JP2015110912A - Exhaust device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem on a conventional EGR control valve that a flow of EGR gas hits against the sleeve front end face of a foreign matter removing pipe and so foreign matters (deposits) enter through an annular clearance formed between the inner periphery of the sleeve front end face of the foreign matter removing pipe and the outer diameter face of a valve shaft into the foreign matter removing pipe and into a bearing hole of a housing.SOLUTION: An EGR control valve is formed so that a virtual extension line of a first inclined surface 96 between a large-diameter shaft part 94 and a small-diameter shaft part 95 of a valve shaft 2 of a poppet valve does not intersect or interfere with a sleeve front end 84 of a foreign matter removing pipe 33 and a virtual extension line of a valve seal surface 85 of a valve body 1 does not intersect or interfere with the sleeve front end 84 of the foreign matter removing pipe 33. This inhibits foreign matters from entering into the foreign matter removing pipe 33 and into a bearing hole 31 of a bearing holder 28, therefore preventing the poppet valve from being disabled or malfunctioned.

Description

  The present invention relates to an exhaust device for an internal combustion engine, and in particular, an exhaust gas (exhaust) circulation device for recirculating a part of exhaust gas (exhaust gas) discharged from a cylinder of the internal combustion engine (engine) to an intake pipe as EGR gas. Related to.

[Conventional technology]
Conventionally, in an internal combustion engine (engine) such as a diesel engine, an exhaust gas recirculation device (EGR system) that reduces nitrogen oxide (NOx) contained in exhaust gas (exhaust gas) discharged from a cylinder of the engine is mounted. ing.
The EGR system recirculates (refluxs) part of the exhaust discharged from the engine cylinders as EGR gas to the intake passage in the intake pipe and mixes it with intake air (fresh air) that has passed through the air cleaner to lower the combustion temperature. This suppresses the generation of NOx.

Here, when the EGR gas is recirculated to the intake passage, the ignitability of the air-fuel mixture in the cylinder of the engine is lowered and the engine output is reduced. Therefore, the flow rate of the EGR gas introduced into the engine cylinder is reduced. It is necessary to adjust according to the driving situation.
Therefore, in the EGR system, an EGR gas flow rate control valve (hereinafter referred to as EGR control valve) is installed in the middle of an exhaust passage pipe (EGR gas pipe) that connects the branch portion of the exhaust passage in the exhaust pipe and the intake passage in the intake pipe. The flow rate of the EGR gas introduced into the engine cylinder is controlled by adjusting the opening of the poppet valve that is the valve body of the EGR control valve.

As described above, the EGR system is provided with an EGR control valve that variably controls the flow rate of the EGR gas flowing through the EGR gas flow path in the EGR gas pipe (see, for example, Patent Document 1).
The EGR control valve includes: an electric motor having a motor shaft and a pinion gear; an intermediate shaft having an intermediate gear that rotates in mesh with the pinion gear; an eccentric shaft having an output gear and eccentric that rotates in mesh with the intermediate gear; A valve, a valve stem, and a connecting link meshing with eccentric are provided.
The intermediate shaft is disposed in the vicinity of the eccentric shaft on the side so that the eccentric and the connecting link are disposed in the vicinity of the electric motor.

[Conventional technical problems]
However, in the conventional EGR control valve, there is no housing wall between the output gear and the eccentric, and it is difficult to arrange a bearing (bearing) that supports the eccentric shaft so as to be slidable in the rotational direction. Met. As a result, the eccentric shaft oscillates, so that the meshing between the intermediate gear and the output gear is poor, and the power of the electric motor is not efficiently transmitted to the eccentric and poppet valves.
Therefore, the EGR control partially shown in FIG. 7 by the present inventors for the purpose of easily transmitting the power of the electric motor to the scotch yoke and the poppet valve by facilitating the arrangement of the bearing that supports the eccentric shaft. A valve (Comparative Example 1) was prototyped (not a well-known technique).

  The EGR control valve of Comparative Example 1 includes an electric actuator having an electric motor and a speed reduction mechanism, an output lever coupled to an output shaft that is an output shaft of the speed reduction mechanism, and an end of the output lever (the rotation of the output shaft). A follower mounted at a position eccentric from the center), a scotch yoke having a yoke groove with which the follower is engaged, a poppet valve connected to the scotch yoke, and the valve head 101 and the valve shaft 102 of the poppet valve are closed. A return spring 103 that biases in the valve direction, and a housing that accommodates the valve head 101, the valve shaft 102, the return spring 103, the electric actuator, and the scotch yoke are provided.

The housing is integrally provided with a valve body 104 that movably accommodates a valve head 101, a valve shaft 102, a return spring 103, a scotch yoke, and the like. This EGR control valve is configured to flow from the inlet port 111 opened at the upstream end of the valve body 104 into the flow path hole 113 via the flow path hole 112. Further, the flow path hole 113 is configured to flow into the flow path hole 115 via the flow path hole 114. Further, it is configured to flow out from the flow path hole 115 to the intake pipe side via an outlet port 116 opened at the downstream end of the valve body 104.
Further, the valve body 104 has an annular partition (partition portion) that divides a flow path hole 112 positioned on the upstream side in the EGR gas flow direction and flow path holes 114 and 115 positioned on the downstream side in the EGR gas flow direction. 117 is provided with an annular valve seat 118. Inside the valve seat 118, a flow path hole (valve hole of the EGR control valve) 113 that connects the flow path hole 112 and the flow path hole 114 is formed.

Here, the valve head 101 of the poppet valve is integrally provided with a truncated cone-shaped (tapered) inclined surface (conical surface) 119 that can be seated on the valve seat (seat edge) of the valve seat 118. The valve body 104 is integrally formed with a bearing holder 122 that holds the outer periphery of a cylindrical sliding bearing 121 that supports the valve shaft 102 so as to be reciprocally slidable in the axial direction thereof.
By the way, the poppet valve is accommodated in an openable and closable manner inside a valve body 104 through which EGR gas containing combustion particulates and exhaust particulates (hereinafter referred to as PM) such as carbon flows. Therefore, during operation of the engine, PM contained in the EGR gas may adhere to and accumulate on the surface of the valve head 101, the outer peripheral surface of the valve shaft 102, and the flow path wall surface of the valve body 104 to form a deposit. There is.

And in the EGR control valve of the comparative example 1, it opens by the flow-path wall surface of the flow-path holes 114 and 115 of the valve body 104, and a cylindrical sliding bearing is provided in the opening side of the bearing hole 123 extended straight from this open side to the back side. 121 is arranged. With this configuration, the bearing hole 123 is opened at the flow path wall surface of the flow path hole 114, and the flow path hole 114 and the bearing hole 123 communicate with each other, so that it is included in the ECR gas flowing through the flow path holes 111 to 114. There is a possibility that foreign matter (deposit) may enter the bearing hole 123.
Therefore, in the EGR control valve of Comparative Example 1, in order to prevent foreign matter from entering the bearing hole 123, the foreign matter removal pipe 124 that covers a part of the outer diameter surface of the valve shaft 102 is installed. The foreign matter removing pipe 124 has a sleeve extending in the axial direction along the outer diameter surface of the valve shaft 102 from the proximal end portion toward the distal end portion.

Further, the base end portion of the sleeve of the foreign matter removing pipe 124 is held by an oil seal 125 installed on the opening side of the bearing hole 123 with respect to the cylindrical sliding bearing 121. Further, the distal end side of the foreign matter removing pipe 124 is configured to protrude from the opening of the bearing hole 123 into the flow path hole 115, and the distal end portion is in sliding contact with the outer diameter surface of the valve shaft 102.
By the way, in the EGR control valve of Comparative Example 1, as shown in FIG. 7, the axial end portion of the valve shaft 102 protrudes from the opening of the bearing hole 123 into the flow path holes 114 and 115, and the flow path hole 114 and 115 pass through the channel hole 113 and project into the channel hole 112. The valve head 101 is fixed to the outer periphery of the tip end of the valve shaft 102 in the axial direction.

That is, the EGR control valve of Comparative Example 1 is an electric actuator through the scotch yoke and the valve shaft 102 by energizing the electric motor from the state in which the valve head 101 is seated on the valve seat 118 and is closed (fully closed). Is applied to the valve head 101, the valve head 101 and the valve shaft 102 are opened (lifted) to the flow path hole 112 side through which the EGR gas flows from the inlet port 111, and the EGR control valve An outward opening type poppet valve that opens the flow path hole 113 that is a valve hole is employed (see FIGS. 7A and 7B).
FIG. 7A shows a closed (fully closed) state in which the valve head 101 of the poppet valve is seated on the valve seat 118 to close the flow path hole 113. FIG. 7B shows a valve opening state in which the valve head 101 of the poppet valve opens (lifts) from the valve seat 118 toward the flow path hole 112 by a predetermined valve lift amount to open the flow path hole 113. Indicates.

A foreign matter removing pipe 124 is disposed between the outer diameter surface of the valve shaft 102 of the poppet valve and the hole wall surface on the opening side of the bearing hole 123 (inner diameter surface of the bearing holder 122). Alternatively, a foreign matter removing function for preventing foreign matter from entering the bearing hole 123 of the valve body 104 may be provided integrally in the vicinity of the opening side of the bearing hole 123 of the valve body 104.
Thereby, in the EGR control valve of Comparative Example 1, the flow path hole 112, the valve from the inlet port 111 is determined by the seat edge of the valve seat 118 and the taper angle (valve angle) of the inclined surface 119 of the valve head 101. A frustoconical cylindrical gap formed between the head 101 and the valve seat 118, and an outer diameter (shaft outer diameter) of the valve shaft 102 flowing into the passage hole 114 through the passage hole 113. The EGR gas flow (arrow shown in the figure) determined by the angle between the outer diameter surface of the valve shaft 102 (EGR gas flow collision point) A and the sleeve front end surface 126 of the foreign matter removal pipe 124 is predetermined. A structure in which an axial distance equal to or greater than (for example, 10 mm) is formed.

However, in the EGR control valve of Comparative Example 1, as shown in FIG. 7B, the flow of EGR gas (shown by the arrow) moves in the axial direction of the valve shaft 102 along the outer diameter surface of the valve shaft 102. Flowing. Then, the flow of the EGR gas hits the sleeve front end surface 126 of the foreign material removal pipe 124, and an annular gap formed between the inner periphery of the sleeve front end surface 126 of the foreign material removal pipe 124 and the outer diameter surface of the valve shaft 102. As a result, foreign matter (deposit) enters the inside of the foreign matter removing pipe 124 and the bearing hole 123 of the housing. As a result, there is a possibility that foreign matter may be caught in the sliding portion (sliding clearance) between the outer diameter surface (sliding surface) of the valve shaft 102 and the inner diameter surface (sliding surface) of the cylindrical sliding bearing 121.
If foreign matter is caught in the sliding clearance, the reciprocating motion of the valve shaft 102 in the axial direction with respect to the cylindrical slide bearing 121 is hindered, and the valve head 101 and the valve shaft 102 cannot operate (valve block) or malfunction. May occur.

International Publication No. 2012/126876

  An object of the present invention is to provide an exhaust system for an internal combustion engine that can prevent foreign matters from entering a foreign matter removing pipe and prevent the valve head and valve shaft from becoming inoperable (bullock) or malfunctioning. There is to do.

  According to the first aspect of the present invention (exhaust device for an internal combustion engine), the projecting shaft is provided on the tip end side in the axial direction from the intermediate shaft portion of the shaft and projects into the flow path from the opening of the bearing hole of the housing. The virtual extension line of the first inclined surface or the first step surface provided between the large-diameter shaft portion and the small-diameter shaft portion is formed so as not to intersect or interfere with the pipe tip portion of the foreign substance removal pipe. In this way, entry of foreign matter (such as deposit) into the foreign matter removal pipe can be suppressed. As a result, foreign matter (such as deposits) can be prevented from entering the bearing hole of the housing, so that it is possible to prevent the valve head and the valve shaft from becoming inoperable (valve block) or malfunctioning.

It is sectional drawing which showed the EGR control valve used for an EGR system (Example 1). It is II-II sectional drawing of FIG. 1 (Example 1). (Example 1) which is the perspective view which showed the electric actuator and the poppet valve. (Example 1) which is the perspective view which showed the electric actuator and the poppet valve. (A) is sectional drawing which showed the periphery structure of an EGR valve | bulb, (b) is explanatory drawing which showed how the EGR gas flows around an EGR valve | bulb (Example 1). (A) is sectional drawing which showed the periphery structure of an EGR valve | bulb, (b) is explanatory drawing which showed how the EGR gas flows around an EGR valve | bulb (Example 2). (A) is sectional drawing which showed the periphery structure of the EGR valve, (b) is explanatory drawing which showed how the EGR gas flows around an EGR valve (comparative example 1).

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

[Configuration of Example 1]
FIGS. 1 to 5 show an EGR control valve (Embodiment 1) used in an EGR system to which the present invention is applied.

An exhaust system (exhaust system) for an internal combustion engine of the present embodiment is an EGR that is a part of exhaust gas (exhaust gas) from an exhaust pipe to an intake pipe of an internal combustion engine (diesel engine: hereinafter referred to as an engine) for traveling a vehicle such as an automobile. An exhaust gas circulation device (EGR system) that recirculates gas is provided.
The EGR system includes an EGR gas pipe that recirculates EGR gas from an exhaust passage in the exhaust manifold or the exhaust pipe to an intake passage in the intake manifold or the intake pipe. In the EGR gas pipe, an EGR gas flow path is formed through which EGR gas flows from the exhaust passage to the intake passage.
The EGR gas pipe is provided with an EGR control valve that variably controls the flow rate of the EGR gas flowing through the EGR gas flow path.

  Here, the EGR system is used as an EGR valve control device (an EGR control device for an internal combustion engine) that controls opening and closing of a poppet valve (poppet type EGR valve) of an EGR control valve based on the operating state of the engine. In this EGR valve control device, a valve body 1 which is a valve body (valve head) of a poppet valve and a valve shaft 2 which is a valve shaft (valve stem) of the poppet valve are arranged in the axial direction (axial direction) of the valve shaft 2. An engine control unit (electronic control unit: hereinafter referred to as ECU) that controls an electric motor (DC motor: hereinafter referred to as motor) M that is incorporated in a reciprocating electric actuator in conjunction with other systems (for example, an intake system, a supercharging pressure control system, etc.) ).

The EGR control valve includes a poppet valve that regulates the flow rate of the EGR gas flowing through the EGR gas flow path, an electric actuator that drives the valve shaft 2 of the poppet valve in its reciprocating direction, a poppet valve, an electric actuator, A scotch yoke 3 having a letter shape (or a rectangular cross section) and a housing 5 that houses (incorporates) a return spring 4 are provided.
Here, the valve body 1, the valve shaft 2, the scotch yoke 3, and the return spring 4 are assembled in advance and assembled to the housing 5 in a valve subassembly state.

The poppet valve includes an annular valve body 1 that opens and closes (changes the opening area) an EGR gas flow path (described later) in the housing 5, and a valve shaft 2 that supports and fixes the valve body 1. An input portion to which the rotational power of the motor M is transmitted from the electric actuator via the scotch yoke 3 is provided at the proximal end portion of the valve shaft 2 in the axial direction.
The scotch yoke 3 is press-fitted (coupled) and fixed to the outer periphery (the upper outer periphery in the figure) of the input portion of the valve shaft 2 so as to be movable together with the valve shaft 2. Alternatively, it is connected and fixed so as to be movable together with the valve shaft 2 by using a coupling means such as laser welding.

The housing 5 is provided with a recess for accommodating the electric actuator between the sensor cover 7 on which the rotation angle sensor 6 that is an EGR opening degree sensor is mounted. The housing 5 is integrally provided with a valve body 11 that houses a poppet valve, a motor case 12 that houses a motor M, a gear case 13 that houses a speed reduction mechanism, and the like.
Of these, an annular valve seat 15 on which the valve body 1 can be seated is press-fitted and fixed to the inner periphery of the partition wall 14 of the valve body 11.

Here, the valve body 1 is a valve head (valve element) that closes and opens the EGR gas flow path (inlet port 21 → flow path holes 22 to 25 → outlet port 26) by contacting and separating from the valve seat 15 of the housing 5. is there.
The valve shaft 2 is a valve stem (valve shaft) that reciprocates in the direction of the central axis of the poppet valve in conjunction with the rotational displacement of the output member. An input portion that receives the power of the electric actuator from the scotch yoke 3 is provided at the proximal end portion of the valve shaft 2 in the axial direction.

Further, an output portion for outputting the power of the electric actuator to the poppet valve is provided at the tip end portion of the valve shaft 2 in the axial direction.
An intermediate portion in the axial direction of the valve shaft 2 is slidably supported by a bearing holder 28 of the housing 5 via a metal bearing 27. An oil seal 29 is mounted on the outer periphery of the intermediate portion of the valve shaft 2 to prevent the lubricating grease and lubricating oil oil from lubricating the sliding portion between the valve shaft 2 and the metal bearing 27.

By the way, the poppet valve is housed in an openable and closable manner inside a valve body 11 through which EGR gas containing exhaust particulates (PM) such as combustion residue and carbon flows. Therefore, during operation of the engine, PM contained in the EGR gas may adhere to and accumulate on the surface of the valve body 1, the outer peripheral surface of the valve shaft 2, and the flow passage wall surface of the valve body 11 to form a deposit. There is.
Therefore, the EGR control valve of the present embodiment is disposed in the bearing hole 31 formed in the bearing holder 28 of the housing 5 so as to protrude from the opening 32 of the bearing hole 31 into the flow path hole 25. By providing the foreign matter removing pipe 33, deposits (foreign matter) formed by PM contained in the EGR gas are prevented from entering the bearing hole 31 formed in the bearing holder 28 of the housing 5. It is configured.

The electric actuator drives a motor M having a motor shaft (hereinafter referred to as a motor shaft) 34 that is a rotating shaft, a reduction mechanism that reduces the rotation of the motor shaft 34 of the motor M by two stages, and the reduction mechanism and the Scotch yoke 3. An output member that includes a conversion mechanism (link mechanism) to be coupled, a speed reduction mechanism, and a part of the conversion mechanism, and that outputs the rotational power of the motor M to the yoke side, and a rotation that detects the rotation angle of the output member And an angle detection device.
The motor M includes an inner rotor (armature) having a motor shaft 34 extending in the rotation axis direction, a cylindrical stator that surrounds the circumference of the armature in a circumferential direction, and a brush holder fixed to the stator. A pair of power supply brushes (first and second brushes) housed and held.

The stator of the motor M includes a motor case (such as a motor yoke) that rotatably accommodates the motor shaft 34 of the armature, and a plurality of stators fixed by an adhesive or the like at equal intervals in the circumferential direction on the inner peripheral surface of the motor yoke. Field magnets and the like.
The armature of the motor M includes an armature core (armature core) coupled to the motor shaft 34 so as to be integrally rotatable, an armature winding (armature coil) wound around the armature core, and a pair of first armatures. And a commutator (commutator) that is pressed against the second brush.

The reduction mechanism is engaged with the pinion gear (input gear, motor gear) 35 fixed to the outer periphery of the tip of the motor shaft 34 of the motor M, the intermediate gear 36 that rotates in mesh with the pinion gear 35, and rotates in mesh with the intermediate gear 36. An output gear (valve gear) 37, an intermediate shaft 38 arranged in parallel with the motor shaft 34, an output shaft 39 arranged in parallel with the motor shaft 34 and the intermediate shaft 38, and the like.
The output member transmits the rotational power of the motor M to the valve body 1 through the valve shaft 2. The output member includes an output gear 37 that rotates by receiving the rotational power of the motor M, and an output shaft 39 that is installed on the rotation center axis of the output gear 37 and is coupled to the output gear 37 so as to be integrally rotatable. ing.
The output gear 37 and the output shaft 39 constitute a part of the speed reduction mechanism, and the output shaft 39 constitutes the output shaft of the speed reduction mechanism.

The output member includes an output lever 41 coupled to the output shaft 39 so as to be integrally rotatable, an eccentric pin (hereinafter referred to as a pivot pin) 42 held at a protruding end of the output lever 41, and an outer periphery of the pivot pin 42. And a ball bearing (follower) 43 that is freely supported. These output lever 41, pivot pin 42 and follower 43 constitute a part of the conversion mechanism.
The output member includes a double ball bearings 44 and 45 that support the output shaft 39 so as to be slidable in the rotation direction, and a cylindrical collar 46 that is press-fitted and fixed to the outer periphery of the double ball bearings 44 and 45. I have.

The output gear 37, the output shaft 39, the output lever 41, the pivot pin 42, the follower 43, the double ball bearings 44 and 45, and the cylindrical collar 46 constituting the output member are assembled in advance in the state of the output gear subassembly and the housing. 5 is assembled. At this time, the pivot pin 42 and the follower 43 are assembled in the yoke groove 47 of the scotch yoke 3.
Here, the conversion mechanism includes the scotch yoke 3, the output lever 41, the pivot pin 42, the follower 43, and the like.

The EGR control valve includes a return spring 4 that biases the valve shaft 2 toward the side where the poppet valve is closed (valve fully closed side). The return spring 4 is a coiled compression spring that generates an elastic force that biases the poppet valve in the valve closing (fully closed) direction with respect to the valve shaft 2.
The return spring 4 is installed so as to surround the periphery of the upper end side of the valve shaft 2 and the bearing holder 28 in a spiral shape. The return spring 4 includes a spring seat portion of an annular spring seat 48 that is locked to a step (annular step) on the upper end side of the valve shaft 2 and a bottom portion of the housing 5 (a cylindrical recess on the outer peripheral side of the bearing holder 28). A coil portion wound in a spiral shape is provided between the spring seat portion at the bottom of the groove 49. The outer peripheral portion of the bearing holder 28 has a function as a spring inner peripheral guide that guides (holds) the coil inner diameter of the return spring 4.

The housing 5 is integrally formed with a valve body 11 that movably accommodates a poppet valve (valve main body 1, valve shaft 2), a scotch yoke 3, a return spring 4, and the like.
A coupling flange 51 is provided on the lower end side (valve seat 15 side) of the valve body 11 in the figure. The coupling flange 51 has a coupling end face that is attached to an attachment member (fixing member) of the EGR control valve, and is fastened and fixed to the attachment surface of the fixing member using a fastener such as a bolt. As a result, the EGR control valve is fixed to the engine-side (vehicle-side) fixing member.

  The housing 5 is integrally formed with a bottomed cylindrical motor case 12 that houses and holds the motor M. The motor case 12 is opened at a cylindrical side wall portion that surrounds the periphery of the motor yoke of the motor M in the circumferential direction, and at one end side of the side wall portion, and is an opening for inserting the motor M into the motor housing chamber during assembly. Part (motor insertion port). The motor insertion opening is closed by the front bracket 52 of the motor M. The front bracket 52 is fastened and fixed to the periphery of the opening of the motor insertion opening of the motor case 12 using bolts or the like. As a result, the motor M is housed and held in the motor housing chamber.

The housing 5 is formed with a gear case 13 that houses the speed reduction mechanism. The gear case 13 has an opening for inserting the electric actuator into the gear housing chamber during assembly. The opening is closed by a sensor cover 7 made of synthetic resin.
The sensor cover 7 has an internal connection connector for electrical connection between the pair of first and second brush terminals 53 protruding from the front bracket 52 of the motor M and the pair of first and second motor terminals (not shown). And a pair of first and second motor terminals and a plurality of sensor terminals of the rotation angle sensor 6 and an external connection connector for electrical connection with an external circuit (ECU or battery).

The gear case 13 is integrally formed with a double ball bearings 44 and 45 and a bearing holder 54 that holds the outer ring portion of the cylindrical collar 46. The bearing holder 54 is disposed so as to surround the double ball bearings 44 and 45 and the cylindrical collar 46 in the circumferential direction.
The bearing holder 54 is a cylindrical first bearing holder that holds the outer ring portion of the cylindrical collar 46. A bearing hole 55 into which the output shaft 39 is rotatably inserted is provided in the bearing holder 54. The bearing hole 55 has a press-fitting hole in which the outer ring portion of the cylindrical collar 46 is press-fitted and fixed.

The double ball bearings 44 and 45 are first bearings (rolling bearings) that are accommodated in the bearing accommodation holes of the bearing holder 54 and support the output shaft 39 of the output member so as to be slidable in the rotation direction.
The double ball bearings 44 and 45 are provided between an inner ring that is press-fitted and fixed to the outer periphery of the intermediate shaft portion of the output shaft 39, an outer ring that is press-fitted and fixed to the inner periphery of the cylindrical collar 46, and two race rings of the inner ring and outer ring Are provided with a plurality of steel balls that are slidably accommodated. In addition, the double ball bearings 44 and 45 include two lip seals (sealing materials) mounted between the two race rings and at both ends in the rotation axis direction from the steel balls, and a plurality of steel balls. Two retainers are provided to prevent the dropout.

The cylindrical collar 46 of this embodiment is integrally formed of metal or synthetic resin. The cylindrical collar 46 is press-fitted and fixed between the outer periphery of each outer ring of the double ball bearings 44 and 45 and the inner periphery of the bearing holder 54 of the gear case 13.
The cylindrical collar 46 is press-fitted between the outer periphery of each outer ring of the double ball bearings 44 and 45 and the inner periphery of the bearing holder 54 of the gear case 13.
A bearing hole that surrounds the periphery of the output shaft 39 in the circumferential direction is formed inside the cylindrical collar 46. The inner periphery of the cylindrical collar 46 has two first and second press-fitting holes formed on the same axis as the bearing hole 55 of the bearing holder 54. Each outer ring which is an outer ring portion of the double ball bearings 44 and 45 is press-fitted and fixed in these first and second press-fitting holes.

  When the electric actuator is supplied with electric power, the motor M that generates rotational power (torque) for reciprocatingly driving the poppet valve, and the deceleration that transmits the rotation of the motor shaft 34 of the motor M to the output shaft 39 after being decelerated by two stages. Mechanism, a conversion mechanism that converts the rotational reciprocating (rotating) motion of the output gear 37 of the speed reduction mechanism into a linear reciprocating motion of the poppet valve (reciprocating motion of the poppet valve in the axial direction), and a rotation angle of the output shaft 39 is detected. A rotation angle detecting device.

As described above, the speed reduction mechanism includes the pinion gear 35, the intermediate gear 36, the output gear 37, the intermediate shaft 38, and the output shaft 39.
The three reduction gears are rotatably accommodated in a gear accommodation chamber that is an internal space formed between the recess of the gear case 13 and the recess of the sensor cover 7.
The pinion gear 35 has a cylindrical portion that is fixed to the outer periphery of the tip of the motor shaft 34 by press-fitting or the like. On the outer periphery of the cylindrical portion, pinion gear teeth 61 that mesh with the intermediate gear 36 are formed.

  The intermediate gear 36 is fitted on the outer periphery of the intermediate shaft 38 so as to be relatively rotatable. The intermediate gear 36 has a cylindrical portion that is rotatably fitted to the outer periphery of the intermediate shaft 38 and rotates around the central axis of the intermediate shaft 38. A large-diameter gear (intermediate gear tooth) 62 that meshes with the pinion gear teeth 61 is formed at one end of the cylindrical portion in the axial direction. A small-diameter gear (intermediate gear teeth) 63 that meshes with the output gear 37 is formed at the other end of the cylindrical portion in the axial direction.

A cylindrical cylindrical boss 64 is integrally formed on the inner peripheral portion of the output gear 37. Further, the output gear 37 has a partially cylindrical (fan-shaped) tooth forming portion on the outer side in the radial direction from the cylindrical boss 64. On the outer periphery of the tooth forming portion, output gear teeth 65 that mesh with the intermediate gear teeth 63 are formed in a fan shape by a predetermined angle.
The output gear 37 is integrally provided with a shaft coupling portion 66 so as to close an opening on one end side (valve side) of the cylindrical boss 64. A fitting portion 67 having a two-surface width (a structure that prevents idling of the output shaft 39 and a rotation preventing structure) is formed through the central portion of the shaft coupling portion 66. The fitting portion 67 is fitted and fixed in a state where the input portion of the output shaft 39 (the first protruding shaft portion of the output shaft 39) is prevented from rotating.

The intermediate shaft 38 is integrally formed of metal or synthetic resin. One end of the intermediate shaft 38 in the axial direction is press-fitted (fixed) into the fitting recess of the gear case 13 of the housing 5. The other end of the intermediate shaft 38 in the axial direction is fitted in the fitting recess of the sensor cover 7.
The output shaft 39 is rotatably or slidably accommodated in the bearing holder 54 of the gear case 13 of the housing 5 via the cylindrical collar 46 and the double ball bearings 44 and 45.

The output shaft 39 includes first and second protruding shaft portions (small-diameter shaft portions) on both sides in the rotation axis direction. Further, between the first and second protruding shaft portions, an intermediate shaft portion (an axial portion, an outer diameter larger than the first and second protruding shaft portions) disposed in the bearing receiving hole of the bearing holder 54 of the gear case 13. Large-diameter large shaft portion) is provided.
The first protruding shaft portion is provided on the base end side (input portion) in the axial direction (rotating shaft direction) of the output shaft 39 and has a two-surface width. The first protruding shaft portion may have a quadrangular cross section. The second protruding shaft portion is provided on the distal end side (output portion) in the axial direction of the output shaft 39 and has a circular cross section. In addition, you may provide 2 surface width in a 2nd protrusion shaft part.
The inner rings of the double ball bearings 44 and 45 are fitted and held on the outer periphery of the intermediate shaft portion of the output shaft 39 by press fitting.

As described above, the conversion mechanism includes the scotch yoke 3, the output lever 41, the pivot pin 42, the follower 43, and the like.
The scotch yoke 3 receives the rotational power of the motor M from the pivot pin 42 via the follower 43 and reciprocates in the axial direction of the valve shaft 2. The scotch yoke 3 is connected to the valve shaft 2 so as to be movable together.
The scotch yoke 3 has a U-shaped input section that receives the power of the output member via the follower 43, and an output section that transmits the power of the output member to the valve shaft 2.
The input portion of the scotch yoke 3 has a polyhedral shape (a cross-sectional U-shape) having at least four first to fourth side surfaces in addition to the two surfaces facing the insertion direction in which the pivot pin 42 and the follower 43 are inserted during assembly. Shape or circular cross section).
The input portion of the scotch yoke 3 may be formed in an annular cross section so as to surround the periphery of the follower 43 in the circumferential direction.

The yoke groove 47 has an opening 71 for inserting the follower 43 into the yoke groove 47 while linearly moving the output member when the output member, particularly the follower 43, is assembled to the scotch yoke 3. The opening 71 is opened in a direction perpendicular to the axial direction of the valve shaft 2, particularly in a direction opposite to the insertion direction in which the pivot pin 42 and the follower 43 are inserted during assembly.
A bottomed circular (or square) cylindrical fitting portion 72 is integrally provided at the output portion of the scotch yoke 3. Inside the fitting portion 72, a press-fit groove 73 into which the base end portion (input portion) in the axial direction of the valve shaft 2 is press-fitted is formed.

The output lever 41 is provided so as to protrude outward in the radial direction of the output shaft 39. The output lever 41 is a link lever that drives and connects the output shaft 39, the pivot pin 42 and the follower 43, and transmits the rotational power of the motor M to the pivot pin 42 and the follower 43.
The base end portion of the output lever 41 is provided with first fitting holes for press-fitting so that the second projecting shaft portion of the output shaft 39 penetrates in the axial direction thereof. Thereby, the output lever 41 is connected to the output shaft 39 so as to be integrally rotatable.
In addition, the distal end portion of the output lever 41 is provided with a second fitting hole for press-fitting so that the pivot pin 42 penetrates in the axial direction thereof. As a result, the pivot pin 42 is coupled to the output lever 41 so as to be integrally rotatable. The second fitting hole is provided at a position eccentric from the rotation center axis of the second protruding shaft portion of the output shaft 39 by a predetermined distance.

The pivot pin 42 is driven into the second fitting hole of the output lever 41 and is press-fitted and fixed to the output portion of the output lever 41. The pivot pin 42 rotatably supports the follower 43. The pivot pin 42 is inserted into the yoke groove 47 of the scotch yoke 3 together with the follower 43.
The follower 43 is slidably accommodated between an inner ring that is press-fitted and fixed to the outer periphery of the pivot pin 42, an outer ring that is in sliding contact with the groove side surface of the yoke groove 47 of the scotch yoke 3, and an inner ring and an outer ring. It is a ball bearing provided with a plurality of steel balls.
The follower 43 is rotatably supported on the outer periphery of the pivot pin 42 and is slidably (rolled) into the yoke groove 47 of the scotch yoke 3. The follower 43 is provided at a position eccentric from the rotation center axis of the second projecting shaft portion of the output shaft 39 by a predetermined distance. Further, the follower 43 is connected to the output shaft 39 through the output lever 41 and the pivot pin 42 so as to be integrally rotatable.

Here, the motor M which is a power source of the electric actuator is electrically connected to an external power source (battery) via a motor drive circuit electronically controlled by the ECU.
The ECU includes a microcomputer having a known structure including functions of a CPU, a memory (ROM, RAM, EEPROM, etc.), an input circuit (input unit), an output circuit (output unit), a power supply circuit, and a timer circuit. Is provided.
The ECU is configured to control the energization of the motor M of the EGR control valve based on a control program stored in the memory of the microcomputer when the ignition switch is turned on (IG / ON).

The sensor output signal (analog voltage signal) from the rotation angle sensor 6 installed in the sensor mounting portion of the sensor cover 7 and the sensor output signals (electric signals) from various sensors are converted into A / D conversion circuits by an A / D conversion circuit. After being D-converted, it is configured to be input to a microcomputer.
Here, not only the rotation angle sensor 6 but also an air flow meter, a crank angle sensor, an accelerator opening sensor, a throttle opening sensor, an intake air temperature sensor, a water temperature sensor, an air-fuel ratio sensor, and an oxygen concentration sensor are included in the input portion of the microcomputer. An exhaust gas (exhaust) sensor or the like is connected.

The rotation angle detection device detects the valve opening degree of the EGR control valve by measuring the rotation angle of the cylindrical magnetic circuit portion provided so as to rotate integrally with the cylindrical boss 64 of the output gear 37 and the magnetic circuit portion. A rotation angle sensor 6 is provided, and a change in relative rotation angle between the magnetic circuit unit and the rotation angle sensor 6 is detected by a magnetic change applied to the rotation angle sensor 6 from the magnetic circuit unit.
The rotation angle sensor 6 is mainly composed of a Hall IC that outputs a sensor output signal (analog voltage signal) corresponding to the magnetic flux density that links the magnetic sensing surface of the semiconductor Hall element to the ECU. Instead of the Hall IC, a non-contact type magnetic detection element such as a Hall element alone or a magnetoresistive element may be used.

The magnetic circuit portion is fixed to the inner periphery of the cylindrical boss 64 with an adhesive or the like. When the cylindrical boss 64 is made of synthetic resin, the magnetic circuit part may be insert-molded on the cylindrical boss 64.
The magnetic circuit section includes a pair of partial cylindrical yokes 74 that are divided into two in the diameter direction of the cylindrical boss 64 and a pair of magnets that are arranged with the magnetic poles in the same direction at the divided sections (opposing sections) of the yoke 74. (Permanent magnet) 75.

Next, details of the valve body 11 and the valve seat 15 of the housing 5 of this embodiment will be briefly described with reference to FIGS.
In the valve body 11, an inlet port 21 → channel holes 22 to 25 → outlet port 26 constituting a part of the EGR gas channel are formed. The valve body 11 includes an EGR gas flow path, a first flow path (inlet side flow path: inlet port 21, flow path hole 22) positioned upstream of the valve seat 15 in the exhaust flow direction, and a valve An annular (cylindrical) partition wall (partition section) that is divided into second flow paths (exit side flow paths: flow path holes 24 and 25, outlet ports 26) located downstream of the seat 15 in the exhaust flow direction. ) 14 is formed.

The first flow path (inlet port 21, flow path hole 22) passes through the center of the first flow path from the inlet port 21 toward the flow path hole 23, and the straight flow path in which the central axis of the first flow path extends straight. It is.
The inlet port 21 opens at the upstream end face of the valve body 11 of the housing 5 and constitutes a flow path inlet for taking in EGR gas which is a part of exhaust gas from an exhaust passage in the exhaust pipe.
The flow path hole 22 is an inlet side EGR gas flow path that is provided upstream of the valve seat 15 in the exhaust flow direction and into which EGR gas flows from the inlet port 21.
The flow path hole 23 is provided so as to penetrate the central portion of the valve seat 15, and is an EGR control valve that communicates the first flow path (flow path hole 22) and the second flow path (flow path hole 24). It is a valve hole (communication hole).

The second channel (channel holes 24 and 25, outlet port 26) passes through the center of the second channel from the channel hole 23 toward the outlet port 26, and the center axis of the second channel (EGR gas flow) It is a curved flow path whose direction changes substantially at a right angle.
The flow path holes 24 and 25 are outlet side EGR gas flow paths that are provided on the downstream side of the valve seat 15 in the exhaust flow direction and guide the EGR gas flowing from the flow path holes 23 to the outlet port 26.
The outlet port 26 opens at the downstream end face of the valve body 11 of the housing 5 and constitutes a flow path outlet for discharging EGR gas to the intake passage in the intake pipe.

An annular circumferential groove 76 is formed in the inner peripheral portion of the partition wall 14 of the valve body 11 so as to surround the periphery of the valve seat 15 in the circumferential direction. The outer periphery of the valve seat 15 having a rectangular cross section is press-fitted and fixed to the bottom surface (peripheral wall) of the circumferential groove 76. An annular valve seat on which a poppet valve can be seated is provided at the seat edge of the valve seat 15. Further, the valve seat 15 communicates with the first flow path (inlet port 21, flow path hole 22) and the second flow path (flow path holes 24, 25, outlet port 26), and EGR gas flows. A passage hole 22 (a valve hole of the EGR control valve, a communication hole) 22 is formed.
The valve body 11 is integrally formed with a cylindrical bearing holder 28 that holds the outer periphery of the metal bearing 27. The bearing holder 28 is disposed so as to surround the circumference of the metal bearing 27 in the circumferential direction.

The metal bearing 27 is formed of a sintered material, has a large number of pores therein, and is a cylindrical sintered oil-impregnated bearing in which the internal pores are impregnated with lubricating oil (second bearing, cylindrical sliding bearing, metal bush). In addition, a large number of internal pore openings (surface pores) are formed on the hole wall surface (inner diameter surface) of the sliding hole.
The metal bearing 27 penetrates into the internal pores due to negative pressure due to linear movement in the forward direction (opening direction) or backward direction (valve closing direction) of the valve shaft 2 inserted into the sliding hole. The lubricating oil oozes out from the opening of the sliding surface (inner diameter surface) with the valve shaft 2, thereby forming an oil film on the sliding portion between the inner diameter surface of the metal bearing 27 and the outer diameter surface of the valve shaft 2. Thus, the valve shaft 2 is supported so as to be reciprocally movable.

The metal bearing 27 supports the valve shaft 2 so as to be slidable in the moving direction. Inside the metal bearing 27, there is formed a sliding hole for supporting the outer peripheral surface of the valve shaft 2 so as to be slidable in the moving direction. A sliding clearance for smooth reciprocation of the valve shaft 2 is provided between the outer peripheral surface of the valve shaft 2 and the inner peripheral surface of the metal bearing 27.
The metal bearing 27 has a cylindrical outer ring portion that is press-fitted and fixed to the wall surface of the bearing press-fitting hole of the bearing holder 28. The outer peripheral portion of the outer ring portion is used as a press-fit fixing portion that is hermetically press-fitted and fixed to a bearing press-fit hole of the bearing holder 28. The outer ring portion is in contact with the first step of the bearing holder 28, so that the press-fitting and fixing position of the metal bearing 27 is restricted.

The bearing holder 28 is a cylindrical second bearing holder that holds the outer ring portion of the metal bearing 27. Inside the bearing holder 28 is formed a bearing hole 31 that opens at the flow path wall surface of the flow path holes 23 and 24 and extends straight in the axial direction of the valve shaft 2 from the opening side to the back side.
The valve shaft 2 is fitted into the bearing hole 31 so as to be reciprocally movable in the axial direction. In addition, an opening (first port) 32 that is opened on the flow path wall surface of the flow path hole 25 is formed on one end side (flow path hole side, opening side) of the bearing hole 31 in the axial direction. In addition, an opening (second port) opened at the wall surface of the gear housing chamber is formed on one end side in the axial direction of the bearing hole 31 (opposite side and back side with respect to the flow path hole side).

The bearing holder 28 is formed in a cylindrical shape so as to surround the metal bearing 27 in the circumferential direction. The bearing holder 28 has an annular first step functioning as a first restricting portion for restricting the press-fit fixing position of the metal bearing 27 and a second restricting portion for restricting the press-fit fixing position of the oil seal 29. An annular second step having a function is provided.
The bearing hole 31 holds a bearing press-fitting hole for press-fitting the outer ring portion of the metal bearing 27, a seal press-fitting hole for press-fitting the outer ring portion of the oil seal 29, and the outer periphery of the foreign matter removing pipe 33. A cylindrical accommodation hole is provided.

Next, details of the oil seal 29 and the foreign matter removing pipe 33 of this embodiment will be briefly described with reference to FIGS.
The oil seal 29 is a hermetic seal reinforced by, for example, an L-shaped metal reinforcing ring, and includes a synthetic rubber seal rubber (elastic deformation portion) that can be elastically deformed in the radial direction and the thrust direction of the valve shaft 2. ing.
The oil seal 29 is accommodated in a seal press-fitting hole that is closer to the opening side of the bearing hole 31 than the metal bearing 27 so as to surround the periphery of the valve shaft 2 in the circumferential direction, and the bearing of the bearing holder 28 of the housing 5. It is a sealing member that seals the space between the hole wall surface of the hole 31 and the outer diameter surface of the valve shaft 2 in a liquid-tight manner.

The metal reinforcing ring has a cylindrical outer ring portion that is press-fitted and fixed to the wall surface of the seal press-fitting hole of the bearing hole 31 of the bearing holder 28. The outer peripheral portion of the outer ring portion is used as a press-fit fixing portion that is press-fit and fixed in a fluid-tight manner into the seal press-fit hole of the bearing hole 31. Further, the outer ring portion is in contact with the second step of the bearing holder 28, thereby restricting the press-fitting and fixing position of the oil seal 29.
The seal rubber has a seal lip that is in sliding contact with the outer peripheral surface (sliding surface) of the valve shaft 2 and seals between the inner periphery of the bearing holder 28 and the outer periphery of the valve shaft 2 in a liquid-tight and air-tight manner. It has a dust seal function. This seal rubber is installed inside the bearing holder 28 so as to surround the periphery of the valve shaft 2 in the circumferential direction.

The foreign matter removal pipe 33 is installed between the outer diameter surface of the intermediate portion of the valve shaft 2 and the inner diameter surface of the bearing holder 28 (hole wall surface of the bearing hole 31). The foreign matter removing pipe 33 is held closer to the opening (first port) 32 of the bearing hole 31 than the metal bearing 27 and passes through the opening 32 of the bearing hole 31 from the inside of the bearing hole 31 to the second flow path (flow path). Hole 24, 25) is provided so as to protrude into the hole 24, 25, covers the outer diameter surface of the valve shaft 2, and has a cylindrical or rectangular tube-shaped sleeve extending in the axial direction along the outer diameter surface of the valve shaft 2. doing.
The sleeve of the foreign matter removing pipe 33 projects into the second flow path (flow path holes 24 and 25) from the sleeve base end portion 81 held in the bearing hole 31 of the bearing holder 28 and the opening 32 of the bearing hole 31. A sleeve protrusion 82 is provided.

The sleeve base end portion 81 is held between the inner periphery of the metal reinforcing ring of the oil seal 29 and the outer periphery of the seal rubber.
The sleeve protruding portion 82 includes a cylindrical sleeve reduced diameter portion 83 whose outer diameter gradually decreases from the sleeve base end portion 81 toward the distal end side in the axial direction of the foreign substance removing pipe 33, and the sleeve reduced diameter portion 83. Of the large diameter shaft portion (to be described later) of the first projecting shaft portion of the valve shaft 2, the inner diameter of the sleeve shaft diameter portion 83 is the smallest so as to be positioned on the most distal end side. It has an annular sleeve tip 84 that is in sliding contact with the outer diameter surface. The sleeve tip 84 constitutes a pipe tip portion (pipe tip surface) of the foreign matter removing pipe 33.

Next, the details of the poppet valves (valve body 1 and valve shaft 2) used in the EGR control valve of this embodiment will be briefly described with reference to FIGS.
As shown in FIG. 5, the EGR control valve of the present embodiment is fully closed (closed) in which the valve body 1 is seated on the valve seat (seat edge) of the valve seat 15 and the flow passage hole 23 which is a valve hole is closed. In the valve state, when the motor M is energized, the power (opening force) of the electric actuator is applied to the valve body 1 via the scotch yoke 3 and the valve shaft 2, so that the poppet valve (valve body 1, valve shaft 2). ) Is opened outward (lift) by a predetermined valve lift amount toward the channel hole 22 side, which is the inlet side channel through which EGR gas flows from the inlet port 21, that is, upstream in the flow direction of EGR gas (exhaust gas). Thus, an open valve type poppet valve that opens the flow path hole 23 is employed.
FIG. 5A shows a closed (fully closed) state in which the valve body 1 of the poppet valve is seated on the valve seat 15 and the flow passage hole 23 is closed. FIG. 5B shows a valve opening state in which the valve body 1 of the poppet valve opens (lifts) from the valve seat 15 to the flow path hole 22 side by a predetermined valve lift amount to open the flow path hole 23. Indicates.

As described above, the poppet valve flows from the valve body 1 that closes and opens the passage hole 23 by contacting and separating from the seat edge of the valve seat 15, and the base end side that is located on the back side of the bearing hole 31 of the housing 5. A valve shaft 2 is provided that extends straight in the axial direction toward the tip side protruding into the passage holes 22 to 25.
In the central portion of the valve body 1, a fitting hole is integrally provided to be fitted to the outer periphery of the tip end of the valve shaft 2 in the axial direction. The fitting hole is formed through the central portion of the valve body 1 in the thickness direction.
A conical valve seal surface (valve face) 85 that can be seated on the seat edge of the valve seat 15 is integrally provided on the outer peripheral portion of the valve body 1. The valve valve seal surface 85 has a predetermined inclination angle so that the outer diameter gradually decreases from the upstream side to the downstream side in the flow direction of the exhaust gas flowing through the inlet port 21, the flow path holes 22 to 25, and the outlet port 26. It is an inclined surface (conical surface) inclined by an amount.
Note that the valve angle (θ1), which is the inclination angle of the virtual extension line of the valve seal surface 85, can be variously changed within a range of, for example, about 45 to 90 ° depending on the type of vehicle such as an automobile and the type of engine. .

The valve shaft 2 is connected to the valve body 1 and the scotch yoke 3 so as to be movable together, and extends straight from the scotch yoke side (base end side) to the EGR valve side (tip side) in the central axis direction of the poppet valve. Has been. The valve shaft 2 is accommodated in the valve body 11 of the housing 5 so as to be slidable in the reciprocating direction.
A conversion mechanism including a scotch yoke 3 is coupled to the outer periphery of the base end side of the valve shaft 2 so as to be integrally movable. Further, the valve body 1 is coupled to the outer periphery of the valve shaft 2 on the front end side so as to be integrally movable.
The valve shaft 2 is installed so as to extend in a perpendicular direction perpendicular to the motor shaft 34, the intermediate shaft 38 and the output shaft 39.
In addition, you may use the poppet valve which comprised the valve body 1 and the valve shaft 2 by integral components.

The valve shaft 2 includes first and second protruding shaft portions 91 and 92 on both sides in the axial direction thereof.
Between the first and second projecting shaft portions 91 and 92, an intermediate shaft portion 93 disposed in the bearing hole 31 of the bearing holder 28 of the valve body 11 is provided.
The tip end portion (output portion) in the axial direction of the valve shaft 2, that is, the first protruding shaft portion 91 is provided on one end side (tip end side) in the axial direction of the valve shaft 2, and is second from the opening 32 of the bearing hole 31. Projecting into the channel (channel holes 24, 25), and projecting from the second channel (channel holes 24, 25) through the channel hole 23 and into the first channel (channel hole 22). It is configured.

The first protruding shaft portion 91 includes a large-diameter shaft portion 94 having substantially the same outer diameter as the intermediate shaft portion 93, a small-diameter shaft portion 95 having a smaller outer diameter than the large-diameter shaft portion 94, and a large-diameter shaft portion 94. A truncated cone-shaped first inclined surface 96 provided between the small-diameter shaft portion 95 and the distal end side in the axial direction with respect to the small-diameter shaft portion 95 and coupled to the valve body 1 so as to be movable together. A coupling shaft portion 97 is provided.
The large diameter shaft portion 94 has a circular cross section. On the outer diameter surface of the large-diameter shaft portion 94, a slidable contact surface with which the sleeve tip 84 of the foreign matter removing pipe 33 is slidably contacted is formed.

The small diameter shaft portion 95 has a circular cross section and has an outer diameter smaller than that of the large diameter shaft portion 94. A coupling shaft portion that joins and fixes the annular valve body 1 by welding, for example, using a welding means such as laser welding, on the distal end side of the small-diameter shaft portion 95, that is, the outer periphery (tip outer periphery) of the output portion of the valve shaft 2. 97 is provided. The coupling shaft portion 97 has substantially the same outer diameter as the small-diameter shaft portion 95.
The first inclined surface 96 is inclined so that the outer diameter gradually decreases from the proximal end side in the axial direction of the valve shaft 2 toward the distal end side. The virtual extension line of the first inclined surface 96 is formed so as not to intersect or interfere with the sleeve tip 84 of the foreign substance removal pipe 33.
The inclination angle (θ2) of the virtual extension line of the first inclined surface 96 can be variously changed within a range of about 30 to 80 °, for example, depending on the type of vehicle such as an automobile and the type of engine.

The base end portion (input portion) in the axial direction of the valve shaft 2, that is, the second projecting shaft portion 92 is provided on the other end side (base end side) in the axial direction of the valve shaft 2, so that the bearing holder 28 slides. Projecting from the opening of the hole and the opening of the bearing hole 31 into the gear housing chamber. The second projecting shaft portion 92 is press-fitted and fitted into the press-fitting groove 73 of the fitting portion 72 of the scotch yoke 3 after the base end portion thereof passes through the through-hole penetrating the center portion of the spring seat 48. Yes.
Note that the base end portion of the second protruding shaft portion 92 of the valve shaft 2 may be fixed to the fitting portion 72 of the scotch yoke 3 by means such as caulking or welding. Further, the valve shaft 2 and the scotch yoke 3 may be configured as an integral part.

  Here, as shown in FIGS. 1 and 5, the EGR control valve of the present embodiment has a central axis that passes through the center of the valve body 1 and extends in the reciprocating direction of the poppet valve as the central axis of the valve body 1. And the center of the first and second flow paths (inlet ports 21 and flow path holes 22 and 24 of the valve body 11) and the valve holes (flow path holes 23 of the valve seat 15) and the reciprocation of the poppet valve. When the central axis extending in the moving direction is the central axis of the first and second flow paths and the valve hole, the central axis of the valve body 1 is coaxial with the central axes of the first and second flow paths and the valve hole. In addition, the flow of EGR gas (shown by arrows) flowing from the flow path hole 22 through the flow path hole 23 into the flow path hole 24 collides with the outer diameter surface of the small-diameter portion 95 of the valve shaft 2 (EGR gas). Collision point) A and foreign matter removal pipe 3 It employs a structure in which the axial distance of more than a predetermined distance (e.g., 10 mm) is formed between the sleeve distal end 84.

[Operation of Example 1]
Next, the operation of the EGR control valve of this embodiment will be briefly described with reference to FIGS.

The motor M that reciprocally drives the valve main body 1 and the valve shaft 2 of the poppet valve of this embodiment is configured to be energized and controlled by the ECU.
Here, when electric power is not supplied to the motor M, the valve main body 1 fixed by welding to the axial output portion (tip outer periphery) of the valve shaft 2 by the biasing force (spring load) of the return spring 4. When the valve seal surface 85 is seated on the seat edge of the valve seat 15, the valve seat 15 is closed (fully closed) to close the flow passage hole 23 (see FIG. 5A).
Therefore, the EGR gas flow path (inlet) formed in the valve body 11 is closed by closing the flow path hole 23 which is a communication hole (valve hole of the EGR control valve) formed through the central portion of the valve seat 15. Port 21 → channel holes 22-25 → outlet port 26) are closed. Thereby, EGR gas does not mix in clean intake air (fresh air) that has passed through the air cleaner (EGR cut).

Next, when the operation state (engine operation state) is such that the EGR control valve is opened, the poppet valve is opened to a predetermined valve opening (valve lift amount or stroke amount) corresponding to the operation state. Open the valve.
Then, electric power is supplied to the motor M, and the motor shaft 34 of the motor M is rotated in the valve opening operation direction. Thereby, the rotational power (torque) of the motor M is transmitted to the pinion gear 35, the intermediate gear 36, and the output gear 37.
Then, the output shaft 39 to which the torque is transmitted from the output gear 37 rotates in the valve opening operation direction by a predetermined rotation angle as the output gear 37 rotates.
Then, the output lever 41 to which the torque is transmitted from the output shaft 39 rotates in the valve opening operation direction by a predetermined rotation angle (a rotation angle equal to the operation angle of the output gear 37) as the output shaft 39 rotates.

Here, the pivot pin 42 is attached to a protruding end portion of the output lever 41, that is, a position eccentric from the rotation center axis of the output shaft 39 by a predetermined distance. When the output shaft 39 and the output lever 41 rotate, the follower 43 supported by the pivot pin 42 is brought into sliding contact with the groove side surface of the yoke groove 47 of the scotch yoke 3 when the output shaft 39 and the output lever 41 rotate. Rotational motion is converted to linear motion.
Then, the valve shaft 2 and the scotch yoke 3 move in the moving direction against the urging force of the return spring 4. At this time, since the valve shaft 2 is guided (guided) in the moving direction by the metal bearing 27 of the housing 5, the valve shaft 2 linearly moves toward the valve opening side in the axial direction.
Then, as the valve shaft 2 moves linearly, the valve body 1 fixed to the valve shaft 2 separates from the seat edge of the valve seat 15, and a predetermined valve lift amount or stroke amount corresponding to the operating state of the engine. By opening outward (lifting) toward the flow path hole 22 side, the valve hole state of the valve seat 15 is opened (see FIG. 5A).

As described above, the air cleaner is controlled by changing the valve opening degree of the EGR control valve by variably controlling the power (drive current value or applied voltage value) supplied to the motor M in accordance with the operating state of the engine. The amount of EGR gas introduced (mixed amount) with respect to clean intake air (fresh air) that has passed through is adjusted. That is, the poppet valve is controlled to open to a valve opening corresponding to the control target value. That is, when the flow path hole 23 of the valve seat 15 is opened, the EGR gas flow path (the inlet port 21 → the flow path holes 22 to 25 → the outlet port 26) is opened.
Therefore, EGR gas that is a part of the exhaust gas flowing out from each cylinder of the engine passes through the EGR gas flow path from the branch portion of the exhaust passage formed in the exhaust pipe, and passes through the intake passage formed in the intake pipe. Recirculated to the junction. Thereby, EGR gas is mixed in the intake air supplied to each cylinder of the engine.
Thereby, harmful substances (for example, NOx) contained in the exhaust gas are reduced.

By the way, in the EGR control valve of the present embodiment, as shown in FIGS. 1 and 5, the central axis of the valve body 1 and the first and second flow paths (inlet port 21, flow path holes 22, 24) and The central axis of the valve hole (flow path hole 23) is coaxial, and the flow of EGR gas (shown by arrows) flowing from the flow path hole 22 through the flow path hole 23 into the flow path hole 24 is An axial distance equal to or greater than a predetermined distance (for example, 10 mm) is formed between a point (EGR gas flow collision point) A that collides with the outer diameter surface of the small-diameter shaft portion 95 and the sleeve tip 84 of the foreign matter removal pipe 33. It has a structure that is
As a result, the EGR gas that has flowed into the flow path hole 22 from the inlet port 21 passes around the entire circumferential direction (all circumferences) of the valve body 1 and the flow path hole 22 as shown in FIG. It flows into a cylindrical gap flow path formed between a cylindrical (or rectangular tube) first flow path wall (inner wall of the valve body 11) surrounding in the circumferential direction.

And the EGR gas that has flowed into the cylindrical clearance channel formed between the entire circumferential direction (the entire circumference) of the valve body 1 and the first channel wall is along the inclination angle of the valve seal surface 85. It is formed between the valve seal surface 85 of the entire circumference of the valve body 1 and a cylindrical (or rectangular tube) flow path wall (inner wall of the valve seat 15) that surrounds the periphery of the flow path hole 23 in the circumferential direction. It flows evenly toward the cylindrical gap channel so as to converge in an inverted truncated cone (funnel) shape, and collides with the outer diameter surface of the small-diameter shaft portion 95 of the valve shaft 2.
The EGR gas that has collided with the outer diameter surface of the small-diameter shaft portion 95 flows along the outer diameter surface of the small-diameter shaft portion 95, and the first inclination between the large-diameter shaft portion 94 and the small-diameter shaft portion 95. It flows evenly around the large-diameter shaft portion 94 (periphery) so as to expand in the shape of a truncated cone along the surface 96.
Therefore, the flow of EGR gas flowing from the flow path hole 24 into the flow path hole 25 along the outer shape of the valve shaft 2 does not hit the sleeve tip 84 of the foreign matter removal pipe 33, and the sleeve tip of the foreign matter removal pipe 33. It is difficult for foreign matter (deposit) to enter the foreign matter removing pipe 33 through an annular gap between the inner periphery of 84 and the outer diameter surface of the large-diameter shaft portion 94 of the valve shaft 2.

[Effect of Example 1]
As described above, in the EGR control valve according to the present embodiment, after the coupling shaft portion 97 of the valve shaft 2 is fitted into the fitting hole of the valve body 1, the valve body 1 and the coupling shaft portion 97 are fixed by welding. doing.
Further, on the distal end side in the axial direction from the intermediate shaft portion 93 fitted in the bearing hole 31 of the housing 5, the opening 32 of the bearing hole 31 of the housing 5 has a second flow path (flow path holes 24, 25). And a first protruding shaft portion 91 that protrudes from the second flow path (flow path holes 24, 25) through the flow path hole 23 into the first flow path (flow path hole 22).

The first protruding shaft portion 91 is provided with a large-diameter shaft portion 94 having the same outer diameter as the intermediate shaft portion 93 and a small-diameter shaft portion 95 having an outer diameter smaller than the large-diameter shaft portion 94. .
Further, in order to prevent foreign matter (such as deposit) from entering the bearing hole 31 of the housing 5 on the outer diameter surface of the large diameter shaft portion 94 of the valve shaft 2, the intermediate shaft portion 93 of the valve shaft 2, A slidable contact surface is formed on which the sleeve tip 84 of the foreign matter removing pipe 33 that covers the periphery of the large-diameter shaft portion 94 slidably contacts.

  The virtual extension line of the first inclined surface 96 having a truncated cone shape provided between the large-diameter shaft portion 94 and the small-diameter shaft portion 95 does not cross or interfere with the sleeve tip 84 of the foreign substance removal pipe 33. By forming the virtual extension line of the frustoconical valve seal surface 85 provided on the outer periphery of the valve body 1 so as not to intersect or interfere with the sleeve tip 84 of the foreign substance removal pipe 33, the valve shaft 2 The flow of the EGR gas flowing into the flow path hole 25 from the flow path hole 24 so as to follow the outer shape of the gas does not hit the sleeve tip 84 of the foreign substance removal pipe 33, and the inside of the sleeve (81 to 84) of the foreign substance removal pipe 33 Intrusion of foreign matter (such as deposits) into the body can be suppressed. As a result, foreign matter (such as deposits) can be prevented from entering the bearing hole 31 of the housing 5, thereby preventing the poppet valves (valve body 1, valve shaft 2) from becoming inoperable (bullock) or malfunctioning. be able to.

[Configuration of Example 2]
FIG. 6 shows an EGR control valve (Embodiment 2) used in an EGR system to which the present invention is applied.
Here, the same reference numerals as those in the first embodiment indicate the same configuration or function, and the description thereof is omitted.

In the EGR control valve of this embodiment, after fitting the coupling shaft portion 97 of the valve shaft 2 into the fitting hole of the valve body 1, the valve body 1 and the coupling shaft portion 97 are fixed by welding.
Further, on the distal end side in the axial direction from the intermediate shaft portion 93 fitted in the bearing hole 31 of the housing 5, the opening 32 of the bearing hole 31 of the housing 5 has a second flow path (flow path holes 24, 25). And a first protruding shaft portion 91 that protrudes from the second flow path (flow path holes 24, 25) through the flow path hole 23 into the first flow path (flow path hole 22).

The first projecting shaft portion 91 includes a large-diameter shaft portion 94 having the same outer diameter as the intermediate shaft portion 93, a small-diameter shaft portion 95 having an outer diameter smaller than the large-diameter shaft portion 94, and the small-diameter shaft portion. A coupling shaft 97 having an outer diameter greater than 95 is provided.
Between the large-diameter shaft portion 94 and the small-diameter shaft portion 95, a truncated cone-shaped first inclined surface 96 that connects the large-diameter shaft portion 94 and the small-diameter shaft portion 95 is formed. In addition, a truncated cone-shaped second inclined surface 98 that connects the small-diameter shaft portion 95 and the coupling shaft portion 97 is formed between the small-diameter shaft portion 95 and the coupling shaft portion 97. The inclination angle (θ3) of the virtual extension line of the second inclined surface 98 can be variously changed within a range of about 20 to 70 °, for example, depending on the type of vehicle such as an automobile and the type of engine.

  In addition, the virtual extension line of the first inclined surface 96 having a truncated cone shape provided between the large-diameter shaft portion 94 and the small-diameter shaft portion 95 does not intersect or interfere with the sleeve tip 84 of the foreign substance removal pipe 33. The virtual extension line of the frustoconical valve seal surface 85 formed on the outer periphery of the valve body 1 is formed so as not to intersect or interfere with the sleeve tip 84 of the foreign substance removal pipe 33.

  Further, a virtual extension line of the second inclined surface 98 having a truncated cone shape provided between the small-diameter shaft part 95 and the coupling shaft part 97 is surrounded by a virtual extension line of the valve seal surface 85 of the valve body 1. By forming so as to be located in the conical region (α), the flow of EGR gas flowing from the flow path hole 24 into the flow path hole 25 along the outer shape of the valve shaft 2 is The contact with the sleeve tip 84 is eliminated, and the entry of foreign matter (such as deposit) into the sleeve (81 to 84) of the foreign matter removing pipe 33 can be suppressed. As a result, foreign matter (such as deposits) can be prevented from entering the bearing hole 31 of the housing 5, thereby preventing the poppet valves (valve body 1, valve shaft 2) from becoming inoperable (bullock) or malfunctioning. be able to.

Further, since the outer diameter of the coupling shaft portion 97 with the valve body 1 in the valve shaft 2 of the poppet valve can be made larger than that in the first embodiment, the first projecting shaft portion 91 of the valve body 1 and the valve shaft 2 can be Even when welding and fixing the tip end side in the axial direction, the shaft diameter in the welded joint portion between the valve body 1 and the joint shaft portion 97 can be sufficiently maintained. Thereby, since the contact area with the valve main body 1 of the circumferential direction of the welding connection part of the valve main body 1 and the coupling shaft part 97 can be increased, the welding strength of the valve main body 1 and the valve shaft 2 is ensured enough. be able to.
As described above, the EGR control valve of this embodiment has the same effect as that of the first embodiment.

[Modification]
In this embodiment, the exhaust control valve used in the exhaust device of the present invention is applied to the EGR control valve used in the exhaust circulation device (EGR system) of the internal combustion engine, but is used in the exhaust device of the present invention. The exhaust control valve to be used may be applied to a waste gate valve, a scroll switching valve, an exhaust flow control valve, an exhaust pressure control valve, an exhaust switching valve, an exhaust throttle valve, or the like incorporated in an exhaust device of an internal combustion engine.

In addition, poppet valves (poppet type EGR valves) are used as valve bodies for EGR control valves and exhaust control valves, but a butterfly valve, flap valve, and plate are connected via a conversion mechanism between the valve and the shaft. A rotary valve such as a valve or a rotary valve may be employed. A double poppet valve may be employed.
Moreover, you may use the operating rod extended in an axial direction instead of the valve shaft 2 as a shaft (valve shaft).

Further, before assembling the output lever 41 to the second projecting shaft portion (output portion) of the output shaft 39, the output lever 41, the pivot pin 42 and the follower 43 are assembled in advance, and these followers are sub-assembled. An assembly may be configured, and the follower subassembly may be assembled to the second protruding shaft portion (output portion) of the output shaft 39.
Further, a follower roller supported rotatably on the outer periphery of the pivot pin (support shaft) 22 may be used instead of the follower 43 formed of a ball bearing.

Further, as the internal combustion engine (engine), a multi-cylinder gasoline engine may be used instead of the multi-cylinder diesel engine. Moreover, you may apply to a single cylinder engine.
In the present embodiment, the frustoconical valve seal surface 85 that can be seated on the seat edge (valve seat) of the valve seat 15 is provided on the outer periphery of the EGR valve (valve head) 1, but the EGR valve (valve head) 1 A pyramidal trapezoidal valve seal surface 85 that can be seated on the seat edge (valve seat) of the valve seat 15 may be provided on the outer periphery of the valve seat 15.

In the present embodiment, the truncated cone-shaped first inclined surface 96 is provided between the large-diameter shaft portion 94 and the small-diameter shaft portion 95 of the first projecting shaft portion 91 of the valve shaft 2. A first inclined surface having a truncated pyramid shape may be provided between the large-diameter shaft portion 94 and the small-diameter shaft portion 95 of the one protruding shaft portion 91. Further, instead of the first inclined surface 96, an annular or square ring-shaped first step surface may be provided between the large-diameter shaft portion 94 and the small-diameter shaft portion 95.
The first step surface is extended in a vertical direction orthogonal to the axial direction (valve axis direction) of the valve shaft 2. Note that the first step surface may be a multi-step structure having two or more steps.

In this embodiment, the truncated cone-shaped second inclined surface 98 is provided between the small-diameter shaft portion 95 and the coupling shaft portion 97 of the first projecting shaft portion 91 of the valve shaft 2. A truncated pyramid-shaped second inclined surface may be provided between the small-diameter shaft portion 95 of the protruding shaft portion 91 and the coupling shaft portion 97. Further, instead of the first inclined surface 96, a second step surface having an annular shape or an annular shape may be provided between the small-diameter shaft portion 95 and the coupling shaft portion 97.
The second step surface is extended in a vertical direction orthogonal to the axial direction (valve axis direction) of the valve shaft 2. Note that the second step surface may be a multi-step structure having two or more steps.

In the present embodiment, as a poppet valve of the EGR (exhaust) control valve, the valve (valve body, valve portion) 1 is in a closed (full closed) state where the valve seat 15 is seated on the seat edge (valve seat). The valve 1 opens outward (lift) toward the flow path hole (first flow path) 22 formed on the upstream side in the exhaust flow direction from the valve seat 15 (by a predetermined valve lift amount or stroke amount). The poppet valve of the outside opening valve type is adopted. However, as the poppet valve of the EGR (exhaust) control valve, the valve is seated from the closed (fully closed) state where the valve is seated on the seat (valve seat). An inner opening valve that opens (lifts) inward (by a predetermined valve lift amount or stroke amount) toward the flow path holes (second flow paths) 24 and 25 formed on the downstream side in the exhaust flow direction. A poppet valve It may be.
That is, the structure of the present invention may be applied to an EGR (exhaust) control valve of an inner opening valve type instead of an EGR (exhaust) control valve of an outer opening valve type.

In the present embodiment, a second flow path (flow path hole 24) located on the downstream side of the exhaust flow direction from the valve seat 15 (for example, the intake passage side in the intake pipe of the internal combustion engine (engine)) as the bearing hole of the housing. Alternatively, a bearing hole 31 that opens at the wall surface of the flow path hole 25) and extends from the opening side to the back side is employed, but the upstream side in the exhaust flow direction from the valve seat 15 as the bearing hole of the housing ( For example, a bearing hole that opens at the wall surface of the first flow path (flow path hole 22) located on the exhaust passage side in the exhaust pipe of the internal combustion engine (engine) and extends from the opening side to the back side may be employed. .
In this case, the protruding shaft portion of the valve shaft protrudes from the opening of the bearing hole into the first flow path (flow path hole 22) and from the first flow path (flow path hole 22) to the valve hole (flow path hole 23). And is configured to protrude into the second flow path (flow path hole 24 or flow path hole 25).

1 Valve body (valve body, valve part, valve head, EGR valve of EGR control valve)
2 Valve shaft (valve shaft of EGR control valve)
5 Housing 15 Valve seat 27 Metal bearing
28 Bearing holder (bearing holder)
29 Oil seal 31 Housing bearing hole 32 Bearing hole opening 33 Foreign matter removal pipe

Claims (13)

(A) The flow path (21, 22, 24-26) through which the exhaust discharged from the internal combustion engine flows, the valve hole (23) communicating with the flow path (21, 22, 24-26), and the valve hole (23 ) Through which the annular sheet (15) and the flow path (21, 22, 24-26) are positioned upstream of the sheet (15) in the exhaust flow direction (21) 22) and the second flow path (24 to 26) positioned downstream of the seat (15) in the exhaust flow direction, and the annular partition (14) and the flow paths (21, 22). , 24-26) and a housing (5, 11, 28) having a bearing hole (31) extending from the opening side to the back side,
(B) a valve (1) which is disposed in the housing (5, 11) so as to be reciprocally movable and closes and opens the valve hole (23) by contacting and separating from the seat (15);
(C) A tip that is arranged so as to be able to move integrally with the valve (1) and protrudes into the flow path (21, 22, 24-26) from the base end side located on the back side of the bearing hole (31). A shaft (2) extending axially toward the side;
(D) a bearing (27) housed in the back side of the bearing hole (31) and supporting the shaft (2) so as to be reciprocally slidable in its axial direction;
(E) The bearing (27) is held on the opening side of the bearing hole (31) and protrudes from the opening (32) of the bearing hole (31) into the second flow path (24 to 26). In the exhaust system for an internal combustion engine provided with a cylindrical foreign matter removing pipe (33) that covers the outer diameter surface of the shaft (2),
The shaft (2) is provided in an intermediate shaft portion (93) to be inserted into the bearing hole (31), and on the tip end side in the axial direction with respect to the intermediate shaft portion (93). ) Having a protruding shaft portion (91) protruding into the flow path (22-25) from the opening (32) of
The protruding shaft portion (91) has a large-diameter shaft portion (94) in which the pipe tip portion (84) of the foreign matter removing pipe (33) is in sliding contact, and is closer to the distal end side in the axial direction than the large-diameter shaft portion (94). A small-diameter shaft portion (95) having an outer diameter smaller than that of the large-diameter shaft portion (94), and between the large-diameter shaft portion (94) and the small-diameter shaft portion (95). The first inclined surface (96) having a truncated cone shape or a truncated pyramid shape, or a first step surface having an annular shape or an annular shape,
The first inclined surface (96) or the virtual extension line of the first step surface is formed so as not to intersect or interfere with the pipe tip portion (84) of the foreign matter removing pipe (33). An exhaust device for an internal combustion engine. The exhaust system for an internal combustion engine according to claim 1,
The protruding shaft portion (91) has a coupling shaft portion (97) that is provided on the tip end side in the axial direction with respect to the small-diameter shaft portion (95) and is connected to the valve (1) so as to be movable together. ,
The exhaust device for an internal combustion engine, wherein the coupling shaft portion (97) has substantially the same outer diameter as the small-diameter shaft portion (95). The exhaust system for an internal combustion engine according to claim 1 or 2,
The protruding shaft portion (91) protrudes from the opening (32) of the bearing hole (31) into the second flow path (24, 25) and from the second flow path (24, 25) to the valve hole. An exhaust system for an internal combustion engine, characterized in that it passes through (23) and protrudes into the first flow path (22). The exhaust device for an internal combustion engine according to any one of claims 1 to 3,
The exhaust device for an internal combustion engine, wherein the valve (1) is welded and fixed to the tip end side in the axial direction of the protruding shaft portion (91). The exhaust system for an internal combustion engine according to any one of claims 1 to 4,
The valve (1) is a truncated cone-shaped or truncated pyramid-shaped valve inclined so that the outer diameter gradually decreases from the upstream side to the downstream side in the flow direction of the exhaust gas flowing through the flow paths (22-24). Having a sealing surface (85);
An exhaust system for an internal combustion engine, wherein a virtual extension line of the valve seal surface (85) is formed so as not to intersect or interfere with a pipe tip portion of the foreign matter removal pipe (33). The exhaust system for an internal combustion engine according to claim 5,
The protruding shaft portion (91) is provided on the distal end side in the axial direction with respect to the small diameter shaft portion (95), has an outer diameter larger than that of the small diameter shaft portion (95), and the valve (1). And a second inclined surface having a truncated cone shape or a truncated pyramid shape provided between the small diameter shaft portion (95) and the coupling shaft portion (97). (98), or having a second step surface having an annular shape or an annular shape,
The second inclined surface (98) or the virtual extension line of the second step surface is formed so as to be located in a region surrounded by the virtual extension line of the valve seal surface (85). An exhaust system for an internal combustion engine. The exhaust system for an internal combustion engine according to any one of claims 1 to 6,
The exhaust system for an internal combustion engine, wherein the foreign matter removing pipe has a cylindrical sleeve (33) extending in an axial direction along an outer diameter surface of the shaft (2). The exhaust system for an internal combustion engine according to claim 7,
The sleeve (33) extends from the sleeve base end (81) held in the bearing hole (31) and the opening (32) of the bearing hole (31) into the second flow path (24 to 26). An exhaust system for an internal combustion engine, comprising a sleeve projecting portion (82) projecting toward the inner surface. The exhaust system for an internal combustion engine according to claim 8,
The sleeve projecting portion (82) is a cylindrical sleeve reduced diameter portion (outer diameter gradually decreasing from the sleeve base end portion (81) toward the distal end side in the axial direction of the foreign matter removing pipe (33) ( 83). An exhaust system for an internal combustion engine, The exhaust system for an internal combustion engine according to claim 9,
The pipe tip portion is provided so as to be positioned on the most distal side in the sleeve diameter-reduced portion (83), and so that the inner diameter is the smallest in the sleeve diameter-reduced portion (83), An exhaust system for an internal combustion engine, characterized in that it is an annular sleeve tip (84) that is in sliding contact with the outer diameter surface of the large-diameter shaft portion (94).   The exhaust device for an internal combustion engine according to any one of claims 1 to 10, wherein the exhaust device is housed in the bearing hole (31), and the hole wall surface of the bearing hole (31) and the intermediate shaft portion ( 93) An exhaust device for an internal combustion engine, comprising an annular seal member (29) for sealing between the outer diameter surface of 93). The exhaust system for an internal combustion engine according to claim 11,
An exhaust system for an internal combustion engine, wherein a base end portion of the foreign matter removing pipe (33) is held by the seal member (29). The exhaust system for an internal combustion engine according to claim 11 or 12,
The exhaust device for an internal combustion engine, wherein the seal member (29) is accommodated closer to the opening side of the bearing hole (31) than the bearing (27).

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