JP7704728B2 - Exhaust pipe - Google Patents

Description

This disclosure relates to an exhaust pipe.

Turbochargers and parts used in the vicinity of vehicle engines are exposed to high-temperature exhaust gases and therefore require high-temperature oxidation resistance, and are also required to be resistant to repeated oxidation as they are repeatedly heated and cooled. In particular, exhaust gas is prone to drift downstream of the turbocharger. For this reason, there is a risk that the heat of drifted exhaust gas may cause localized damage to the part of the exhaust pipe fastened by a V-clamp downstream of the turbocharger, as described in Patent Document 1.

In response to this, it has been considered to construct these parts from highly heat-resistant materials, but this can make machining the shape, welding, etc. difficult and increase costs. Furthermore, there are cases where it is difficult to change the material of a part partially. In such cases, it becomes necessary to change the material of the entire part even though only a part of it will be damaged by high temperatures, resulting in unnecessary increases in costs.

JP 2018-59461 A

In view of these problems, it has been considered to improve the heat resistance of the exhaust pipe by clamping a cover member between the edges of the exhaust pipe opening, which are fastened with a V-clamp or the like, and locally covering the periphery of the edges on the inner circumferential surface of the exhaust pipe with the cover member. However, there is a risk that such a cover member may shift circumferentially along the edges of the exhaust pipe opening due to the effects of vehicle vibration and the repeated thermal expansion due to heating and contraction due to cooling.

On the other hand, it is conceivable that such a cover member may not be provided around the entire edge of the opening, but may be positioned so as not to cover part of the edge. In such cases, exposed areas are formed around the edge that are not covered by the cover member. If such a cover member becomes misaligned in the circumferential direction, there is a risk that areas that are prone to localized damage due to biased exhaust gas will not be covered by the cover member.

In one aspect of the present disclosure, it is desirable to suppress displacement of the cover member provided at the end of the exhaust pipe.

One aspect of the present disclosure is an exhaust pipe that forms a flow path for exhaust gas of a vehicle, and includes a first end, a first flange portion, and a cover member. The first end has a first opening. The first flange portion is provided at the first end. The cover member is provided at the first end. The first flange portion is configured to be fastened to a second flange portion provided at a second end of another exhaust pipe connected to the first end of the exhaust pipe. The cover member has a clamping portion and an inner peripheral portion. The clamping portion is clamped by the first end and the second end when the first flange portion and the second flange portion are fastened. The inner peripheral portion covers a portion of the inner peripheral surface of the exhaust pipe adjacent to the first opening. The cover member is a curved member extending from the third end to the fourth end, and is configured to be provided at the first end so that the third end and the fourth end face each other with a gap therebetween. The exhaust pipe further includes a suppression portion that suppresses the cover member provided at the first end from being displaced along the first edge portion that surrounds the first opening.

According to the above-described configuration, the suppression portion can suppress displacement of the cover member in the circumferential direction of the first opening, thereby suppressing displacement of the cover member provided at the end of the exhaust pipe.
In one aspect of the present disclosure, the other exhaust pipe may discharge exhaust gas that has passed through an outlet of a wastegate, which is a flow path of exhaust gas that bypasses turbine blades of a turbocharger. The outlet may be configured to be opened and closed by a valve body that rotates about a rotation axis extending along an edge of the outlet. The outlet may include a first opening and an outlet of the wastegate. A section of the flow path of the exhaust gas inside the exhaust pipe and the other exhaust pipe may be defined as an inlet section. In the first opening, a linear area through which the rotation axis of the outlet of the wastegate passes when the rotation axis is moved along the flow direction of the exhaust gas in the inlet section may be defined as a rotation axis area, and a area through which the outlet passes when the outlet is moved along the flow direction of the exhaust gas in the inlet section may be defined as an outlet area. The gap in the cover member may be located on the opposite side of the outlet area from a straight line that includes the rotation axis area and is parallel to the rotation axis area.

Here, the portion of the inner circumferential surface of the exhaust pipe that is not covered by the cover member due to the gaps in the cover member being located therein is defined as the exposed portion. With the above configuration, it is possible to prevent the flow of exhaust gas from concentrating on the exposed portion of the inner circumferential surface of the exhaust pipe.

In one aspect of the present disclosure, a portion of the first end that faces the clamping portion of the cover member may be the clamping surface. The suppression portion may have a first suppression portion and a second suppression portion. The first suppression portion is a recessed portion in the clamping surface of the first end. The second suppression portion protrudes from the clamping portion toward the first end and is disposed on the first suppression portion.

According to the above configuration, it is possible to suitably suppress displacement of the cover member provided at the end of the exhaust pipe.
In one aspect of the present disclosure, a portion of the first end portion that faces the clamping portion of the cover member may be the clamping surface. The suppression portion may be a portion that protrudes from the clamping surface of the first end portion toward the other exhaust pipe. The cover member may be provided at the first end portion with the gap positioned at the suppression portion.

The above configuration effectively prevents the cover member provided at the end of the exhaust pipe from shifting.

FIG. 2 is a cross-sectional view taken along an axis of first and second end portions of first and second exhaust pipes that are fastened together in the first embodiment. FIG. 2 is a perspective view of a first end portion of a first exhaust pipe in the first embodiment. 10 is an enlarged view of a first suppression portion of a first edge portion, a slit of a cover member, and a second suppression portion in the first embodiment. FIG. FIG. 4 is a front view of a first end of a first exhaust pipe, illustrating the position of a slit in a cover member in the first embodiment. 13 is a front view of a first end of a first exhaust pipe, illustrating the position of a slit in a cover member in a modified example of the first embodiment. FIG. 13 is a front view of a first end of a first exhaust pipe, illustrating the position of a slit in a cover member in a modified example of the first embodiment. FIG. FIG. 11 is a perspective view of a first end portion of a first exhaust pipe according to a second embodiment. 13 is an enlarged view of a first suppression portion of a first edge portion and a second suppression portion of a cover member in a second embodiment. FIG. FIG. 13 is a perspective view of a first end portion of a first exhaust pipe according to a third embodiment. 13 is an enlarged view of a first suppression portion of a first edge portion and a slit of a cover member in a third embodiment. FIG.

Embodiments of the present disclosure will be described below with reference to the drawings. Note that the embodiments of the present disclosure are not limited to the following embodiments, and may take various forms as long as they fall within the technical scope of the present disclosure.

[1. First embodiment]
[(1) First exhaust pipe]
The first exhaust pipe 1 constitutes a flow path for exhaust gas from an engine of a vehicle (see FIG. 1). As an example, the first exhaust pipe 1 is fastened by a V-clamp 5 to the downstream side of a second exhaust pipe 3 (in other words, another exhaust pipe) that discharges exhaust gas from a turbocharger. The first exhaust pipe 1 is also configured to accommodate a purification member (e.g., a catalyst or a filter) that purifies the exhaust gas.

The first and second exhaust pipes 1, 3 may be made of, for example, austenitic steel material having heat resistance. However, the first and second exhaust pipes 1, 3 are not limited to being made of austenitic steel material, and may be made of other steel materials having heat resistance. Furthermore, the second exhaust pipe 3 may be made of a material having higher heat resistance than the material making up the first exhaust pipe 1.

The first exhaust pipe 1 includes a first end portion 10, a first opening 11, a first flange portion 12, and a cover member 2 (see FIGS. 1 and 2).
The first opening 11 is a circular opening located at the first end 10 of the first exhaust pipe 1. The first opening 11 is located upstream in the flow direction of exhaust gas in the first exhaust pipe 1, and is connected to the second exhaust pipe 3. The first opening 11 is not limited to being circular, and may have various shapes. Hereinafter, a straight line that passes through the center of the first opening 11 and is perpendicular to the first opening 11 will be referred to as an axis 11A.

The first flange portion 12 is provided at the first end portion 10 of the first exhaust pipe 1 and is used for fastening to the second exhaust pipe 3 .
The first end portion 10 surrounds the first opening 11 and extends in a plane in a direction perpendicular to the axis 11A of the first opening 11. The first end portion 10 includes a groove portion 13 and a first edge portion 14.

The first edge 14 is a portion that protrudes from the first end 10 toward the second exhaust pipe 3 along the axis 11A, and is adjacent to and surrounds the first opening 11. The clamping surface 14A located at the top of the first edge 14 extends in a plane in a direction perpendicular to the axis 11A. The inner circumferential surface of the first edge 14 forms the inner circumferential surface 15 of the first exhaust pipe 1.

The groove portion 13 is a groove-shaped portion provided in the first end portion 10 and surrounds the first opening 11. The groove portion 13 is provided adjacent to the outside of the first edge portion 14, and the outer peripheral surface 14B of the first edge portion 14 protrudes from the bottom surface of the groove portion 13 along the axis 11A.

The first edge portion 14 is provided with a first suppression portion 14C, which will be described later.
The cover member 2 has heat resistance and is provided at the first end portion 10. The configuration of the cover member 2 will be described later.

In addition, hereinafter, a section including the first and second openings 11, 31 in the exhaust gas flow path inside the first and second exhaust pipes 1, 3 will be referred to as an inlet section I (see FIG. 1).
[(2) Second exhaust pipe]
The second exhaust pipe 3 includes a second end 30, a second opening 31, a second flange portion 32, and a wastegate 6 (see FIG. 1).

The second opening 31 is located at the second end 30 of the second exhaust pipe 3. The second opening 31 is connected to the first opening 11 of the first exhaust pipe 1, and has the same shape as the first opening 11 (for example, a circle).

The second flange portion 32 is provided at the second end portion 30 of the second exhaust pipe 3 and is used for fastening to the first exhaust pipe 1 .
The second end 30 surrounds the second opening 31 and extends in a plane in a direction perpendicular to the axis 11A of the first opening 11 of the first exhaust pipe 1 connected to the second opening 31. The second end 30 includes a recess 33.

The recess 33 is formed in the second end 30 adjacent to and surrounding the second opening 31 , and has a bottom surface 34 and a first inner circumferential surface 35 .
The bottom surface 34 is a portion that extends in a plane in a direction perpendicular to the axis 10A of the first opening 11 connected to the second opening 31, and is provided so as to go around the inner circumferential surface of the second exhaust pipe 3. In addition, the bottom surface 34 forms a step on the inner circumferential surface of the second exhaust pipe 3, and divides the inner circumferential surface into a first inner circumferential surface 35 and a second inner circumferential surface 36.

The first inner circumferential surface 35 is adjacent to the second opening 31 and surrounds the second opening 31. The first inner circumferential surface 35 is adjacent to the second inner circumferential surface 36 across the bottom surface 34, and the diameter of the first inner circumferential surface 35 is larger than the diameter of the second inner circumferential surface 36.

[(3) Westgate]
The wastegate 6 is an exhaust gas flow path provided inside the second exhaust pipe 3, and an outlet 60 of the wastegate 6 is provided upstream of the second opening 31 (see FIG. 1). Exhaust gas that bypasses the turbine blades of the turbocharger passes through the wastegate 6. On the other hand, exhaust gas that has passed through the turbine blades passes through areas inside the second exhaust pipe 3 other than the wastegate 6. Therefore, exhaust gas that has passed through the turbine blades and exhaust gas that has bypassed the turbine blades and flows out from the outlet 60 of the wastegate 6 flow out from the second opening 31 of the second exhaust pipe 3.

The outlet 60 of the wastegate 6 is located in the inlet section I described above. In the first embodiment, as an example, the inlet section I extends straight along the axis 11A (in other words, the flow direction of the exhaust gas), and the outlet 60 of the wastegate 6 faces the first opening 11 of the first exhaust pipe 1 along the axis 11A.

A swing-type valve is provided at the outlet 60 of the wastegate 6, and the outlet 60 is opened and closed by a valve body 61 that rotates around a rotation axis 61A that extends along the edge surrounding the outlet 60. In other words, the rotation axis 61A is included in the tangent line of the edge of the outlet 60.

(4) Fastening of exhaust pipe
When the first opening 11 of the first exhaust pipe 1 and the second opening 31 of the second exhaust pipe 3 are connected, the first flange portion 12 and the second flange portion 32 are fastened together by a V-clamp 5 (see FIG. 1 ). Note that the first and second flange portions 12, 32 may be fastened together by means other than the V-clamp 5 (for example, by fastening with bolts or by welding, etc.).

When the first and second flange portions 12, 32 are fastened, the first edge portion 14 of the first end portion 10 of the first exhaust pipe 1 fits into the recessed portion 33 of the second end portion 30 of the second exhaust pipe 3. In other words, the first edge portion 14 and the recessed portion 33 are used for positioning when connecting the first exhaust pipe 1 and the second exhaust pipe 3.

When the first edge 14 is fitted into the recess 33, the clamping surface 14A of the first edge 14 faces the bottom surface 34 of the recess 33, and the outer peripheral surface 14B of the first edge 14 abuts against the first inner peripheral surface 35 of the recess 33. At this time, the outer portion of the groove 13 at the first end 10 abuts against the second end 30, and the inner peripheral surface 15 of the first exhaust pipe 1 and the second inner peripheral surface 36 of the second exhaust pipe 3 become flush with each other. In addition, a ring-shaped gasket 4 is placed in the groove 13 of the first end 10 to seal the gap between the first opening 11 and the second opening 31.

[(5) Cover Member]
The above-mentioned cover member 2 is sandwiched between the first end 10 of the first exhaust pipe 1 and the second end 30 of the second exhaust pipe 3 which are fastened together (see FIG. 1). The cover member 2 is a member curved in an arc extending from the third end 22 to the fourth end 23 (see FIGS. 2 and 3). In other words, the cover member 2 is C-shaped.

For this reason, the cover member 2 is provided on the first edge 14 of the first end 10 so that the third end 22 and the fourth end 23 face each other with a gap (hereinafter, slit 24) formed between them. As an example, the cover member 2 is press-fitted into the first edge 14 and provided on the first edge 14 in a state in which elastic deformation has occurred. The elastic force of the cover member 2 then encourages the position of the cover member 2 to be maintained. When the cover member 2 is attached to the first edge 14, it is arranged in a curved arc shape along the edge of the first opening 11.

The cover member 2 includes a clamping portion 20 , an inner peripheral portion 21 , and a second suppressing portion 25 .
The clamping portion 20 is a portion that extends in the radial direction of the cover member 2 .
The inner peripheral portion 21 is a wall-like portion that protrudes from the edge portion on the inner peripheral side of the clamping portion 20 , and is provided from the third end portion 22 to the fourth end portion 23 of the clamping portion 20 .

When the cover member 2 is provided on the first edge portion 14, the clamping portion 20 faces the clamping surface 14A of the first edge portion 14, and the inner peripheral portion 21 covers a portion of the inner peripheral surface 15 of the first exhaust pipe 1 adjacent to the first opening 11. At this time, the inner peripheral portion 21 may be in contact with the inner peripheral surface 15, or a slight gap may be formed between the inner peripheral portion 21 and the inner peripheral surface 15. Then, when the first and second flange portions 12, 32 are fastened, the clamping portion 20 is clamped between the clamping surface 14A and the bottom surface 34 of the recessed portion 33 of the second end portion 30.

The second suppression unit 25 will be described later.
Furthermore, the cover member 2 is made of a material that has higher heat resistance than the material that makes up the first end 10 of the first exhaust pipe 1, etc. Specifically, the cover member 2 may be made of a ferritic steel material, as an example. Of course, the cover member 2 may be made of other materials. Furthermore, the heat resistance of the material that makes up the cover member 2 may be the same as the heat resistance of the material that makes up the first end 10 of the first exhaust pipe 1, etc., or it may be lower.

The cover member 2 may further have an outer peripheral portion that is a wall-shaped portion that protrudes from the edge of the outer peripheral side of the clamping portion 20 in the same direction as the inner peripheral portion 21. The outer peripheral portion may also be provided from the third end 22 to the fourth end 23 of the clamping portion 20.

[(6) Suppression part]
The first suppression portion 14C of the first edge portion 14 in the first exhaust pipe 1 and the second suppression portion 25 of the cover member 2 suppress the cover member 2, which is clamped between the first and second end portions 10, 30, from being displaced circumferentially along the first edge portion 14 (see Figures 2 to 4).

The first suppression portion 14C is a notch in the first edge portion 14, and forms a recessed portion on the downstream side of the clamping surface 14A. As an example, the first suppression portion 14C forms a rectangular parallelepiped recess in the first edge portion 14, and has two wall surfaces 14D that extend downstream from the end of the clamping surface 14A and face each other in the circumferential direction.

The second suppression portion 25 is provided at the fourth end portion 23 of the cover member 2 and protrudes from the clamping portion 20 toward the first exhaust pipe 1 (in other words, toward the first end portion 10). Of course, the second suppression portion 25 may also be provided at the third end portion 22 of the cover member 2.

The cover member 2 is provided so that the first suppression portion 14C is located in the slit 24, and the second suppression portion 25 is disposed in the first suppression portion 14C. More specifically, the second suppression portion 25 extends in a curved manner from a portion located at the fourth end portion 23 of the clamping portion 20 toward the first suppression portion 14C. The second suppression portion 25 is caught on one of the wall surfaces 14D of the first suppression portion 14C, thereby suppressing the cover member 2 from being displaced in the circumferential direction of the first opening 11.

[(7) Slit Position]
Since the cover member 2 is provided with the slits 24, the portion of the inner circumferential surface 15 of the first exhaust pipe 1 where the slits 24 are located is an exposed portion that is not covered by the cover member 2. For this reason, if the flow of exhaust gas from the second exhaust pipe 3 concentrates on the exposed portion, there is a risk that the exposed portion will be damaged. Therefore, the position of the slits 24 in the cover member 2 is adjusted so that the flow of exhaust gas does not concentrate on the exposed portion (see FIG. 4). As an example, the position of the slits 24 is determined based on the rotation axis 61A of the valve body 61 in the valve at the outlet 60 of the wastegate 6.

Here, in the first opening 11, when the rotating shaft 61A is moved along the flow direction of the exhaust gas in the inlet section I (in other words, the axis 11A), the linear area through which the rotating shaft 61A passes is defined as the rotating shaft area 62A. Also, in the first opening 11, when the outlet 60 of the wastegate 6 is moved along the flow direction of the exhaust gas in the inlet section I, the area through which the outlet 60 passes is defined as the outlet area 60A.

The slit 24 includes the rotation axis region 62A and is located on the opposite side of the exit region 60A from the straight line 62B that is parallel to the rotation axis region 62A. Note that the straight line 62B crosses the first opening 11 and the first edge portion 14.

(8) Modifications of slit position
In addition, when the orientation of the outlet 60 of the wastegate 6 is inclined with respect to the axis 11B, the position of the slit 24 may be adjusted based on the direction of the exhaust gas passing through the outlet 60 (hereinafter, the outlet direction) so that the flow of the exhaust gas does not concentrate on the exposed portion. It should be noted that in this case, the outlet direction is inclined with respect to the axis 11B.

That is, the wastegate 6 has an exit section 63 and an entry section 64. The exit section 63 is a curved section that includes the exit 60 (see FIG. 5). The above-mentioned exit direction is determined based on the degree of curvature of the exit section 63 and the direction of the exit 60. The entry section 64 is a section that extends in a straight line adjacent to the upstream side of the exit section 63. The exhaust gas that enters the exit section 63 passes through the entrance 63A of the exit section 63 along the extension direction of the entry section 64 (hereinafter, the entry direction). The entry direction is different from the exit direction.

Here, the portion of the inner circumferential surfaces 15, 36 of the first and second exhaust pipes 1, 3 that form the inlet section I through which the outlet 60 of the wastegate 6 passes when the outlet 60 is moved in the outlet direction is defined as the first extension region 60B. The first extension region 60B intersects with the first edge portion 14 or is located upstream of the first edge portion 14.

The portion of the first edge 14 through which the first extension region 60B passes when moved in the flow direction of the exhaust gas in the inlet section I is defined as a first impossible region N0. The portion of the first edge 14 facing the first impossible region N0 across the center of the first opening 10 (in other words, the axis 11A) is defined as a second impossible region N1. The first impossible region N0 and the second impossible region N1 are in a point-symmetric relationship with respect to the axis 11A.

The flow of exhaust gas from the wastegate 6 tends to concentrate in the peripheral portion of the first impossible area N0 on the inner surface 15 of the first exhaust pipe 1. Furthermore, after the exhaust gas collides with the peripheral portion of the first impossible area N0, it heads toward the front of the peripheral portion, so the flow of exhaust gas from the wastegate 6 also tends to concentrate in the peripheral portion of the second impossible area N1 on the inner surface 15 of the first exhaust pipe 1.

For this reason, the slits 24 of the cover member 2 may be arranged in areas other than the first and second impossible areas N0 and N1 of the first edge portion 14. This helps to prevent the flow of exhaust gas from concentrating on the exposed portion.

Alternatively, the position of the slit 24 may be determined as follows. That is, in the inner circumferential surfaces 15, 36 of the first and second exhaust pipes 1, 3 forming the inlet section I, the portion through which the inlet 63A of the outlet section 63 passes when the inlet 63A is moved in the entry direction is defined as the second extension region 63B (see FIG. 6). The second extension region 63B is located upstream of the first edge 14. The portion of the first edge 14 through which the second extension region 63B passes when moved in the exhaust gas flow direction of the inlet section I is defined as the reference region R.

Furthermore, in the first edge portion 14, the area between the first impossible area NO and the end of the reference area R closest to the first impossible area NO is defined as an intermediate area. The first impossible area NO and the intermediate area are defined as a third impossible area N2. In addition, in the first edge portion 14, the portion facing the third impossible area N2 across the center of the first opening 10 is defined as a fourth impossible area N3. The third impossible area N2 and the fourth impossible area N3 are in a point-symmetric relationship with respect to the axis 11A.

Considering the shape of the wastegate 6, the flow of exhaust gas from the wastegate 6 tends to concentrate in the peripheral portion of the third impossible area N2 on the inner surface 15 of the first exhaust pipe 1. Furthermore, the flow of exhaust gas from the wastegate 6 also tends to concentrate in the peripheral portion of the fourth impossible area N3 on the inner surface 15 of the first exhaust pipe 1.

For this reason, the slits 24 of the cover member 2 may be arranged in areas other than the third and fourth impossible areas N2 and N3 of the first edge portion 14. This helps to prevent the flow of exhaust gas from concentrating on the exposed portion.

[2. Second embodiment]
The first exhaust pipe 1 of the second embodiment differs from that of the first embodiment in the configuration of the suppression portion. The following describes the differences between the first exhaust pipe 1 of the second embodiment and the first embodiment.

In the second embodiment, the first suppression portion 14C of the first exhaust pipe 1 forms a recessed portion on the clamping surface 14A, as in the first embodiment (see Figures 7 and 8). In the second embodiment, the first suppression portion 14C forms, as an example, a triangular recess on the first edge portion 14 when viewed in the radial direction.

On the other hand, the second suppression portion 25 of the cover member 2 is provided at a position away from the third and fourth ends 22, 23 of the cover member 2, and is configured as a protrusion that protrudes toward the first exhaust pipe 1 side in the clamping portion 20. As an example, the second suppression portion 25 has a triangular bent shape.

The cover member 2 is provided so that the second suppression part 25 is disposed in the first suppression part 14C. As an example, the second suppression part 25 is fitted into the first suppression part 14C, thereby suppressing the cover member 2 from being displaced in the circumferential direction of the first opening 11.

[3. Third embodiment]
The first exhaust pipe 1 of the third embodiment differs from that of the first embodiment in the configuration of the suppression portion. The following describes the differences between the first exhaust pipe 1 of the third embodiment and the first embodiment.

In the third embodiment, the cover member 2 does not have a second suppression portion (see Figures 9 and 10). On the other hand, the first suppression portion 14C of the first exhaust pipe 1 is configured as a portion that protrudes from the clamping surface 14A of the first edge portion 14 toward the second exhaust pipe 3.

The cover member 2 is provided on the first edge portion 14 so that the first suppression portion 14C is located in the slit 24. In other words, the first suppression portion 14C is located between the third and fourth ends 22, 23 of the cover member 2, and the third or fourth end 22, 23 of the cover member 2 abuts against the first suppression portion 14C, thereby suppressing the displacement of the cover member 2 in the circumferential direction of the first opening 11. Note that there is a slight gap between the first suppression portion 14C and the third and fourth ends 22, 23, but the third and fourth ends 22, 23 may abut against the first suppression portion 14C.

[4. Effects]
(1) According to the first and second embodiments, the first suppression portion 14C of the first exhaust pipe 1 and the second suppression portion 25 of the cover member 2 can suppress displacement of the cover member 2 provided at the first end portion 10 of the first exhaust pipe 1. Furthermore, according to the third embodiment, the first suppression portion 14C and the slits 24 of the cover member 2 can suppress displacement of the cover member 2 provided at the first end portion 10 of the first exhaust pipe 1.

(2) The position of the slit 24 in the cover member 2 is determined based on the position of the rotation axis 62 when the valve body 61 opens and closes the outlet 60 of the wastegate 6. That is, the slit 24 includes the rotation axis region 62A in the first opening 10, and is located on the opposite side of the outlet region 60A from a straight line 62B parallel to the rotation axis region 62A. Therefore, when the valve body 61 opens the outlet 60, the valve body 61 prevents the exhaust gas flowing out of the outlet 60 from moving toward the slit 24. This prevents the flow of exhaust gas from concentrating on the exposed portion of the inner surface 15 of the first exhaust pipe 1.

5. Other embodiments
(1) In the first to third embodiments, a cover member 2 may be provided on the second end portion 30 with a similar configuration, and the cover member 2 may cover the inner peripheral surface of the second exhaust pipe 3 .

In the first to third embodiments, the cover member 2 is provided on the first end 10 located downstream of the turbocharger and upstream of the first exhaust pipe 1 that houses the purification member. However, this is not limited to this, and for example, the downstream end of the first exhaust pipe 1, the end of another exhaust pipe mounted on the vehicle, and the end of the exhaust pipe fastened to these ends may be configured in the same manner as the first and second ends 10, 30. Then, the cover member 2 may be provided on these fastened ends in the same manner as in the above embodiments.

(2) In the first to third embodiments, the clamping portion 20 of the cover member 2 is disposed on the clamping surface 14A located at the top of the first edge portion 14. However, for example, the portion adjacent to the first opening 11 at the first end portion 10 formed as a flat surface without a step may be used as the clamping surface, and the clamping portion 20 of the cover member 2 may be disposed on the clamping surface. Also, for example, a step may be formed surrounding the first opening 11 by recessing the portion adjacent to the first opening 11 at the first end portion 10, and the bottom surface of the step may be used as the clamping surface, and the clamping portion 20 of the cover member 2 may be disposed on the clamping surface. Then, similarly to the first to third embodiments, the first suppression portion 14C may be formed in the portion where the clamping portion 20 is disposed, and the second suppression portion 25 may be formed in the cover member 2.

(3) Multiple functions possessed by one component in the above embodiments may be realized by multiple components, or one function possessed by one component may be realized by multiple components. Also, multiple functions possessed by multiple components may be realized by one component, or one function realized by multiple components may be realized by one component. Also, part of the configuration of the above embodiments may be omitted. Also, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

1...first exhaust pipe, 10...first end, 11...first opening, 11A...axis, 12...first flange portion, 14...first edge portion, 14A...clamping surface, 14B...outer peripheral surface, 14C...first suppression portion, 14D...wall surface, 15...inner peripheral surface, 2...cover member, 20...clamping portion, 21...inner peripheral portion, 22...third end portion, 23...fourth end portion, 24...slit, 25...second suppression portion, 3...second exhaust pipe, 30...second end portion, 31...second opening, 32...second flange portion, 33...depression portion, 34...bottom surface, 35...first inner peripheral surface, 36...second inner peripheral surface, 5...V-clamp, 6...wastegate, 60...outlet, 60A...outlet area, 61...valve body, 62...rotation shaft, 62A...rotation shaft area, 62B...straight line.

Claims (4)

An exhaust pipe forming a flow path of exhaust gas of a vehicle,
a first end portion having a first opening;
A first flange portion provided at the first end portion;
a cover member provided at the first end,
the first flange portion is configured to be fastened to a second flange portion provided at a second end portion of another exhaust pipe connected to the first end portion of the exhaust pipe,
The cover member is
a clamping portion that is clamped between the first end portion and the second end portion when the first flange portion and the second flange portion are fastened to each other;
an inner circumferential portion that covers a portion of an inner circumferential surface of the exhaust pipe that is adjacent to the first opening,
the cover member is a curved member extending from a third end to a fourth end, and is configured to be provided on the first end such that the third end and the fourth end face each other with a gap therebetween;
The exhaust pipe further includes a suppression portion that suppresses displacement of the cover member provided at the first end along a first edge portion that surrounds the first opening. 2. The exhaust pipe according to claim 1,
the other exhaust pipe discharges exhaust gas that has passed through an outlet of a wastegate, which is a flow path for exhaust gas that bypasses turbine blades of a turbocharger, and the outlet is configured to be opened and closed by a valve body that rotates around a rotation axis extending along an edge of the outlet;
a section of a flow path of exhaust gas inside the exhaust pipe and the other exhaust pipe, the section including the first opening and the outlet of the wastegate, is defined as an inlet section;
In the first opening, a linear region through which the rotation axis of the outlet of the wastegate passes when the rotation axis is moved along the flow direction of the exhaust gas in the inlet section is defined as a rotation axis region, and a region through which the outlet passes when the outlet is moved along the flow direction of the exhaust gas in the inlet section is defined as an outlet region,
an exhaust pipe, the gap of the cover member being located on the opposite side of the outlet region from a straight line that includes the rotation shaft region and is parallel to the rotation shaft region; The exhaust pipe according to claim 1 or 2,
A portion of the first end portion facing the clamping portion of the cover member is a clamping surface,
The suppression portion is
a first suppression portion that is a recessed portion on the clamping surface of the first end portion;
A second suppression portion protruding from the clamping portion toward the first end portion and disposed on the first suppression portion;
An exhaust pipe having The exhaust pipe according to claim 1 or 2,
A portion of the first end portion facing the clamping portion of the cover member is a clamping surface,
the suppression portion is a portion of the first end portion that protrudes from the clamping surface toward the other exhaust pipe,
The cover member is provided at the first end with the gap positioned at the suppression portion.

Images