JP6304161B2 - Exhaust system for multi-cylinder engine - Google Patents

Description

  The present invention relates to an exhaust device for a multi-cylinder engine.

  2. Description of the Related Art Conventionally, in an engine such as an automobile, an exhaust system for an engine that increases engine torque by promoting exhaust using the ejector effect has been developed.

  In an exhaust device that promotes exhaust using the ejector effect, for example, as described in Patent Document 1, the engine area can be increased more effectively by changing the flow passage area of the exhaust passage. I have something to do.

  The exhaust system of the engine described in Patent Document 1 is such that the flow area decreases toward the downstream side in order from the upstream side to the downstream side portion of the independent exhaust passage connected to each of the plurality of cylinders. And a constricted portion formed with a plurality of gas passages that communicate with each other independently, a tubular confluence portion where the exhaust gas that has passed through each gas passage merges, and a tubular shape in which the flow area increases toward the downstream side A diffuser unit is provided, and the flow channel area of each gas passage in the throttle unit can be changed.

  The throttle portion, the merging portion, and the diffuser portion constitute a so-called dynamic pressure exhaust system. That is, the dynamic pressure exhaust system raises the flow rate of the exhaust gas flowing in from the independent exhaust passage at the throttle part and causes the high-speed exhaust gas to flow into the merge part to generate a negative pressure in the merge part. The exhaust gas is sucked out (scavenged) from other independent exhaust passages.

  The structure of the aperture portion will be specifically described. The throttle part is composed of an inner pipe connected to the independent exhaust passage, and an outer pipe surrounding the peripheral surface of the inner pipe, the merging part, and a cylindrical movable part formed by integrating the diffuser part. ing. The diameter of the inner tube is reduced toward the downstream side, and an opening for communicating the inside of the inner tube with the outside of the inner tube is formed in the peripheral wall. The outer tube has a smaller diameter toward the downstream side. Between the inner pipe and the outer pipe, there is formed a flow path that guides the exhaust gas flowing out from the opening formed in the peripheral wall of the inner pipe to the junction. By displacing the outer pipe (movable part) along the flow direction of the exhaust gas with respect to the inner pipe, the flow area between the inner pipe and the outer pipe, and consequently the flow area of the gas passage in the throttle part is changed. Is done.

  As a method of displacing the movable part along the flow direction of the exhaust gas, for example, it is conceivable to displace the movable part by a link mechanism and an actuator. Specifically, for example, it is conceivable to connect, via a link mechanism, a pin protruding from the outer peripheral surface of the movable part and an actuator that performs a linear operation at a position away from the central axis of the movable part. When the actuator is actuated, the link mechanism swings around the pin along the exhaust gas flow direction, and the movable part is displaced along the exhaust gas flow direction along with the swing.

JP2013-57255A

  However, the following problem may occur between the above-described pin and the link mechanism. That is, when the movable part vibrates due to engine vibration or exhaust pulsation, contact noise may be generated between the link and the pins constituting the link mechanism due to the vibration of the movable part. Also, when the center axis of the pin insertion hole of the link is inclined with respect to the center axis of the pin due to manufacturing errors, the pin is inclined to the inner wall surface of the pin insertion hole when the link swings. Contact in state. As a result, contact noise is generated between the inner wall surface of the pin insertion hole and the pin, excessive wear occurs on the inner wall surface or the pin of the pin insertion hole, or the pin is stuck on the inner wall surface of the pin insertion hole. As a result, there is a possibility that the movement of the link becomes worse (a so-called “galling” phenomenon) or the pin is fixed to the inner wall surface of the pin insertion hole.

  The present invention has been made in view of the above circumstances, and contact noise, galling, fixation, and excessive wear are caused at the connection point between the movable part and the mechanism for displacing the movable part of the dynamic pressure exhaust system. It is an object to provide an exhaust device for a multi-cylinder engine that can be suppressed.

  In order to solve the above-described problems, the present invention provides a plurality of independent exhaust passages that are independently connected to a plurality of cylinders of an engine having a plurality of cylinders, or a branching in the middle portion and the exhaust order is continuous. Nozzle portion formed with a plurality of internal passages extending from a plurality of independent exhaust passages including independent exhaust passages connected to a plurality of cylinders to which gas discharged from each of the independent exhaust passages flows independently And an inflow part into which the gas discharged from the nozzle internal passage flows in, and an aggregation part in which the gas that has passed through the inflow part gathers, and the gas flow is downstream of the nozzle part in the gas flow direction. Cylindrical movable which is provided so as to be displaceable in the upstream and downstream directions and reduces the flow area of the inflow portion when displaced upstream, and expands the flow area of the inflow portion when displaced downstream And the movable part A moving mechanism for displacing in the upstream / downstream direction, the moving mechanism having a rocking center at a position radially outside of the movable portion and provided so as to be rockable along the upstream / downstream direction. And an operation unit including a first surface formed of a concave surface having an arcuate cross section on one side in the upstream / downstream direction, and a second surface formed of a convex surface having an arcuate cross section on the other side in the upstream / downstream direction; A swing mechanism that swings the operation unit along the upstream and downstream directions, a convex surface along the first surface of the operation unit, and a second surface of the operation unit that are provided on an outer periphery of the movable unit. A groove portion having an inner wall surface that is supported by the convex surface and the concave surface so as to be slidable from both sides in the upstream and downstream directions, and the operation portion is moved along with the swing of the operation portion. The movable part is moved up and down while sliding in the groove part. To provide an exhaust apparatus for a multi-cylinder engine equipped with the section to be operated for displacing the direction.

  According to the present invention, the first surface and the second surface of the operation portion are supported by the inner wall surface of the groove portion of the operated portion so as to be slidable from both sides in the upstream and downstream directions. Since the operation part has a contact surface with the operated part formed in an arc shape in cross section, the contact area with the operated part becomes larger than in the case where the contact surface is not in an arc shape in cross section. Accordingly, since the first surface of the operation unit contacts the convex surface of the operated portion with a wide contact area, and the second surface of the operation unit contacts the concave surface of the operated portion with a wide contact area, the operation unit is operated. The occurrence of galling, sticking, and excessive wear due to contact with the part is suppressed, rattling is less likely to occur, and the generation of contact noise is also suppressed.

  In the present invention, the operated part includes a first operated part having the convex surface, and a second operated part having the concave surface and separate from the first operated part. It is preferable.

  According to this configuration, since the operated part includes the first operated part and the second operated part that is separate from the first operated part, the operated part is easily manufactured. In addition, it is possible to easily form a groove portion having a curved inner wall surface.

  In the present invention, the operation part has a ring shape having an inner diameter larger than an outer diameter of the movable part and surrounds the movable part, and the first operated part and the second operated part. Is preferably formed in a ring shape along the entire circumference of the outer peripheral surface of the movable part.

  According to this configuration, since the force of the operation unit can be transmitted to the movable unit over the entire circumference, the movable unit can be appropriately displaced along the upstream and downstream directions.

  In the present invention, a flange portion projects from the outer peripheral surface of the movable portion, and of the first operated portion and the second operated portion, the upstream surface of the operated portion located upstream. Is preferably in contact with the flange portion.

  According to this structure, since the force of the operation part can be reliably transmitted to the movable part via the flange part, the movable part can be appropriately displaced along the upstream and downstream directions.

  In the present invention, it is preferable that the first operated portion is a seal ring.

  According to this configuration, it is possible to easily prevent contact noise, galling, excessive wear and sticking, and ensure sealing performance by using a general seal ring used for preventing fluid leakage. Manufacturing costs can be reduced.

  In the present invention, the first surface of the operation portion is configured by a part of a first spherical surface centered on a point located on the central axis of the movable portion, and the first operated portion A convex surface is configured by a part of a spherical surface along the first spherical surface, and the second surface of the operation unit is configured by a part of a second spherical surface centered on the point, and the second surface It is preferable that the concave surface of the operated portion is constituted by a part of a spherical surface along the second spherical surface.

  According to this configuration, even if the axial direction of the operating unit is inclined with respect to the axial direction of the first operated unit and the axial direction of the second operated unit due to a manufacturing error or the like, the first surface of the operating unit Is in proper contact with the convex surface of the first operated part, and the second surface of the operating part is in proper contact with the concave surface of the second operated part, so that contact noise, galling, excessive wear, and sticking are further reduced. It can be surely suppressed.

  In the present invention, the point when the movable portion is at the most upstream position of the movable region and the point when the movable portion is at the most downstream position of the movable region are the central axis of the nozzle portion. It is preferable to be located above.

  According to this configuration, even when the movable unit may be displaced in a direction orthogonal to the upstream / downstream direction with the swing of the operation unit, when the movable unit is at the most upstream position and at the most downstream position, The movable part is disposed at a position where the central axis thereof coincides with the central axis of the nozzle part. Therefore, when the movable part is at the most upstream position and when it is at the most downstream position, the movable part can be arranged at an appropriate position.

  In the present invention, the point when the movable portion is at the most upstream position of the movable region and the point when the movable portion is at the most downstream position of the movable region are It is preferable to be close to the intersection of the perpendicular line drawn to the central axis of the movable part and the central axis.

  According to this configuration, even if the movable portion is displaced in a direction orthogonal to the upstream / downstream direction with the swing of the operation portion, the displacement amount in that direction is a minute amount. Therefore, it is possible to prevent the position of the movable portion from being shifted in a direction orthogonal to the upstream / downstream direction when the movable portion is swinging. In addition, since the first surface of the operation unit properly contacts the convex surface of the first operated part and the second surface of the operation unit appropriately contacts the concave surface of the second operated part, contact sound, galling, Excessive wear and sticking can be more reliably suppressed.

  In the present invention, the swing mechanism includes an eccentric cam provided at a position radially outside of the movable portion, an actuator for applying a rotational force to the eccentric cam, and a pivot disposed at the swing center. , A pivot support portion that supports the pivot portion, a displacement portion that is displaced in the upstream / downstream direction as the eccentric cam rotates, and a connecting portion that connects the displacement portion, the pivot portion, and the operation portion It is preferable to comprise.

  According to this configuration, it is possible to reduce the driving force required for the actuator in order to maintain the state in which the movable portion is displaced upstream, thereby reducing the size of the actuator. More specifically, in order to maintain the state where the movable part is displaced upstream (the state where the flow path area of the inflow part is reduced), the movable part is not displaced downstream by the pressure of the exhaust gas. It is necessary to cause the actuator to generate a driving force in a direction that displaces the movable part upstream. In this configuration, since the eccentric cam and a displacement portion that is displaced in the upstream / downstream direction with the rotation of the eccentric cam are interposed between the actuator and the movable portion, an attempt is made to rotate the eccentric cam by the exhaust gas. Force (hereinafter referred to as “cam rotational force due to exhaust gas”) is reduced between the eccentric cam and the displacement portion, and is thus required for the actuator to counter the cam rotational force due to exhaust gas. Driving force is reduced.

  Further, according to this configuration, the force that the exhaust gas presses the movable portion downstream is transmitted to both the pivot support portion and the eccentric cam, so that the pressing force is distributed to the pivot support portion and the eccentric cam. The Thereby, the cam rotational force by exhaust gas is reduced, and as a result, the driving force required for the actuator can be reduced.

  In the present invention, the actuator applies a rotational force to the camshaft fixed to the eccentric cam, and when the movable portion is at the most upstream position in the movable region, the axis of the camshaft is the eccentricity. It is preferable that the cam is positioned in the vicinity of a reference line passing through the radial center of the cam and along the upstream and downstream directions.

  According to this configuration, the cam rotational force generated by the exhaust gas has a magnitude near zero, so that the driving force required for the actuator can be significantly reduced.

  In the present invention, the actuator applies a rotational force to a camshaft fixed to the eccentric cam, and the pivot support portion slides the pivot portion in a predetermined direction connecting the pivot portion and the camshaft. The support is preferably displaceable.

  According to this configuration, when the eccentric cam rotates, when the displacement portion is displaced in a predetermined direction connecting the pivot portion and the camshaft while being displaced in the upstream / downstream direction, the pivot portion is accompanied by the displacement of the eccentric cam. Since the displacement is performed in the predetermined direction, the movable portion can be smoothly displaced in the upstream and downstream directions.

  In the present invention, the actuator includes a rod, and an actuator body that applies a rotational force to a camshaft fixed to the eccentric cam by reciprocating the rod, It is preferable to further include a lever that is pivotally connected to the rod, and the camshaft is fixed to a position of the lever that is separated from a connecting portion between the lever and the rod.

  According to this configuration, it is possible to reduce the driving force (tensile force or pressing force) required for the actuator (direct acting actuator) in order to keep the movable portion displaced upstream. More specifically, the cam rotational force due to the exhaust gas is transmitted to the rod through the lever. In order to counter this cam rotational force, the actuator body needs to apply a force in the direction of pulling or pressing the lever to the rod. According to this configuration, as described above, since the cam rotational force due to the exhaust gas is reduced, the driving force (tensile force or pressing force) required for the actuator can be reduced.

  As described above, according to the present invention, it is possible to suppress the occurrence of contact noise, galling, sticking, and excessive wear at the connection portion between the mechanism that displaces the movable part of the dynamic pressure exhaust system and the movable part. it can.

1 is a schematic configuration diagram of an exhaust device for a multi-cylinder engine according to a first embodiment of the present invention. 1 is a schematic side view of an exhaust device for a multi-cylinder engine according to a first embodiment of the present invention. 1 is a schematic front view of an exhaust device for a multi-cylinder engine according to a first embodiment of the present invention. It is a figure which shows the downstream end part of a nozzle part. It is a V direction arrow directional view in FIG. It is a fragmentary sectional view showing an exhaust device of a multi-cylinder engine when a slide part concerning a 1st embodiment exists in the most upstream position. It is a fragmentary sectional view which shows the exhaust apparatus of the multicylinder engine shown in FIG. 6 in the state which cut | disconnected the moving mechanism along the upstream / downstream direction of a gas flow. It is a fragmentary sectional view showing an exhaust device of a multi-cylinder engine when a slide part concerning a 1st embodiment exists in the most downstream position. It is a fragmentary sectional view which shows the exhaust apparatus of the multicylinder engine shown in FIG. 8 in the state which cut | disconnected the moving mechanism along the upstream / downstream direction of a gas flow. It is the figure which showed the driving | running state (operation area | region) of the engine in 1st Embodiment of this invention. FIG. 5 is a schematic side view of an exhaust device for a multi-cylinder engine according to a second embodiment of the present invention. It is a fragmentary sectional view showing an exhaust device of a multi-cylinder engine when a slide part concerning a 2nd embodiment is in the most upstream position. It is a fragmentary sectional view which shows the exhaust apparatus of the multicylinder engine shown in FIG. 12 in the state which cut | disconnected the moving mechanism along the upstream / downstream direction of a gas flow. It is a fragmentary sectional view showing an exhaust device of a multi-cylinder engine when a slide part concerning a 2nd embodiment is in the most downstream position. It is a fragmentary sectional view which shows the exhaust apparatus of the multicylinder engine shown in FIG. 14 in the state which cut | disconnected the moving mechanism along the upstream / downstream direction of a gas flow. It is sectional drawing which shows a motion of the moving mechanism which concerns on 2nd Embodiment, (a) is a figure which shows a state when a slide part exists in a most upstream position, (b) is a state when a slide part exists in a midstream position (C) is a figure which shows a state when a slide part exists in a most downstream position. It is a figure which shows the force which acts on the eccentric cam of the moving mechanism which concerns on 2nd Embodiment, (a) is a figure which shows a state when a slide part exists in a most upstream position, (b) is a figure which shows a slide part in a midstream position. The figure which shows a state at a time, (c) is a figure which shows a state when a slide part exists in a most downstream position. It is a figure which shows the force which acts on the eccentric cam of the moving mechanism which concerns on 2nd Embodiment, a pivot part, an operation part, and an actuator, and is a figure which shows a state when a slide part exists in a most upstream position. It is a figure which shows the force which acts on an operation part and an actuator when a lever part is fixed to a rocking | fluctuating arm, and is a figure which shows a state when a slide part exists in a most upstream position.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an exhaust device 100 for a multi-cylinder engine according to an embodiment of the present invention. FIG. 2 is a schematic side view of FIG. FIG. 3 is a schematic front view of FIG. In FIG. 1, illustration of a moving mechanism 90 described later is omitted.

  In the following description, the upstream side in the exhaust gas flow direction is “upstream side”, the downstream side in the exhaust gas flow direction is “downstream side”, the upstream end is “upstream end”, and the downstream side is The end portion is referred to as a “downstream end portion”, and the direction along the flow of the exhaust gas is referred to as an “upstream / downstream direction”.

  As shown in FIG. 1, an exhaust device 100 for a multi-cylinder engine in the present embodiment is attached to the engine 1. The engine 1 according to the present invention is an in-line four-cylinder four-cycle gasoline engine in which four cylinders 12a to 12d are arranged in the vehicle width direction. The cylinder head 9 of the engine 1 is formed with a first cylinder 12a, a second cylinder 12b, a third cylinder 12c, and a fourth cylinder 12d in order from the right side of the vehicle along the vehicle width direction.

  In the engine 1, the air-fuel mixture in the cylinder is ignited at a timing shifted by 180 ° C. in each of the cylinders 12 a to 12 d so that the intake stroke, the compression stroke, the expansion stroke, and the exhaust stroke are shifted by 180 ° A. It is configured. In the present embodiment, ignition is performed in the order of the first cylinder 12a → the third cylinder 12c → the fourth cylinder 12d → the second cylinder 12b, and the exhaust stroke and the like are performed in this order.

  As shown in FIG. 1, the cylinder head 9 of the engine 1 is provided with a spark plug 15 for igniting the air-fuel mixture at a position facing the combustion chamber of each cylinder 12.

In the cylinder head 9, two intake ports 17 and two exhaust ports 18 are formed for each cylinder 12. The intake port 17 is for introducing intake air into each cylinder 12. The exhaust port 18 is for exhausting the exhaust from each cylinder 12. Each intake port 17 is provided with an intake valve 19 for opening and closing the intake port 17 to communicate or block the intake port 17 and the inside of the cylinder 12. Each exhaust port 18 is provided with an exhaust valve 20 for opening and closing the exhaust port 18 to communicate or block the exhaust port 18 and the inside of the cylinder 12. The intake valve 19 is driven by an intake valve drive mechanism 30 to open and close the intake port 17, and the exhaust valve 20 is driven by an exhaust valve drive mechanism 40 to open and close the exhaust port 18.

  The intake valve drive mechanism 30 includes an intake camshaft 31 connected to the intake valve 19 and an intake VVT (Valiable Valve Timing) 32. The intake camshaft 31 is connected to the crankshaft via a known power transmission mechanism such as a chain / sprocket mechanism, and rotates with the rotation of the crankshaft to open and close the intake valve 19. The intake VVT 32 changes the phase difference between the intake camshaft 31 and a predetermined driven shaft that is arranged coaxially with the intake camshaft 31 and is directly driven by the crankshaft. As a result, the intake VVT 32 changes the phase difference between the crankshaft and the intake camshaft 31, that is, the valve timing of the intake valve 19. As the intake VVT 32, a hydraulic type or an electromagnetic type is used.

  The exhaust valve drive mechanism 40 has substantially the same structure as the intake valve drive mechanism 30, and the exhaust camshaft 41 connected to the exhaust valve 20 and the crankshaft, and the phase difference between the exhaust camshaft 41 and the crankshaft. And an exhaust VVT 42 that changes the valve timing of the exhaust valve 20 by changing the above.

  Next, the configuration of the exhaust device 100 for a multi-cylinder engine according to the present embodiment will be described in detail.

  As shown in FIG. 1, an exhaust device 100 for a multi-cylinder engine includes four independent exhaust pipes 52 that are independently connected to the cylinders 12a to 12d of the engine 1 and bundled at their downstream ends, and independent exhaust pipes. A dynamic pressure exhaust system 60 connected to the downstream end of 52, a downstream exhaust pipe 80 connected to the downstream end of the dynamic pressure exhaust system 60, and a slide portion 62 (to be described later) of the dynamic pressure exhaust system 60 in the upstream and downstream directions. And a moving mechanism 90 (see FIGS. 2 and 3) for sliding displacement.

<Configuration of downstream side exhaust pipe 80>
The downstream exhaust pipe 80 is a substantially cylindrical member in which one passage is formed. As will be described later, the exhaust gas discharged from each cylinder 12 independently passes through each independent exhaust pipe 52 and then merges in the dynamic pressure exhaust system 60, and then passes through the downstream exhaust pipe 80. It is discharged outside the exhaust device 100. A catalyst device, a muffler, and the like are arranged in the downstream side exhaust pipe 80.

<Configuration of independent exhaust pipe 52>
The independent exhaust pipe 52 is a member extending downstream from the exhaust port 18 of the cylinder 12 as shown in FIG. Each independent exhaust pipe 52 is formed with an independent exhaust passage 52 a that guides the exhaust gas discharged from the cylinder 12 to the dynamic pressure exhaust system 60. Each independent exhaust pipe 52 extends toward the upstream end of the dynamic pressure exhaust system 60, is bundled near the upstream end of the dynamic pressure exhaust system 60, and is connected to the upstream end of the dynamic pressure exhaust system 60.

<Configuration of dynamic pressure exhaust system 60>
The dynamic pressure exhaust system 60 increases the flow rate of the exhaust gas discharged from the independent exhaust pipe 52, generates a negative pressure with the high-speed exhaust gas, and sucks the exhaust gas from the other independent exhaust pipe 52 with the negative pressure. It is configured to (scavenge). As shown in FIG. 1, the dynamic pressure exhaust system 60 as a whole has its flow path area gradually reduced toward the downstream side, and then extended while maintaining a constant state, and then toward the downstream side. It has a shape that gradually increases.

  As shown in FIG. 1, the dynamic pressure exhaust system 60 includes a cylindrical outer shell 61 having an upstream end connected to an independent exhaust pipe 52 and a downstream end connected to a downstream exhaust pipe 80, and the outer shell 61. Each having a nozzle portion 64, a slide portion 62, and a diffuser portion 63 accommodated therein. The nozzle part 64, the slide part 62, and the diffuser part 63 are arranged in this order from the upstream side.

<Configuration of nozzle part 64>
As shown in FIG. 7, the nozzle portion 64 is a tubular member extending in the upstream / downstream direction, and extends from the downstream end of the independent exhaust pipe 52 to the downstream side. The nozzle portion 64 is disposed at the upstream end portion in the outer shell 61. The nozzle portion 64 is formed with four in-nozzle passages 64a (see FIGS. 4 and 7) into which the exhaust discharged from the independent exhaust passages 52 flows independently. The four in-nozzle passages 64a are provided corresponding to the four independent exhaust passages 52, respectively. As shown in FIGS. 4 and 7, the nozzle passages 64 a have the same structure and are arranged at equal intervals (90 ° intervals) around the central axis X <b> 1 of the nozzle portion 64.

  As shown in FIG. 7, the nozzle part 64 has a nozzle side straight part 64b and a nozzle side reduced diameter part 64c.

  The nozzle-side straight portion 64b has a cylindrical shape that extends downstream from the downstream end of the independent exhaust pipe 52 while maintaining the same diameter. The in-nozzle passage 64a in the nozzle-side straight portion 64b extends linearly along the central axis X1 of the nozzle portion 64.

  As shown in FIGS. 7 and 8, an upstream buffer member 65 is provided at the lower end portion of the peripheral wall of the nozzle side straight portion 64b. The upstream buffer member 65 is a ring-shaped member attached to the outer peripheral surface of the nozzle portion 64. The outer peripheral surface of the upstream buffer member 65 has a shape (a cross-sectional arc shape) along an inner peripheral surface of a curved portion 62 a described later in the slide portion 62. Specifically, the outer peripheral surface of the upstream buffer member 65 is formed so as to form a part of a first spherical surface C1 having a radius R1 centered on a point P1 on the central axis X1 of the nozzle portion 64. That is, when the upstream buffer member 65 is cut along a plane passing through the central axis X1, the outer edge of the cut surface (the edge opposite to the central axis X1) becomes an arc shape. The point P1 is located upstream of the upstream buffer member 65 on the central axis X1.

  Although the material of the upstream buffer member 65 is not particularly limited, for example, it can be configured by combining expanded graphite and a stainless mesh. Specifically, for example, a belt-shaped stainless steel mesh sheet overlapped with a belt-shaped expanded graphite sheet is wound into a ring shape, and the wound material is pressure-molded so that the outer peripheral surface has a circular arc shape in cross section. Thus, the upstream buffer member 65 can be manufactured. A ring-shaped member using expanded graphite is generally used as a seal ring such as a gasket. In the present embodiment, the cost for the upstream buffer member 65 can be reduced by using the seal ring that is generally used as described above for the upstream buffer member 65.

  As shown in FIG. 7, the upstream buffer member 65 includes the nozzle portion 64 and the slide portion 62 when the slide portion 62 is displaced in the upstream direction to a predetermined position (the most upstream position in the movable region of the slide portion 62 described later). It is arrange | positioned so that it may be pinched | interposed between. That is, the upstream buffer member 65 is disposed so as to contact the curved portion 62a of the slide portion 62 when the slide portion 62 is displaced to the predetermined position. By being arranged in this way, the upstream buffer member 65 prevents the slide portion 62 from being displaced in the upstream direction from the predetermined position. That is, the upstream buffer member 65 defines the most upstream position (the most upstream position) of the movable region of the slide portion 62.

  The nozzle-side reduced diameter portion 64c extends from the downstream end of the nozzle-side straight portion 64b to the downstream side, and has a substantially truncated cone shape that is reduced in diameter toward the downstream side. That is, the peripheral wall of the nozzle-side reduced diameter portion 64c is configured to incline toward the central axis X1 as it goes downstream. Accordingly, the flow passage area of the nozzle inner passage 64a in the nozzle side reduced diameter portion 64c is smaller than the flow passage area of the nozzle inner passage 64a in the nozzle side straight portion 64b. Specifically, the flow path area in the nozzle-side straight part 64b is constant over the entire upstream and downstream direction, and the flow path area in the nozzle-side reduced diameter part 64c decreases toward the downstream side. The inner diameter of the downstream end of the nozzle part 64 is set to, for example, about half of the inner diameter of the upstream end of the nozzle part 64.

  As shown in FIGS. 4 and 7, the peripheral wall of the nozzle-side reduced diameter portion 64c is formed with an opening 64d that allows the inside and outside of the nozzle passage 64a to communicate with each other. As shown in FIG. 4, the openings 64 d are provided at equal intervals (at intervals of 90 °) around the central axis X <b> 1 of the nozzle portion 64. As shown in FIG. 5, a part of the peripheral wall of the nozzle-side reduced diameter portion 64c is cut out in a substantially semicircular shape from the downstream end toward the upstream side to form an opening 64d. Here, since the peripheral wall of the nozzle-side reduced diameter portion 64c is inclined toward the central axis X1 toward the downstream side as described above, the opening portion 64d opens toward the downstream side.

<Configuration of Slide Unit 62>
The slide portion (corresponding to the “movable portion” of the present invention) 62 is a tubular member that is coaxial with the nozzle portion 64 and the outer shell 61 and extends in the upstream / downstream direction. That is, the center axis X2 of the slide part 62 coincides with the center axis X1 of the nozzle part 64 and the center axis X3 of the outer shell 61.

  One passage is formed in the slide portion 62. The slide portion 62 is driven by the actuator 70 and is displaced in the upstream and downstream directions in order to change the flow passage area of the passage through which the exhaust gas flowing into the nozzle passage 64a from the independent exhaust passage 52a passes.

  As shown in FIGS. 7 and 9, the downstream end portion of the slide portion 62 slides and displaces in the diffuser portion 63 in the upstream and downstream directions.

  The slide part 62 is a cylindrical member that includes a curved part 62a, a slide-side reduced diameter part 62b, and a slide-side straight part 62c, and extends in the upstream and downstream directions. The curved portion 62a and the slide-side reduced diameter portion 62b correspond to the “inflow portion” of the present invention. The slide-side straight portion 62c corresponds to the “aggregation portion” of the present invention.

  As shown in FIGS. 7 and 9, the curved portion 62 a is a cylindrical portion extending from the upstream end of the slide portion 62 to the downstream side. The inner peripheral surface of the curved portion 62a is formed so as to form a part of the first spherical surface C1 having a radius R1 with the point P1 on the central axis X2 of the slide portion 62 as the center. That is, when the curved portion 62a is cut along a plane passing through the central axis X2, the inner edge of the cut surface (the edge on the central axis X2 side) becomes an arc shape. The point P1 is located on the upstream side of the curved portion 62a on the central axis X2.

  The slide side reduced diameter portion 62b is a cylindrical portion extending from the downstream end of the curved portion 62a to the downstream side, and has a shape extending along the nozzle side reduced diameter portion 64c. That is, the slide-side reduced diameter portion 62b is configured to incline toward the central axis X2 side of the slide portion 62 toward the downstream side, and is formed in a truncated cone shape that decreases in diameter toward the downstream side. Accordingly, the flow path area of the slide-side reduced diameter portion 62b becomes smaller toward the downstream side.

  The curved portion 62 a and the slide-side reduced diameter portion 62 b are disposed so as to cover the downstream end portion of the nozzle portion 64.

  Specifically, as shown in FIGS. 6 and 7, when the slide portion 62 is displaced to the most upstream position, the curved portion 62a and the slide-side reduced diameter portion 62b of the slide portion 62 are replaced with the nozzle-side straight portion 64b. The downstream end portion of the nozzle, the nozzle-side reduced diameter portion 64c, and the upstream-side buffer member 65. The inner peripheral surface of the curved portion 62 a is in contact with the outer peripheral surface of the upstream buffer member 65. In this state, the curved portion 62a, the slide-side reduced diameter portion 62b, and the nozzle-side reduced diameter portion 64c are not in contact with each other, but their distances are small and close to each other.

  On the other hand, as shown in FIGS. 8 and 9, when the slide part 62 is displaced to the most downstream position, the curved part 62a and the slide-side reduced diameter part 62b cover the nozzle-side reduced diameter part 64c. In this state, the inner peripheral surface of the curved portion 62a is largely separated from the outer peripheral surface of the upstream buffer member 65.

  The raised portion 62d is provided at the downstream end of the slide-side reduced diameter portion 62b. As shown in FIGS. 6 to 9, the raised portion 62 d protrudes radially outward from the outer peripheral surface of the slide-side reduced diameter portion 62 b and is formed over the entire circumference of the slide-side reduced diameter portion 62 b. . The downstream portion of the raised portion 62d is cut out in a ring shape over the entire circumferential direction. A ring-shaped downstream buffer member 66 is attached to the notch.

  The outer peripheral surface of the downstream buffer member 66 has a shape (circular arc) along the inner peripheral surface (concave surface) of a bulging portion 61e of the outer shell 61 described later. Specifically, as shown in FIG. 9, the outer peripheral surface of the downstream buffer member 66 is a part of the second spherical surface C <b> 2 having a radius R <b> 2 centered on the point P <b> 2 on the central axis X <b> 2 of the slide portion 62. It is formed to make. That is, when the downstream buffer member 66 is cut along a plane passing through the central axis X2, the outer edge (edge opposite to the central axis X2) of the cut surface becomes an arc shape. The point P2 is located upstream of the downstream buffer member 66 on the central axis X2.

  The downstream buffer member 66 can be made of the same material as the upstream buffer member 65.

  As shown in FIGS. 8 and 9, the downstream buffer member 66 slides with the outer shell 61 when the slide part 62 is displaced in the downstream direction to a predetermined position (the most downstream position of the movable region of the slide part 62 described later). It arrange | positions so that it may be pinched | interposed between the parts 62. That is, the downstream buffer member 66 is disposed so as to contact the inner peripheral surface of the bulging portion 61e of the outer shell 61 when displaced to the predetermined position. By being arranged in this way, the downstream buffer member 66 prevents the slide portion 62 from being displaced in the downstream direction from the predetermined position. That is, the downstream buffer member 66 defines the most downstream position (the most downstream position) of the movable region of the slide portion 62.

  As shown in FIGS. 6 and 7, when the slide portion 62 is displaced to the most upstream position, the slide-side reduced diameter portion 62b comes close to almost the entire nozzle portion-side reduced diameter portion 64c. As indicated by the arrows, each opening 64d of the nozzle side reduced diameter portion 64c is substantially closed by the slide side reduced diameter portion 62b. Specifically, although there is a slight gap between the slide-side reduced diameter portion 62b and the nozzle-side reduced diameter portion 64c, the gap is narrow, so the slide-side reduced diameter portion 62b and the nozzle-side reduced diameter portion The exhaust gas hardly flows into the space between 64c. Accordingly, the exhaust gas flowing into the nozzle inner passage 64a from the independent exhaust passage 52 passes through the nozzle inner passage 64a without flowing out of the nozzle portion 64 from the opening 64d, and flows downstream from the downstream end of the nozzle inner passage 64a. To go.

On the other hand, as shown in FIGS. 8 and 9, when the slide part 62 is slid from the most upstream position to the downstream side and reaches the most downstream position, the slide side reduced diameter part 62 b is changed to the nozzle part side reduced diameter part 6.
It is greatly separated from 4c to the downstream side. Accordingly, a passage is formed between the reduced diameter portions 62b and 64c, and each opening 64d is opened. For this reason, in a state in which the slide portion 62 is displaced to the most downstream position, a part of the exhaust gas flowing into the nozzle inner passage 64a from the independent exhaust passage 52 is transferred to the slide side reduced diameter portion 62b and the nozzle portion side reduced diameter portion 64c. It flows downstream through a passage formed between them (hereinafter referred to as “external passage 64e”). That is, as indicated by an arrow in FIG. 9, the exhaust gas flowing from the independent exhaust passage 52 into the nozzle inner passage 64a passes through the external passage 64e in addition to the nozzle inner passage 64a.

  As described above, in this embodiment, the position of the slide portion 62 is displaced to the most upstream position and the downstream position, so that the exhaust gas flowing into the nozzle inner passage 64a from the independent exhaust passage 52 can be reduced. The passages that pass through are switched to only the nozzle inner passage 64a, the nozzle inner passage 64a, and the external passage 64e, thereby switching the passage area of the passage through which the exhaust gas passes. That is, when the position of the slide part 62 is the most upstream position, the flow passage area of the passage through which the exhaust gas passes is minimized, and the position of the slide part 62 is further downstream than the most upstream position. This channel area is made larger than the minimum. And the speed of the exhaust discharged downstream from the nozzle passage 64a is switched along with the switching of the flow path area. Specifically, when the position of the slide portion 62 is the most upstream position and the flow passage area of the passage through which the exhaust gas passes is minimized, the speed at which the exhaust is discharged downstream from the nozzle inner passage 64a is Get higher. On the other hand, when the position of the slide portion 62 is the most downstream position and the flow passage area of the passage through which the exhaust passes is maximized, the speed at which the exhaust gas is discharged downstream from the nozzle inner passage 64a can be kept low. .

  Here, each intra-nozzle passage 64a communicates with each independent exhaust passage 52 individually. Therefore, the exhaust in the nozzle passage 64a flows down without mixing with the exhaust in the other nozzle passage 64a. On the other hand, the space between the slide portion-side reduced diameter portion and the nozzle portion-side reduced diameter portion communicates with the entire circumference around the central axis X1. However, since the opening 64d is opened in the downstream direction as described above, the exhaust gas that has passed through the independent exhaust passage 52 and the nozzle inner passage 64a in the external passage 64e is also another independent exhaust passage 52, 64a. It flows down independently with little mixing with the exhaust that passed through.

  The slide-side straight portion 62c is discharged from each of the independent exhaust passages 52 and exhaust gas that has independently passed through the nozzle passage 64a or the nozzle passage 64a and the external passage 64e, that is, is discharged from each of the cylinders 12a to 12d. This is where the exhaust gas merges.

  The slide-side straight portion 62c has a constant flow area at the downstream portion so that the exhausts discharged from the cylinders 12a to 2d merge, mix well, and are well rectified.

  In the present embodiment, the upstream portion of the slide-side straight portion 62c is configured so that the flow channel area decreases toward the downstream side, while the downstream portion extends downstream with a constant flow channel area. Specifically, the upstream portion of the slide-side straight portion 62c has a substantially truncated cone shape whose diameter decreases toward the downstream side with the central axis X2 as the center, and the downstream portion of the slide-side straight portion 62c is It has a cylindrical shape with a constant diameter. The upstream portion of the slide-side straight portion 62c extends continuously from the downstream end of the slide-side reduced diameter portion 62b, and the downstream portion of the slide-side straight portion 62c has a constant flow area from the downstream end of the upstream portion. It extends in.

  A flange portion 62e that protrudes radially outward from the outer peripheral surface is provided on the outer peripheral surface of the downstream portion of the slide-side straight portion 62c. The flange portion 62e is formed integrally with the slide side straight portion 62c.

<Configuration of diffuser unit 63>
The diffuser portion 63 is a cylindrical portion that is configured so that the flow passage area increases toward the downstream side. Specifically, the upstream portion 63a of the diffuser portion 63 has a cylindrical shape with a constant diameter in the upstream and downstream directions. The portion 63b on the downstream side of the upstream portion 63a has a substantially truncated cone shape whose diameter increases toward the downstream side.

  Inside the diffuser part 63, the downstream end part of the slide side straight part 62c is inserted from the upstream side. The downstream end portion of the slide-side straight portion 62 c is slidably supported by the inner peripheral surface of the upstream portion 63 a of the diffuser portion 63. The inner diameter of the upstream portion 63a of the diffuser portion 63 is set to be slightly larger than the outer diameter of the downstream end portion of the slide-side straight portion 62c. When the slide portion 62 is displaced, the downstream end portion of the slide-side straight portion 62 c moves in the upstream and downstream directions along the axial direction of the diffuser portion 63 in the diffuser portion 63.

  The diffuser portion 63 is fixed to the outer shell 61 in a state where the slide portion 62 is slidably supported as described above. In the present embodiment, the diffuser portion 63 is welded to the outer shell 61.

<Configuration of outer shell 61>
As described above, the outer shell 61 is a tubular member that houses the nozzle portion 64, the slide portion 62, the diffuser portion 63, the upstream side buffer member 65, and the downstream side buffer member 66. As shown in FIGS. 6 and 7, the outer shell 61 includes a first portion 61a, a second portion 61b, a third portion 61c, and a fourth portion 61d in order from the upstream.

  The first portion 61a surrounds (covers) the upstream portion of the slide portion 62, the nozzle portion 64, and the upstream buffer member 65, and extends in a cylindrical shape toward the downstream side while maintaining the same diameter in the upstream and downstream directions. ing.

  The second portion 61b surrounds the upstream portion of the slide-side reduced diameter portion 62b, the raised portion 62d, the downstream buffer member 66, and the straight portion 62c of the slide portion 62, and extends downstream. The second portion 61b is configured to incline toward the central axis X2 as it goes downstream, and is formed in a truncated cone shape that decreases in diameter toward the downstream side.

  A bulging portion 61e bulging outward is formed at the downstream end of the second portion 61b in the upstream / downstream direction over the entire circumferential direction. The bulging part 61e is formed over a predetermined length in the upstream / downstream direction. Specifically, the length of the bulging portion 61e in the upstream / downstream direction is substantially the same as the length of the downstream buffer member 66 in the upstream / downstream direction. The inner peripheral surface of the bulging portion 61e is formed in a shape (circular arc shape) along the outer peripheral surface of the downstream buffer member 66. Specifically, as shown in FIG. 9, the inner peripheral surface of the bulging portion 61 e is a part of the second spherical surface C <b> 2 having a radius R <b> 2 centered on the point P <b> 2 on the central axis X <b> 3 of the outer shell 61. It is formed to make. That is, when the bulging portion 61e is cut along a plane passing through the central axis X3, the inner edge (edge on the central axis X3 side) of the cut surface becomes an arc shape. The point P2 is located on the upstream side of the bulging portion 61e on the central axis X3.

  The third portion 61c surrounds a cylindrical downstream portion of the slide-side straight portion 62c and an operated portion 92 described later. A through hole 61f is formed in the third portion 61c. The through hole 61f is a hole through which a swing arm 74 described later is inserted. The through hole 61f is formed in such a size that the swing arm 74 does not interfere with the peripheral edge of the through hole 61f when the swing arm 74 swings in the upstream / downstream direction.

  The fourth portion 61 d surrounds the diffuser portion 63 and is formed in a substantially truncated cone shape along the outer shape of the diffuser portion 63. The diffuser portion 63 is fixed to the fourth portion 61d.

<Configuration of moving mechanism 90>
A moving mechanism 90 for slidably moving the slide portion 62 will be described.

  As shown in FIGS. 2 and 3, the moving mechanism 90 in this embodiment includes an actuator 70, a lever portion 94, a shaft 73, a swing arm 74 (see FIGS. 3 and 6 to 9), and an operation portion 75. (See FIGS. 6 to 9) and an operated portion 92 (see FIGS. 6 to 9).

  The actuator 70, the lever portion 94, the shaft 73, and the swing arm 74 constitute the swing mechanism of the present invention.

  In the example shown in FIGS. 2 and 3, the actuator 70 is a direct-acting diaphragm type actuator. The actuator 70 includes an actuator main body 71 in which a diaphragm (not shown) is incorporated, and a rod 72 extending from the actuator main body 71 in a direction along the central axis X <b> 3 of the outer shell 61. When the actuator main body 71 is operated, the rod 72 is linearly displaced in a direction in which it is in contact with or separated from the actuator main body 71 (advance toward the downstream side and retreat toward the upstream side).

  The lever portion 94 is a plate-like member that connects the rod 72 and the shaft 73. One end portion of the lever portion 94 is swingably connected to the tip portion of the rod 72 (the end portion on the side opposite to the actuator body 71). As the rod 72 is displaced (forward and backward), the lever portion 94 swings along the upstream / downstream direction about the shaft 73.

  The shaft 73 is a columnar member and extends from the lever portion 94 toward the outer shell 61. The end portion of the shaft 73 on the lever portion 94 side is fixed to the central portion of the lever portion 94. As the lever portion 94 swings, the shaft 73 rotates around its central axis.

  6-9, the swing arm 74 passes from the outside of the outer shell 61 through the through hole 61f of the outer shell 61 and extends to the vicinity of the slide-side straight portion 62c. A through hole 74 a for fixing the swing arm 74 to the shaft 73 is formed at the end of the swing arm 74 opposite to the slide portion 62 (end on the side opposite to the slide portion). The end of the shaft 73 on the outer shell 61 side is press-fitted into the through hole 74 a of the swing arm 74. By this press-fitting, the end of the swing arm 74 on the side opposite to the slide portion is fixed to the shaft 73. As the shaft 73 rotates, the swing arm 74 swings around the shaft 73 along the upstream and downstream directions. That is, the swing arm 74 has the swing center Y0 at the end on the side opposite to the slide portion, and swings around the swing center Y0.

  The rod 72, lever portion 94, shaft 73, and swing arm 74 constitute a link mechanism. By this link mechanism, the linear forward and backward movements of the rod 72 are converted into the swinging motion of the swinging arm 74.

  6-9, the operation part 75 is provided in the edge part by the side of the slide part 62 in the rocking | swiveling arm 74. As shown in FIG. The operation unit 75 is formed of a truncated cone-shaped peripheral wall whose diameter decreases toward the downstream side, and the outer peripheral surface and the inner peripheral surface of the peripheral wall are curved in a spherical shape. The upstream end of the operation unit 75 is formed integrally with the end of the swing arm 74 on the slide unit 62 side. The thickness of the operation unit 75 is constant throughout.

  The operation unit 75 swings around the swing center Y0 together with the swing arm 74 along the upstream / downstream direction (centering on the shaft 73).

  When the operating portion 75 is viewed from the upstream side or the downstream side, the operating portion 75 has a ring shape that has an inner diameter larger than the outer diameter of the slide-side straight portion 62c and surrounds the slide-side straight portion 62c. An insertion hole 75a (see FIGS. 6 and 8) through which the slide-side straight portion 62c is inserted is formed at the center of the operation portion 75. The diameter of the insertion hole 75a is larger than the outer diameter of the slide side straight portion 62c and smaller than the outer diameter of the first operated portion 78 described later.

  The operation unit 75 has a first surface that is an inner peripheral surface of the operation unit 75 on the upstream side, and a second surface that is an outer peripheral surface of the operation unit 75 on the downstream side.

  The first surface of the operation unit 75 is a concave surface having an arcuate cross section. Specifically, the first surface of the operation unit 75 is constituted by a part of a third spherical surface C3 having a radius R3 centered on a point P3 on the central axis X2 of the slide unit 62. As the operating unit 75 swings, the center point P3 of the third spherical surface C3 moves on an arc centered on the swing center Y0. When the movable part 62 is at the most upstream position of the movable region, the center point P3 is on the center axis X2 of the slide part 62, the center axis X1 of the nozzle part 64, and the center axis X3 of the outer shell 61 and the center of oscillation. It is located upstream of Y0 (see FIG. 7). On the other hand, when the movable portion 62 is at the most downstream position of the movable region, the center point P3 is on the center axis X2 of the slide portion 62, the center axis X1 of the nozzle portion 64, and the center axis X3 of the outer shell 61. It is located downstream from the moving center Y0 (see FIG. 9).

  A center point P3 when the slide portion 62 is at the most upstream position of the movable region (hereinafter referred to as “center point P3 of the most upstream position”) and a position when the slide portion 62 is at the most downstream position of the movable region. The center point P3 (hereinafter referred to as “the center point P3 at the most downstream position”) is the intersection of a perpendicular line from the swing center Y0 of the swing arm 74 to the center axis X2 of the slide portion 62 and the center axis X2. It is close to K (see FIGS. 7 and 9). The distance S1 (see FIG. 7) between the center point P3 at the most upstream position and the intersection K is equal to the distance S2 (see FIG. 9) between the center point P3 at the most downstream position and the intersection K.

  Since the center point P3 of the most upstream position and the center point P3 of the most downstream position are close to the intersection point K, even if the center point P3 is displaced while drawing a circular locus, the direction is perpendicular to the upstream and downstream directions. The displacement amount of the center point P3 is a minute amount (a value near zero). Therefore, when the slide part 62 moves between the most upstream position and the most downstream position of the movable region, the center point P3 is substantially on the center axis X1 of the nozzle part 64 and the center axis X3 of the outer shell 61. is there.

  The second surface of the operation unit 75 is a convex surface having an arcuate cross section. Specifically, the second surface of the operation unit 75 is configured by a part of a fourth spherical surface C4 having a radius R4 with the center point P3 of the third spherical surface C3 as the center.

  6-9, the to-be-operated part 92 is provided in the outer peripheral surface of the downstream part of the slide side straight part 62c. The operated portion 92 includes a groove portion 93 (see FIGS. 7 and 9) having an inner wall surface that supports the operating portion 75 from both sides in the upstream and downstream directions in a slidable manner. The inner wall surface of the groove 93 is formed by a convex surface along the first surface of the operation unit 75 and a concave surface along the second surface of the operation unit 75.

  The operated portion 92 includes a first operated portion 78 having the convex surface, and a second operated portion 76 having the concave surface and separate from the first operated portion 78. The groove portion 93 is formed between the convex surface of the first operated portion 78 and the concave surface of the second operated portion 76. The width of the groove 93 (the interval between the convex surface and the concave surface) is substantially the same as the thickness of the operation unit 75. The 1st to-be-operated part 78 and the 2nd to-be-operated part 76 are formed in the ring shape along the perimeter of the outer peripheral surface of the slide side straight part 62c.

  The first operated portion 78 is disposed on the upstream side of the second operated portion 76. The 1st to-be-operated part 78 is arrange | positioned so that the convex surface may face the downstream. The upstream surface of the first operated portion 78 is in contact with the downstream surface of the flange portion 62 e of the slide portion 62. The first operated portion 78 can be made of the same material as that of the upstream buffer member 65.

  The convex surface of the first operated portion 78 has an arcuate cross section. Specifically, the convex surface of the first operated portion 78 is constituted by a part of a third spherical surface C3 (which may be a spherical surface having a radius slightly smaller than the radius R3). That is, the convex surface of the first operated portion 78 is along the first surface of the operating portion 75 and is in contact with the first surface of the operating portion 75. The first surface of the operation unit 75 is slidable with respect to the convex surface of the first operated unit 78.

  The second operated portion 76 is arranged such that the concave surface faces the upstream side. The second operated portion 76 is a cylindrical fixing portion 76b fixed to the outer peripheral surface of the slide-side straight portion 62c, and extends from the upstream end of the fixing portion 76b to the upstream side to support the second surface of the operating portion 75. Supporting part 76a. The support portion 76a is a frustoconical peripheral wall whose diameter increases toward the upstream side. The upstream surface of the support portion 76 a is the concave surface of the second operated portion 76.

  The concave surface of the second operated portion 76 has an arcuate cross section. Specifically, the concave surface of the second operated portion 76 is constituted by a part of a fourth spherical surface C4 (a spherical surface having a radius slightly larger than the radius R4). That is, the concave surface of the second operated portion 76 is along the second surface of the operating portion 75 and is in contact with the second surface of the operating portion 75. The second surface of the operation unit 75 is slidable with respect to the convex surface of the second operated unit 76.

  In the moving mechanism 90 configured as described above, when the rod 72 is displaced by the actuator main body 71, the lever portion 94 swings with the shaft 73 as a fulcrum, and accordingly, the shaft 73 rotates about its central axis. . As the shaft 73 rotates, the swing arm 74 and the operation unit 75 swing. As the operating unit 75 swings, the operated unit 92 displaces the sliding unit 62 in the upstream and downstream directions while sliding the operating unit 75 in the groove 93 (see FIGS. 7 and 9).

  Here, the actuator main body 71 is controlled to be turned on and off, and the position of the rod 72 is switched between two positions, the first position and the second position. Switching is possible at two positions, the most upstream position and the most downstream position. For example, when the actuator 70 is turned on, the slide portion 62 is set to the most upstream position, and when the actuator 70 is turned off, the slide portion 62 is set to the most downstream position.

<Control system configuration>
Next, a control system of the exhaust device 100 according to the present embodiment will be described. Each part of the exhaust device 100 of this embodiment is centrally controlled by an ECU (Electronic Control Unit) (not shown). The ECU is a microprocessor that includes a CPU, a ROM, a RAM, and the like.

  The ECU inputs the driving state of the vehicle from a sensor (not shown) that detects the driving state (driving region) of the vehicle, performs various determinations and calculations based on the driving state, and controls each part of the exhaust device 100. Control.

  In the present embodiment, as shown in FIG. 10, as operating regions, a low-speed high-load region (first region) A1 where the engine speed is low and the engine load is high, and a low-speed and low-load region where the engine speed is low and the engine load is low. (Second area) A2 and a high speed area (third area) A3 where the engine speed is high and the engine load is high are set.

  Hereinafter, the control content implemented in each operation area | region is demonstrated.

(Control in the low speed and high load area A1)
In the low speed and high load region A1, the actuator 70 is controlled by the ECU so that the slide portion 62 is displaced to the most upstream position. Specifically, in the low speed and high load region A1, the ECU performs control to turn on the actuator 70.

  This control is performed mainly for the purpose of enhancing the ejector effect and promoting scavenging in each of the cylinders 12a to 12d by the ejector effect to ensure engine torque.

  When the slide portion 62 is displaced to the most upstream position, the first surface and the second surface of the operation portion 75 are supported from both sides in the upstream / downstream direction by the inner wall surface of the groove portion 93 included in the operated portion 92. Since the operation portion 75 has a contact surface with the operated portion 92 formed in an arc shape in cross section, the contact area with the operated portion 92 becomes larger than when the contact surface is not in an arc shape in cross section. Accordingly, the first surface of the operation unit 75 contacts the convex surface of the operated portion 92 with a wide contact area, and the second surface of the operation unit 75 contacts the concave surface of the operated portion 92 with a wide contact area. The occurrence of galling, sticking, and excessive wear due to the contact of the portion 75 with the operated portion 92 is suppressed, rattling is less likely to occur, and the generation of contact sound is also suppressed.

(Control in low speed and low load area A2)
In the low-speed and low-load region A2, the actuator 70 is controlled by the ECU so that the slide part 62 is displaced to the most downstream position. Specifically, in the low speed and low load region A2, the ECU performs control to turn off the actuator 70.

  This control mainly secures the amount of residual gas in the cylinders 12a to 12d, suppresses the pumping loss of the intake air, suppresses the combustion temperature, and suppresses the increase of the cooling loss, thereby achieving an appropriate engine torque. It is implemented for the purpose of ensuring.

  Even when the slide portion 62 is displaced to the most downstream position, the first surface and the second surface of the operation portion 75 are supported from both sides in the upstream / downstream direction by the inner wall surface of the groove portion 93 of the operated portion 92. Therefore, the occurrence of galling, sticking, and excessive wear due to the operation unit 75 coming into contact with the operated unit 92 is suppressed, and rattling is less likely to occur, and the generation of contact sound is also suppressed.

(Control in high speed area A3)
In the high speed region A3, the actuator 70 is controlled by the ECU so that the slide portion 62 is displaced to the most downstream position. Specifically, in the high speed region A3, the ECU performs control to turn off the actuator 70.

  This control is mainly performed for the purpose of keeping the back pressure low, thereby improving the scavenging performance and ensuring high engine torque.

  In the control in the high speed region A3, as in the control in the low speed and low load region A2, the occurrence of galling, sticking, and excessive wear due to the operation portion 75 coming into contact with the operated portion 92 is suppressed, and rattling occurs. The generation of contact sound is suppressed because it is less likely to occur.

  As described above, according to this embodiment, the first surface and the second surface of the operation portion 75 are supported by the inner wall surface of the groove portion 93 of the operated portion 92 with a wide contact area from both sides in the upstream and downstream directions. Therefore, the occurrence of galling, sticking, and excessive wear due to the operation unit 75 coming into contact with the operated unit 92 is suppressed, and rattling is less likely to occur, and the generation of contact sound is also suppressed.

  In addition, according to the present embodiment, the operated portion 92 includes the first operated portion 78 and the second operated portion 76 that is separate from the first operated portion 78. The portion 92 can be easily manufactured, and the groove portion 93 having a curved inner wall surface can be easily formed.

  In addition, according to the present embodiment, the operation unit 75, the first operated unit 78, and the second operated unit 76 are formed in a ring shape along the entire circumference of the slide unit 62. 75 force (force of the swing arm 74) can be transmitted to the slide portion 62 over the entire circumference, and as a result, the slide portion 62 can be appropriately displaced along the upstream and downstream directions. it can.

  Further, according to the present embodiment, the flange portion 62e protrudes from the outer peripheral surface of the slide side straight portion 62c, and the first operated portion 78 is in contact with the flange portion 62e. For this reason, the force of the operating portion 75 (the force of the swing arm 74) can be reliably transmitted to the slide portion 62 via the flange portion 62e, so that the slide portion 62 is appropriately displaced along the upstream and downstream directions. Can be made.

  In addition, according to the present embodiment, since the first operated portion 78 is a seal ring, contact noise, galling, excessive wear, and a general seal ring used for fluid leakage prevention, and Suppression of sticking and securing of sealing properties can be easily achieved, and the manufacturing cost can be suppressed.

  Further, according to the present embodiment, the first surface of the operation unit 75 and the convex surface of the first operated portion 78 are configured by a part of the third spherical surface C3, and the second surface and the second surface of the operation unit 75 are configured. The concave surface of the operated portion 76 is constituted by a part of the fourth spherical surface C4. For this reason, even if the axial direction X2 of the slide portion 62 is inclined with respect to the axial direction X1 of the nozzle portion 64 or the axial direction X3 of the outer shell 61 due to a manufacturing error or the like, the first surface of the operation portion 75 is the first surface. Proper contact with the convex surface of the operated portion 78, and the second surface of the operating portion 75 properly contacts the concave surface of the second operated portion 76, so that contact sound, galling, excessive wear, and sticking are more reliably ensured. Can be suppressed.

  Further, according to the present embodiment, the center point P3 at the most upstream position and the center point P3 at the most downstream position are located on the center axis X2 of the nozzle portion 64. For this reason, even if the slide part 62 is displaced in the direction orthogonal to the upstream / downstream direction with the swing of the operating part 75, the slide part 62 is located when the slide part 62 is in the most upstream position or the most downstream position. Is arranged at a position where the central axis X2 coincides with the central axis X1 of the nozzle portion 64. Therefore, when the slide part 62 is at the most upstream position and when it is at the most downstream position, the slide part 62 can be arranged at an appropriate position.

  Further, according to the present embodiment, the center point P3 at the most upstream position and the center point P3 at the most downstream position are the intersection K between the perpendicular line extending from the swing center Y0 to the center axis of the slide portion 62 and the center axis. Is close to. For this reason, even if the slide part 62 is displaced in the direction orthogonal to the upstream / downstream direction, the amount of displacement in that direction is very small. Therefore, when the slide part 62 is swinging, it is possible to prevent the position of the slide part 62 from shifting in a direction orthogonal to the upstream / downstream direction. Further, since the first surface of the operation unit 75 properly contacts the convex surface of the first operated portion 78 and the second surface of the operation unit 75 properly contacts the concave surface of the second operated portion 76, the contact Sound, galling, excessive wear, and sticking can be more reliably suppressed.

  In the above-described embodiment, both the first surface and the second surface of the operation unit 75 are part of a spherical surface, and the convex surface of the first operated unit 78 and the concave surface of the second operated unit 76 are both. Although it consists of a part of spherical surface, it is not restricted to this. If the operation part 75 is slidable in contact with the inner wall surface of the groove part 93 of the operated part 92 with a large area, the first surface, the second surface, the convex surface, and the concave surface are configured by curved surfaces other than spherical surfaces. May be.

  In the above embodiment, the inner diameter of the upstream portion 63a of the diffuser portion 63 is set to be slightly larger than the outer diameter of the downstream end portion of the slide-side straight portion 62c. If contact noise, galling, or sticking is a concern due to thermal deformation, a clearance may be set between the two so as not to make contact.

  Further, in the above embodiment, all the cylinders 12 a to 12 d are connected to the independent exhaust passages 52 independently (each individually), and thereby the number of independent exhaust passages 52 connected to the engine 1 is four. However, it is not limited to this. For example, among the cylinders 12, the first cylinder 12a and the fourth cylinder 12d are independently connected to the independent exhaust passages 52, 52, while the exhaust strokes are not adjacent to each other and the second cylinder 12b does not have a continuous exhaust sequence. The third cylinder 12c may be connected to one independent exhaust passage 52 that is bifurcated in the middle. Specifically, the independent exhaust passage 52 connected to the second cylinder 12b and the third cylinder 12c branches into two passages from the downstream side to the upstream side in the middle portion, and one of the branch passages The second cylinder 12b may be connected to the other, and the third cylinder 12c may be connected to the other branch passage. By adopting such a configuration, the number of independent exhaust passages 52 connected to the engine 1 is three, and the structure of the exhaust device is simplified.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In addition, about the structure similar to 1st Embodiment, the same referential mark is attached | subjected and the description is abbreviate | omitted.

  The moving mechanism 90A in this embodiment includes an actuator 70 (see FIG. 11), a lever portion 94, a shaft 73A (corresponding to the “camshaft” of the present invention), and swing arms 81b and 81c (FIGS. 12 to 16). , 18), an operating portion 75, an operated portion 92, an eccentric cam 80, a pivot portion 81d, a pivot support portion 82, and an outer ring portion 81a.

  In the present embodiment, the outer shell 61 includes a cover portion 61f that accommodates the eccentric cam 80 and the outer ring portion 81a, and a pivot support portion 82 that supports the pivot portion 81d.

  The cover portion 61f is a portion that bulges radially outward on the downstream side of the bulging portion 61e in the outer shell 61. The cover portion 61f rotatably supports the shaft 73A via a cylindrical bush (not shown).

  The pivot support portion 82 is a portion that bulges outwardly in the radial direction on the downstream side of the bulging portion 61 e in the outer shell 61. The pivot support portion 82 is formed on the side opposite to the cover portion 61 f in the outer shell 61 in the radial direction. The pivot support portion 82 has a cylindrical slide support surface 82 a (see FIGS. 12 to 15) extending radially outward on the inside thereof. The slide support surface 82a supports a spherical pivot portion 81d, which will be described later, so as to be slidable in a direction connecting the pivot portion 81d and the shaft 73A.

  Inside the diffuser part 63, the downstream end part of the slide side straight part 62c is inserted from the upstream side. The inner diameter of the upstream portion 63a of the diffuser portion 63 is set to be larger than the outer diameter of the downstream end portion of the slide-side straight portion 62c. Specifically, when the slide portion 62 is at the most upstream position and at the most downstream position (see FIGS. 12 to 15, 16 (a), (c)), the downstream end portion of the slide-side straight portion 62 c is detected. When the outer peripheral surface is separated from the inner peripheral surface of the upstream portion 63a of the diffuser portion 63 and the slide-side straight portion 62c comes closest to the pivot support portion 82 as the eccentric cam 80 rotates (see FIG. 16B). Further, the inner diameter of the upstream portion 63 a of the diffuser portion 63 is set so that the outer peripheral surface of the downstream end portion of the slide-side straight portion 62 c is in contact with the inner peripheral surface of the upstream portion 63 a of the diffuser portion 63.

  The actuator 70, lever portion 94, shaft 73A, swing arms 81b and 81c, eccentric cam 80, pivot portion 81d, pivot support portion 82, and outer ring portion 81a constitute the swing mechanism of the present invention. The outer ring portion 81a, the swing arms 81b and 81c, the operation portion 75, and the pivot portion 81d are integrally formed.

  As shown in FIGS. 12 to 16 and 18, the eccentric cam 80 is a disc-shaped cam provided at a position radially outside the slide-side straight portion 62 c of the movable portion 62. The shaft 73A is fixed, and rotates with the rotation of the shaft 73A. The radial center C (see FIGS. 12, 14, and 17) of the eccentric cam 80 is displaced in the upstream / downstream direction along with the rotation of the shaft 73A, and in a direction connecting the axis Q of the shaft 73A and the pivot portion 81d. Displace.

  Specifically, in the state where the radial center C of the eccentric cam 80 is located on the upstream side of the axis Q of the shaft 73A (see FIGS. 12, 13, 16 (a), 17 (a)), the shaft 73A. 12 rotates counterclockwise (counterclockwise) in FIG. 12, and the center C of the eccentric cam 80 is aligned at the same position in the upstream / downstream direction with respect to the axis Q of the shaft 73A (FIG. 16B). , 17 (b)), the state shifts to a state where the center C of the eccentric cam 80 is located downstream from the axis Q of the shaft 73A (see FIGS. 14, 15, 16 (c), 17 (c)). To do.

  In the state where the center C in the radial direction of the eccentric cam 80 is located downstream of the axis Q of the shaft 73A (see FIGS. 14, 15, 16 (c) and 17 (c)), the shaft 73A is shown in FIG. , The center C of the eccentric cam 80 is aligned at the same position in the upstream and downstream direction with respect to the axis Q of the shaft 73A (FIGS. 16B and 17B). )), The center C of the eccentric cam 80 transitions to a state (see FIGS. 12, 13, 16 (a), 17 (a)) located upstream of the axis Q of the shaft 73A.

  In a state where the center C of the eccentric cam 80 is located on the most upstream side (see FIGS. 12 and 13), the axis Q of the shaft 73A passes through the center C of the eccentric cam 80 and extends along the upstream and downstream directions. It is located in the vicinity of X4 (see FIG. 17A). That is, the distance S3 between the reference line X4 and the axis Q of the shaft 73A is a value near zero. A straight line X5 in FIG. 17A is a line that passes through the axis Q of the shaft 73A and is parallel to the reference line X4. In FIG. 17 (a), the distance S3 is shown to be approximately equal to the radius of the shaft 73A in order to make the drawing easier to see, but actually, the distance S3 is set to be smaller than the radius of the shaft 73A.

  In this state, the position of the slide portion 62 becomes the most upstream position (see FIGS. 12 and 13), and as a result, the passage through which the exhaust gas flowing into the nozzle passage 64a from the independent exhaust passage 52 passes is only the nozzle passage 64a. It becomes. As a result, the flow path area of the passage through which the exhaust gas passes in the slide-side reduced diameter portion 62b is minimized.

  On the other hand, in a state where the center C of the eccentric cam 80 is located on the most downstream side (see FIGS. 14 and 15), the shaft center Q of the shaft 73A passes through the center C of the eccentric cam 80 and extends in the upstream / downstream direction. It is located in the vicinity of the reference line X4 (see FIG. 17C). That is, the distance S4 between the reference line X4 and the axis Q of the shaft 73A is a value near zero. Note that a straight line X5 in FIG. 17C is a line that passes through the axis Q of the shaft 73A and is parallel to the reference line X4. In FIG. 17C, the distance S4 is shown to be approximately equal to the radius of the shaft 73A in order to make the drawing easier to see, but actually, the distance S4 is set smaller than the radius of the shaft 73A.

  In this state, the position of the slide portion 62 is the most downstream position (see FIGS. 14 and 15), and thereby the passage through which the exhaust gas flowing from the independent exhaust passage 52 into the nozzle passage 64a passes is the nozzle passage 64a and It becomes the external passage 64e. As a result, the flow passage area of the passage through which the exhaust gas passes becomes larger than in the case of FIGS.

  As shown in FIGS. 12 to 16 and 18, the outer ring portion 81 a (corresponding to the “displacement portion” of the present invention) is an annular member that is rotatably fitted on the outer periphery of the eccentric cam 80. As the eccentric cam 80 rotates, the outer ring portion 81a is displaced in the direction connecting the axis Q of the shaft 73A and the pivot portion 81d while being displaced in the upstream and downstream directions. That is, the outer ring portion 81 a is displaced in accordance with the movement of the center C of the eccentric cam 80. In the state shown in FIG. 16B, that is, when the slide part 62 is at the center position between the most upstream position and the most downstream position, the outer ring part 81 a and the slide side straight part 62 c are closest to the pivot support part 82. To do.

  The swing arms 81b and 81c are rod-shaped members corresponding to the connecting portion of the present invention. As shown in FIGS. 12 to 16 and 18, the swing arm 81 b connects the outer ring portion 81 a and the operation portion 75, and the swing arm 81 c connects the operation portion 75 and the pivot portion 81 d. The swing arm 81b and the swing arm 81c each extend in a direction connecting the outer ring portion 81a and the pivot portion 81d, and these are arranged on the same straight line.

  As the shaft 73A rotates, the swing arms 81b and 81c swing along the upstream / downstream direction about the pivot portion 81d (see FIGS. 12 to 16). That is, the swing arms 81b and 81c swing around the swing center N with the center N of the pivot portion 81d as the swing center.

  13 and 15, a point K is an intersection of a straight line L1 connecting the axis Q of the shaft 73A and the center N of the pivot portion 81d and the center axes X1 and X2, and a point M is the eccentric cam 80. This is an intersection of a straight line L2 connecting the center C and the center N of the pivot part 81d and the central axes X1 and X2.

  The pivot portion 81d is a spherical portion provided at the tip of the swing arm 81c. The pivot portion 81d slides and displaces in a direction connecting the pivot portion 81d and the shaft 73A while contacting the slide support surface 82a of the slide support portion 82.

  As shown in FIG. 11, the actuator 70 includes a rod 72 and an actuator body 71 that reciprocates the rod 72. The rod 72 extends from the actuator body 71 in a direction inclined with respect to the central axis X3 of the outer shell 61. When the actuator main body 71 is operated, the rod 72 is linearly displaced in a direction in which it is in contact with or separated from the actuator main body 71 (advance toward the downstream side and retreat toward the upstream side).

  As shown in FIG. 11, one end portion of the lever portion 94 is swingably connected to the tip portion of the rod 72, and the other end portion of the lever portion 94 is fixed to the shaft 73A. The connecting portion between the lever portion 94 and the rod 72 is located closer to the central axis X3 side of the outer shell 61 than the connecting portion (fixed portion) between the lever portion 94 and the shaft 73A. The rod 72, the lever portion 94, and the shaft 73A constitute a link mechanism that converts the linear motion of the rod 72 into the rotational motion of the shaft 73A. The eccentric cam 80, the outer ring portion 81a, the swinging arms 81a and 81b, the pivot portion 81d, The pivot support portion 82 constitutes a cam mechanism for converting the rotational motion of the shaft 73A into the swing motion of the swing arms 81a and 81b.

  In the present embodiment, the center point P3 at the most upstream position and the center point P3 at the most downstream position are located upstream from the intersection K (see FIGS. 7 and 9).

  When the movable portion 62 is at the most upstream position of the movable region, the intersection point M is on the central axis X2 of the movable portion 62, the central axis X1 of the nozzle portion 64, and the central axis X3 of the outer shell 61 and from the intersection point K. Located upstream (see FIG. 7). On the other hand, when the movable portion 62 is at the most downstream position of the movable region, the intersection point M is on the central axis X2 of the movable portion 62, the central axis X1 of the nozzle portion 64, and the central axis X3 of the outer shell 61 and the intersection point K. It is located on the downstream side (see FIG. 9).

  The distance between the intersection K and the intersection M when the movable part 62 is at the most upstream position (see FIG. 7) is the distance between the intersection K and the intersection M when the movable part 62 is at the most downstream position (see FIG. 9). be equivalent to.

  In the present embodiment, the eccentric cam 80 rotates with the rotation of the shaft 73A, so that the position of the slide portion 62 is the most upstream position (see FIGS. 12 and 13) and the downstream position (see FIG. 14). , 15), thereby switching the flow path area of the passage through which the exhaust gas passes.

  Next, the force which acts on the structural member of the moving mechanism 90A will be described with reference to FIGS. FIGS. 17A and 18 show a state when the movable portion 62 is at the most upstream position of the movable region, and FIG. 17B shows a state when the movable portion 62 is at the middle position of the movable region. FIG. 17C shows a state when the movable portion 62 is at the most downstream position of the movable region. In FIG. 18, it is assumed that the forces are balanced in the entire moving mechanism 90A.

  Inside the movable part 62, exhaust gas flows toward the downstream side. For this reason, as shown in FIG. 18, the movable portion 62 receives a pressing force F <b> 1 in the direction toward the downstream side from the exhaust gas, and the pressing force F <b> 1 is transmitted to the operation portion 75 via the operated portion 92. A part of the force F6 of the pressing force F1 received by the operation unit 75 is transmitted to the outer ring portion 81a via the swing arm 81b, and a force F4 obtained by subtracting the force F6 from the force F1 is transmitted via the swing arm 81c. It is transmitted to the pivot part 81d. That is, the magnitude of the force F1 is equal to the sum of the magnitude of the force F4 and the magnitude of the force F6. Then, the force F6 directed in the downstream direction is transmitted from the outer ring portion 81a to the eccentric cam 80, and the force F4 directed in the downstream direction is transmitted from the pivot portion 81d to the pivot support portion 82 (see FIG. 18). .

  The eccentric cam 80 that has received the force F6 from the outer ring portion 81a applies a force F2 (reaction force) directed in the upstream direction to the outer ring portion 81a (see FIGS. 17A and 17). The force F2 is a component force (the force in the clockwise direction in FIGS. 17A and 18) that opposes the force with which exhaust gas tries to rotate the eccentric cam 80 (hereinafter referred to as “cam rotational force due to exhaust gas”). ) F22 and a component force (force toward the upstream side) f21 that opposes the force of the exhaust gas pressing the shaft 73A downstream. The component force f22 is a force obtained from the driving force F3 of the actuator 70 (see FIG. 18). A straight line L3 in FIGS. 17 and 18 is an action line of the force f21 and is a straight line passing through the action point of the force f21 and the axis Q of the shaft 73A. The straight line L4 is a line of action of the force f22, and is a straight line parallel to the direction in which the rod 72 of the actuator 70 advances and retreats.

  In order to apply the component force f22 to the eccentric cam 80, the actuator 70 may pull the rod 72 with a force F3 having the same direction as the component force f22 and a magnitude based on the component force f22. The actuator main body 71 of the actuator 70 can hold the position in the upstream / downstream direction of the movable portion 62 by pulling the rod 72 with the force F3. Note that the force f31 in FIG. 18 is a component force in the upstream and downstream direction of the force F3, and the force f32 is a component force in a direction parallel to the straight line L3.

  As can be seen from FIGS. 17 (a) to (c), in the state shown in FIG. 17 (a), the component force f22 is significantly smaller than in the states shown in FIGS. 17 (b) and 17 (c). Yes. This is because the cam rotation force by the exhaust gas (the same force as the component force f22 and the opposite direction force) is reduced between the eccentric cam 80 and the outer ring portion 81a. This is because it is most reduced when it is at the most downstream position of the movable region (see FIG. 17C). That is, as the angle θ formed by the force F6 and the straight line L3 at the point of application of the force F6 (the upstream end portion of the eccentric cam 80 in FIG. 17) is smaller, in other words, as the distance S3 is smaller, the cam rotational force caused by the exhaust gas. Becomes smaller. From this, it can be seen that the movable portion 62 can be kept in the most upstream position only by generating the actuator 70 with a very small tensile force F3.

  On the other hand, as shown in FIG. 19, when the lever portion 94 is fixed to the swing arm 74, the cam rotational force due to the exhaust gas is not reduced, so the actuator 70 is larger than the force F <b> 3 in this embodiment. It is necessary to generate a driving force (tensile force) F7. Note that the force f71 in FIG. 19 is a component force in the upstream and downstream direction of the force F7, and the force f72 is a component force in the direction along the lever portion 94 of the force F7.

  As described above, according to the present embodiment, the driving force (tensile force) required for the actuator 70 (direct acting actuator) to maintain the state in which the movable portion 62 is displaced upstream is reduced. Accordingly, the actuator 70 can be reduced in size. More specifically, in order to maintain the state in which the movable part 62 is displaced upstream (the state in which the flow path area of the slide-side reduced diameter part 62b is reduced), the movable part 62 is moved downstream by the pressure of the exhaust gas. In order not to displace, it is necessary to cause the actuator 70 to generate a driving force (tensile force) F3 in a direction that displaces the movable portion 62 upstream. In this embodiment, since the eccentric cam 80 and the outer ring portion 81a that is displaced in the upstream / downstream direction with the rotation of the eccentric cam 80 are interposed between the actuator 70 and the movable portion 62, the cam rotation by the exhaust gas is performed. The force is reduced between the eccentric cam 80 and the outer ring portion 81a, whereby the driving force F3 required for the actuator 70 to counter the cam rotational force caused by the exhaust gas is reduced.

  In addition, according to the present embodiment, the force that the exhaust gas presses the movable portion 62 downstream is transmitted to both the pivot support portion 82 and the eccentric cam 80, so that the pressing force is eccentric with the pivot support portion 82. Distributed to the cam 80 (force F4 and force F6). Thereby, the cam rotational force by exhaust gas is reduced, and as a result, the driving force F3 required for the actuator 70 can be reduced.

  Further, according to the present embodiment, when the movable portion 62 is at the most upstream position in the movable region, the shaft center Q of the shaft 73A passes through the radial center C of the eccentric cam 80 and in the upstream / downstream direction. Since it is located in the vicinity of the reference line X4 along, the cam rotational force due to the exhaust gas has a magnitude near zero. Thereby, the driving force F3 (refer FIG. 18) required for the actuator 70 can be reduced significantly.

  In addition, according to the present embodiment, the pivot support portion 82 supports the pivot portion 81d so as to be slidable in the direction A (see FIG. 16) connecting the pivot portion 81d and the shaft 73A. Can be smoothly displaced in the upstream and downstream directions.

1 Engine 12a-12d Cylinder 52a Independent exhaust passage 61 Outer shell 62 Slide part (movable part)
62b Slide side reduced diameter part (inflow part)
62c Slide side straight part (aggregation part)
62e Flange part 64 Nozzle part 64a Passage in nozzle 70 Actuator 73A Shaft (camshaft)
74 Oscillating arm 75 Operating section 76 Second operated section 78 First operated section 80 Eccentric cam 81a Outer ring section (displacement section)
81b, 81c Swing arm (connecting part)
81d Pivot part 82 Pivot support part 90 Movement mechanism 92 Operated part 93 Groove part C Center of eccentric cam C3 Third spherical surface (first spherical surface)
C4 Fourth spherical surface (second spherical surface)
P3 Center point of the third sphere (center point of the first sphere)
P4 Center point of the fourth sphere (center point of the second sphere)
K Intersection point Q Shaft axis Y0 Center of swing

Claims (12)

A plurality of independent exhaust passages that are independently connected to the plurality of cylinders of an engine having a plurality of cylinders, or independent exhaust passages that are branched in the middle and connected to a plurality of cylinders whose exhaust order is not continuous A nozzle portion extending from a plurality of independent exhaust passages and formed with a plurality of nozzle internal passages into which gas discharged from each of the independent exhaust passages independently flows;
An inflow portion into which the gas discharged from the nozzle passage flows in, and a collecting portion into which the gas that has passed through the inflow portion gathers, and the upstream and downstream of the gas flow on the downstream side of the nozzle portion in the gas flow direction A cylindrical movable portion that is provided so as to be displaceable in a direction, and that reduces the flow area of the inflow portion when displaced upstream and expands the flow area of the inflow portion when displaced downstream; ,
A moving mechanism for displacing the movable part in the upstream and downstream directions,
The moving mechanism has a swing center at a position radially outside of the movable portion and is swingable along the upstream / downstream direction, and has a cross-sectional circle on one side in the upstream / downstream direction. An operating portion having a first surface made of an arc-shaped concave surface and a second surface made of a convex surface having an arc-shaped cross section on the other side in the upstream and downstream directions;
A rocking mechanism for rocking the operating portion along the upstream and downstream directions;
Provided on the outer peripheral portion of the movable portion, and having a convex surface along the first surface of the operation portion and a concave surface along the second surface of the operation portion, the operation portion can be slid by the convex surface and the concave surface. Includes a groove portion having an inner wall surface supported from both sides in the upstream / downstream direction, and the movable portion is displaced in the upstream / downstream direction while sliding the operation portion in the groove portion as the operation portion swings. And an exhaust device for a multi-cylinder engine.   The operated portion includes a first operated portion having the convex surface, and a second operated portion having the concave surface and separate from the first operated portion. The exhaust device for a multi-cylinder engine according to claim 1. The operation part has a ring shape having an inner diameter larger than an outer diameter of the movable part and surrounding the movable part,
3. The multi-cylinder according to claim 2, wherein the first operated portion and the second operated portion are formed in a ring shape along the entire circumference of the outer peripheral surface of the movable portion. Engine exhaust system.   A flange portion projects from the outer peripheral surface of the movable portion, and the upstream surface of the operated portion located upstream from the first operated portion and the second operated portion is the flange portion. The exhaust device for a multi-cylinder engine according to claim 3, wherein the exhaust device is in contact.   The exhaust device for a multi-cylinder engine according to any one of claims 2 to 4, wherein the first operated portion is a seal ring. The first surface of the operation portion is configured by a part of a first spherical surface centered on a point located on the central axis of the movable portion, and the convex surface of the first operated portion is the first surface. A part of a sphere along one sphere,
The second surface of the operation portion is configured by a part of a second spherical surface centered on the point, and the concave surface of the second operated portion is a spherical surface along the second spherical surface. The exhaust device for a multi-cylinder engine according to any one of claims 2 to 5, wherein the exhaust device is configured by a section.   The point when the movable portion is at the most upstream position of the movable region and the point when the movable portion is at the most downstream position of the movable region are located on the central axis of the nozzle portion. The exhaust system for a multi-cylinder engine according to claim 6. The point when the movable portion is at the most upstream position of the movable region and the point when the movable portion is at the most downstream position of the movable region are the center axis of the movable portion from the swing center The exhaust system for a multi-cylinder engine according to claim 7, wherein the exhaust system is close to an intersection of the perpendicular line and the central axis. The swing mechanism is
An eccentric cam provided at a position radially outside of the movable portion;
An actuator for applying a rotational force to the eccentric cam;
A pivot portion disposed at the swing center;
A pivot support part for supporting the pivot part;
A displacement portion that is displaced in the upstream / downstream direction along with the rotation of the eccentric cam;
The exhaust device for a multi-cylinder engine according to any one of claims 1 to 8, further comprising a connecting portion that connects the displacement portion, the pivot portion, and the operation portion. The actuator applies a rotational force to a camshaft fixed to the eccentric cam;
When the movable portion is at the most upstream position in the movable region, the camshaft has an axial center passing through the radial center of the eccentric cam and in the vicinity of a reference line along the upstream and downstream directions. The exhaust system for a multi-cylinder engine according to claim 9, wherein The actuator applies a rotational force to a camshaft fixed to the eccentric cam;
The exhaust device for a multi-cylinder engine according to claim 9 or 10, wherein the pivot support portion supports the pivot portion so as to be slidable in a direction connecting the pivot portion and the camshaft. The actuator includes a rod, and an actuator body that applies a rotational force to a camshaft fixed to the eccentric cam by reciprocating the rod.
The swing mechanism further includes a lever rotatably connected to the rod,
The exhaust device for a multi-cylinder engine according to any one of claims 9 to 11, wherein the camshaft is fixed to a position of the lever that is separated from a connecting portion between the lever and the rod.

Images