JP3432930B2 - Exhaust system for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system for an internal combustion engine.
In the middle of the exhaust passage formed in the shell
A rotary shaft rotatably supported by a valve housing in the valve,
A flow rate adjusting valve having a valve body fixed to the rotating shaft and a rotating biasing spring for exerting a spring force for rotating the rotating shaft is provided.
Set relates to an exhaust system of an internal combustion engine to be kicked. 2. Description of the Related Art Conventionally, such an apparatus is disclosed in, for example,
It is known from, for example, JP-A-221130. [0003] In such an exhaust system, a minute gap is set between the valve body and the inner surface of the valve housing in order to ensure smooth rotation of the flow control valve. Inevitably, in the above-described conventional apparatus, the rotating shaft rattles along the axial direction, and the generation of abnormal noise due to the rattling is inevitable. The present invention has been made in view of such circumstances, and an exhaust system for an internal combustion engine in which rattling along a rotation axis of a flow control valve is avoided to prevent generation of abnormal noise. The purpose is to provide. [0005] In order to achieve the above object, an invention according to claim 1 is provided in an exhaust system of an internal combustion engine.
In the middle of the exhaust passage formed in the shell
A rotating shaft rotatably supported by the valve housing, a valve body fixed to the rotating shaft, and a rotating biasing spring for exerting a spring force for rotating the rotating shaft. in an exhaust system of an internal combustion engine flow amount adjustment valve is eclipsed set comprising, shell and valves
Isolated from inside the housing and outside the shell
An isolated spring chamber is formed adjacent to the valve housing.
Is, the spring force is the spring chamber, which urges the rotation urging spring, a pivot shaft provided separately from the said rotation urging spring to the spring chamber side
Axially biasing spring to exert is housed, the rotation axis,
A contact surface facing the spring chamber is provided, and the valve housing is provided with a restricting portion for restricting the axial movement of the rotating shaft by contacting the contact surface, and the spring chamber is detachably fixed to the shell. did
It is shielded from outside air by a cover, and this cover
Can be removed for maintenance and inspection of both springs.
It is characterized by the ability to work. According to the construction of the first aspect of the present invention, the rotating shaft of the flow rate adjusting valve is one side in the axial direction by the axial biasing spring.
That is, the rotation shaft is urged toward the spring chamber , and the contact surface of the rotation shaft is pressed against the regulating portion on the valve housing side, so that the rotation shaft is prevented from rattling along the axial direction. Also above
Both springs housed in the spring chamber are peeled outside the shell.
No rust on both springs
Also, the springs may not be damaged by pebbles that have been repelled.
No. In addition, the contact surface of the rotating shaft presses against the regulating portion of the valve housing.
The spring chamber from inside the valve housing
It is possible to minimize gas leakage into the chamber,
Even if there is a gas leak inside, the spring chamber
Gas leaks out of the shell due to the
The cover is cooled by outside air
Overheating of the spring chamber can be avoided as much as possible. Also hippo
The spring from the shell for maintenance and inspection.
Is possible. An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 8 show an embodiment of the present invention. FIG. 1 is a plan view of a muffler, and FIG.
2 is an enlarged sectional view of FIG. 2, FIG. 3 is a longitudinal sectional view of the muffler along line 3-3 in FIG. 2, FIG. 4 is a longitudinal sectional view of the muffler along line 4-4 in FIG. 2, and FIG. FIG. 6 is an enlarged sectional view taken along line 5-5 of FIG.
7 is a sectional view taken along the line 7-7 in FIG. 6, and FIG. 8 is a sectional view taken along the line 8-8 in FIG. First, in FIGS. 1 to 4, a shell 12 of a muffler 11 provided in the middle of an exhaust system of an internal combustion engine is formed in a cylindrical shape, and one end wall 12a of the shell 12 has an engine body ( connected single exhaust introduction pipe 13 for guiding exhaust gas from not shown), also a pair of exhaust gas discharging pipe 14 to the other end wall 12b of the shell 12 _1, 14 ₂ are connected in parallel to each other. In the shell 12, the first, second, third and fourth partition walls 15, 16, 17, 18 are arranged at positions sequentially spaced from one end wall 12a side to the other end wall 12b side.
Are fixedly arranged such that the outer edges of these 15 to 18 are welded to the inner peripheral surface of the shell 12. Thereby, the first muffler chamber 19 between the one end wall 12a and the first partition 15, the second muffler chamber 20 between the first and second bulkheads 15, 16 and the third muffler chamber between the second and third bulkheads 16,17. A muffling chamber 21, a third muffling chamber 22 between the third and fourth bulkheads 17 and 18, and a fifth muffling chamber 23 between the fourth bulkhead 18 and the other end wall 12 b are formed in the shell 12. Thus, the first partition 15
Are arranged relatively close to one end wall 12a of the shell 12, and the first partition wall 15 is provided with a number of small holes (not shown) evenly over substantially the entire surface thereof. The first, second and third exhaust introduction pipes 13 are provided.
First inner pipe 2 penetrating partition walls 15, 16, 17
4 is connected to one end of the first inner pipe 2.
The other end of 4 is opened to the fourth sound deadening chamber 22. Moreover, a large number of through holes 25 are formed in a peripheral wall of a portion of the first inner pipe 24 corresponding to the third sound deadening chamber 21. The fourth muffling chamber 2 extends between the fourth and fifth muffling chambers 22 and 23.
A second inner pipe 26 having one end opposed to the other end opening of the first inner pipe 24 at an interval in the second inner pipe 24 is disposed so as to penetrate the fourth partition 18. A third inner pipe 27 having a relatively small diameter and a fourth inner pipe 28 having a relatively large diameter are provided in parallel between the fourth muffler chamber 22 and the second muffler chamber 20. At the end of the fourth inner pipe 28 in the second muffler chamber 20, there is provided a flow control valve 30 for adjusting the amount of exhaust gas flowing in the exhaust passage from the fourth inner pipe 28 to the second muffler chamber 20. Mounted. This flow control valve 3
0 indicates that the flow resistance is variable in accordance with the exhaust pressure. When the internal combustion engine is running at a low speed and the exhaust pressure is relatively low, the flow resistance is increased to reduce the exhaust flow, thereby reducing the exhaust noise. When the exhaust pressure becomes relatively high while the internal combustion engine is rotating at a high speed, the flow resistance is reduced to increase the flow rate of the exhaust gas, thereby increasing the output by reducing the exhaust resistance. Further, a pair of fifth inner pipes 31 ₁ and 31 ₂ having one ends opened to the second sound deadening chamber 20 are provided with second and third inner pipes 31 ₁ and 312, respectively.
And a fourth are disposed in parallel through the partition wall 16, 17, 18, these inner pipe 31 _1, 31 ₂ at the other end is secured to the other end wall 12b of the shell 12, both the exhaust outlet pipe 14 ₁ and 14 ₂ are the fifth inner pipes 31 ₁ and 3
It is individually connected to the 1 ₂ at the other end. In addition, the fifth inner pipes 31 ₁ and 31 ₂
As shown in FIG. 5, a large number of through holes 32, 3
There are provided sound absorbing portions 36, 36 filled with a sound absorbing material 35 between an inner tube portion 33 having 2 and an outer tube portion 34 coaxially surrounding the inner tube portion 33. Referring to FIG. 6, FIG. 7 and FIG.
The flow control valve 30 includes a valve housing 38, a rotation shaft 39 rotatably supported by the valve housing 38, a valve body 40 housed in the valve housing 38 and fixed to the rotation shaft 39. A muffler including a rotation urging spring 41 for urging the rotation shaft 39 to one side around the axis thereof, and an axial urging spring 42 for urging the rotation shaft 39 to one side in the axial direction. 11 is fixedly supported by the shell 12. The valve housing 38 is intended first and second housing half 38 formed in each dish _1, 38 ₂ are configured their open ends mutually welded, bonded to, hollow It is formed in a box shape. Moreover at a position corresponding to one another of the two housing halves 38 _1, 38 _2, supporting holes 43 and 44 are provided coaxially. _On the outer surface of the first housing half 38 ₁ , a dish-shaped case member 45 opened to the shell 12 side is fixed by welding, and the case member 45 and the first housing half 38 ₁ are fixed. A metal bearing 46 facing the support hole 43 is sandwiched between the two. On the other hand, the second outer surface of the housing halves 38 _2, second
Dish-shaped support member 47 opened to the housing half 38 ₂
Are welded, and a metal bearing 48 facing the support hole 44 is provided between the support member 47 and the second housing half 38 _2.
Is pinched. The rotating shaft 39 is rotatably supported by both metal bearings 46 and 48. The rotating shaft 39 has a large-diameter shaft portion 39a housed in the valve housing 38 and a small-diameter shaft portion 39a which is smaller in diameter toward one side in the axial direction. The small-diameter shaft portion 3 coaxially connected to one end of the large-diameter shaft portion 39a via a contact surface 39b formed in a tapered shape.
9c and a small-diameter shaft portion 39d coaxially connected to the other end of the large-diameter shaft portion 39a. The small-diameter shaft portion 39c on one side in the axial direction is pierced through the bearing metal 46 to enable sliding around the axis.
Further, the small-diameter shaft portion 39d on the other side in the axial direction is pierced through the bearing metal 48 to enable sliding around the axis. In addition, the bearing metal 46 is provided with a tapered restricting portion 46a that is in contact with the contact surface 39b of the rotating shaft 39 to restrict the movement of the rotating shaft 39 to one side in the axial direction. The large-diameter shaft portion 39a of the rotating shaft 39 has
The valve body 40 housed in the valve housing 38 with the outer edge thereof closely approaching the inner surface of the valve housing 38,
8 so as to form an inflow chamber 49 therebetween. On the other hand, in the valve housing 38, an inlet pipe 50 whose inner end opening projects into the inflow chamber 49 so as to face the valve body 40 and whose outer end projects outside is fixedly provided. The outlet end of the fourth inner pipe 28 is fitted to the end with a spacer 51 formed by forming a metal mesh in a ring shape therebetween. As shown by the solid line in FIG. 8, the valve element 40 is positioned at the minimum flow rate position P where the volume of the inflow chamber 49 is minimized.
₁ and are those capable of turnable operation between the flow rate maximum position P ₂ in which the volume is maximum of the inflow chamber 49, as indicated by the chain line in FIG. 8, the flow rate minimum position P _1, the valve member 40 Is the inlet pipe 50
Inner to an end opening abuts Sadamari by closing the inner end opening of the inlet tube 50, also the maximum flow rate position P ₂ is an inner end stopper 40a which is provided continuously on the valve body 40 of the inlet pipe 50 of the It is determined by abutting on the side wall. By the way, the exhaust pressure from the inner end opening of the inlet pipe 50 acts on the valve element 40 in the direction of operating the valve element 40 on the side of increasing the volume of the inflow chamber 49. A recess 40b is provided in the center of the surface of the inlet 40 on the side of the inlet pipe 50 to receive the exhaust pressure, and a reinforcement is provided between the back surface of the recess 40b and the large-diameter shaft portion 39a of the rotating shaft 39. A member 52 is provided. [0021] the valve to the housing 38, the flow rate minimum position communication start point is set within the operating range of the valve body 40 from P ₁ to the maximum flow rate position P ₂ P _C (see FIG. 8) the maximum flow rate position P ₂ exit window 53 which communicates directly to the inlet chamber 49 when the valve body 40 on the side has passed is facing the inflow chamber 49 in response to the valve body 40 is operated from the communication start point P _C at the maximum flow rate position P ₂ side The area is provided so as to gradually increase. [0022] In operation process from the flow minimum position P ₁ of Thus to the valve body 40 to the maximum flow rate position P _2, from the flow rate minimum position P ₁ to the communication start point P _C inlet chamber from the inlet pipe 50 4
While exhaust gas flowing to 9 flows to the exit window 53 through the gap between the inner surface of the outer edge and the valve housing 38 of the valve body 40, from the communication start point P _C to the maximum flow rate position P _2, from the inflow chamber 49 Exhaust gas flows directly to the exit window 53. The shell 12 open ended in the open end of the case member 45 which dish shape formed is continuously provided in the housing halves 38 ₁ of the valve housing 38 rectangular in side flanges 4
5a is provided integrally. On the other hand, the shell 12 is provided with a hole 54 corresponding to the case member 45, and the flange 45 a contacts the inner surface of the shell 12 around the hole 54. Moreover, a plurality of, for example, four insertion holes 55 are provided in the flange 45a, and nuts 56 connected to the insertion holes 55 are fixed to the flange 45a on the surface opposite to the contact surface with the shell 12. You. A cover 57 for covering the hole 54 is detachably fixed to the shell 12 with a gasket 58 interposed between the shell 57 and the outer surface of the shell 12. That is, the cover 57
The cover 57, the gasket 58, and the shell 12 are detachably fixed to the shell 12 by a plurality of bolts 59 that are screwed into the nuts 56 through the insertion holes 55, respectively. Moreover, the cover 57 is formed in a cap shape with a cross-sectional shape bulging outward. Between the cover 57 and the case member 45,
A spring chamber 60 is formed which is isolated from the inside of the shell 12 and the inside of the valve housing 38 and is also cut off from the outside of the shell 12. In the spring chamber 60, a rotation urging spring 41 and an axial urging are provided. The springs 42 are housed together. That is, the small-diameter shaft portion 39c, which is one end of the rotating shaft 39, protrudes into the spring chamber 60, and the spring receiving member 61 fixed to the end of the small-diameter shaft portion 39c and the spring chamber 60. The rotation urging spring 41 and the axial urging spring 42 are arranged between the case member 45 and a dish-shaped locking member 62 welded to the inner end side. Rotation urging spring 41 Thus is a torsion spring wound helically around the small-diameter shaft portion 39c, exert a spring force biasing rotated toward the valve element 40 to the flow rate minimum position P ₁ side Both ends of the rotation urging spring 41 are engaged with the spring receiving member 61 and the locking member 62, respectively, for the sake of simplicity. The axial biasing spring 42 is a coil spring for surrounding and bending the small diameter shaft portion 39c, and has a spring receiving member 61 and a locking member 62 for exerting a spring force for biasing the rotating shaft 39 to one side in the axial direction. It is contracted between. In addition, the rotation urging spring 41 is arranged so as to surround the axial urging spring 42. Next, the operation of this embodiment will be described. The communication start point P set within the operating range of the valve body 40 is provided in the valve housing 38 of the flow control valve 30 disposed in the muffler 11. exit window 53 which gradually a large area facing the inlet chamber 49 in response to actuation of the valve body 40 from _C to the maximum flow rate position P ₂ side. Therefore, the minimum flow rate P
During operation of the valve body 40 to the communication start point P _C from _1, Sadamari is flow resistance by a gap formed between the inner surface of the outer edge and the valve housing 38 of the valve body 40 between the inlet chamber 49 and the exit window 53, the start communicating during operation of the valve body 40 from the point P _C up to the maximum flow rate position P ₂ will be the inflow chamber 49 is communicated directly to the exit window 53, the area facing the inlet chamber 49 of the exit window 53 closer to the maximum flow rate position P ₂ growing. Thus while the valve body 40 is operated from the flow rate minimum position P ₁ to the maximum flow rate position P _2, the fourth inner pipe 28 second
The flow resistance of the exhaust passage between the silencing chambers 20 is reduced. [0028] Thus by flow resistance in accordance with the operating position of the rotational position or the valve body 40 of the rotary shaft 39, the position of the communication start point P _C of the exit window 53 starts directly communicates with the inflow chamber 49, and an outlet Although will be determined by the area facing the inlet chamber 49 of the exit window 53 in a state where the window 53 is in communication directly into the inflow chamber 49, define a communication start point P _C at any position of the operating range of the valve body 40 Also, the area of the exit window 53 facing the inflow chamber 49, that is, how the shape of the exit window 53 is determined can be arbitrarily set. It is possible to arbitrarily set the flow resistance, that is, the flow amount. In such a flow control valve 30, the rotating shaft 39 is urged by a rotating urging spring 41 to increase the flow resistance. The side is also biased. For this reason, the rotating shaft 39
The contact surface 39b provided on the valve housing 38 is pressed against the restricting portion 46a provided on the valve housing 38 side, so that the rotation shaft 39 is prevented from rattling along the axial direction, and the vibration caused by the rattling is reduced. The generation of sound is prevented. In addition, the rotation urging spring 41 is disposed around the rotation shaft 39 in the spring chamber 60 so as to surround the axial urging spring 42. In spite of this, the arrangement space for both springs 41 and 42 can be minimized. Further, the spring chamber 60 is isolated from the inside of the shell 12 and the inside of the valve housing 38 and is also shut off from the outside of the shell 12. By storing both springs 41 and 42 in the spring chamber 60, Since the springs 41 and 42 are not exposed to the outside of the shell 12, rust does not occur on the springs 41 and 42, and the springs 41 and 42 are not damaged by pebbles or the like that are repelled. . In addition, since the contact surface 39b of the rotating shaft 39 is pressed against the restricting portion 46a of the metal bearing 46, it is possible to prevent gas from leaking from the valve housing 38 into the spring chamber 60 as much as possible. Even if there is a gas leak inside, the gas is not leaked to the outside of the shell 12 because the spring chamber 60 is isolated from the outside, and the inside of the spring chamber 60 is overheated because the cover 57 is cooled by the outside air. Is prevented as much as possible, and both springs 41 and 42 are prevented from suffering heat damage as much as possible. In particular, since the cover 57 has an outwardly swelling cross-sectional shape, the cooling area by the outside air can be made relatively large, and the cooling effect can be further improved. Further, the cover 57 is detachably fixed to the shell 12 so as to cover the hole 54 provided in the shell 12, and the cover 57 is detached from the shell 12 to maintain and inspect the springs 41 and 42. It is possible to do. Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible. For example, an electric actuator is connected to the rotating shaft 39, and the flow amount adjusting valve in which the rotating shaft 39 is rotated by the actuator to the side where the flow resistance is reduced by the valve element 40 is provided with an exhaust valve. The present invention can also be applied to an exhaust device provided in the middle of the flow path. As described above, according to the present invention, the inside of the shell
And within the valve housing and the shell
A spring chamber that is isolated from the outside is located adjacent to the valve housing.
The spring chamber is formed with a pivot for urging the pivot.
A biasing spring, provided separately by rotation axis with the rotation urging spring
Axial spring that exerts spring force to urge the spring toward the spring chamber
The rotary shaft is provided with a contact surface facing the spring chamber side, and the valve housing is provided with a restricting portion for restricting the axial movement of the rotary shaft by contacting the contact surface. , The spring chamber
Insulated from outside air by a cover detachably attached to the shell
By removing this cover from the shell, both springs
Maintenance and inspection of the shaft, it is possible to prevent the rotating shaft from rattling along the axial direction by pressing the contact surface of the rotating shaft against the restricting portion of the valve housing. Generation of abnormal noise due to rattling of the shaft is prevented.
The two springs housed in the above-mentioned spring chamber are connected to the outside of the shell.
No rust occurs on both springs
That both springs are damaged by pebbles, etc.
Not even. In addition, the contact surface of the rotating shaft is regulated by the valve housing.
From inside the valve housing
Gas leakage into the spring chamber can be avoided as much as possible,
Even if gas leaks into the spring chamber,
Because the chamber is isolated from the outside,
The cover does not leak due to outside air
As a result, overheating of the spring chamber is avoided as much as possible.
The spring is prevented from suffering heat damage as much as possible. More cover
Can be removed from the shell for maintenance and inspection of the spring.
It is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a muffler. FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. FIG. 3 is a longitudinal sectional view of the muffler taken along line 3-3 in FIG. 2; FIG. 4 is a longitudinal sectional view of the muffler taken along line 4-4 in FIG. 2; FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. 2; FIG. 7 is a sectional view taken along line 7-7 of FIG. 6; FIG. 8 is a sectional view taken along line 8-8 in FIG. 2; [Explanation of Reference Numerals] 30: Flow amount adjusting valve 38: Valve housing 39: Rotating shaft 39b: Contact surface 40: Valve element 41: Rotating biasing spring 42 ..Axial biasing springs 46a ... Regulators 57 ... Covers 60 ... Spring chambers 61 ... Spring receiving members

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01N 1/08 F01N 7/08

Claims (1)

(57) [Claim 1] A shell interposed in an exhaust system of an internal combustion engine
In the middle of the exhaust passage formed in (12), the shell (1)
2) a rotating shaft (39) rotatably supported by the valve housing (38) in the inside, a valve element (40) fixed to the rotating shaft (39), and the rotating shaft (39). in an exhaust system of an internal combustion engine that the rotation urging spring which exerts a spring force (41) and the flow amount adjusting valve provided with a (30) is eclipsed set to turn biased to the shell (12) and the valve housing (38 ) Inside
Cut off and outside of shell (12)
A spring chamber (60) is formed adjacent to the valve housing (38).
The spring chamber (60) has a rotating urging spring (4).
1) and the rotation biasing spring (41) are provided separately from each other.
A spring force for urging the driving shaft (39) toward the spring chamber (60) is generated.
And an axially biasing spring (42) which is in contact with the spring chamber (60).
b) is provided, the valve housing (38) is provided with a restricting portion (46a) for restricting the axial movement of the rotating shaft (39) by contacting the contact surface (39b), and the spring chamber (60 ) is provided. )
Is a cover (5) detachably fixed to the shell (12).
7) The cover (57) is shut off from the outside air
By removing the springs (41, 4)
2) Maintenance, characterized in that it possible to perform the inspection, the exhaust equipment of internal combustion engine.