JP2006274821A - Exhaust device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the sealability of a valve by preventing deposit components from being adhered to the valve installed in an exhaust pipe. <P>SOLUTION: This exhaust device of an internal combustion engine 2 comprises a main exhaust pipe 10 for passing exhaust gases discharged from the internal combustion engine 2, a bypass exhaust pipe 20 branching from and converging to the main exhaust pipe 10, a main catalyst device 40 installed in the main exhaust pipe 10, a bypass catalyst device 21 installed in the bypass exhaust pipe 20, and a flow switching part 30 installed in the main exhaust pipe 10 and switching the flow of exhaust gases. The flow switching part 30 comprises a seat 31 in which an opening part 31a is formed, a cover 32 seated on the seat 31 and closing the opening part 31a, and a cover rotating means converting the force of the cover 32 pressing the seat 31 into a force for rotating the cover 32 about the opening part 31a on the seat 31. When the cover 32 is seated on the seat 31, it is rotated by a prescribed amount while coming into contact with the seat 31. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exhaust device for an internal combustion engine.

  2. Description of the Related Art As an exhaust gas purification device for automobiles, an apparatus using a carrier carrying platinum, rhodium or the like is known. In such an exhaust gas purification device, it is necessary to raise the temperature to activate the catalyst (300 to 400 ° C.), and exhaust gas can hardly be purified at a low temperature such as immediately after the engine is started. For this reason, the conventional exhaust gas purification apparatus has been activated early by taking measures such as arranging the catalyst as close to the engine as possible or incorporating a heater in the catalyst carrier.

  However, if the catalyst continues to be exposed to high temperature conditions with a rapid temperature change, it will deteriorate early. For this reason, bringing the catalyst closer to the engine unnecessarily accelerates the deterioration of the catalyst, which in turn reduces the exhaust gas purification efficiency.

Therefore, in order to prevent deterioration of the catalyst due to heat, a structure has been proposed in which an exhaust pipe directly under the engine is branched and a main flow path for exhaust gas and a bypass flow path disposed in parallel with the main flow path are installed. . A catalyst device that is activated at an early stage, such as a catalyst carrier with a heater, is installed in the bypass channel. Further, the main catalyst device is installed at a site where the main flow path and the bypass flow path merge again to form one exhaust pipe. When the exhaust gas is at a low temperature, such as when the engine is started, the exhaust gas flows through the bypass channel, and when the exhaust gas becomes a high temperature, the exhaust gas flows through the main channel. Thus, in order to switch the flow of the exhaust gas in the main flow path and the bypass flow path, a valve for switching the flow in the exhaust pipe is provided (see Patent Document 1).
JP 09-72210 A

  However, in the above-described automobile exhaust gas purification apparatus, there is a possibility that the sealing performance may be deteriorated due to deposit components in the exhaust gas adhering to the vicinity of the valve that distributes the exhaust gas flow path. When the sealing performance deteriorates, the exhaust gas leaks into the main flow path when the engine is started, and not only the exhaust gas purification performance but also the noise reduction performance is deteriorated, and the entire exhaust performance is deteriorated.

  The present invention has been made paying attention to such conventional problems, and an object of the present invention is to provide an exhaust system for an internal combustion engine that prevents adhesion of deposit components and improves the sealing performance of a valve.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

  The present invention includes a main exhaust pipe (10) through which exhaust gas discharged from an internal combustion engine (2) passes, a bypass exhaust pipe (20) branched upstream from the main exhaust pipe (10), and joined downstream. A main catalyst device (40) provided downstream in the exhaust gas flow direction from a junction (10b) between the main exhaust pipe (10) and the bypass exhaust pipe (20), and a bypass provided in the bypass exhaust pipe (20) An exhaust system for an internal combustion engine (2) comprising a catalyst device (21) and a flow switching section (30) for switching the flow of exhaust gas through the main exhaust pipe (10), wherein the flow switching section (30 ) Is provided in the main exhaust pipe (10) and has a seat (31) in which an opening (31a) is formed, and a lid that sits on the seat (31) and closes the opening (31a). (32) and the lid (32) attaches the sheet (31). A lid rotating means for converting the pressing force into a force for the lid (32) to rotate about the opening (31a) on the sheet (31), and the lid (32) is applied to the sheet (31). When seated, the seat (31) is rotated while being in contact with the seat (31).

  According to the present invention, since the lid rotates when seated on the seat and the deposit attached to the seat is scraped off, deterioration of the sealing performance of the flow switching portion can be prevented, thereby improving the exhaust performance of the internal combustion engine. Can be made.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram for explaining an exhaust gas purification system using an exhaust device for an internal combustion engine according to the present invention.

  An exhaust gas purification system 1 that purifies exhaust gas discharged from the engine 2 includes a main exhaust pipe 10, a bypass exhaust pipe 20, an on-off valve 30, and a main catalyst device 40.

  The main exhaust pipe 10 branches off from the bypass exhaust pipe 20 at the branch portion 10a. Further, the main exhaust pipe 10 joins again with the bypass exhaust pipe 20 branched at the junction 10b. The main exhaust pipe 10 is formed larger than the opening area of the bypass exhaust pipe 20. A main catalyst device 40 is provided downstream of the junction 10 b of the main exhaust pipe 10.

  The bypass exhaust pipe 20 includes an early activation catalyst device 21. The early activation catalyst device 21 is, for example, a catalyst device with a heater. The early activation catalyst device 21 is located upstream of the exhaust gas flow from the main catalyst device 40. Therefore, the early activation catalyst device 21 is configured to be exposed to exhaust gas having a temperature higher than that of the exhaust gas flowing into the main catalyst device 40.

  The open / close valve 30 is provided in the main exhaust pipe 10. The on-off valve 30 is provided between the branch portion 10 a and the junction portion 10 b of the main exhaust pipe 10 and the bypass exhaust pipe 20. The on-off valve 30 is selectively controlled whether or not the exhaust gas is allowed to pass through the main exhaust pipe 10 according to a command from the control unit 3 (hereinafter referred to as “ECU”).

  The main catalyst device 40 and the early activation catalyst device 21 oxidize hydrocarbon (HC) and carbon monoxide (CO) in the exhaust gas and simultaneously reduce nitrogen oxide (NOx) when the exhaust air-fuel ratio is near the stoichiometric air-fuel ratio. Possible three-way catalyst.

  In the exhaust gas purification system 1, when the engine is cold such as when the engine is started, the open / close valve 30 is closed to prevent the exhaust gas from passing through the main exhaust pipe 10. Therefore, the exhaust gas discharged from the engine 2 passes through the bypass exhaust pipe 20. The early activation catalyst device 21 provided in the bypass exhaust pipe 20 is activated early by high-temperature exhaust gas or a heater. Therefore, the early activation catalyst device 21 purifies the exhaust gas while the main catalyst device 40 is not activated as when the engine is started. When the main catalyst device 40 is activated, the open / close valve 30 is opened to allow the exhaust gas to pass through the main exhaust pipe 10 to purify the exhaust gas.

  FIG. 2 is an enlarged view of the opening / closing valve 30 of the exhaust device of the internal combustion engine of the first embodiment according to the present invention, FIG. 2 (A) is an overall view, and FIG. 2 (B) is a portion B of FIG. FIG.

  As shown in FIG. 2A, the opening / closing valve 30 includes a seat 31, a valve lid 32, and an arm 33.

  The sheet 31 is a plate-like object having a certain thickness. The seat 31 is provided in the main exhaust pipe 10 perpendicular to the flow direction of the exhaust gas. The sheet 31 includes a circular opening 31a for allowing exhaust gas to pass therethrough. In the sheet 31, an annular groove 31c is formed around the opening 31a.

  The valve lid 32 is formed in a disk shape having a larger diameter than the opening 31a. The valve lid 32 is made of metal. On the contact surface 32 a between the valve lid 32 and the seat 31, a convex portion 32 b that engages with a groove portion 31 c formed in the seat 31 is provided in an annular shape. Thus, the valve lid 32 is closed by engaging the annular groove 31c and the convex portion 32b to cover the opening 31a, thereby preventing the passage of exhaust gas.

  As shown in FIG. 2B, the width of the convex portion 32b is formed narrower than the width of the groove portion 31c. Further, the convex portion 32b is formed so as to have a gap between the projecting surface 32c of the convex portion 32b and the bottom surface 31d of the groove portion 31c when the valve lid 32 is seated on the seat 31. Similarly, there is a gap between the side surface 32d of the convex portion 32b and the inner wall surface 31e of the groove portion 31c.

  As shown in FIG. 2A, a cylindrical shaft portion 32g is vertically provided on the upper surface 32f of the valve lid 32. Further, the shaft portion 32g is covered with a covered cylindrical bearing portion 34 that is inserted into the shaft portion 32g so as to be rotatable and slidable. The bearing portion 34 is inserted through the shaft portion 32g from the opening. The bearing portion 34 is linked to the shaft portion 32g inside. The lid portion of the bearing portion 34 is provided with an arm connecting portion 34 a that is rotatably connected to the arm 33.

  The arm 33 is rotatably attached to the arm attachment portion 35. The arm 33 is turned in the exhaust gas flow direction around the arm mounting portion 35 by an electric motor (not shown) to open and close the valve lid 32, and the convex portion 32b of the valve lid 32 and the groove portion 31c of the seat 31 are securely engaged. be able to.

  3A and 3B are diagrams showing the convex portion 32b of the valve lid 32, FIG. 3A is a diagram showing the contact surface 32a with the seat 31, and FIG. 3B is a diagram showing the projection 32n forming the convex portion 32b. It is the perspective view seen from the contact surface 32a side.

  As shown in FIG. 3A, the convex portion 32b is formed by continuously arranging a large number of projecting portions 32n in an annular shape. The protrusion 32n is formed in a triangular prism shape as shown in FIG. The protrusion 32 has an isosceles triangle whose bottom bisector passes through the center of the valve lid 32 and whose apex is on the center side of the valve lid 32. The vertex angle of the isosceles triangle is an acute angle. The protrusion 32n is continuously arranged concentrically with the valve lid 32. Further, as shown in FIG. 3B, the protrusion 32n is disposed so that the end points of the bases of the adjacent protrusions n are in contact with each other.

  FIG. 4 is a cross-sectional view of a state in which the shaft portion 32g formed on the valve lid 32 of the on-off valve 30 in this embodiment is inserted into the bearing portion 34, and FIG. 4B is a cross-sectional view taken along the line BB in FIG. 4A as viewed from the direction of the arrow L. FIG.

  As shown in FIG. 4A, right-angled triangular inclined convex portions 32j are provided at equal intervals on the outer peripheral surface of the shaft portion 32g so as to protrude in the outer peripheral direction and have a bottom side on the valve lid upper surface 32f. A guide piece 32m is provided on the inclined surface 32k of the inclined convex portion 32j. A sliding convex portion 34 d is provided on the inner peripheral surface of the bearing portion 34. The sliding protrusions 34d are provided at equal intervals similarly to the inclined protrusions 32j. The sliding convex portion 34d is formed in parallel with the inclined surface 32k of the inclined convex portion 32j, and includes a sliding inclined surface 34e that slides on the inclined surface 32k. A guide groove 34b is formed in the sliding inclined surface 34e. As shown in FIG. 4B, the guide groove 34b is slidably engaged with the guide piece 32m. A spring 34c is loosely inserted into the guide groove 34b.

  Next, the operation when the valve lid 32 is seated on the seat 31 will be described. FIG. 5 is a view showing a state in which the valve lid 32 is seated on the seat 31, FIG. 5 (A) is a view immediately after the valve lid 32 is grounded to the seat 31, and FIG. It is a figure which shows the state which pressed 32 from the direction of arrow F. FIG.

  When the arm 33 is pressed in the direction of arrow F from the state shown in FIG. 5A, the valve lid 32 rotates on the seat 31 and the point P moves in the direction of arrow R as shown in FIG. . Note that the point P is given for explanation.

  The mechanism by which the valve lid 32 rotates will be described. When the arm 33 is pressed and the bearing 34 is pushed into the valve lid 32, the guide piece 32m slides in the guide groove 34b as shown in FIG. Further, the inclined surface 32k of the inclined convex portion 32j formed on the outer peripheral surface of the shaft portion 32g of the valve lid 32 and the inclined surface 32e of the sliding convex portion 34d formed on the inner peripheral surface of the bearing portion 34 slide. The valve lid 32 rotates in the direction of arrow R. On the other hand, when the pushed valve lid 32 is returned, it rotates in the opposite direction by the reaction force of the spring 34c loosely inserted into the guide groove 34b. In addition, in order to clarify these operations, the distance that the bearing portion 34 is pushed in is shown long, but the distance that is actually pushed is short and the distance that the point P moves is also short.

  6A and 6B are diagrams showing the action on the deposited deposit. FIG. 6A shows a state before the valve lid 32 is brought into contact with the seat 31, and FIG. 6B shows the valve lid 32 on the seat 31. It is a figure which shows the state after pressing and the valve lid | cover 32 rotated.

  From the state shown in FIG. 6A, when the arm 33 is pressed and the bearing portion 34 is pushed into the shaft portion 32a of the valve lid 32 as shown in FIG. 5, the deposit 50 is pressed and the groove portion 31c and the convex portion 32b are pressed. Fill the gap. When pushed further, the valve lid 32 rotates as shown in FIG. The convex portion 32 b rotates inside the groove portion 32 c as the valve lid 32 rotates, and scrapes the accumulated deposit 50. Further, as shown in FIG. 3, the convex portion 32b is a set of triangular prism-shaped projections 32n, so that the deposit 50 scraped off by the projection 32n is placed between the adjacent projections 32n from the groove 32c to the center side. To discharge.

  According to this embodiment, the sealing performance of the on-off valve 30 can be further improved by filling the gap between the groove portion 32c and the convex portion 31e with the deposit. Further, by rotating on the seat 31 when the valve lid 32 is pressed, it is possible to scrape and remove the excess deposit accumulated in the groove 31c. Further, the scraped deposit can be placed on the center side and discharged from the opening 31a due to the shape of the protrusion 32n constituting the protrusion 32b. Therefore, in the present embodiment, the sealing performance can be stabilized by using the deposit for improving the sealing performance and further removing the excess deposit.

(Second Embodiment)
FIG. 7 is a view showing a valve lid 132 and a bearing portion 134 of an on-off valve 130 of a second embodiment of an exhaust system for an internal combustion engine according to the present invention. FIG. 7 (A) is a cross-sectional view, and FIG. It is a top view.

  In the following embodiments, the same reference numerals are given to the portions that perform the same functions as those of the above-described embodiments, and overlapping descriptions are omitted as appropriate.

  The valve lid 132 includes a shaft portion 132g at the center. The bearing portion 134 is formed in a covered cylindrical shape, and is slidably inserted through the shaft portion 132g. The bearing portion 134 includes an arm connecting portion 134a (not shown) at the upper portion, and is rotatably connected to the arm 33.

  As shown in FIG. 7A, a compression spring 136 is interposed between the shaft portion 132g and the bearing portion 134. The valve lid 132 and the bearing portion 134 are connected to each other by a plurality of link arms 137. A link attachment portion 132k is provided on the upper surface 132f of the valve lid 132. Similarly, a link attachment portion 134d is provided on the bottom surface of the bearing portion 134. Both ends of the link arm 137 are rotatably attached to the link attaching portions 132k and 134d. As shown in FIG. 7B, the link arm 137 connecting the two link attachment portions and each link attachment portion is 90 ° around the valve lid 132 in order to press the valve lid 132 evenly. There are four places each.

  8A and 8B are diagrams showing the action when the bearing portion 134 is pushed in the direction of arrow F. FIG. 8A is a cross-sectional view, and FIG. 8B is a plan view.

  As shown in FIG. 8A, when the bearing portion 134 of the valve lid 132 is pushed in the direction of arrow F, it rotates in the direction of arrow R by the action of the link mechanism described above. When the pushed-in valve lid 132 is returned, the bearing portion 134 is returned in the direction opposite to the arrow F by the reaction force of the compression spring 136 interposed in the bearing portion 134. Therefore, the valve lid 132 rotates in the direction opposite to the arrow R by the action of the link mechanism including the link arm 137.

  According to the present embodiment, by sliding and rotating the valve lid 132 on the seat 31 as in the first embodiment, effects such as improved sealing performance and removal of excess deposits are exhibited, and the sealing performance is stabilized. Can do.

(Third embodiment)
FIG. 9 is a view showing the convex portion 232b of the valve lid 232 and the groove portion 231c of the seat 231 according to the third embodiment of the present invention. FIG. 9 (A) is a bottom view of the valve lid 232, and FIG. FIG. 9C is a perspective view of a protruding portion 232n forming the convex portion 232b, and FIG.

  As shown in FIG. 9A, the convex portion 232d is formed by continuously arranging the protruding portions 232n in an annular shape around the rotation axis of the valve lid 232. As shown in FIG. 9B, the protrusion 232n is formed in a shape having an inclined surface. The shape of the contact surface between the protrusion 232n and the valve lid 232 is an isosceles triangle similar to that of the first embodiment. Further, as shown in FIG. 9C, the protruding portion 232n is formed in a shape in which the protruding amount increases in the outer peripheral direction from the apex of the isosceles triangle formed on the contact surface 232a.

  According to the present embodiment, since the shape of the convex portion 232d is inclined in the circumferential direction, the scraped deposit is more easily discharged from the groove portion 231c than in the first embodiment. Therefore, the deposit attached to the sheet 231 is further less likely to accumulate, and the sealing performance can be further improved.

(Fourth embodiment)
10A and 10B are views showing a fourth embodiment of the present invention in which a heat dissipation fin 338 is mounted on the upper surface of the valve lid 332, FIG. 10A is a side view, and FIG. 10B is a plan view. . An arrow G indicates the flow direction of the exhaust gas.

  As shown in FIG. 10A, the valve lid 332 is located downstream of the seat 31 in the exhaust gas flow direction. Therefore, the valve lid 332 is exposed to high-temperature exhaust gas through the opening 31 a of the seat 31 and the seat 31. Therefore, a large number of fins 338 are arranged in a lattice pattern on the upper surface of the valve lid 332. As the provided fins 338 radiate heat, an increase in temperature of the valve lid 332 can be suppressed.

  According to the present embodiment, heat can be efficiently radiated by the fins 338 provided on the valve lid 332. Thus, the sealing performance of the on-off valve 30 can be further improved by preventing the deformation of the valve lid 332 due to thermal expansion.

(Fifth embodiment)
FIGS. 11A and 11B are views showing a fifth embodiment of the present invention in which fins 438 for radiating heat are mounted in a lattice shape on the bottom surface of the valve lid 432, FIG. 11A is a side view, and FIG. It is a bottom view. An arrow G indicates the flow direction of the exhaust gas.

  The valve lid 432 is located upstream of the seat 31 in the exhaust gas flow direction. A fin 438 is provided on the bottom surface of the valve lid 432 so as to be inserted through the opening 31 a of the seat 31. The valve lid 432 is exposed to high-temperature exhaust gas from its upper surface. Therefore, the fin 438 provided on the bottom surface of the valve lid 432 dissipates heat, so that the temperature rise of the valve lid 432 can be suppressed.

  According to the present embodiment, since the fins 438 are provided on the valve lid 432, heat can be radiated efficiently. Thus, by preventing the deformation of the valve lid 432 due to thermal expansion, the sealing performance of the on-off valve 30 can be further improved as in the fourth embodiment.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

  For example, a plurality of grooves and protrusions may be formed concentrically from the center of the lid that rotates.

It is a figure which shows the structure of the exhaust apparatus of an internal combustion engine. It is an enlarged view of the on-off valve of the exhaust apparatus of 1st Embodiment by this invention. It is a figure which shows the convex part of the valve | bulb cover of the exhaust apparatus of 1st Embodiment by this invention. It is a figure which shows the rotation mechanism of the valve lid of the on-off valve of the exhaust apparatus of 1st Embodiment by this invention. It is a figure which shows operation | movement of the on-off valve of the exhaust apparatus of 1st Embodiment by this invention. It is a figure which shows the effect | action with respect to the deposit from the groove part of the sheet | seat of the exhaust apparatus of 1st Embodiment by this invention. It is a figure which shows the rotation mechanism of the valve lid of the on-off valve of the exhaust apparatus of 2nd Embodiment by this invention. It is a figure which shows the effect | action of the rotation mechanism of the valve lid of the on-off valve of the exhaust apparatus of 2nd Embodiment by this invention. It is a figure which shows the shape of the valve | bulb cover of the on-off valve of the exhaust apparatus of 3rd Embodiment by this invention. It is an enlarged view of the on-off valve of the exhaust apparatus of 4th Embodiment by this invention. It is an enlarged view of the on-off valve of the exhaust apparatus of 5th Embodiment by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Exhaust gas purification system 2 Internal combustion engine 10 Main exhaust pipe 20 Bypass exhaust pipe 21 Early activation catalyst apparatus (bypass catalyst apparatus)
30 Open / close valve (flow switching part)
31 sheet 31c groove (annular groove)
32 Valve lid (lid)
32b Convex part (annular convex part)
40 Main catalyst unit

Claims (12)

A main exhaust pipe through which exhaust gas discharged from the internal combustion engine passes;
A bypass exhaust pipe branched from the main exhaust pipe upstream and joined downstream;
A main catalyst device provided downstream in the exhaust gas flow direction from the junction of the main exhaust pipe and the bypass exhaust pipe;
A bypass catalyst device provided in the bypass exhaust pipe;
A flow switching unit for switching the flow of exhaust gas in the main exhaust pipe;
An exhaust system for an internal combustion engine comprising:
The flow switching unit is
A sheet provided in the main exhaust pipe and having an opening formed therein;
A lid that sits on the seat and closes the opening;
Lid rotating means for converting the force with which the lid presses the sheet into a force with which the lid rotates around the opening on the sheet;
With
When the lid is seated on the seat, the lid rotates by a predetermined amount while contacting the seat.
An exhaust system for an internal combustion engine. The lid rotating means includes
A rotation axis of the lid;
A bearing portion slidably inserted through the rotating shaft;
A guide groove formed obliquely on the inner peripheral surface of the bearing portion;
A guide piece that is formed on the outer peripheral surface of the rotary shaft, slidably engages with the guide groove, and the lid rotates by sliding the guide groove;
An elastic body that urges the rotating shaft and the bearing portion in a direction away from each other, and is loosely inserted into the guide groove with one end locked to the guide piece;
The exhaust system for an internal combustion engine according to claim 1, comprising: The lid rotating means includes
A rotation axis of the lid;
A bearing portion slidably inserted through the rotating shaft;
An elastic body interposed between the rotating shaft and the bearing portion and biasing in a direction in which the rotating shaft and the bearing portion are separated;
Linking the lid and the bearing portion so as to be rotatable, and rotating the lid by pressing the bearing portion in the direction of the rotation axis;
The exhaust system for an internal combustion engine according to claim 1, comprising: The sheet is provided with an annular groove,
The lid includes an annular protrusion that engages with the groove.
The exhaust device for an internal combustion engine according to any one of claims 1 to 3, wherein the exhaust device is an internal combustion engine. The convex portion is formed by arranging a plurality of polyhedrons in an annular shape around the rotation axis of the lid,
The polyhedron is in contact with adjacent polyhedrons;
The exhaust system for an internal combustion engine according to claim 4, wherein The convex part has an inclined surface whose height increases toward the outer peripheral side of the lid,
6. An exhaust system for an internal combustion engine according to claim 4, wherein the exhaust system is an internal combustion engine. The polyhedron is a columnar body,
6. An exhaust system for an internal combustion engine according to claim 5, wherein: The columnar body is formed of a triangular prism that narrows toward the rotation center side.
The exhaust system for an internal combustion engine according to claim 7. The lid includes a heat dissipation member,
The exhaust device for an internal combustion engine according to any one of claims 1 to 8, wherein the exhaust device is an internal combustion engine. The heat dissipation member is provided on the side opposite to the contact surface with the sheet.
An exhaust system for an internal combustion engine according to claim 9. The heat dissipation member is provided on the contact surface side with the sheet, and is inserted through the opening.
An exhaust system for an internal combustion engine according to claim 9. A main exhaust pipe through which exhaust gas discharged from the internal combustion engine passes;
A bypass exhaust pipe branched from the main exhaust pipe upstream and joined downstream;
A main catalyst device provided downstream in the exhaust gas flow direction from the junction of the main exhaust pipe and the bypass exhaust pipe;
A bypass catalyst device provided in the bypass exhaust pipe;
A sheet provided in the main exhaust pipe and having an opening formed therein;
A lid that sits on the seat and switches the flow of exhaust gas through the main exhaust pipe by closing the opening;
A deposit removing method for removing deposits adhering to the lid of an exhaust device of an internal combustion engine comprising:
The lid is attached to the sheet by converting the pressing force of the lid onto the sheet into a force by which the lid rotates around the opening on the sheet and the lid rotates while contacting the sheet. Remove deposits,
A method for removing deposits from an exhaust device of an internal combustion engine.