the increase in cost.

  According to the second feature of the present invention, the cylindrical portion integrally provided on the flange main body is welded to the converter case, and the cylindrical portion penetrates the auxiliary flange plate, so that the auxiliary flange plate is overlapped with the thick flat plate portion. It becomes possible to weld the flange main body in the state of the state to the converter case.

  According to the third feature of the present invention, since the inner peripheral side of the cylindrical portion is welded to the converter case, the flange main body can be easily welded to the converter case regardless of the relative positions of the converter case and the auxiliary case plate. And a uniform weld can be obtained.

  According to the fourth feature of the present invention, since the annular protrusion disposed on the upstream side along the exhaust flow direction from the welded portion of the tubular portion to the converter case is projected on the inner periphery of the tubular portion, It can suppress that the high temperature exhaust gas which distribute | circulates the inside of a cylinder part hits a welding part directly, and can contribute to the durability improvement of a welding part.

  According to the fifth feature of the present invention, since the outer peripheral side of the cylindrical portion is welded to the converter case, there is no welded portion in contact with the high-temperature exhaust gas circulating in the cylindrical portion, and the durability of the welded portion is improved. Can be planned.

  Furthermore, according to the sixth aspect of the present invention, since the engaging portion integrally provided on the outer periphery of the auxiliary flange plate engages with the outer periphery of the thick flat plate portion, the auxiliary flange plate is attached to the thick flat plate portion mainly composed of the flange. It becomes easy to hold and convey in an overlapped state, and since the relative positions of the flange main body and the auxiliary flange plate can be determined and assembled, the assembly becomes easy.

It is a disassembled perspective view of the catalytic converter of 1st Embodiment. It is a longitudinal cross-sectional view of a part of a joint part of a catalytic converter and other exhaust system parts. It is a disassembled perspective view of a flange. It is a longitudinal cross-sectional view corresponding to FIG. 2 of 2nd Embodiment. It is a disassembled perspective view corresponding to FIG. 1 of a prior art example.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. First, in FIGS. 1 and 2, a converter of a catalytic converter constituting a part of an exhaust system of an internal combustion engine mounted on a vehicle. The case 11 is connected to a cylindrical case main part 11a for accommodating a catalyst carrier (not shown), an upstream connecting cylinder part 11b connected to one end of the case main part 11a, and the other end of the case main part 11a. And a downstream connection cylinder portion 11c. Another exhaust system, such as a turbocharger, connected to the catalytic converter on the upstream side of the upstream side connecting cylinder portion 11b, which is one end portion of the converter case 11, is connected to the catalytic converter at the upstream side thereof. A first flange 13 </ b> A for connection with the component 12 is provided, and the downstream end connecting tube portion 11 c, which is the other end portion of the converter case 11, has an end portion opposite to the case main portion 11 a. Two flanges 14 are provided.

  A part of the converter case 11 is covered with first and second heat shield covers 15 and 16. The first heat shield cover 15 is formed so as to cover almost half of the outer periphery of the case main portion 11a, and the second heat shield cover 16 is formed of the exhaust system component 12 of the upstream connection cylinder portion 11b. It is formed so as to cover the part facing the opposite side.

  A support stay 17 for fastening the first heat shield cover 15 and the second heat shield cover 16 together by fastening on the outer surface of the end portion near the case main portion 11a in the upstream connection cylinder portion 11b. It is fixed by welding.

  The second heat shield cover 16 is fastened and supported by the first and second fastened portions 16a and 16b that are fastened and supported by the first flange 13A, and the support stay 17. The third fastened portion 16c is formed, and the first to third fastened portions 16a to 16c are formed with insertion holes 18 through which bolts (not shown) are inserted.

  The first flange 13A has a first support portion 19 for fastening and supporting the first fastened portion 16a in the second heat shield cover 16, and the second fastened portion 16b. And a second support portion 20 for fastening and supporting.

  Referring also to FIG. 3, the first flange 13 </ b> A has a planar sealing surface 23 that abuts the gasket 22 interposed between the first flange 13 </ b> A and the third flange 21 of the exhaust system component 12. In a non-welded state, including a flange main body 26A that has at least a meat flat plate portion 24 and is fixed to the upstream connection cylinder portion 11b of the converter case 11, and the first and second support portions 19 and 20. It consists of a thin auxiliary flange plate 27 that is stacked on the thick flat plate portion 24.

  The flange main body 26A is integrally formed with the thick flat plate portion 24 and a cylindrical portion 25 that continues to the thick flat plate portion 24 and penetrates the auxiliary flange plate 27. The flange main body 26A exhausts the flange main body 26A. A flow passage 28 is formed.

  The auxiliary flange plate 27 includes a thin plate-shaped flange main portion 29 and first and second support portions 19 and 20 integrally connected to the flange main portion 29, and the first and second support portions. 19 and 20 are extended from the flange main part 29 while being bent so as to be in contact with the inner surfaces of the first and second fastened parts 16a and 16b in the second heat shield cover 16.

  The stacked thick flat plate portion 24 and the auxiliary flange plate 27 are fastened to the third flange 21 of the exhaust system component 12 by fastening at a plurality of locations, for example, four locations, and the thick flat plate. Four attachment holes 31 corresponding to attachment holes 30 provided at four locations spaced apart in the circumferential direction of the portion 24 are provided in the flange main portion 29 of the auxiliary flange plate 27. The first and second support portions 19 and 20 are formed with insertion holes 32 corresponding to the insertion holes 18 of the first and second fastened portions 16a and 16b in the second heat shield cover 16, respectively. The

  The flange main body 26 </ b> A is fixed to the upstream connection cylinder part 11 b by welding the cylinder part 25 to the upstream connection cylinder part 11 b of the converter case 11. The circumferential side is welded to the upstream connecting cylinder portion 11b. That is, the end of the upstream connection tube 11b opposite to the case main portion 11a is fitted into the tube 25, and the end of the upstream connection tube 11b is a welded portion by fillet welding. 33 is fixed to the inner periphery of the cylindrical portion 25.

  In addition, an annular protrusion 25a is integrally provided on the inner periphery of the cylindrical portion 25, and the annular protrusion 25a extends along the exhaust flow direction 34 of the exhaust gas flowing through the exhaust flow passage 28 in the flange main body 26A. And disposed on the upstream side of the welded portion 33.

  Further, for example, at two locations on the outer periphery of the auxiliary flange plate 27, engaging portions 35 that engage with the outer periphery of the thick flat plate portion 24 in the flange main body are integrally provided.

  Next, the operation of the first embodiment will be described. A first flange 13A provided in the converter case 11 of the catalytic converter for connection to the exhaust system component 12 is interposed between the exhaust system component 12 and the exhaust system component 12. A flange main body 26A having at least a thick flat plate portion 24 having a flat sealing surface 23 with which the interposed gasket 22 abuts and fixed to the upstream connecting tube portion 11b of the converter case 11, and a second shielding member. The thin-walled auxiliary flange plate 27 that has the first and second support portions 19 and 20 for supporting the heat cover 16 and is superposed on the thick-plate portion 24 in a non-welded state. Since the flat plate portion 24 and the auxiliary flange plate 27 are fastened to the exhaust system component 12 by a plurality of joints, for example, four joints, the first and the second heat shield covers 16 are supported. Even if the shape of the entire first flange 13A is complicated by having the second support portions 19 and 20, both the flange main body 26A and the auxiliary flange plate 27 can be formed by press working. Costs can be reduced while ensuring strength and sealing performance. Moreover, since the auxiliary flange plate 27 is superposed on the thick flat plate portion 24 in a non-welded state, it is possible to suppress the occurrence of thermal distortion and to suppress the heat conduction from the first flange 13A to the second heat shield cover 16 side. In addition, even if the mounting position of the second heat shield cover 16 is changed, it is only necessary to replace the auxiliary flange plate 27, and it can be applied to a plurality of types of catalytic converters while suppressing an increase in cost.

  Further, the flange main body 26A is integrally provided with a cylindrical portion 25 penetrating the auxiliary flange plate 27, and the cylindrical portion 25 is welded to the upstream connection cylindrical portion 11b of the converter case 11. Therefore, the auxiliary flange plate It becomes possible to weld the flange main body 26 </ b> A in a state where 27 is superposed on the thick flat plate portion 24 to the converter case 11.

  Moreover, since the inner peripheral side of the cylindrical portion 25 is welded to the upstream connecting cylindrical portion 11b of the converter case 11, the flange main body 26A is connected to the converter case 11 regardless of the relative positions of the converter case 11 and the auxiliary case plate 27. It can be easily welded, and a uniform weld 33 can be obtained.

  Further, an annular protrusion 25a is provided on the inner periphery of the cylindrical portion 25 so as to protrude upstream from the welded portion 33 of the cylindrical portion 25 to the converter case 11 along the exhaust flow direction 34. It is possible to suppress the high-temperature exhaust gas flowing through the portion 25 from directly hitting the welded portion 33, and to contribute to improving the durability of the welded portion 33.

  Further, since the engaging portion 35 that engages with the outer periphery of the thick plate portion 24 in the flange main body 26A is integrally provided on the outer periphery of the auxiliary flange plate 27, the auxiliary plate is supported by the thick plate portion 24 of the flange main body 26A. The flange plate 27 can be easily held and transported in a stacked state, and the relative positions of the flange main body 26A and the auxiliary flange plate 27 can be determined and assembled, so that the assembly is facilitated.

  The second embodiment of the present invention will be described with reference to FIG. 4, but the parts corresponding to the first embodiment are only given the same reference numerals and shown in detail. Omitted.

  The fourth flange 13B provided in the converter case 11 includes a thick flat plate portion 24 having a planar seal surface 23 that abuts the gasket 22 interposed between the third flange 21 of the exhaust system component 12. It comprises at least a flange main body 26B that is secured to the upstream connecting cylinder portion 11b of the converter case 11 and a thin auxiliary flange plate 27 that is superposed on the thick flat plate portion 24 in a non-welded state.

  The flange main body 26 </ b> B is formed so as to integrally include the thick flat plate portion 24 and a cylindrical portion 37 that continues to the thick flat plate portion 24 and penetrates the auxiliary flange plate 27.

  The flange main body 26 </ b> B is fixed to the upstream connection cylinder part 11 b by welding the cylinder part 37 to the upstream connection cylinder part 11 b of the converter case 11. The side is welded to the upstream connecting cylinder 11b. That is, the end portion of the upstream connection tube portion 11b is fitted in the tube portion 37, and the end portion of the tube portion 37 is fixed to the outer periphery of the upstream connection tube portion 11b by a welded portion 38 by fillet welding. Is done.

  According to the second embodiment, since the outer peripheral side of the cylindrical portion 37 is welded to the converter case 11, there is no welded portion 38 in contact with the high-temperature exhaust gas circulating in the cylindrical portion 37, The durability of the welded portion 38 can be improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

11 ... converter case 12 ... exhaust system parts 13A, 13B ... flange 16 ... heat shield covers 19, 20 ... support 22 ... gasket 23 ... seal surface 24 ... Thick flat plate portions 25, 37 ... cylindrical portion 25a ... annular projections 26A, 26B ... flange main body 27 ... auxiliary flange plate 34 ... exhaust flow direction 35 ... engagement portion

Claims (6)

  Flange (13A, 13B) for connection with other exhaust system parts (12) is provided at the end of the converter case (11) of the catalytic converter that constitutes a part of the exhaust system of the internal combustion engine, In the flange structure of the catalytic converter in which support portions (19, 20) for supporting a heat shield cover (16) covering a part of the converter case (11) are provided on the flanges (13A, 13B), the flanges (13A, 13B) ) Has at least a thick flat plate portion (24) having a planar sealing surface (23) for contacting a gasket (22) interposed between the exhaust system component (12) and the converter case ( 11) The flange main body (26A, 26B) to be fixed to 11) and the thin-walled auxiliary member (19, 20) which is superposed on the thick plate (24) in a non-welded state. The thick plate portion (24) and the auxiliary flange plate (27), which are formed of a flange plate (27), are fastened to the exhaust system component (12) by joint fastening at a plurality of locations. The catalytic converter flange structure.   The flange main body (26A, 26B) is integrally provided with a cylindrical portion (25, 37) passing through the auxiliary flange plate (27), and the cylindrical portion (25, 37) is welded to the converter case (11). The flange structure of the catalytic converter according to claim 1, wherein   The flange structure of the catalytic converter according to claim 2, wherein an inner peripheral side of the cylindrical portion (25) is welded to the converter case (11).   An annular protrusion disposed on the inner periphery of the tubular portion (25) on the upstream side along the exhaust flow direction (34) from the welded portion (33) of the tubular portion (25) to the converter case (11). The flange structure of the catalytic converter according to claim 3, wherein (25a) is projected.   The flange structure of the catalytic converter according to claim 2, wherein an outer peripheral side of the cylindrical portion (37) is welded to the converter case (11).   The engaging portion (35) that engages with the outer periphery of the thick flat plate portion (24) is integrally provided on the outer periphery of the auxiliary flange plate (27). The flange structure of the catalytic converter described in the paragraph.

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