JP2018091151A - bracket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bracket which can suppress peeling from a case.SOLUTION: A bracket includes a top plate part, a pair of side wall parts extending from both ends of the top plate part in a width direction to one side in a height direction, a pair of flange parts extending from the one side of the pair of side wall parts in the height direction to the outside in the width direction, and having an outer end face in the width direction fixed to an outer circumferential face of a case of an exhaust emission control device via a weld part, and a second side wall part extending from at least one of both ends of the top plate part in the length direction to the one side in the height direction, and fixed to the outer circumferential face of the case so that a maximum stress is not generated at both ends of the weld part in the length direction.SELECTED DRAWING: Figure 2D

Description

  The present invention relates to a bracket for fixing an exhaust emission control device to a fixed portion.

  2. Description of the Related Art Conventionally, there has been known an exhaust purification device that is provided in an exhaust system of an internal combustion engine such as an engine and removes carbon monoxide, unburned hydrocarbons, and the like in exhaust gas discharged from the internal combustion engine. It has been conventionally known that an exhaust purification device having a structure arranged around an internal combustion engine is supported by the internal combustion engine via a bracket.

  In FIGS. 10 to 12 of Patent Document 1, a case (catalyst case) of an exhaust purification device (catalyst device) disposed in an exhaust system is fixed to a vehicle body or an engine via a so-called hat-shaped bracket. A structure for supporting the part is disclosed. The bracket extends from the top plate portion, a pair of side wall portions extending from one end in the width direction of the top plate portion to one side in the height direction, and from the one end portion in the height direction of the pair of side wall portions to the outside in the width direction. And a pair of flange portions. In the case of this structure, the outer end surfaces in the width direction of the pair of flange portions of the bracket are fixed to the outer peripheral surface of the case of the exhaust purification device via the welded portion.

Japanese Utility Model Publication No. 4-54929

  In the case of the structure described in FIGS. 10 to 12 of Patent Document 1, the vibration of the engine is transmitted to the exhaust purification device via the bracket, and stress concentration occurs at both ends in the longitudinal direction of the welded portion. Generally, both ends in the longitudinal direction of the welded portion are likely to be the starting point of peeling compared to other parts, so if the stress at the both ends in the lengthwise direction is large, the bracket will peel off from the case of the exhaust purification device. there is a possibility.

  The objective of this invention is providing the bracket which can suppress peeling from the case of an exhaust gas purification apparatus.

  The bracket according to the present invention includes a top plate portion, a pair of side wall portions extending from one end in the width direction of the top plate portion to one side in the height direction, and a width direction outer side from one height direction end of the pair of side wall portions. A pair of flange portions extending and having a width direction outer end surface fixed to the outer peripheral surface of the case of the exhaust gas purification apparatus via a welded portion, and at least one of the lengthwise ends of the top plate portion from one side in the height direction A second side wall portion that extends and is fixed to the outer peripheral surface of the case so that maximum stress is not generated at both ends in the length direction of the weld portion.

  According to the bracket of the present invention, peeling from the case of the exhaust gas purification device can be suppressed.

Schematic showing an exhaust system according to an embodiment of the present invention. Top view of bracket Side view of bracket Front view of bracket Perspective view of bracket Plan view of bracket of comparative example Side view of comparative bracket

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, embodiment described below is an example and this invention is not limited by this embodiment.

  FIG. 1 is a schematic view showing an example of an exhaust system according to the present invention. In FIG. 1, the X axis, the Y axis, and the Z axis are drawn. In the following description, the left-right direction in FIG. 1 is referred to as the X direction or the vehicle front-rear direction, the right direction is referred to as “+ X direction” or “vehicle front side”, and the left direction is referred to as “−X direction” or “vehicle rear side”. Further, the vertical direction in FIG. 1 is referred to as the Y direction or the vehicle vertical direction, the upward direction is referred to as “+ Y direction” or “vehicle upper side”, and the downward direction is referred to as “−Y direction” or “vehicle lower side”. Further, in FIG. 1, a direction perpendicular to the paper surface is referred to as a Z direction or a vehicle width direction, a front direction is referred to as “+ Z direction” or “vehicle right side”, and a back direction is referred to as “−Z direction” or “vehicle left side”.

  As shown in FIG. 1, the exhaust system 1 extends from an exhaust manifold 3 provided on the right side of the vehicle of the engine 2, a turbocharger 4 connected to a collecting portion of the exhaust manifold 3, and the turbocharger 4. An upstream exhaust passage 5, a post-treatment device 6, and a downstream exhaust passage 7. In the case of the present embodiment, the above-described members are arranged on the right side of the engine 2 in the vehicle. However, the arrangement of the above members with respect to the engine 2 in the vehicle width direction is not limited to the illustrated structure.

  The direction (opening direction), size, and shape of the exhaust gas outlet 4a of the turbocharger 4 are comprehensively determined based on the shape, size, installation location, and the like of the aftertreatment device 6. Here, the direction of the exhaust gas outlet 4a is the -X direction. The shape of the exhaust gas outlet 4a is a general circular shape. The installation location of the post-processing device 6 is set at a position in the −X direction of the turbocharger 4.

  The upstream exhaust passage 5 is constituted by an internal space of a hollow tubular tube 8. The pipe 8 has a function as a flow path for allowing the exhaust gas flowing into the internal space from the upstream opening to flow along the extending direction of the pipe 8 and to flow out from the downstream opening.

  The upstream end of the pipe 8 is connected to the exhaust gas outlet 4a. On the other hand, the downstream end of the pipe 8 is fixed to the upstream end of the post-processing device 6. The extending direction, length, and hollow cross-sectional shape of the straight tube 8 are comprehensively determined based on the direction of the exhaust gas outlet 4a, the position of the DOC 11 (described later) in the post-processing device 6, and the like.

  The extending direction of the tube 8 is tilted three-dimensionally based on, for example, the position of the DOC 11. Here, in order to make the explanation easy to understand, the pipe 8 is extended in the same −X direction as the exhaust gas outlet 4 a as shown in FIG. 1. The length of the pipe 8 is preferably as short as possible in order to prevent heat dissipation between the turbocharger 4 and the DOC 11.

  As described above, the upstream end of the aftertreatment device 6 that is an exhaust purification device is connected to the downstream end of the pipe 8. The post-processing device 6 is configured such that a DOC 11 for purifying exhaust gas and a diesel particulate filter (DPF) 12 are accommodated in a tubular case 10.

  The case 10 is fixed to the engine 2 via a bracket 14 that is fixed to the outer peripheral surface of the case 10 by welding. Specifically, in the case of the present embodiment, the bracket 14 is attached to the second bracket 15 protruding rightward from the engine 2 (attached from the front). A detailed structure of the bracket 14 and a support structure for supporting the bracket 14 with respect to the case 10 will be described later.

  The DOC 11 and the DPF 12 are held in the case 10 with an inorganic mat. The DOC 11 is formed in a column shape. Here, in order to make the explanation easy to understand, the DOC 11 extends in the −Y direction. Note that the basic structure and function of the DOC 11 are the same as those of conventionally known DOCs, and thus detailed description thereof is omitted.

  The DPF 12 is formed in a column shape. Further, the DPF 12 extends in the −Y direction, like the DOC 11. Since the basic structure and function of the DPF 12 are the same as those of conventionally known DPFs, detailed description thereof is omitted.

  A downstream exhaust passage 7 is connected to the downstream end of the post-processing device 6. The exhaust gas purified by the post-processing device 6 passes through the downstream exhaust passage 7 and is led out to the outside. The downstream side of the downstream side exhaust passage 7 extends linearly in the −X direction, and the exhaust gas is led backward from the rear end of the downstream side exhaust passage 7.

  Next, with reference to FIGS. 2A to 2D, the structure of the bracket 14 and the details of the support structure for supporting and fixing the bracket 14 to the case 10 will be described. In the following description, the horizontal direction in FIG. 2A is referred to as the “width direction”, and the vertical direction is referred to as the “length direction”. The vertical direction in FIG. 2C is referred to as a “height direction”.

  Regarding the width direction, the direction approaching the center in the width direction of the bracket 14 is the inside, and the direction away from the center in the width direction of the bracket 14 is the outside. Further, regarding the width direction, “one side” corresponds to the right side of FIG. 2A, and similarly, “the other side” corresponds to the left side of FIG. 2A.

  Regarding the length direction, the direction approaching the center in the length direction of the bracket 14 is the inside, and the direction away from the center in the length direction of the bracket 14 is the outside. With respect to the length direction, “one side” corresponds to the upper side of FIG. 2A, and similarly “the other side” corresponds to the lower side of FIG. 2A.

  Regarding the height direction, “one side” corresponds to the lower side of FIG. 2C, and similarly “other side” corresponds to the upper side of FIG. 2C. 2A to 2D show a state in which the bracket 14 is fixed by welding to the case 10 with the case 10 omitted.

  The bracket 14 is a so-called hat-side bracket, and is formed, for example, by bending a rectangular plate member made of stainless steel. The bracket 14 includes a top plate part 141, a pair of side wall parts 142a and 142b (hereinafter referred to as "first side wall part 142a" and "second side wall part 142b"), and a third side wall part 142c (" And a pair of flange portions 143a and 143b (hereinafter referred to as “first flange portion 143a” and “second flange portion 143b”). Such a bracket 14 is for supporting the post-processing device 6 (specifically, the case 10 of the post-processing device 6) with respect to the engine 2.

  The top plate portion 141 is a portion for fixing the bracket 14 to a fixed portion such as the engine 2 (specifically, the second bracket 15). Such a top plate 141 has a rectangular plate shape that is long in the length direction when viewed from the height direction. Two round holes 144a and 144b are formed in the top plate portion 141 so as to be separated in the length direction. Bolts (not shown) are inserted into the round holes 144a and 144b, respectively, and fastened with nuts (not shown). Thereby, the bracket 14 is fixed to the second bracket 15. The number of round holes for inserting the bolts is not limited to two, and may be one, for example. In that case, the round hole is preferably provided at the center in the length direction. Further, the number of round holes may be three or more. In that case, the round holes may be provided at equal intervals or at irregular intervals.

  In the case of this embodiment, the round holes 144a and 144b have the same circular shape as viewed from the height direction. Further, the center of one of the round holes 144a and 144b and the center of the other round hole 144b are aligned in the width direction. However, a configuration in which the center of one round hole 144a and the center of the other round hole 144b are shifted in the width direction may be employed.

  The positional relationship between the round holes 144a and 144b is appropriately determined in consideration of the assembled state of the bracket 14, the case 10, and the engine 2. Further, the shape and number of holes provided in the top plate portion 141 are not limited to this embodiment. In addition, as an example of the assembly state to the vehicle body, the bracket is such that a virtual plane passing through the center of one round hole 144a and the center of the other round hole 144b is parallel to, for example, the vertical direction (vertical direction of the vehicle) 14 can be fixed to the second bracket 15.

  The first side wall portion 142a is a plate-like member extending from the width direction one side edge (the right end edge in FIG. 2A) of the top plate portion 141 to the height direction one side (the lower side in FIG. 2C). Specifically, in the case of the present embodiment, the first side wall portion 142 a extends in a state orthogonal to the top plate portion 141.

  The second side wall 142b is a plate-like member that extends from the other edge in the width direction of the top plate 141 (the left edge in FIG. 2A) to one side in the height direction (the lower side in FIG. 2C). Specifically, in the case of the present embodiment, the second side wall portion 142b extends in a state orthogonal to the top plate portion 141.

  The first side wall part 142a and the second side wall part 142b as described above have the same rectangular plate shape as viewed from the width direction (the shape shown in FIG. 2B). Moreover, the 1st side wall part 142a and the 2nd side wall part 142b are continuing in the height direction over the full length regarding a length direction. That is, the first side wall portion 142a and the second side wall portion 142b are not formed with a discontinuous portion such as a through hole or a notch that is discontinuous in the height direction. In addition, the shape of the 1st side wall part 142a and the 2nd side wall part 142b is not limited to the case of this embodiment. Moreover, the shapes of the first side wall part 142a and the second side wall part 142b can be made different.

  Specifically, for example, the inclination angle of the first side wall portion 142a with respect to the top plate portion 141 can be made different from the inclination angle of the second side wall portion 142b with respect to the top plate portion 141. Moreover, the height direction dimension of the 1st side wall part 142a and the height direction dimension of the 2nd side wall part 142b can also be varied. The shapes of the first side wall part 142 a and the second side wall part 142 b are appropriately changed according to the attachment position to the case 10.

  The 3rd side wall part 142c is a plate-shaped member extended from the length direction one side edge (upper end edge of FIG. 2A) of the top-plate part 141 to the height direction one side (lower side of FIG. 2C). Specifically, in the case of this embodiment, the third side wall portion 142 c extends in a state orthogonal to the top plate portion 141. In addition, the angle which the 3rd side wall part 142c makes with respect to the top-plate part 141 is not limited to the case of this embodiment. Specifically, for example, one end in the height direction of the third side wall portion 142c can be set to one side in the length direction than the other end in the height direction.

  The third side wall portion 142c has a rectangular plate shape when viewed from the length direction (the shape shown in FIG. 2C). Moreover, the 3rd side wall part 142c is following in the height direction over the full length regarding the width direction. That is, the third side wall portion 142c is not formed with a discontinuous portion such as a through hole or a notch that is discontinuous in the height direction. The shape of the third side wall portion 142c is not limited to the case of this embodiment. The shape of the third side wall portion 142 c is appropriately changed according to the attachment position to the case 10.

  The vicinity of one end in the height direction on one side in the length direction of the third side wall 142c is, for example, arc welded to the case 10 over almost the entire region in the width direction. In other words, the vicinity of one end in the height direction on one side in the length direction of the third side wall 142c is the outer peripheral surface of the case 10 via the welded portion 17b (corresponding to the “second welded portion” of the present invention). Fixed to.

  In addition, the position of the welding part 17b is not limited to the case of this embodiment. Specifically, for example, in addition to the one side surface in the length direction of the third side wall portion 142c, the outer peripheral surface of the case 10 is also connected to the width direction one side end surface and the other side end surface of the third side wall portion 142c via the welded portion 17b. Can be fixed to.

  The 1st flange part 143a is a plate-shaped member extended from the height direction one side edge of the 1st side wall part 142a to the width direction one side. Specifically, in the case of this embodiment, the first flange portion 143a extends in a state orthogonal to the first side wall portion 142a (in other words, parallel to the top plate portion 141).

  The 2nd flange part 143b is a plate-shaped member extended to the width direction other side from the height direction one side edge of the 2nd side wall part 142b. Specifically, in the case of this embodiment, the second flange portion 143b extends in a state orthogonal to the second side wall portion 142b (in other words, parallel to the top plate portion 141).

  The first flange portion 143a and the second flange portion 143b are rectangular plate shapes having the same shape (the shape shown in FIG. 2A) viewed from the height direction. Moreover, the 1st flange part 143a and the 2nd flange part 143b are continuing in the width direction over the full length regarding a length direction. That is, the first flange portion 143a and the second flange portion 143b are not formed with discontinuous portions such as through holes or notches that are discontinuous in the width direction.

  One end face in the width direction of the first flange portion 143a is, for example, arc welded to the case 10 over almost the entire length direction. In other words, the one end surface in the width direction of the first flange portion 143a is fixed to the outer peripheral surface of the case 10 via the welded portion 17a (corresponding to the “welded portion” of the present invention).

  The other end surface in the width direction of the second flange portion 143b is, for example, arc welded to the case 10 over substantially the entire length direction. In other words, the other end surface in the width direction of the second flange portion 143b is fixed to the outer peripheral surface of the case 10 via the welded portion 17a.

<Effect of this embodiment>
The effect of this embodiment will be described with reference to a comparative example. FIG. 2A shows a graph showing the stress distribution applied to the welded portion 17a in the bracket 14 of the present embodiment. 3A and 3B show a bracket 14a of a comparative example. FIG. 3A shows a graph showing the stress distribution applied to the welded portion 17a in the bracket 14a of the comparative example. Note that the structure of the bracket 14a of the comparative example is different from the structure of the bracket 14 of the present embodiment only in that the third side wall portion 142c and the welded portion 17b are not provided, and the other structure is the bracket of the present embodiment. This is the same as the structure of 14.

  In addition, the operation and effect of the present embodiment described below is when the vibration of the engine 2 is transmitted to the post-processing device 6 via the bracket 14 and a load is repeatedly applied to the top plate portion 141 in the height direction. Is assumed. The stress generated by such a load is large on one side in the length direction, and gradually decreases toward the other side in the length direction. The following description is given regarding the first side wall portion 142a of the bracket 14 of the present embodiment and the first side wall portion 142d of the bracket 14a of the comparative example.

  The repetitive load applied to the top plate portion 141 in the height direction is transmitted through the first side wall portions 142a and 142d and the first flange portion 143a, and is repeatedly applied as a tensile compressive load in the width direction to the welded portion 17a. Is done. Therefore, the stress distribution of the welded portion 17a shown in FIGS. 2A and 3A relates to the stress generated in the welded portion 17a based on the tensile compressive load in the width direction as described above.

  In the case of the bracket 14a of the comparative example, in addition to the stress on one side in the length direction of the welded portion 17a being larger than the stress on the other side in the lengthwise direction, stress concentration at both ends in the lengthwise direction of the welded portion 17a As shown in the stress distribution, the stress generated at one end portion in the longitudinal direction of the welded portion 17a is larger than the other portions. Furthermore, generally, the end portion in the length direction of the welded portion 17a is likely to be a starting point of peeling compared to other portions. Therefore, there is a possibility that the bracket 14a is peeled off from the case 10 starting from the one end portion in the length direction of the welded portion 17a.

  On the other hand, in the bracket 14 of this embodiment, the welding part 17b is provided in the height direction one side edge vicinity in the length direction one side of the 3rd side wall part 142c. Therefore, a part of stress in the vicinity of one end portion in the longitudinal direction of the welded portion 17a can be shared by the welded portion 17b. Thereby, as shown in the stress distribution of FIG. 2A, the stress on the inner side in the length direction becomes larger than the stress at both ends in the length direction of the welded portion 17a. In other words, no maximum stress is generated at both ends in the length direction of the welded portion 17a. 2A shows the stress distribution in the bracket 14a of the comparative example for comparison.

  For this reason, even when a repeated load is applied to the top plate portion 141 in the height direction, peeling is less likely to occur at both ends in the length direction of the welded portion 17a. Further, the inner side in the length direction of the welded portion 17a is less likely to be a starting point of peeling than both ends in the length direction. As a result, it can suppress that the bracket 14 peels from the case 10. FIG.

<Modification>
In addition, in the said embodiment, in order to reduce the stress of the length direction one side edge part with a large load stress among the length direction both ends of the welding part 17a, the length direction one side edge part of the top-plate part 141 is shown. The third side wall 142c is provided on the first side and the vicinity of one end of the third side wall 142c in the height direction is welded to the case 10, but the present invention is not limited to this.

  Specifically, for example, in addition to the third side wall part 142c, a fourth side wall part extending from the other edge in the longitudinal direction of the top plate part 141 to one side in the height direction is provided, and the height of the fourth side wall part is provided. The vicinity of the unidirectional end may be welded to the case 10. By carrying out like this, a part of stress in the length direction other side of the welding part 17a can be shared by the welding part which joins a 4th side wall part and the case 10, and the length direction other side of the welding part 17a The stress applied to the end can also be reduced.

  Note that, as described above, the occurrence of peeling from both ends in the length direction of the welded portion 17a can be suppressed by preventing the maximum stress from being generated at both end portions in the lengthwise direction of the welded portion 17a. Therefore, the size and shape of the third and fourth sidewall portions, the size of the welded portion that joins the third and fourth sidewall portions and the case 10 (that is, the third and fourth sidewall portions are fixed to the case 10). (Fixed strength in the case) can be appropriately changed according to the applied load.

  Moreover, in the said embodiment, although the 3rd side wall part 142c was welded with respect to the outer peripheral surface of case 10, it is not limited to this. The method of fixing the third side wall portion 142c to the outer peripheral surface of the case 10 is not particularly limited as long as the stress at one end portion in the longitudinal direction of the welded portion 17a can be reduced.

  Moreover, in the said embodiment, although the height direction one side edge vicinity of the 3rd side wall part 142c was fixed with respect to the case 10, it is not limited to this. Specifically, for example, a third flange portion extending to one side in the length direction is provided at one end portion in the height direction of the third side wall portion 142c, and the third flange portion is attached to the case 10 by, for example, welding. It may be fixed.

  Moreover, although the said embodiment demonstrated what accommodated DOC11 and DPF12 in case 10, it is not limited to this. For example, the DPF 12 may be omitted. Further, instead of the DOC 11, various catalysts for purifying exhaust gas such as a lean NOx trap catalyst (LNT) and a selective catalytic reduction catalyst (SCR) as other catalysts may be used. Further, various catalysts for purifying exhaust gas, such as DOC, LNT, and SCR, may be accommodated on the downstream side of the catalyst instead of the DPF 12.

  The support structure of the exhaust purification apparatus of the present invention is useful for a structure in which the exhaust purification apparatus is attached to a member that generates vibrations such as an engine.

DESCRIPTION OF SYMBOLS 1 Exhaust system 2 Engine 3 Exhaust manifold 4 Turbocharger 4a Exhaust gas outlet 5 Upstream exhaust passage 6 Post-processing device 7 Downstream exhaust passage 8 Pipe 10 Case 11 DOC
12 DPF
14, 14a Bracket 141 Top plate part 142a, 142d First side wall part 142b Second side wall part 142c Third side wall part 143a First flange part 143b Second flange part 144a, 144b Round hole 15 Second bracket 17a, 17b Welding part

Claims (4)

The top plate,
A pair of side wall portions extending from one side in the height direction from both ends in the width direction of the top plate portion;
A pair of flange portions extending outward in the width direction from one end in the height direction of the pair of side wall portions, and having an outer end surface in the width direction fixed to the outer peripheral surface of the case of the exhaust gas purification apparatus via a welded portion;
The first plate is fixed to the outer peripheral surface of the case so as to extend from at least one of the lengthwise ends of the top plate to one side in the height direction and to prevent the maximum stress from being generated at both lengthwise ends of the welded portion. Two side walls,
With bracket. The second side wall is joined to the outer peripheral surface of the case via a second weld.
The bracket according to claim 1. The second side wall portion is provided only in one of the lengthwise one side end and the other side end of the top plate portion,
The bracket according to claim 1. The second side wall portion is provided at each of one end portion and the other end portion in the length direction of the top plate portion, and the fixing strength to the outer peripheral surface of the case is different from each other.
The bracket according to claim 1.

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