JP6812741B2 - Seal structure of exhaust purification device - Google Patents

Description

The present invention relates to a seal structure of an exhaust gas purification device.

Conventionally, an exhaust gas purification device that purifies the exhaust gas discharged from an engine is known. As such an exhaust gas purification device, for example, in Patent Document 1, an upstream side pipe portion (referred to as an inner shell in Patent Document 1) in which a filter for exhaust gas purification is arranged inside and an upstream side pipe portion thereof. It is disclosed that the downstream side pipe portion is arranged in parallel with respect to the above side, and a communication portion for communicating the exhaust outlet of the upstream side pipe portion and the exhaust inlet of the downstream side pipe portion is provided. Further, in Patent Document 1, as a sealing structure of such an exhaust gas purification device, a gas sealing member sandwiched between an upstream side pipe portion and a downstream side pipe portion (referred to as a sealing material in Patent Document 1) is provided. What you have is disclosed.

Japanese Unexamined Patent Publication No. 2005-155533

In the case of the seal structure of the exhaust purification device as described above, when the upstream pipe portion and the downstream pipe portion are thermally deformed in the axial direction and the radial direction, the gas seal member is attached to the upstream pipe portion and the downstream pipe portion. There is a possibility that the gas seal member will not be in close contact with the upstream pipe portion or the downstream pipe portion because it cannot be deformed following the thermal deformation. In this case, the gas seal member cannot exert its sealing function, and as a result, the exhaust gas on the upstream side of the filter may bypass the filter on the downstream side without passing through the filter.

The present invention has been made in view of the above, and an object of the present invention is to filter the exhaust on the upstream side of the filter when the upstream pipe portion and the downstream pipe portion are thermally deformed in the axial and radial directions. It is an object of the present invention to provide a seal structure of an exhaust purification device capable of suppressing bypassing to the downstream side of the filter without passing through the filter.

In order to achieve the above object, the seal structure of the exhaust purification device according to the present invention includes an upstream pipe portion in which the exhaust discharged from the engine flows inside and a filter for exhaust purification is arranged inside. Seal of an exhaust purification device including a downstream pipe portion arranged in parallel with the upstream pipe portion and a communication portion communicating the exhaust outlet of the upstream pipe portion and the exhaust inlet of the downstream pipe portion. A gas seal member which is sandwiched between the upstream side pipe portion and the downstream side pipe portion, forms a part of a wall portion of the communication portion, and suppresses exhaust leakage from the communication portion, and the above. When the upstream side pipe portion and the downstream side pipe portion are thermally deformed in the axial direction and the radial direction, the gas seal member is brought into close contact with the upstream side pipe portion and the downstream side pipe portion in accordance with the thermal deformation. With a thermal deformation following structure , one direction in the axial direction is the first direction, the direction opposite to the first direction in the axial direction is the second direction, and the radial direction is from the upstream side pipe portion. When the direction approaching the downstream pipe portion is the third direction and the direction opposite to the third direction in the radial direction is the fourth direction, the gas seal member in the pipe wall portion of the upstream pipe portion. A protrusion protruding in the third direction is provided on the portion on the side of the first direction, and a portion of the pipe wall portion of the downstream side pipe portion on the side of the protrusion in the second direction. Is provided with an inclined portion that is inclined obliquely with respect to the axial direction, and the thermal deformation following structure is provided on the side of the pipe wall portion of the downstream side pipe portion in the second direction with respect to the inclined portion. The portion is provided with a spring structure for urging the inclined portion in the first direction, and the gas seal member is urged by the spring structure from the inclined portion in the first direction and the said. A pressure in the fourth direction is applied, and a pressure in the second direction is applied from the side surface of the protrusion facing the second direction, from the protrusion of the pipe wall portion of the upstream pipe portion. Is also characterized in that it has a structure in which the pressure in the third direction is applied from the portion on the side in the second direction .
Alternatively, in order to achieve the above object, the seal structure of the exhaust purification device according to the present invention includes an upstream pipe portion in which the exhaust discharged from the engine flows inside and a filter for exhaust purification is arranged inside. An exhaust purification device including a downstream side pipe portion arranged in parallel with the upstream side pipe portion, and a communication portion for communicating the exhaust outlet of the upstream side pipe portion and the exhaust inlet of the downstream side pipe portion. A gas seal member that is sandwiched between the upstream side pipe portion and the downstream side pipe portion, constitutes a part of the wall portion of the communication portion, and suppresses exhaust leakage from the communication portion. When the upstream side pipe portion and the downstream side pipe portion are thermally deformed in the axial direction and the radial direction, the gas seal member is attached to the upstream side pipe portion and the downstream side pipe portion in accordance with the thermal deformation. It is provided with a thermal deformation following structure for close contact, one direction in the axial direction is the first direction, the direction opposite to the first direction in the axial direction is the second direction, and the upstream side pipe in the radial direction. When the direction from the portion approaching the downstream side pipe portion is the third direction and the direction opposite to the third direction in the radial direction is the fourth direction, the gas in the pipe wall portion of the upstream side pipe portion. A protrusion protruding in the third direction is provided on the portion on the side of the seal member in the first direction, and the side of the pipe wall portion of the downstream side pipe portion in the second direction with respect to the protrusion. The portion is provided with an inclined portion that is inclined obliquely with respect to the axial direction, and the thermal deformation following structure is formed between the side surface of the protruding portion facing the second direction and the gas seal member. The gas seal member is provided with a spring structure that applies pressure in the second direction to the gas seal member, and the gas seal member is subjected to pressure in the second direction from the spring structure. Pressure is applied from the inclined portion in the first direction and the fourth direction, and the pressure in the third direction is applied from the portion of the pipe wall portion of the upstream side pipe portion in the second direction to the protrusion. It is characterized by having a structure that imparts.

According to the present invention, since the above-mentioned thermal deformation following structure is provided, the gas seal member is the upstream side pipe even when the upstream side pipe portion and the downstream side pipe portion are thermally deformed in the axial direction and the radial direction. It is possible to prevent the portion or the downstream side pipe portion from becoming in close contact with each other. As a result, it is possible to prevent the exhaust gas on the upstream side of the filter from bypassing to the downstream side of the filter without passing through the filter.

It is a block diagram which shows typically the structure of a part of the vehicle which concerns on embodiment. 2 (a) and 2 (b) are cross-sectional views for explaining the outline configuration and the details of the seal structure of the exhaust gas purification device according to the embodiment. 3A and 3B are cross-sectional views for explaining the outline configuration and the details of the seal structure of the exhaust gas purification device according to the modified example of the embodiment. It is sectional drawing for demonstrating the seal structure which concerns on a comparative example.

Hereinafter, the seal structure 60 of the exhaust gas purification device 10 according to the embodiment of the present invention will be described with reference to the drawings. Specifically, first, the schematic configuration of the vehicle 1 to which the exhaust gas purification device 10 according to the present embodiment is applied will be described, then the schematic configuration of the exhaust gas purification device 10 will be described, and then the details of the seal structure 60 will be described. To do.

FIG. 1 is a configuration diagram schematically showing a partial configuration of a vehicle 1 according to the present embodiment. The vehicle 1 is provided in the engine 2, the intake passage 4 through which the intake air introduced into each cylinder 3 of the engine 2 passes, the exhaust passage 5 through which the exhaust gas discharged from each cylinder 3 of the engine 2 passes, and the exhaust passage 5. It is provided with an arranged exhaust gas purification device 10. The seal structure 60 according to the present embodiment is the seal structure of the exhaust gas purification device 10. The type of the engine 2 is not particularly limited, and a diesel engine, a gasoline engine, or the like can be used. In this embodiment, a diesel engine is used as an example of the engine 2.

2 (a) and 2 (b) are cross-sectional views for explaining the schematic configuration of the exhaust gas purification device 10 and the details of the seal structure 60 according to the present embodiment. Specifically, FIG. 2A shows a schematic cross section obtained by extracting a part of the cut surface obtained by cutting the exhaust gas purification device 10 at the surface including the central axis 100 of the upstream side pipe portion 30 above the central axis 100. It is a figure. FIG. 2B is an enlarged cross-sectional view of the peripheral structure of the gas seal member 61 of FIG. 2A.

With reference to FIG. 2A, the exhaust gas purification device 10 parallels the filter 20 for exhaust gas purification, the upstream pipe portion 30 in which the filter 20 is arranged, and the upstream pipe portion 30. It includes an arranged downstream side pipe portion 40, a communication portion 50 that communicates the upstream side pipe portion 30 and the downstream side pipe portion 40, and a seal structure 60.

Here, in FIG. 2A, one of the axial directions (direction along the central axis 100) of the upstream side pipe portion 30 and the downstream side pipe portion 40 (the left direction in the figure) is referred to as a first direction. The direction opposite to the first direction is referred to as the second direction. Further, the direction in which the upstream side pipe portion 30 and the downstream side pipe portion 40 approach the downstream side pipe portion 40 from the upstream side pipe portion 30 in the radial direction (direction perpendicular to the axial direction) is referred to as a third direction, and is referred to as a third direction. The direction opposite to is referred to as the fourth direction. The exhaust gas discharged from the engine 2 flows in the first direction inside the upstream pipe portion 30, and flows in the second direction inside the downstream pipe portion 40.

The specific configuration of the filter 20 is not particularly limited as long as it can collect PM and the like contained in the exhaust gas. In the present embodiment, as an example of the filter 20, a diesel particulate filter, specifically, a wall-through type diesel particulate filter is used.

The pipe wall portion 31 constituting the upstream side pipe portion 30 includes a cylindrical wall portion 32 (cylindrical pipe wall portion) extending in the axial direction of the upstream side pipe portion 30 and a first direction side of the cylindrical wall portion. It is provided with a vertical wall portion 33 that is connected to the end surface and extends in the radial direction of the upstream side pipe portion 30. The filter 20 is arranged inside the cylindrical wall portion 32. Further, the exhaust outlet 34 of the upstream pipe portion 30 is provided on the cylindrical wall portion 32 on the downstream side (first direction side) of the filter 20.

The axial direction of the downstream pipe portion 40 is parallel to the axial direction of the upstream pipe portion 30. Specifically, the downstream side pipe portion 40 according to the present embodiment is composed of an annular pipe arranged around the upstream side pipe portion 30. That is, the downstream pipe portion 40 according to the present embodiment corresponds to the outer pipe portion arranged outside in the radial direction of the upstream pipe portion 30, and the upstream pipe portion 30 is inside in the radial direction of the downstream pipe portion 40. It corresponds to the inner tube part arranged in.

Further, the pipe wall portion 41 constituting the downstream side pipe portion 40 extends in the axial direction and is axially connected to the inner cylindrical wall portion 42 located on the side closer to the upstream side pipe portion 30 (the side in the fourth direction). Starting from the outer cylindrical wall portion 43 that extends and is located on the side farther from the upstream side pipe portion 30 (the side in the third direction) and the end portion of the outer cylindrical wall portion 43 on the first direction side, the fourth from here. It includes an inlet-side vertical wall portion 44 extending in the direction, and an exit-side vertical wall portion 45 extending in the fourth direction from the end of the outer cylindrical wall portion 43 on the second direction side as a starting point. ..

As will be described later, an inclined portion 46 (FIG. 2B) is provided around the gas seal member 61 in the inner cylindrical wall portion 42 of the downstream side pipe portion 40, and this inclined portion is provided. A spring structure 63 (FIG. 2A) is arranged on the end face of the 46 on the second direction side. Further, as will be described later, the spring structure 63 according to the present embodiment has a structure in which the exhaust gas flowing through the downstream pipe portion 40 does not pass through the spring structure 63.

The exhaust inlet 48 of the downstream pipe portion 40 is composed of a space provided at the end portion of the inner cylindrical wall portion 42 on the first direction side. That is, the end on the first direction side of the inner cylindrical wall portion 42 is not connected to the vertical wall portion 44 on the entrance side, and the end on the first direction side of the inner cylindrical wall portion 42 and the vertical wall portion 44 on the entrance side. A space is provided between the space and the exhaust port 48. Further, the exhaust inlet 48 is provided at a position facing the exhaust outlet 34 of the upstream pipe portion 30.

The exhaust outlet 49 of the downstream pipe portion 40 is provided near the end portion on the second direction side in the axial direction of the downstream pipe portion 40. As an example of this, the exhaust outlet 49 according to the present embodiment is provided on the outlet side vertical wall portion 45. However, the location where the exhaust outlet 49 is formed is not limited to this, and for example, the exhaust outlet 49 may be provided on the outer cylindrical wall portion 43. Further, the formation location of the exhaust outlet 49 is not limited to the end portion on the second direction side in the axial direction of the downstream side pipe portion 40 as described above, but the end portion on the second direction side of the downstream side pipe portion 40. It may be provided in a place other than the above.

The material of the upstream pipe portion 30 and the downstream pipe portion 40 may be any material having corrosion resistance to exhaust gas, and the specific material thereof is not particularly limited, but in the present embodiment, stainless steel or the like is used. Metallic material is used.

The communication portion 50 of the exhaust purification device 10 is a portion that communicates the exhaust outlet 34 of the upstream pipe portion 30 and the exhaust inlet 48 of the downstream pipe portion 40, and the exhaust gas that has passed through the exhaust outlet 34 flows into the exhaust inlet 48. It is a passage part that passes by before. Specifically, the communication portion 50 according to the present embodiment is in a region partitioned by the pipe wall portion 31 of the upstream side pipe portion 30, the pipe wall portion 41 of the downstream side pipe portion 40, and the gas seal member 61 described later. It is provided. After passing through the filter 20, the exhaust gas discharged from the engine 2 is discharged from the exhaust outlet 34 of the upstream side pipe portion 30, then passes through the communication portion 50, and is downstream from the exhaust inlet 48 of the downstream side pipe portion 40. It flows into the inside of the side pipe portion 40. After that, the exhaust gas flows inside the downstream side pipe portion 40 and flows out from the exhaust outlet 49 of the downstream side pipe portion 40.

Here, the upstream side pipe portion 30 according to the present embodiment is detachably attached to the exhaust gas purification device 10. As an example of this configuration, the upstream side pipe portion 30 according to the present embodiment is connected to the downstream side pipe portion 40 of the exhaust gas purification device 10 by a fastening member. As an example of the fastening member, the bolt 70 and the nut 71 are used in this embodiment. Specifically, the vertical wall portion 33 of the upstream side pipe portion 30 according to the present embodiment extends so as to overlap the inlet side vertical wall portion 44 of the downstream side pipe portion 40, and the bolt 70 and the nut 71 extend. By fastening the portion where the vertical wall portion 33 of the upstream side pipe portion 30 and the inlet side vertical wall portion 44 of the downstream side pipe portion 40 overlap, the upstream side pipe portion 30 and the downstream side pipe portion 40 can be attached and detached. Is connected to.

According to the exhaust gas purification device 10, since the upstream side pipe portion 30 in which the filter 20 is arranged is detachably attached to the exhaust gas purification device 10, the upstream side pipe portion 30 can be easily removed from the exhaust gas purification device 10. By removing it, the filter 20 can be easily cleaned and replaced. Further, the upstream pipe portion 30 in which the cleaned filter 20 and the replaced filter 20 are arranged can be easily attached to the exhaust gas purification device 10. As described above, according to the exhaust gas purification device 10, the maintenance work of the filter 20 can be easily performed.

Subsequently, the details of the seal structure 60 will be described. As shown in FIG. 2A, the seal structure 60 prevents the exhaust gas on the upstream side of the filter 20 from passing through the filter 20 and bypassing the exhaust gas on the downstream side of the filter 20 (that is, passing through the filter 20). It is sealed (to suppress the exhaust that bypasses without). Specifically, the seal structure 60 includes a gas seal member 61 and a thermal deformation following structure 62.

The gas seal member 61 is sandwiched between the pipe wall portion 31 of the upstream side pipe portion 30 and the pipe wall portion 41 of the downstream side pipe portion 40, and is a part of the wall portion of the communication portion 50 (the second of the communication portion 50). It is arranged so as to form a part of the wall on the direction side). The specific type of the gas sealing member 61 is not particularly limited as long as it can seal the exhaust gas, but in the present embodiment, as an example, a gasket, specifically a graphite gasket, more specifically. An expanded graphite gasket is used for this.

Although this expanded graphite gasket has good gas sealability, it cannot be said that the dimensional restoration property is very good. Therefore, when the members around the expanded graphite gasket (upstream side pipe portion 30 and downstream side pipe portion 40) are thermally deformed, the expanded graphite gasket changes its dimensions in accordance with the dimensional changes of the surrounding members. Is not easy.

Subsequently, the details of the peripheral structure of the gas seal member 61 will be described. As shown in FIG. 2B, of the cylindrical wall portion 32 of the pipe wall portion 31 of the upstream side pipe portion 30, the portion on the side in the first direction in the axial direction from the gas seal member 61 has a third direction. A protruding portion 35 is provided on the surface. Further, of the inner cylindrical wall portion 42 of the pipe wall portion 41 of the downstream side pipe portion 40, the portion on the side in the second direction from the protrusion 35 is provided with an inclined portion 46 that is inclined obliquely with respect to the axial direction. Has been done.

The gas seal member 61 includes a side surface 36 of the protrusion 35 facing the second direction, and a portion of the cylindrical wall portion 32 of the upstream pipe portion 30 that is closer to the second direction than the protrusion 35. It is sandwiched between the inclined surface 47 (the surface facing the direction between the first direction and the fourth direction) of the inclined portion 46.

Specifically, the gas seal member 61 has an annular shape as a whole. Then, the inner peripheral surface of the ring of the gas seal member 61 is in close contact with the outer peripheral surface of the cylindrical wall portion 32, and the surface of the ring on the first direction side is in close contact with the side surface 36 of the protrusion 35 on the second direction side. ing. Further, the corner portion of the ring of the gas seal member 61 in the direction between the second direction and the third direction is a chamfered portion (chamfered portion), and this chamfered portion is formed on the inclined surface 47 of the inclined portion 46. It is in close contact.

With reference to FIG. 2A again, the thermal deformation following structure 62 of the seal structure 60 is the upstream pipe portion 30.
And when the downstream side pipe portion 40 is thermally deformed in the axial direction and the radial direction, the gas seal member 61 is changed to the pipe wall portion 31 of the upstream side pipe portion 30 and the pipe of the downstream side pipe portion 40 in accordance with the thermal deformation. It has a structure that is in close contact with the wall portion 41.

As an example of this structure, the thermal deformation following structure 62 according to the present embodiment is provided in a portion of the pipe wall portion 41 of the downstream side pipe portion 40 on the side in the second direction from the inclined portion 46, and the inclined portion 46 is provided. Is provided with a spring structure 63 for urging the gas in the first direction, and pressure is applied to the gas seal member 61 from the inclined portion 46 urged by the spring structure 63 in the first direction and the fourth direction, and the protrusion portion is provided. A pressure in the second direction is applied from the side surface 36 facing the second direction side of the 35, and the third direction from the portion of the pipe wall portion 31 of the upstream side pipe portion 30 on the side in the second direction from the protrusion 35. It has a structure that applies the pressure of.

Further, the spring structure 63 according to the present embodiment has a function as an urging member for urging the inclined portion 46 in the first direction, and also a part of the pipe wall portion 41 (inner cylindrical wall) of the downstream side pipe portion 40. It also has a function as a member constituting a part of the portion 42). Therefore, the spring structure 63 according to the present embodiment has a structure in which the exhaust gas flowing through the downstream side pipe portion 40 does not leak to the outside of the downstream side pipe portion 40 through the spring structure 63. As an example of such a structure, the spring structure 63 according to the present embodiment is composed of a bellows-shaped elastic member and a leaf spring-shaped elastic member.

Specifically, in the spring structure 63 according to the present embodiment, a bellows-shaped elastic member connects the end surface of the inclined portion 46 on the second direction side and the outlet side vertical wall portion 45 of the downstream pipe portion 40. As shown above, the structure is arranged in an annular shape. As a result, the spring structure 63 urges the inclined portion 46 in the first direction while preventing the exhaust gas flowing inside the downstream side pipe portion 40 from passing through the spring structure 63.

(Modified example of embodiment)
The configurations of the exhaust gas purification device 10 and the seal structure 60 are not limited to those described above, and for example, the configurations described below (configurations of modified examples) can be used. 3A and 3B are cross-sectional views for explaining the schematic configuration of the exhaust gas purification device 10a and the details of the seal structure 60a according to the modified example of the above embodiment. Specifically, FIG. 3A is a schematic cross section obtained by extracting a part of the cut surface obtained by cutting the exhaust gas purification device 10a on the surface including the central axis 100 of the upstream side pipe portion 30a, which is above the central axis 100. It is a figure. FIG. 3B is an enlarged cross-sectional view of the peripheral structure of the gas seal member 61 of FIG. 3A.

FIG. 2 shows that the exhaust gas purification device 10a according to this modification is provided with an upstream pipe portion 30a instead of the upstream pipe portion 30 and a downstream pipe portion 40a instead of the downstream pipe portion 40. It is different from the exhaust purification device 10 shown in (a). Further, the seal structure 60a according to the present modification is different from the seal structure 60 shown in FIG. 2A in that the thermal deformation follow-up structure 62a is provided instead of the thermal deformation follow-up structure 62.

As shown in FIG. 3A, the downstream side pipe portion 40a does not have the spring structure 63, and the portion corresponding to the spring structure 63 in FIG. 2A is the inner cylindrical wall portion 42 of the pipe wall portion 41. It is different from the downstream side pipe portion 40 of FIG. 2 (a) in that it is.

As shown in FIG. 3B, the upstream side pipe portion 30a is different from the upstream side pipe portion 30 shown in FIGS. 2A and 2B in that the protrusion 35a is provided in place of the protrusion 35. It's different. The protrusion 35a is arranged on the first direction side of the gas seal member 61 so as not to be in close contact with the gas seal member 61 and to have a predetermined space between the protrusion 35a and the gas seal member 61. It is different from part 35.

The thermal deformation following structure 62a is different from the thermal deformation following structure 62 shown in FIG. 2A in that the spring structure 63a is provided instead of the spring structure 63. As shown in FIG. 3B, the spring structure 63a is provided between the side surface 36 of the protrusion 35a facing the second direction and the side surface of the gas seal member 61 facing the first direction. Therefore, the structure is such that pressure is applied to the gas seal member 61 in the second direction. As an example of this, the spring structure 63a according to the present modification is arranged between the plate member 64 in contact with the side surface of the gas seal member 61 on the first direction side, and the plate member 64 and the side surface 36 of the protrusion 35a. A spring 65 that urges the plate member 64 to the side in the second direction is provided.

The thermal deformation following structure 62a includes the above-mentioned spring structure 63a, and further applies pressure in the second direction from the spring structure 63a to the gas seal member 61, so that the inclined portion 46 gives the first direction and the first pressure. The structure is such that pressure is applied in four directions, and pressure in the third direction is applied from a portion of the pipe wall portion 31 of the upstream side pipe portion 30a on the side of the protrusion 35a in the second direction.

As the spring 65, a bellows-shaped elastic member or a leaf spring-shaped elastic member may be used as in the spring structure 63 according to FIG. 2A, but in the case of this modification, the exhaust gas is transmitted. Since it is not necessary to have a function to prevent it, for example, a coil spring or the like can be used. Therefore, in this modification, a coil spring is used as an example of the spring 65.

Subsequently, the action and effect of the seal structure 60 and the seal structure 60a will be described while comparing with the seal structure 330 according to the comparative example. FIG. 4 is a cross-sectional view for explaining the seal structure 330 according to the comparative example. Specifically, FIG. 4 is a schematic cross-sectional view of the exhaust gas purification device 300 provided with the seal structure 330 in the same manner as in FIG. 2A. Shown. The seal structure 330 according to the comparative example is different from the seal structure 60 of FIG. 2A and the seal structure 60a of FIG. 3A in that it does not include the thermal deformation following structures 62 and 62a.

In the case of the seal structure 330 according to the comparative example, when the upstream side pipe portion 310 and the downstream side pipe portion 320 of the exhaust purification device 300 thermally expand in the axial direction, the upstream side pipe portion 310 and the downstream side pipe portion 320 are shown in the drawing. Deforms in the A direction of. In this case, the gas seal member 61 receives pressure in the compression direction from the protrusion 35 and the inclined portion 46. On the other hand, when the upstream pipe portion 310 and the downstream pipe portion 320 are thermally contracted in the axial direction, the upstream pipe portion 310 and the downstream pipe portion 320 are deformed in the direction opposite to the A direction. In this case, it is difficult for the gas seal member 61 to be deformed (expanded) following the thermal deformation of the upstream pipe portion 310 and the downstream pipe portion 320, and as a result, the gas seal member 61 is formed by the upstream pipe portion 310. Alternatively, the downstream side pipe portion 320 may be separated from the pipe wall portion and may not be in close contact with the pipe wall portion.

When the gas seal member 61 does not come into close contact with the pipe wall portion in this way, the gas seal member 61 cannot exert its sealing function, and as a result, the exhaust gas on the upstream side of the filter 20 does not pass through the filter 20 and is filtered. There is a possibility of bypassing to the downstream side of 20. Specifically, the exhaust gas on the upstream side of the filter 20 does not pass through the filter 20 and passes through the portion between the cylindrical wall portion 32 of the upstream pipe portion 310 and the inner cylindrical wall portion 42 of the downstream pipe portion 320. It may pass (ie, bypass) and flow into the downstream pipe section 320.

Further, in the case of the seal structure 330 according to the comparative example, when the upstream side pipe portion 310 and the downstream side pipe portion 320 are thermally expanded in the radial direction, the upstream side pipe portion 310 and the downstream side pipe portion 320 are in the B direction in the drawing ( Transforms in the third direction). Even in this case, it is difficult for the gas seal member 61 to be deformed following the thermal deformation of the upstream pipe portion 310 and the downstream pipe portion 320, and as a result, the gas seal member 61 is the upstream pipe portion 310 or It is separated from the pipe wall portion of the downstream side pipe portion 320 and does not adhere to the pipe wall portion, and the exhaust on the upstream side of the filter 20 does not pass through the filter 20 and bypasses to the downstream side of the filter 20. there is a possibility.

On the other hand, according to the seal structure 60 according to the present embodiment described in FIGS. 2A and 2B, the upstream side pipe is provided with the thermal deformation following structure 62 having the spring structure 63. Even when the portion 30 and the downstream side pipe portion 40 are thermally deformed in the axial direction and the radial direction, the spring structure 63 follows the thermal deformation, and the spring structure 63 with respect to the gas seal member 61. Pressure is applied in the first direction and the fourth direction from the urged inclined portion 46, and pressure in the second direction is applied from the side surface 36 of the protrusion 35 facing the second direction side, and the upstream side pipe portion 30 is applied. By applying a pressure in the third direction from the portion of the pipe wall portion 31 in the second direction to the protrusion 35, the gas seal member 61 is attached to the pipe wall portion 31 and the downstream side pipe of the upstream side pipe portion 30. It can be brought into close contact with the pipe wall portion 41 of the portion 40. As a result, it is possible to prevent the exhaust gas on the upstream side of the filter 20 from bypassing to the downstream side of the filter 20 without passing through the filter 20.

Similarly, according to the seal structure 60a described above in FIGS. 3A and 3B, since the thermal deformation following structure 62a having the spring structure 63a is provided, the upstream side pipe portion 30a and the downstream side pipe portion 30a and the downstream side pipe portion are provided. Even when the 40a is thermally deformed in the axial direction and the radial direction, the spring structure 63a follows the thermal deformation, and a pressure is applied to the gas seal member 61 in the second direction from the spring structure 63a. , The pressure in the first direction and the fourth direction is applied from the inclined portion 46, and the pressure in the third direction is applied from the portion of the pipe wall portion 31 of the upstream side pipe portion 30a in the second direction from the protrusion 35a. By doing so, the gas seal member 61 can be brought into close contact with the pipe wall portion 31 of the upstream side pipe portion 30a and the pipe wall portion 41 of the downstream side pipe portion 40a. As a result, it is possible to prevent the exhaust gas on the upstream side of the filter 20 from bypassing to the downstream side of the filter 20 without passing through the filter 20.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and various modifications and modifications are made within the scope of the gist of the present invention described in the claims. Is possible.

1 Vehicle 2 Engine 10, 10a Exhaust purification device 20 Filter 30, 30a Upstream pipe 31 Pipe wall 34 Exhaust outlet 35, 35a Protrusions 40, 40a Downstream pipe 41 Pipe wall 46 Inclined 48 Exhaust inlet 50 Communication Part 60, 60a Seal structure 62, 62a Thermal deformation follow-up structure 63 Spring structure 64 Plate member 65 Spring

Claims (3)

The exhaust gas discharged from the engine flows inside, and the upstream pipe portion in which the exhaust purification filter is arranged, the downstream pipe portion arranged in parallel with the upstream pipe portion, and the downstream pipe portion described above. A seal structure of an exhaust purification device including a communication portion that communicates an exhaust outlet of an upstream pipe portion and an exhaust inlet of the downstream pipe portion.
A gas seal member sandwiched between the upstream pipe portion and the downstream pipe portion, which constitutes a part of the wall portion of the communication portion and suppresses exhaust leakage from the communication portion.
When the upstream side pipe portion and the downstream side pipe portion are thermally deformed in the axial direction and the radial direction, the gas seal member is brought into close contact with the upstream side pipe portion and the downstream side pipe portion in accordance with the thermal deformation. With a thermal deformation follow-up structure that allows
In the axial direction, one direction is the first direction, the axial direction is the second direction opposite to the first direction, and the radial direction is the direction from the upstream side pipe portion to the downstream side pipe portion. When the third direction is set and the direction opposite to the third direction in the radial direction is set as the fourth direction,
A protrusion protruding in the third direction is provided on a portion of the pipe wall portion of the upstream side pipe portion on the side of the gas seal member in the first direction.
Of the pipe wall portion of the downstream side pipe portion, a portion on the side of the protrusion in the second direction is provided with an inclined portion that is inclined obliquely with respect to the axial direction.
The thermal deformation following structure is provided in a portion of the pipe wall portion of the downstream side pipe portion on the side of the inclined portion in the second direction, and a spring that urges the inclined portion in the first direction. The gas seal member is provided with a structure, and pressures in the first direction and the fourth direction are applied to the gas seal member from the inclined portion urged by the spring structure, and the side of the protrusion in the second direction. The pressure in the second direction is applied from the side surface facing the above, and the pressure in the third direction is applied from the portion of the pipe wall portion of the upstream side pipe portion in the second direction with respect to the protrusion. The seal structure of the exhaust purification device, which is the structure. The exhaust gas discharged from the engine flows inside, and the upstream pipe portion in which the exhaust purification filter is arranged, the downstream pipe portion arranged in parallel with the upstream pipe portion, and the downstream pipe portion described above. A seal structure of an exhaust purification device including a communication portion that communicates an exhaust outlet of an upstream pipe portion and an exhaust inlet of the downstream pipe portion.
A gas seal member sandwiched between the upstream pipe portion and the downstream pipe portion, which constitutes a part of the wall portion of the communication portion and suppresses exhaust leakage from the communication portion.
When the upstream side pipe portion and the downstream side pipe portion are thermally deformed in the axial direction and the radial direction, the gas seal member is brought into close contact with the upstream side pipe portion and the downstream side pipe portion in accordance with the thermal deformation. With a thermal deformation follow-up structure that allows
In the axial direction, one direction is the first direction, the axial direction is the second direction opposite to the first direction, and the radial direction is the direction from the upstream side pipe portion to the downstream side pipe portion. When the third direction is set and the direction opposite to the third direction in the radial direction is set as the fourth direction,
A protrusion protruding in the third direction is provided on the portion of the pipe wall portion of the upstream side pipe portion on the side of the gas seal member in the first direction.
Of the pipe wall portion of the downstream side pipe portion, a portion on the side of the protrusion in the second direction is provided with an inclined portion that is inclined obliquely with respect to the axial direction.
The thermal deformation following structure is provided between the side surface of the protrusion facing the second direction and the gas seal member, and applies a pressure in the second direction to the gas seal member. In addition to having a spring structure, pressure in the second direction is applied to the gas seal member from the spring structure, and pressures in the first direction and the fourth direction are applied from the inclined portion to the upstream side. A seal structure for an exhaust purification device, which is a structure for applying pressure in the third direction from a portion of the pipe wall portion on the side of the pipe portion in the second direction with respect to the protrusion. The seal structure of the exhaust gas purification device according to claim 1 or 2 , wherein the upstream pipe portion is detachably attached to the exhaust gas purification device.

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