JP6522978B2 - Exhaust flow path valve device - Google Patents

Description

  The present invention relates to an exhaust flow path valve device.

  2. Description of the Related Art In an exhaust system of an internal combustion engine, there is known an exhaust flow path valve device which switches a flow path form by opening and closing an exhaust flow path. In this type of valve device, a valve body for closing or opening the opening is provided, and when the pressure of the exhaust gas on the upstream side is low, the opening is closed by the valve body and the valve is closed. On the other hand, when the pressure of the exhaust gas on the upstream side becomes high, the valve body is moved by the pressure of the exhaust gas, the valve is opened with the opening opened, and the form of the exhaust passage is switched.

  By the way, in the operation in which the above-mentioned valve body opens and closes the opening, when the valve body strikes the valve seat via the shock absorbing material, a hitting sound may be generated, which may cause a passenger of the vehicle to feel uncomfortable. In order to suppress such hitting noise, in the valve device described in Patent Document 1, a part of the shock absorbing material so that the shock absorbing material and the valve are in contact from a position close to the axis of the support that supports the valve. Is thicker than the other parts.

JP, 2011-69251, A

  However, Patent Document 1 presupposes a valve device in which a valve body is provided at the opening of a pipe end forming an exhaust flow passage, and a valve device in which an opening and a valve body are provided on the side surface of a pipe is not considered. The

  The present invention is directed to a valve device in which an opening and a valve body are provided on a side surface of an exhaust flow path, and it is an object of the present invention to suppress a striking sound generated when the valve body strikes a valve seat surface via a buffer material.

  One aspect of the present invention is an exhaust flow path valve device, which comprises a pipe, a valve body, a support, and a shock absorbing material. The pipe forms an exhaust flow path and has an opening on the side. The valve opens and closes the opening. The support supports the valve body so as to be rotationally movable about the rotation axis so as to close or open the opening by the valve body. The cushioning material is provided on the valve seat surface which is a portion around the opening in the pipe. Specifically, the cushioning material is formed with a lower portion and a higher portion which is closer to the rotation axis than the lower portion and higher than the lower portion with respect to the valve seat surface. Ru.

  According to such a configuration, in the valve device in which the opening and the valve body are provided on the side surface of the exhaust flow path, the shock absorbing material and the valve body abut from a position close to the rotation axis of the valve body. It becomes possible to suppress the hitting sound which occurs when a valve body hits a valve seat surface.

  In the above configuration, the shock absorbing material may be in the form of a sheet, and may be provided with a bend with respect to the valve seat surface, and the high portion may be a bulge formed by the bending of the shock absorbing material. According to such a configuration, in the valve device in which the opening and the valve body are provided on the side surface of the exhaust flow passage, the high portion can be formed by the portion where the buffer material is bent and formed. By so doing, the deflection of the high portion absorbs the impact when the valve body strikes the shock absorbing material. Therefore, when the valve body comes into contact with the valve seat surface via the shock absorbing material, it is possible to further suppress the generation of the hitting sound as compared to the case where the shock absorbing material does not form a deflection.

  In the above configuration, the buffer material may be in the form of a sheet having a constant thickness, and the high portion may be a bulge formed by folding back part of the buffer material. According to such a configuration, in the valve device in which the opening and the valve body are provided on the side surface of the exhaust flow channel, the high portion can be formed by the portion where the sheet-like buffer material is folded back. Therefore, it is not necessary to prepare a shock absorbing material having a special shape such as a partially different thickness, and the like, with a simple configuration, suppressing striking sound generated when the valve body hits the valve seat surface via the shock absorbing material. Is possible.

  In the above configuration, the exhaust flow path valve device further includes a spacer provided between the valve seat surface and the shock absorbing material, the shock absorbing material is a sheet having a constant thickness, and the high portion is the shock absorbing material. It may be a bulge formed by covering the spacer. According to such a configuration, in the valve device in which the opening and the valve body are provided on the side surface of the exhaust flow channel, the high portion can be formed at the portion where the spacer is covered by the buffer material. Therefore, it is not necessary to prepare a shock absorbing material having a special shape such as a partially different thickness, and the like, with a simple configuration, suppressing striking sound generated when the valve body hits the valve seat surface via the shock absorbing material. Is possible.

  In the above configuration, the shock absorbing material is a sheet having a portion in which the thickness monotonously increases from the low portion to the high portion, the low portion is formed at a position farthest from the rotation axis, and the high portion is the thickest of the shock absorbing material It may be a place. According to such a configuration, in the valve device in which the opening and the valve body are provided on the side surface of the exhaust flow path, it is possible to effectively suppress the striking sound generated when the valve body strikes the valve seat surface via the buffer material. Is possible.

It is an outline view of a valve device for exhaust flow passages of a 1st embodiment. It is II-II sectional drawing of FIG. It is a schematic diagram which shows arrangement | positioning of the shock absorbing material of the valve apparatus for exhaust flow paths of 1st Embodiment. It is an expanded sectional view of the valve device for exhaust flow paths of a 1st embodiment. It is an expanded sectional view of the valve device for exhaust flow paths of a 2nd embodiment. It is an expanded sectional view of the valve device for exhaust flow paths of a 3rd embodiment. It is an expanded sectional view of the valve device for exhaust flow paths of a 4th embodiment.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings.
[1. First embodiment]
[1-1. Constitution]
An exhaust flow path valve device (hereinafter referred to as "valve device") 100 of the first embodiment shown in Figs. 1 and 2 is provided in an exhaust flow path of exhaust gas discharged from an internal combustion engine mounted on a vehicle. The valve device 100 according to the first embodiment is attached to the side surface of the pipe 1 that communicates a plurality of chambers formed in the muffler in the interior of the muffler (not shown) that constitutes a part of the exhaust flow path. The opening 100A (exhaust gas bypass flow passage) is opened and closed from the outside of the pipe 1.

The valve device 100 includes a pipe 1, a valve body 2, a support 3, a shock absorbing material 41, a spring 5 and a shaft 6.
The pipe 1 forms an exhaust flow path in the muffler, and the valve body 2 blocks the pipe 1 around the opening 100A and the opening 100A around the opening 100A for discharging the exhaust gas flowing into the pipe 1 downstream on the side And the valve seat surface 100 B covered by the valve body 2. The opening 100A is formed in a rectangular shape in plan view.

  The valve body 2 is a member having a curved surface shape corresponding to the outer surface shape of the pipe 1, is rotatably supported by the support 3 via the shaft 6 and closes or opens the opening 100A from the outside of the pipe 1; Adjust the flow rate of the exhaust gas flowing downstream. The valve body 2 is formed with a hole (not shown) for inserting the shaft 6.

  The support 3 is provided at a position close to the opening 100A, supports the shaft 6 along the axial direction of the pipe 1, and supports the valve body 2 rotatably movably via the shaft 6 as described above. The support 3 is formed with a shaft hole 3A for inserting the shaft 6 therein.

  The shock absorbing material 41 is provided on the valve seat surface 100B as shown in FIG. The buffer material 41 is a metal (for example, stainless steel) mesh member (wire mesh), and is formed in a sheet shape having a constant thickness. As shown in FIG. 4, the cushioning material 41 is given a chevron-like deflection at a position close to the shaft 6 so as to protrude toward the valve body 2, and a protrusion 411 is formed by the deflection. That is, the cushioning material 41 is flat with a flat portion 410 (corresponding to an example of a lower portion) which is a portion farther from the shaft 6 than the projecting portion 411 and whose height based on the valve seat surface 100B is constant. A protrusion 411 (corresponding to an example of a high portion) which is a portion closer to the shaft 6 than the portion 410 and having a height higher than the flat portion 410 is formed. The portion of the cushioning material 41 excluding the projecting portion 411 is joined to the valve seat surface 100B by spot welding or the like. That is, in the lower surface of the shock absorbing material 41, the portion excluding the protrusion 411 abuts on the valve seat surface 100B, and the protrusion 411 is separated from the valve seat surface 100B, and between the protrusion 411 and the valve seat surface 100B. A gap (space) is formed.

  The buffer material 41 has the first buffer sheet 41 a and the second buffer sheet 41 b disposed so as to sandwich the opening 100 A from both sides in the axial direction of the pipe 1 and the opening 100 A orthogonal to the axial direction of the pipe 1. A third buffer sheet 41c and a fourth buffer sheet 41d are disposed so as to sandwich from both sides in the direction. The third buffer sheet 41 c is provided on the side closer to the shaft 6, and the fourth buffer sheet 41 d is provided on the side farther from the shaft 6. In the present embodiment, the protrusion 411 is formed on each of the first buffer sheet 41a, the second buffer sheet 41b, and the third buffer sheet 41c.

  The spring 5 is provided around the shaft 6 (with the shaft 6 inserted), one end abuts on at least one of the pipe 1 and the support 3, and the other end abuts on the valve body 2, The valve 2 is biased in a direction to close the opening 100A.

[1-2. Action]
Next, the operation of the valve device 100 will be described. The exhaust gas flowing into the muffler from the internal combustion engine passes through an upstream chamber (not shown) in the muffler and is introduced into the pipe 1, flows downstream through the valve device 100, and is discharged to the outside through a tail pipe (not shown).

  When the rotational speed of the internal combustion engine is low, the pressure of the exhaust gas is low. The force exerted by the pressure of the exhaust gas in the pipe 1 on the valve body 2 in this state is smaller than the force exerted by the load by the spring 5 on the valve body 2 at the time of valve closing. Therefore, the opening 100 A of the pipe 1 is closed by the valve body 2. Specifically, the valve body 2 and the valve seat surface 100B of the pipe 1 abut each other via the shock absorbing material 41, and the opening 100A is closed.

  On the other hand, when the rotational speed of the internal combustion engine is increased and the pressure of the exhaust gas is increased, the force exerted on the valve body 2 by the pressure of the exhaust gas in the pipe 1 is higher than the force exerted on the valve body 2 at the time of valve closing. Will also grow. As a result, the valve body 2 is rotationally moved about the shaft 6, the opening 100A is opened, and the inside and the outside of the pipe 1 are communicated via the opening 100A.

  As shown in FIG. 2, when the valve body 2 rotationally moves about the shaft 6 to close the opening 100A, the projection 411 of the buffer material 41 first abuts on the valve body 2. Furthermore, since the protrusion 411 is formed by the bending of the shock absorbing material 41 as described above, the load applied to the protrusion 411 when the valve body 2 abuts on the protrusion 411 is the peak of the protrusion 411 ( It is dispersed in the outward direction (the direction of the arrow B) from the point where the valve body 2 is first hit.

  In addition, when the valve body 2 hits the shock absorbing material 41, the moving speed in the direction in which the valve body 2 is closed after contact with the projecting portion 411 decreases rapidly, so the valve body 2 contacts the flat portion 410. The speed is lower than when the valve body 2 abuts on the protrusion 411.

[1-3. effect]
According to the first embodiment described above, the following effects can be obtained.
(1a) In the valve device 100 of the first embodiment, the cushioning member 41 has a flat portion 410 and a valve seat surface which is a portion closer to the shaft 6 than the flat portion 410 and compared to the flat portion 410. A protrusion 411 with a high height based on 100 B is formed. According to such a configuration, in the valve device 100 in which the opening 100A and the valve body 2 are provided on the side surface of the pipe 1, the shock absorbing material 41 abuts on the valve body 2 from a position close to the shaft 6. Thus, it is possible to suppress the tapping noise generated when the valve body 2 hits the valve seat surface 100B.

  (1b) The shock absorbing material 41 is in the form of a sheet having a constant thickness, and is provided with a deflection with respect to the valve seat surface 100B. According to such a configuration, in the valve device 100 in which the opening 100A and the valve body 2 are provided on the side surface of the pipe 1, the projecting portion 411 can be formed at a portion where the sheet-like buffer material 41 is bent. . By so doing, the deflection of the protrusion 411 absorbs the impact when the valve body 2 strikes the shock absorbing material 41. That is, when the valve body 2 abuts on the protrusion 411, the load applied to the protrusion 411 is dispersed outward from the top of the protrusion 411, and the protrusion 411 absorbs an impact, making it difficult for a knocking noise to occur. Become. Therefore, according to the first embodiment, when the valve body 2 hits the valve seat surface 100B through the shock absorbing material 41, generation of a striking sound is further suppressed as compared to the case where the bending is not formed through the shock absorbing material. Can. In addition, it is not necessary to prepare a buffer material having a special shape such as a partially different thickness, and further, it is not necessary to cause the valve seat surface 100B or a part of the valve body 2 to protrude, and realize with a simple configuration. Can.

[2. Second embodiment]
[2-1. Constitution]
The valve device 200 of the second embodiment shown in FIG. 5 is different from the valve device 100 of the first embodiment in that a shock absorbing material 42 is provided instead of the shock absorbing material 41. The other basic configuration is the same as that of the first embodiment, and the same reference numerals are used for the configuration common to the first embodiment, and the description is omitted.

  The shock absorbing material 42 is provided on the valve seat surface 100B as in the first embodiment. The buffer material 42 is a metal (for example, stainless steel) mesh member (wire mesh), and is formed in a sheet shape having a constant thickness. The cushioning material 42 is folded back at its end close to the shaft 6, and the folded portion forms a protrusion 421. That is, the cushioning material 42 has a flat portion 420 (corresponding to an example of a lower portion) having a constant height based on the valve seat surface 100B and a flat portion that is closer to the shaft 6 than the flat portion 420 and is flat. A projecting portion 421 (corresponding to an example of a high portion) having a height higher than that of the portion 420 is formed. The protrusion 421 has a thickness twice that of the flat portion 420. Moreover, the shock absorbing material 42 is joined to the valve seat surface 100B by spot welding etc., and the whole lower surface of the shock absorbing material 42 is in contact with the valve seat surface 100B.

  Although not illustrated, the shock absorbing material 42 of the second embodiment also includes first to fourth shock absorbing sheets arranged in the same manner as the shock absorbing material 41 (FIG. 3) of the first embodiment. In the present embodiment, an end portion of each of the first buffer sheet, the second buffer sheet, and the third buffer sheet, which is close to the shaft 6, is folded back, and the folded portion forms the protrusion 421. .

[2-2. effect]
According to the second embodiment described above, the following effects can be obtained in addition to the effects of (1a) of the first embodiment described above.

  (2a) The shock absorbing material 42 is in the form of a sheet having a constant thickness, and the protrusion 421 has a bulge formed by folding back part of the shock absorbing material 42. According to such a configuration, in the valve device 200 in which the opening 100A and the valve body 2 are provided on the side surface of the pipe 1, the projecting portion 421 can be formed at the portion where the sheet-like buffer material 42 is folded back. By doing this, the projecting portion 421 absorbs the impact when the valve body 2 strikes the shock absorbing material 42. That is, since the protrusion 421 is formed to be thicker than the thickness of the shock absorbing material 42, the protrusion protrudes when the valve body 2 abuts on the protrusion 421 compared to the case where the shock absorbing material is not formed. The part 421 absorbs the impact, making it less likely that a hitting sound will occur. Therefore, according to the second embodiment, when the valve body 2 hits the valve seat surface 100B via the shock absorbing material 42, compared to the case where the shock absorbing material is not formed which does not form a folded back portion, the generation of striking noise is further enhanced. It can be suppressed. Further, as in the first embodiment, it is not necessary to prepare a special-shaped cushioning material having a partially different thickness or the like, and further, there is no need to cause the valve seat surface 100B or a part of the valve body 2 to protrude. It can be realized by a simple configuration.

[3. Third embodiment]
[3-1. Constitution]
The valve device 300 of the third embodiment shown in FIG. 6 is different from the valve device 100 of the first embodiment in that a shock absorber 43 is provided instead of the shock absorber 41 and a spacer 7 is further provided. The other basic configuration is the same as that of the first embodiment, and the same reference numerals are used for the configuration common to the first embodiment, and the description is omitted.

  The shock absorbing material 43 is provided on the valve seat surface 100B as in the first embodiment. The buffer material 43 is a metal (for example, stainless steel) mesh member (wire mesh), and is formed in a sheet shape having a constant thickness.

  The spacer 7 is a metal (for example, stainless steel) rod-like member provided between the valve seat surface 100 </ b> B and the shock absorbing material 43. The spacer 7 is disposed along the shaft 6 at a position close to the opening 100 A, and a protrusion 431 is formed by covering a part of the cushioning material 43 with the spacer 7. That is, the cushioning material 43 is flat with a flat portion 430 (corresponding to an example of a lower portion) which is a portion farther from the shaft 6 than the projecting portion 431 and which has a constant height based on the valve seat surface 100B. A protruding portion 431 (corresponding to an example of a high portion) which is a portion closer to the shaft 6 than the portion 430 and higher in height than the flat portion 430 is formed. The protrusion 431 protrudes by the thickness of the spacer 7 compared to the flat portion 430. The cushioning material 43 is joined to the valve seat surface 100B by spot welding or the like, and the lower surface of the cushioning material 43 excluding the projecting portion 431 is in contact with the valve seating surface 100B.

  Although not shown, the cushioning material 43 of the third embodiment also includes first to fourth cushioning sheets arranged in the same manner as the cushioning material 41 (FIG. 3) of the first embodiment. In the present embodiment, each of the first buffer sheet, the second buffer sheet, and the third buffer sheet covers the spacer 7 to form the protrusion 431.

[3-2. effect]
According to the third embodiment described above, the following effects can be obtained in addition to the effects of (1a) of the first embodiment described above.

  (3a) The valve device 300 includes the spacer 7 provided between the valve seat surface 100 </ b> B and the shock absorbing material 43. The cushioning material 43 is in the form of a sheet having a constant thickness, and the protrusion 431 has a bulge formed by a part of the cushioning material 43 covering the spacer 7. According to such a configuration, in the valve device 300 in which the opening 100A and the valve body 2 are provided on the side surface of the pipe 1, the projecting portion 431 can be formed at the portion where the spacer 7 is covered by the buffer material 43. Therefore, according to the third embodiment, when the valve body 2 hits the valve seat surface 100B through the shock absorbing material 43, the generation of the striking sound is suppressed compared to the case where the shock absorbing material is not covering the spacer 7 Can. Further, as in the first and second embodiments, it is not necessary to prepare a special-shaped cushioning material having a partially different thickness or the like, and further, it is necessary to make the valve seat surface 100B and a part of the valve body 2 protrude. It can be realized by a simple configuration.

[4. Fourth embodiment]
[4-1. Constitution]
The valve device 400 of the fourth embodiment shown in FIG. 7 is different from the valve device 100 of the first embodiment in that a shock absorbing material 44 is provided instead of the shock absorbing material 41. The other basic configuration is the same as that of the first embodiment, and the same reference numerals are used for the configuration common to the first embodiment, and the description is omitted.

  The shock absorbing material 44 is provided on the valve seat surface 100B as in the first embodiment. The shock absorbing material 44 is a metal (for example, stainless steel) mesh member (wire mesh). The cushioning material 44 is in the form of a sheet having a monotonously increasing thickness from the lowest part 440 which is farthest from the shaft 6 and the thinnest part to the high part 441 closest to the shaft 6 and the thickest part. The shock absorbing material 44 is joined to the valve seat surface 100B by spot welding or the like, and the entire lower surface is in contact with the valve seat surface 100B.

  Although not shown, the cushioning material 44 of the fourth embodiment also includes first to fourth cushioning sheets arranged in the same manner as the cushioning material 41 (FIG. 3) of the first embodiment. In the present embodiment, only the fourth buffer sheet is formed into a sheet having a constant thickness, and each of the first buffer sheet, the second buffer sheet, and the third buffer sheet has a thickness closer to the shaft 6 Is formed in a sheet shape that increases (monotonously increases). The thicknesses of the first buffer sheet, the second buffer sheet, and the third buffer sheet are set so as to increase in proportion to the distance from the shaft 6 (linearly) as the shaft 6 is approached.

[4-2. effect]
According to the fourth embodiment described above, the following effects can be obtained in addition to the effects of (1a) of the first embodiment described above.

  (4a) Since the shock absorbing material 44 is in the form of a sheet having a portion in which the thickness monotonously increases from the low portion 440 to the high portion 441, the generation of the hitting sound can be suppressed for a long time. That is, the cushioning material 44 is permanently deformed by repetition of the opening and closing of the valve body 2 and elasticity decreases (a so-called sag occurs). In this respect, the shock absorbing material 44 of the fourth embodiment is formed to be thicker toward the shaft 6 side, which is a side on which stagnation is likely to occur, and therefore, the influence of the occurrence of stagnation can be suppressed. Further, as in the first, second, and third embodiments, it is not necessary to cause the valve seat surface 100B or a part of the valve body 2 to protrude, and this can be realized by a simple configuration.

In each of the above-described embodiments, the central axis of the shaft 6 corresponds to an example of the rotation axis in the claims.
[5. Other embodiments]
As mentioned above, although embodiment of this invention was described, it can not be overemphasized that this invention can take various forms, without being limited to the said embodiment.

  (5a) Although the shock absorbing material 41, the shock absorbing material 42, the shock absorbing material 43, and the shock absorbing material 44 illustrated the structure which is a metal mesh member in each said embodiment, it is not limited to this. For example, it may be made of another material having heat resistance and buffer property.

  (5b) In the first embodiment, the configuration in which the buffer material 41 is a member formed in a sheet shape having a constant thickness is illustrated, but the present invention is not limited to this. For example, the thickness may be different depending on the part.

  (5c) In the first embodiment, the configuration in which the protrusion 411 is formed on each of the first buffer sheet 41a, the second buffer sheet 41b, and the third buffer sheet 41c has been exemplified, but the protrusion is described The position of 411 is not limited to this. For example, it may be formed only in the 3rd buffer sheet 41c, and may be formed only in the 1st buffer sheet 41a and the 2nd buffer sheet 41b.

  (5d) In the second embodiment, a part of the shock absorbing material 42 (the first shock absorbing sheet, the second shock absorbing sheet, and the third shock absorbing sheet, respectively) close to the shaft 6 is folded back and the protrusion 421 is Although the formed configuration is illustrated, the shape of the protrusion 421 is not particularly limited. It is sufficient if at least a part of the end close to the shaft 6 is folded back so as to project relative to the other part, for example, only the third buffer sheet may be folded, or the first buffer sheet And only the second buffer sheet may be folded back.

  (5e) In the said 3rd Embodiment, although the spacer 7 illustrated the structure which is a rod-shaped member made from metal, it is not limited to this. For example, the spacer 7 may be made of another material having heat resistance. Moreover, it may be in a shape other than a rod shape, or may be divided into a plurality of places at positions close to the shaft 6 of the shock absorbing material 43.

  (5f) In the fourth embodiment, the cushioning material 44 (the first cushioning sheet, the second cushioning sheet, and the third cushioning sheet, respectively) has a thickness monotonously in a straight line from the low portion 440 to the high portion 441. Although the sheet-like structure which has an increasing part was illustrated, it is not limited to this. For example, the cushioning material 44 may be in the form of a sheet having a portion in which the thickness from the lower portion 440 to the upper portion 441 monotonously increases in a curved shape instead of a linear shape. Also, for example, the buffer sheet with monotonously increasing thickness may be only the third buffer sheet, or may be only the first buffer sheet and the second buffer sheet.

  (5g) The function of one component in the above embodiment may be distributed as a plurality of components, or the function of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. Further, part of the configuration of the above embodiment may be omitted as long as the problem can be solved. In addition, at least a part of the configuration of the above-described embodiment may be added to or replaced with the configuration of the other above-described embodiment. In addition, all the aspects contained in the technical thought specified from the wording as described in a claim are embodiment of this invention.

  DESCRIPTION OF SYMBOLS 1 ... Pipe, 2 ... Valve body, 3 ... Support body, 3A ... Shaft hole, 5 ... Spring, 6 ... Shaft, 7 ... Spacer, 41, 42, 43, 44 ... Buffer material, 41a, 41b, 41c, 41d ... Buffer sheet, 100, 200, 300, 400 ... valve device, 100 A ... opening, 100 B ... valve seat surface, 410, 420, 430 ... flat part, 411, 421, 431 ... projecting part, 440 ... lower part, 441 ... high Department.

Claims (3)

A pipe forming an exhaust flow path and having an opening on the side surface;
A valve body for opening and closing the opening;
A support for rotatably supporting the valve body about a rotational axis so as to close or open the opening by the valve body;
A buffer provided on a valve seat surface which is a portion around the opening in the pipe;
Equipped with
A lower portion and a higher portion that is closer to the rotation axis than the lower portion and is higher in height than the lower portion with respect to the valve seat surface are formed in the buffer material. ,
The shock absorbing material is in the form of a sheet, and is provided with a deflection with respect to the valve seat surface.
The valve device for an exhaust passage , wherein the high portion is a bulge formed by the bending of the buffer material . The exhaust flow path valve device according to claim 1, wherein
  The valve device for an exhaust flow path, wherein the buffer material is in the form of a sheet having a constant thickness. The exhaust flow path valve device according to claim 1 or 2, wherein
  The cushioning material is a first cushioning sheet and a second cushioning sheet arranged to sandwich the opening from both sides in the axial direction of the pipe, and the cushioning material from both sides in a direction orthogonal to the axial direction of the pipe A third buffer sheet and a fourth buffer sheet arranged to sandwich
  The third buffer sheet is provided on the side closer to the rotation axis, and the fourth buffer sheet is provided on the side farther from the rotation axis.
  A valve device for an exhaust flow passage, wherein the raised portion is formed on each of the first buffer sheet, the second buffer sheet, and the third buffer sheet.