Catalytic converter

Abstract

To provide a catalyst device capable of suppressing cracking of a case.SOLUTION: A catalyst device includes: a catalyst; a case 22 accommodating the catalyst; and a bracket 23 welded to an outer surface 22a of the case 22 and connected to an engine via a stay 16. The bracket 23 includes a plate part 24 and an erected part 25 that is erected from the plate part 24 and to which the stay 16 is connected. An edge part of the plate part 24 includes: an inner edge part 31 connected to the erected part 25; an outer edge part 32 welded to the case 22; and a connecting edge part 33 connecting the inner edge part 31 with the outer edge part 32. The connecting edge part 33 includes: a first edge part 33a connected to the inner edge part 31; a second edge part 33b extending in a direction different from that in which the first edge part 33a extends and connected to the outer edge part 32; and a corner part 33c connecting the first edge part 33a with the second edge part 33b. The second edge part 33b is not welded to the outer surface 22a of the case 22. The corner part 33c does not come into contact with the outer surface 22a of the case 22.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a catalytic converter. [Background technology]

[0002] The catalytic converter disclosed in Patent Document 1 is supported on the engine via a stay. More specifically, one end of the stay is connected to a bracket formed on a case of the catalytic converter, and the other end of the stay is connected to a cylinder block of the engine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 3-43527 Summary of the Invention [Problem to be solved by the invention]

[0004] When the bracket is welded to the case, engine vibrations are transmitted to the case via the stays, brackets, and welds, which can cause stress to concentrate at and around the welds on the case, which can lead to cracks in the case. [Means for solving the problem]

[0005] A catalytic converter for solving the above problems comprises a catalyst, a case for housing the catalyst, and a bracket welded to the outer surface of the case and connected to an engine via a stay, the bracket having a plate portion and an erect portion standing from the plate portion and to which the stay is connected, the edge portion of the plate portion having an inner edge portion connected to the erect portion, an outer edge portion welded to the outer surface of the case, and a connecting edge portion connecting the inner edge portion and the outer edge portion, the connecting edge portion having a first edge portion connected to the inner edge portion, a second edge portion extending in a direction different from the extension direction of the first edge portion and connecting to the outer edge portion, and a corner portion connecting the first edge portion and the second edge portion, the second edge portion is not welded to the outer surface of the case, and the corner portion is not in contact with the outer surface of the case.

[0006] The inventor discovered that when the outer edge and second edge of the bracket are welded to the case, stress is particularly concentrated in the portion of the case facing the corner and its surroundings. Therefore, by not welding the second edge to the case and not allowing the corner to contact the outer surface of the case, engine vibration is prevented from being transmitted to the case via the corner. As a result, stress is prevented from concentrating in the portion of the case facing the corner and its surroundings, and cracks in the case can be prevented. [Brief description of the drawings]

[0007] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] 1 is a photograph showing a first connecting edge of a bracket. [Diagram 5] 3 is a view of the catalytic converter as seen from the arrow A in FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, one embodiment of the catalyst device will be described with reference to Figs. <Exhaust unit> As shown in Fig. 1, the exhaust unit 10 includes an exhaust manifold 11 and a catalytic converter 12. The exhaust manifold 11 has an upstream pipe 13 and a downstream pipe 14. The upstream pipe 13 has four branch pipes 13a and a collecting pipe 13b. The catalytic converter 12 is disposed between the collecting pipe 13b of the upstream pipe 13 and the downstream pipe 14.

[0009] The exhaust unit 10 is fixed to an engine 15. The exhaust manifold 11 is fixed to a cylinder head of the engine 15. The catalytic converter 12 is fixed to a cylinder block of the engine 15 via a stay 16 in the form of a long plate.

[0010] Exhaust gas emitted from an engine 15 flows into the catalytic converter 12 through an upstream pipe 13. The catalytic converter 12 purifies the exhaust gas that flows in. The purified exhaust gas flows out into a downstream pipe 14.

[0011] <Catalyst device> The catalytic converter 12 includes a catalyst 21, a case 22, and a bracket 23. The case 22 houses the catalyst 21. The bracket 23 is welded to an outer surface 22a of the case 22.

[0012] <Case> The case 22 is cylindrical. The case 22 has a first rib 221 and a second rib 222. The first rib 221 and the second rib 222 are each a portion protruding from an outer surface 22a of the case 22. The first rib 221 is connected to the collecting pipe 13b. The second rib 222 is connected to the downstream pipe 14.

[0013] <bracket> As shown in FIGS. 2 and 3, the bracket 23 has a plate portion 24 and a plate-shaped erect portion 25 erected from the plate portion 24 in approximately the thickness direction of the plate portion 24.

[0014] The edge of the plate portion 24 has an inner edge portion 31, an outer edge portion 32, a first connecting edge portion 33, and a second connecting edge portion . The inner edge 31 is an edge that is connected to the standing portion 25. The outer edge 32 is an edge that is welded to the outer surface 22a of the case 22. The catalytic converter 12 has a welded portion 26 at which the case 22 and the outer edge 32 of the bracket 23 are welded together. The welded portion 26 is connected to the second rib 222.

[0015] The inner edge portion 31 is U-shaped. The inner edge portion 31 has a pair of first edge constituent portions 311 and a second edge constituent portion 312. The outer edge portion 32 is L-shaped. The outer edge portion 32 includes a third edge constituent portion 321 extending along the axis of the case 22 and a fourth edge constituent portion 322 extending in the circumferential direction of the case 22. Each of the pair of first edge constituent portions 311 is inclined with respect to the direction in which the third edge constituent portion 321 extends. Also, each of the pair of first edge constituent portions 311 is inclined with respect to the direction in which the fourth edge constituent portion 322 extends. The pair of first edge constituent portions 311 extend approximately parallel to each other. The second edge constituent portion 312 connects the first edge constituent portions 311. The second edge constituent portion 312 is perpendicular to the pair of first edge constituent portions 311.

[0016] The first connecting edge 33 connects the first end 31a of the inner edge 31 and the first end 32a of the outer edge 32. The first connecting edge 33 has a first edge 33a, a second edge 33b, and a corner 33c. The first edge 33a is connected to the first end 31a of the inner edge 31. The second edge 33b is connected to the first end 32a of the outer edge 32. The second edge 33b extends in a direction different from the direction in which the first edge 33a extends. The corner 33c connects the first edge 33a and the second edge 33b. The second connecting edge 34 connects the second end 31b, which is the end opposite to the first end 31a of the inner edge 31, and the second end 32b, which is the end opposite to the first end 32a of the outer edge 32.

[0017] As shown in FIG. 4, the second edge 33b is not welded to the outer surface 22a of the case 22. 4 and 5, the corner 33c is raised above the outer surface 22a of the case 22. The corner 33c is not in contact with the outer surface 22a of the case 22. At the corner 33c, a gap S exists between the plate portion 24 and the outer surface 22a of the case 22.

[0018] <Stay> As shown in FIG. 1, the stay 16 has a first end 16a and a second end 16b. As shown in FIG. 2, the first end 16a of the stay 16 is connected to the erected portion 25 of the bracket 23 by a first bolt B1. More specifically, the first end 16a of the stay 16 is connected to a portion of the erected portion 25 of the bracket 23 that is erected from the second edge forming portion 312 of the inner edge portion 31. The axis of the first bolt B1 extends substantially parallel to the first edge forming portion 311 of the inner edge portion 31. The axis of the first bolt B1 extends in a direction perpendicular to the second edge forming portion 312 of the inner edge portion 31. The second end 16b of the stay 16 is connected to the engine 15 by a second bolt B2.

[0019] The operation and effects of this embodiment will be described. (1) The inventor discovered that when the outer edge 32 and the second edge 33b of the bracket 23 are welded to the case 22, stress is particularly concentrated in the portion of the case 22 facing the corner 33c and its surroundings. For this reason, by not welding the second edge 33b to the case 22 and not bringing the corner 33c into contact with the outer surface 22a of the case 22, the vibration of the engine 15 is prevented from being transmitted to the case 22 via the corner 33c. As a result, stress is prevented from being concentrated in the portion of the case 22 facing the corner 33c and its surroundings, and thus cracks in the case 22 can be prevented.

[0020] This embodiment can be modified as follows: The embodiment and the modified examples can be combined with each other to the extent that there is no technical contradiction. The shape of the case 22 is not limited to a cylindrical shape. The case 22 may be, for example, a rectangular tube shape.

[0021] The inner edge portion 31 does not have to be U-shaped. The outer edge portion 32 does not have to be L-shaped. The second connecting edge 34 of the bracket 23 may have a third edge connected to the second end 31b of the inner edge 31, a fourth edge extending in a direction different from the extending direction of the third edge and connected to the second end 32b of the outer edge 32, and a second corner connecting the third edge and the fourth edge. In this case, as in the above embodiment, the fourth edge is not welded to the outer surface 22a of the case 22, and the second corner is not brought into contact with the outer surface 22a of the case 22.

[0022] The welded portion 26 does not have to be connected to the second rib 222. [Explanation of symbols]

[0023] 10...Exhaust unit 11...Exhaust manifold 12...Catalyst device 13…Upstream piping 13a...Branch pipe 13b…collecting pipe 14…Downstream piping 15…Engine 16...Stay 16a...first end 16b…Second end 21...Catalyst 22…Case 22a…External surface 23…Bracket 24...Plate part 25…Upright section 26…Welded section 31…Inner edge 31a...first end 31b…Second end 32…Outer edge 32a...first end 32b…Second end 33...First connecting edge portion 33a...first edge 33b…Second edge 33c…corner 34...Second connecting edge 221…First Rib 222…Second rib 311...first edge component 312...Second edge component 321...Third edge component 322...Fourth edge component B1…First bolt B2…Second bolt S…Gap

Claims

[Claim 1] A catalyst; A case that accommodates the catalyst; a bracket welded to an outer surface of the case and connected to an engine via a stay; Equipped with The bracket has a plate portion and an upright portion that stands upright from the plate portion and to which the stay is connected, the edge of the plate portion has an inner edge portion connected to the standing portion, an outer edge portion welded to an outer surface of the case, and a connecting edge portion connecting the inner edge portion and the outer edge portion, the connecting edge portion has a first edge portion connected to the inner edge portion, a second edge portion extending in a direction different from the extending direction of the first edge portion and connected to the outer edge portion, and a corner portion connecting the first edge portion and the second edge portion, the second edge is not welded to an outer surface of the case; A catalytic converter device, characterized in that the corner portion is not in contact with an outer surface of the case.

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