JP6794803B2 - Bracket and bracket support structure - Google Patents

Description

The present disclosure relates to brackets and bracket support structures.

Conventionally, an exhaust purification device provided in an exhaust system of an internal combustion engine for removing carbon monoxide, unburned hydrocarbons, and the like in the exhaust gas discharged from the internal combustion engine is known. It has been conventionally known that among such exhaust gas purification devices, those having a structure arranged around the internal combustion engine are supported by the internal combustion engine via brackets.

In FIGS. 10 to 12 of Patent Document 1, a so-called hat for supporting a case (catalyst case) of an exhaust purification device (catalyst device) arranged in an exhaust system to a fixed portion such as a vehicle body or an engine. Mold brackets are disclosed. This bracket extends outward in the width direction from the top plate portion, a pair of side wall portions extending from both ends in the width direction of the top plate portion to one side in the height direction, and one end portion in the height direction of the pair of side wall portions. It is provided with a pair of flange portions. In the case of this structure, the outer end faces of the pair of flange portions of the bracket in the width direction are fixed to the outer peripheral surface of the case of the exhaust gas purification device via the welded portions.

Jikkenhei 4-544929

However, in the structure described in FIGS. 10 to 12 of Patent Document 1, stress concentration due to vehicle body vibration occurs at the welded end portion at the welded portion connecting the bracket and the case of the exhaust gas purification device. In general, both ends in the length direction of the welded portion are more likely to be the starting point of peeling than other parts, so if the stress at both ends in the length direction is large, there is a problem that the bracket may be peeled off from the case. ..

An object of the present disclosure is to provide a bracket and a bracket support structure capable of reliably preventing the bracket from coming off the case.

The brackets of this disclosure are
The top plate portion and the top plate portion extend from both ends in the width direction to one side in the height direction, extend from one end in the height direction to the outside in the width direction, and the outer end in the width direction extends through the welded portion. With a pair of legs, which are fixed to the outer peripheral surface of the case,
At least one leg of the pair of legs has a notch that separates the weld in the length direction.

The bracket support structure of the present disclosure is
The bracket is supported by the case via the weld.

According to the present disclosure, it is possible to reliably prevent the bracket from coming off the case.

Schematic diagram showing an exhaust system according to an embodiment of the present disclosure. Top view of bracket and stress distribution of weld Side view of bracket Front view of bracket AA sectional view of FIG. 2A Perspective view of bracket Plan view of bracket and stress distribution view of welded part according to comparative example Side view of the bracket according to the comparative example Side view of the bracket according to the first modification Side view of the bracket according to the second modification

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below are examples, and the present disclosure is not limited to the embodiments.

FIG. 1 is a schematic view showing an example of an exhaust system according to the present disclosure. In addition, 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 a Y direction or a vehicle vertical direction, an upward direction is referred to as "+ Y direction" or "vehicle upper side", and a downward direction is referred to as "-Y direction" or "vehicle lower side". Further, in FIG. 1, the direction perpendicular to the paper surface is referred to as the Z direction or the vehicle width direction, the front direction is referred to as "+ Z direction" or "vehicle right side", and the 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 gathering portion of the exhaust manifold 3, and a turbocharger 4. It includes an upstream exhaust passage 5, an aftertreatment device 6, and a downstream exhaust passage 7. In the case of the present embodiment, each of the above members is arranged on the right side of the vehicle of the engine 2. However, in the vehicle width direction, the arrangement of the above members with respect to the engine 2 is not limited to the structure shown in the figure.

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 aftertreatment device 6 is set at a position in the −X direction of the turbocharger 4.

The upstream exhaust passage 5 is composed of an internal space of a hollow tubular pipe 8. The pipe 8 has a function as a flow path for allowing the exhaust gas that has flowed into the internal space from the upstream opening to flow along the extending direction of the pipe 8 and flowing 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 aftertreatment device 6. The extending direction, length, and hollow cross-sectional shape of the straight pipe 8 are comprehensively determined based on the direction of the exhaust gas outlet 4a, the position of the DOC 11 (described later) in the aftertreatment device 6, and the like.

The extending direction of the pipe 8 is three-dimensionally tilted based on, for example, the position of the DOC 11. Here, for the sake of clarity, the pipe 8 is extended in the same −X direction as the exhaust gas outlet 4a, as shown in FIG. Further, 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 which is an exhaust purification device is connected to the downstream end of the pipe 8. The aftertreatment device 6 includes a DOC 11 and a diesel particulate filter (DPF) 12 for purifying the exhaust gas in a tubular case 10.

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

The DOC 11 and DPF 12 are held in the case 10 with an inorganic mat. The DOC 11 is formed in a columnar shape. Here, for the sake of clarity, the DOC 11 extends in the −Y direction. Since the basic structure and function of the DOC 11 are the same as those of the conventionally known DOC, detailed description thereof will be omitted.

The DPF 12 is formed in a columnar 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 the conventionally known DPF, detailed description thereof will be omitted.

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

Next, with reference to FIGS. 2A to 2E, details of the structure of the bracket 14 and the support structure of the bracket 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 a "width direction", and the vertical direction is referred to as a "length direction". Further, the front-back direction of FIG. 2A and the vertical direction of FIGS. 2C and 2D are referred to as "height direction". With respect to the width direction, the direction closer to the center portion in the width direction of the bracket 14 is the inside, and the direction away from the center portion in the width direction of the bracket 14 is the outside. Further, in 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. Further, in the height direction, the "one side" corresponds to the back side of FIG. 2A and the lower side of FIGS. 2C and 2D, and the "other side" also corresponds to the front side of FIG. 2A and the upper side of FIGS. 2C and 2D. 2A to 2E show a state in which the bracket 14 is welded and fixed to the case 10 in a state where the case 10 is omitted.

The bracket 14 is a so-called hat-shaped bracket, and is formed by, for example, bending a rectangular plate-shaped member made of stainless steel. The bracket 14 includes a top plate portion 141, a pair of side wall portions 142, and a pair of flange portions 143. Such a bracket 14 is for supporting the aftertreatment device 6 (specifically, the case 10 of the aftertreatment 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 an engine 2 (specifically, a second bracket 15). Such a top plate portion 141 has a rectangular plate shape that is long in the length direction when viewed from the height direction. The top plate portion 141 is formed by arranging two round holes 144a and 144b side by side in a state of being separated in the length direction. Bolts (not shown) are inserted into the round holes 144a and 144b, respectively, and fastened to nuts (not shown). As a result, the bracket 14 is fixed to the second bracket 15.

In the case of the present embodiment, the round holes 144a and 144b are circular in shape as seen from the height direction. Also, round hole 144a, the center axis _{O 144a} of one of the circular hole 144a of the 144b, and the same central axis _{O 144b} of the other round holes 144b, are aligned with respect to the width direction. However, the center _{O 144a} of one of the round holes 144a, and the center _{O 144b} of the other round holes 144b, may be adopted are displaced in the width direction. 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. As an example of the state of being assembled to the vehicle body, the virtual plane passing through the central axis O _144a of one round hole _144a and the central axis O _144b of the other round hole 144b is, for example, in the vertical direction (vertical direction of the vehicle). The bracket 14 can be fixed to the second bracket 15 so as to be parallel.

The pair of side wall portions 142 are plate-shaped members extending from both end edges in the width direction of the top plate portion 141 to one side in the height direction (lower side in FIG. 2C). Specifically, in the case of the present embodiment, the pair of side wall portions 142 extend from both end edges in the width direction of the top plate portion 141 to one side in the height direction in a state orthogonal to the top plate portion 141. Such a pair of side wall portions 142 are rectangular plates having the same shape (shape shown in FIG. 2B) when viewed from the width direction.

The shape of the pair of side wall portions 142 is not limited to the case of this embodiment. Further, the shapes of the pair of side wall portions 142 can be made different from each other. Specifically, for example, the inclination angle of one side wall portion 142 of the pair of side wall portions 142 with respect to the top plate portion 141 and the inclination angle of the other side wall portion 142 with respect to the top plate portion 141 may be different. it can. Further, the height direction dimension of one side wall portion 142 and the height direction dimension of the other side wall portion 142 can be made different from each other. The shape of the pair of side wall portions 142 is appropriately changed according to the mounting position on the case 10.

The pair of flange portions 143 are plate-shaped members extending outward in the width direction from the pair of side wall portions 142. Specifically, in the case of the present embodiment, the pair of flange portions 143 are orthogonal to the pair of side wall portions 142 outward in the width direction from one end in the height direction of the pair of side wall portions 142 (in other words, the top plate portion). It extends in a state (parallel to 141). Such a pair of flange portions 143 have plate shapes having the same shape (shape shown in FIG. 2A) when viewed from the height direction.

Hereinafter, the structure of the welded portion 16 constituting the support structure of the bracket according to the present disclosure will be described.
The welded portion 16 is divided by a notch portion 17 (described later) at a central portion in the length direction. The welded portion 16 joins the outer end surface in the width direction of the flange portion 143 divided at the central portion in the length direction and the outer peripheral surface of the case 10.

In the following description of each part of the bracket 14, the leg portion 145 may be used as including the side wall portion 142 and the flange portion 143. That is, the bracket 14 includes a pair of legs 145. The leg portion 145 is a side wall portion 142 as a plate-like member extending from both end edges in the width direction of the top plate portion 141 in the height direction (lower side in FIG. 2C), and the side wall portion 142 outside the width direction from the pair of side wall portions 142. It has a flange portion 143 as a plate-shaped member extending to the surface.

The cut portion 17 is provided in at least one of the pair of leg portions 145, and divides the welded portion 16 in the length direction. Whether the cut portion 17 is provided in both leg portions 145 or one of the leg portions 145 is determined by, for example, the position, shape, and size of the cut portion 17 provided in the leg portion 145. As will be described later, it is comprehensively determined based on the stress generated in the welded portion 16 when a load is repeatedly applied to the top plate portion 141 in the width direction.

As shown in FIG. 2A, the cut portion 17 is provided in each of the pair of leg portions 145.
As shown in FIG. 2B, the notch 17 is provided at the center of the leg 145 in the length direction. As shown in FIGS. 2D and 2E, the cut portion 17 extends from the outer end surface in the width direction of the flange portion 143 to the side wall portion 142, and has a slit 171 having a constant groove width and a diameter having the same size as the groove width. It has a semicircular back edge 172 and the like. Thereby, for example, when a load is repeatedly applied to the top plate portion 141 in the width direction, the stress generated on the back side edge 172 can be reduced.

<Effect of this embodiment>
The effect of this embodiment will be described with reference to comparative examples. FIG. 2A shows a graph showing the stress distribution applied to the welded portion 16 in the present embodiment. Further, in FIG. 2A, a graph showing the stress distribution applied to the welded portion 16 in the comparative example is shown by a broken line. FIG. 3A is a plan view of the bracket 14 according to the comparative example. FIG. 3B is a side view of the bracket 14 according to the comparative example. FIG. 4A shows a welded portion 16 in the comparative example and a graph showing the stress distribution applied to the welded portion 16. The pair of side wall portions 142 of the bracket 14 in the comparative example are continuous in the height direction over the entire length in the length direction. That is, the pair of side wall portions 142 are not formed with discontinuous portions such as a notch portion 17 that are discontinuous in the height direction. Further, the pair of flange portions 143 in the comparative example are continuous in the width direction over the entire length in the length direction. That is, the pair of flange portions 143 are not formed with discontinuous portions such as a notch portion 17 that are discontinuous in the width direction.

Further, the operation / effect of the present embodiment described below is based on the assumption that a load is repeatedly applied to the top plate portion 141 in the width direction. The following description will be given with respect to one leg portion 145 (side wall portion 142 and flange portion 143) of the bracket 14 of the present embodiment. The repetitive load applied to the top plate portion 141 is transmitted through one leg portion 145 and is repeatedly applied to the welded portion 16 as a tensile compression load in the width direction. Therefore, the stress distribution of the welded portion 16 shown in FIGS. 2A and 3A relates to the stress generated in the welded portion 16 based on the tensile compressive load in the width direction as described above.

As an example of the repetitive load applied to the top plate portion 141, there is a torsional load shown in the direction of the solid line and the direction of the broken line in FIGS. 2A and 3A. The position of the torsion center in the torsional load is the central portion in the length direction of the top plate portion 141 as shown in FIGS. 2A and 3A. In addition, the following description assumes a case where a torsional load in the solid line direction is applied to the bracket 14 as an example.

In the comparative example, when the torsional load in the solid line direction shown in FIG. 3A is applied to the bracket 14, as shown in FIG. 3A, the stress generated in the welded portion 16 due to the torsional load is the central portion in the length direction of the welded portion 16. It increases as it approaches one end 16b in the length direction from 16a. Further, the stress generated in the welded portion 16 due to the torsional load increases as the welded portion 16 approaches the other end 16c in the length direction from the central portion 16a in the length direction. As a result, one end 16b in the length direction and the other end 16c in the length direction become locations where a large stress concentration occurs. In this case, the bracket 14 may be peeled off from one end 16b in the length direction or the other end 16c in the length direction.

On the other hand, the leg portion 145 of the bracket 14 in the present embodiment has a notch portion 17 so as to divide the welded portion 16 in the length direction. FIG. 2A shows the central side ends 16d and 16e in the length direction of the divided welded portions 16. As a result, when the torsional load in the solid line direction shown in FIG. 2A is applied to the bracket 14, the stress generated in the welded portion 16 due to the torsional load is the central end in the length direction of the welded portion 16 as shown in FIG. 2A. The 16d and 16e are larger than the comparative example, and the central end 16d and 16e in the length direction are larger than the comparative example, and the one end 16b in the length direction and the other end 16c in the length direction are smaller than the comparative example. As a result, the stress generated in the welded portion 16 due to the torsional load is made uniform. As a result, a large stress concentration does not occur at one end 16b in the length direction and the other end 16c in the length direction, and the bracket 14 can be prevented from peeling from the case 10.

<Modification example>
Next, each modification will be described with reference to FIGS. 4A and 4B. FIG. 4A is a side view of the bracket 14 according to the first modification.

In the above embodiment, as shown in FIG. 2B, the back edge 172 of the notch 17 has a semicircular shape having a diameter having the same diameter as the groove width of the slit 171.

On the other hand, in the modified example 1, as shown in FIG. 4A, the back side edge 172 has a circular shape having a diameter larger than the groove width of the slit 171. Thereby, for example, the stress generated on the inner edge 172 due to the torsional load can be further reduced.

In the first modification, the positions, shapes, and sizes of the slit 171 and the back edge 172 are determined according to the stress generated in the welded portion 16 due to the torsional load.

For example, the higher the position of the back edge 172, the greater the stress generated at the central end 16d, 16e in the longitudinal direction due to the torsional load, and the greater the stress, the greater the stress generated at one end 16b in the longitudinal direction and the other end in the longitudinal direction. The stress generated in 16c tends to be small. As a result, the position where the back edge 172 is provided is determined so that the stress generated at the central side ends 16d and 16e in the length direction and the stress generated at one end 16b in the length direction and the other end 16c in the length direction are the same. As a result, the stress generated in the welded portion 16 due to the torsional load can be made more uniform.

Further, for example, the larger the diameter of the circular shape of the inner edge 172, the greater the stress generated at the central side ends 16d and 16e in the length direction due to the torsional load, and the larger the stress, the larger the one end 16b and the length in the length direction. The stress generated at the other end 16c in the direction tends to be small. As a result, the size of the circular shape of the back edge 172 is such that the stress generated at the central side ends 16d and 16e in the length direction and the stress generated at the one end 16b in the length direction and the other end 16c in the length direction are the same. The stress generated in the welded portion 16 due to the torsional load can be made more uniform.

Further, for example, as the groove width of the slit 171 is narrowed, the welding length of the welded portion 16 becomes longer, so that the stress generated in the welded portion 16 due to the torsional load can be reduced.

Further, the combination of the position of the slit 171 and the position of the back side edge 172 is, for example, the combination of the groove width of the slit 171 and the diameter of the back side edge 172 depends on the stress generated in the welded portion 16 due to the torsional load. Is appropriately selected.

FIG. 4B is a side view of the bracket 14 according to the modified example 2.
In the first modification, the back edge 172 has a circular shape. On the other hand, in the second modification, the back edge 172 has a water droplet shape having a semicircular shape having a diameter larger than the groove width, as shown in FIG. 4B. In the second modification, as in the first modification, the positions, shapes, and sizes of the slit 171 and the back edge 172 are determined according to the stress generated in the welded portion 16 due to the torsional load.

In the above embodiment, the cut portions 17 are provided in the pair of leg portions 145, respectively. The present invention is not limited to this, and the cut portion 17 may be provided in either one of the pair of leg portions 145 in response to the stress generated in the welded portion 16 due to, for example, a torsional load.

Further, in the above embodiment, the cut portion 17 is provided in the side wall portion 142 and the flange portion 143. The present invention is not limited to this, and may be provided only on the flange portion 143 according to the stress generated on the welded portion 16 due to, for example, a torsional load.

Further, in the above-described embodiment and each modification, the cut portion 17 is provided according to the stress generated in the welded portion 16 due to the torsional load as an example of the repeated load applied to the top plate portion 141. However, the present invention is not limited to this, and the cut portion 17 may be provided according to the stress generated in the welded portion 16 due to the tensile compression load in the length direction or the width direction.

Further, in the above embodiment, the case 10 containing the DOC 11 and the DPF 12 has been described, but the present invention is not limited to this. For example, DPF12 may be omitted. Further, instead of DOC11, various catalysts for purifying exhaust gas may be used, such as a lean NOx trap catalyst (LNT) as another catalyst and a selective catalytic reduction catalyst (SCR). Further, various catalysts for purifying exhaust gas such as DOC, LNT, SCR, etc. may be accommodated downstream of the catalyst instead of DPF12.

The bracket of the present disclosure is useful as a support structure of an exhaust gas purification device, which is required to surely prevent the bracket from peeling off from the case of the exhaust gas purification device.

6 Aftertreatment device 10 Case 14 Bracket 141 Top plate 142 Side wall 143 Flange 144a, 144b Round hole 145 Leg 16 Welded 17 Notch 171 Slit 172 Back side edge

Claims (3)

The top plate portion and the top plate portion extend from both ends in the width direction to one side in the height direction, extend from one end in the height direction to the outside in the width direction, and the outer end in the width direction extends through the welded portion. With a pair of legs, which are fixed to the outer peripheral surface of the case,
At least one leg of the pair of legs have a cut portion for dividing the welded portion in the length direction,
The leg portion has a side wall portion extending from one end in the width direction of the top plate portion to one side in the height direction, and a flange portion extending outward in the width direction from one end portion in the height direction.
The cut portion is provided in the flange portion and the side wall portion.
The cut portion has a slit extending from the outer end in the width direction to the side wall portion, and a semicircular inner side having a diameter larger than the groove width of the slit, which is provided in the side wall portion and communicates with the slit. Bracket with rim and . The bracket according to claim 1, wherein the cut portion is provided at a central portion in the length direction of the leg portion. A bracket support structure in which the bracket according to claim 1 or 2 is supported on the case via the welded portion.

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