JP3326745B2 - Exhaust flow control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust passage control valve used as a bypass valve for opening and closing a bypass passage of a silencer provided in an exhaust system of an engine.

[0002]

2. Description of the Related Art An exhaust passage control valve includes a housing through which exhaust gas of an engine flows, a valve body mounted on the housing, and a valve spring for urging the valve body to a closed side. The valve is configured to be opened when the above occurs.

[0003] Conventionally, as an exhaust passage control valve,
In general, a butterfly valve that opens and closes by rotation of a valve body about a shaft is used, but this requires a bearing that supports the shaft of the valve body, which increases costs. Therefore, Japanese Patent Application Laid-Open
According to Japanese Patent No. 287118, as a low-cost exhaust flow control valve requiring no bearing, a spiral valve body having an outer peripheral portion seated on an annular valve seat portion of a housing is used as a valve body, and a spiral winding axis is used. A valve configured to be opened and closed by expansion and contraction of a valve body in a direction has also been proposed.

In this case, a spring receiver is fixed to the housing so as to face the opening side of the valve body, and a valve spring made of a compression coil spring is interposed between the spring receiver and the valve body.

[0005]

In the exhaust flow path control valve for urging the spiral valve body to the closing side by the compression coil spring as described above, the opening and closing vibration of the valve body occurs when the exhaust pressure acts. was there. Also, in order to open and close the valve at a stroke when the exhaust pressure reaches a predetermined value, and to close at a stroke when the exhaust pressure falls below the predetermined value, the winding diameter and the number of turns of the compression coil spring are increased and the spring constant is increased. Although it is necessary to set it low, as a result, the valve spring becomes large and it becomes difficult to make the exhaust flow control valve compact.

In order to solve such a problem, the valve spring is
It consists of a torsion coil spring having a coiled body and arms at both ends of the body. Arms at both ends are provided in a pair of first spring receivers provided on the housing on both sides around the valve seat. Each of the arms is slidably engaged in the longitudinal direction, and the body is supported by the second spring receiver provided at the center of the valve body, and the valve body is pressed to the closing side via the body. Conceivable. In this one,
The urging force of the valve body toward the closing side is mainly obtained by the bending reaction force of the arms at both ends of the torsion coil spring. Then, when the body of the torsion coil spring is displaced to the opening side of the valve body due to extension to the opening side of the valve body, the arm slides with respect to the first spring receiver, and the arm part that generates a bending reaction force is effective. Length increases. Therefore, the bending reaction force of the arm does not increase to the left, and the spring constant can be reduced without increasing the size of the valve spring. Further, with the movement of the valve element, sliding friction of the arm portion with respect to the first spring receiver and friction between the coil-shaped wires in the body portion occur,
A vibration damping effect by friction is obtained, and opening and closing vibration of the valve body is effectively prevented.

When a torsion coil spring is used as a valve spring as described above, the center of the torsion coil spring generally follows a predetermined diameter line of the valve body by a second spring receiver. And the housing portion on one side and the other side around the valve seat portion, respectively, on one side and the other in the longitudinal direction of the body with respect to the second diameter line of the valve element orthogonal to the predetermined diameter line. A pair of first spring receivers are provided so as to be offset and along a plane parallel to the predetermined diameter line.
It is conceivable that each arm of the torsion coil spring is engaged with the spring support in an orthogonal state. However, in this case, the amount of the first spring receiver projecting outward in the radial direction with respect to the valve seat increases, and the valve becomes larger.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to reduce the size of an exhaust passage control valve using a torsion coil spring as a valve spring.

[0009]

Means for Solving the Problems In order to solve the above problems,
The present invention includes a housing through which exhaust gas of an engine flows, a valve body mounted on the housing, and a valve spring for urging the valve body toward a closing side, and opens when an exhaust pressure becomes a predetermined value or more. An exhaust flow path control valve, wherein a spirally wound valve body having an outer peripheral portion seated on an annular valve seat portion of a housing is used as a valve body. The valve spring is constituted by a torsion coil spring having a coiled body and arms at both ends of the body, and the valve spring is provided on both sides around the valve seat. The arms at both ends are slidably engaged in the longitudinal direction of each arm with a pair of first spring receivers provided on the portion, and the body is supported by a second spring receiver provided at the center of the valve body. And pressing the valve body to the closing side via the body portion, wherein the first and second spring receivers are placed at the position of the valve body. Are provided so as to be line-symmetrical with respect to the first diameter line of the valve body, and when viewed from the direction of the winding axis of the spiral of the valve body, each arm portion of the valve body is orthogonal to the first diameter line. A state in which the center line of the body and the first diameter line are obliquely oblique at a predetermined angle by the second spring receiver so that the center line of the body is oblique to the diameter line of the second spring at each of the first spring receivers. I support it.

According to the present invention, the second portion on the outer periphery of the valve seat portion is provided.
The first spring receiver is provided at the intersection with the diameter line. Therefore, the amount of protrusion of the first spring receiver outward in the radial direction with respect to the valve seat can be reduced as much as possible, and the valve can be downsized.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 denotes a silencer provided in an exhaust system of an engine.
End walls 11 ₁ , 11 ₂ closing one end and the other end of the shell 10
A first and a second pair of separators 12 ₁ and 12 ₂ are provided in the muffler main body constituted by: and a space in the main body is formed by a first space between the one end wall 11 ₁ and the first separator 12 ₁ . 1 muffling room 13 ₁
When, a second silencing chamber 13 ₂ between the first separator 12 ₁ and the second separator 12 _2, the second separator 12 ₂ and the other end wall 1
It is Kukaku and a third silencing chamber 13 ₃ between 1 _2. The muffler 1 further includes an exhaust inflow pipe 14 penetrating from the one end wall 11 ₁ through the first separator 12 ₁ and the second separator 12 ₂ to reach the third muffler chamber 13 ₃ , and a _second end wall 11 ₂ from the other end wall 11 ₂ . a second separator 12 ₂ and the first separator 12 ₁ and the first silencing chamber 13 exhaust outlet pipe 15 to reach the ₁ through a pair of first silencing chamber 13 ₁ and the second silencing chamber 13 ₂ communicates the 1 inner pipe 1
6 _1, 16 ₁ and the third silencing chamber 13 ₃ from the second separator 1
2 ₂ and the second inner pipe 16 ₂ extending in the first silencing chamber 13 ₁ side through the, the second inner pipe 16 ₂ first silencing chamber 13
_An exhaust passage control valve 2 serving as a bypass valve communicating with ₁ is provided.

[0012] the exhaust inlet pipe in the second portion located silencing chamber 13 in the _second 14 and a number of through holes 14a are formed, the exhaust inlet pipe 14 exhaust gas flowing from the through hole 14a and the second
Silencer 13 ₂ , first inner pipe 16 ₁ and first silencer 13
Flows to the exhaust outlet pipe 15 through the ₁ and expansion silencing effect in the second silencing chamber 13 ₂ first silencing chamber 13 ₁ Tokyo is to be obtained. Further, the third noise reduction chamber 13 of the exhaust gas inlet pipe 14 is provided.
_A large number of through holes 14b are also formed in the portion located in the inside _{3 so that} the resonance muffling effect in the third muffling chamber 133 is normally obtained.

The exhaust passage control valve 2 is configured to open when the exhaust pressure rises due to high speed rotation of the engine. Then, when the exhaust flow path control valve 2 opens, the bypass passage extending from the third silencing chamber 13 ₃ to the first silencing chamber 13 ₁ through the second inner pipe 16 ₂ is opened, the exhaust inlet pipe 1
Distribution path of the exhaust gas from 4, a route to the second silencing chamber 13 ₂ and the first inner pipe 16 ₁ and the first silencing chamber 13 ₁ and the exhaust outlet pipe 15 via a third silencing chamber 13 ₂ via the bypass passage and the first silencing chamber 13 ₁ is two lines of a path leading to the exhaust outlet pipe 15, loss of engine power due to increase in the exhaust pressure is prevented.

[0014] exhaust flow path control valve 2, as shown in FIGS. 2 through 5, a housing 20 in which the exhaust gas from the second inner pipe 16 ₂ flows, the valve body is attached to the housing 20 2
1 and a valve spring 22 for urging the valve body 21 to the closing side, and the exhaust pressure is equal to or higher than the pressure (valve opening set pressure) corresponding to the set load of the valve spring 22 in the initial state (closed state). Open when it becomes.

The housing 20 includes the second inner pipe 16
It is composed of a pipe-shaped member fitted to ₂ . And
The distal end of housing 20 which projects into the first muffler chamber 13 ₁ and enlarged to form a flange, and constitutes an annular valve seat portion 20a in the flange.

The valve body 21 is formed of a spiral valve body having an outer peripheral portion seated on a valve seat portion 20a, and a closed state in which the winding portions on the outer peripheral side and the inner peripheral side of the spiral overlap each other. The valve is opened when the valve element 21 extends in the direction of the winding axis of the spiral. Here, the valve body 21 may be formed of a single spiral plate, but in the present embodiment, as shown in FIG. 8, a pair of spiral plates 21 ₁ , 21 ₁ ,.
21 ₂ combined double spiral, both spiral plate 21 _1, 21 ₂
Is butt-welded to the semicircular central portion 21a of the semicircular string 21a to form a spiral valve body 21. Then, the outer peripheral portions of the two spiral plates 21 ₁ and 21 ₂ are overlapped and seated on the valve seat portion 20a, and the claw pieces 20b formed at a plurality of locations around the valve seat portion 20a are swaged to form the two spiral plates 21 ₁ and 21 2. ₂ is fixed to the valve seat 20a.

The valve spring 22 includes a coiled body 22a,
It is constituted by a torsion coil spring having arms 22b, 22b at both ends of the body 22a. And, the valve seat 20a
A pair of first spring receivers 23, 23 are provided on the housing 20 on both sides around the arm. The two arms 22b, 22b of the valve spring 22 are respectively provided on the first spring receivers 23, 23 in the longitudinal direction of each arm 22b. The second spring receiver 24 is provided at the center of the valve body 21, and the body 22 a of the valve spring 22 is supported by the second spring receiver 24. Thus, valve element 2
1 is pressed to the closing side via the body 22a by the bending reaction force of the arms 22b, 22b of the valve spring 22.

By the way, in order to obtain the opening and closing characteristics of a valve with a small transient state, the valve is opened at a stroke when the exhaust pressure reaches a predetermined value, and is closed at a stroke when the exhaust pressure falls below the predetermined value, the spring constant of the valve spring 22 is set low. It becomes necessary. Here, according to the present embodiment, the valve spring 22 is extended by the extension of the valve body 21 to the open side.
Is displaced to the opening side of the valve body 21,
The arm portion 22b of the valve spring 22 slides with respect to the first spring receiver 23, and the effective length of the arm portion 22b that generates a bending reaction force increases. Therefore, the bending reaction force of the arm portion 22b does not increase to the left,
Eventually, the spring constant decreases. In addition, with the movement of the valve body 21, sliding friction of the arm portion 22 b with respect to the first spring receiver 23 and friction between the coiled wires in the body portion 22 a are generated, and a vibration damping action due to the friction is obtained. Opening and closing vibration is effectively prevented.

In this embodiment, both first spring supports 2 are provided.
3 and 23 are provided so as to be in line symmetry with respect to a predetermined first diameter line a of the valve body 21, and the valve spring 22 is viewed from the winding axis direction (opening / closing direction) of the spiral of the valve body 21. Each of the arms 22b is the second of the valve body 21 orthogonal to the first diameter line a.
The center line c of the body 22a of the valve spring 22 and the first diameter line a are predetermined by the second spring receiver 24 so that the center line c of the valve spring 22 is oblique to the diameter line b of each of the first spring supports 23. It is supported in an oblique state at an angle. As shown by phantom lines in FIG. 5, the body portion 22a of the valve spring 22 is offset from one side and the other in the longitudinal direction of the body portion 22a at portions of the housing 20 on one side and the other side around the valve seat portion 20a. A pair of first spring supports 23 ', 23' along a plane parallel to the center line c of
And each arm 2 of the valve spring 22 is provided in each first spring receiver 23 ′.
It is conceivable to engage the second spring 2b in an orthogonal state. However, in this case, the amount of the first spring receiver 23 'projecting radially outward with respect to the valve seat portion 20a becomes large, and the valve becomes large.
On the other hand, according to the present embodiment, the first spring receiver 23
Of the valve seat 20a in the radially outward direction is reduced, which is advantageous in reducing the size of the valve.

Each of the first spring supports 23 is connected to the housing 2.
Each of the first spring supports 23 is connected to an attachment portion 25 formed on the housing 20 for each first spring support 23. The mounting portion 25 is formed with a pair of tongue pieces 25a, 2 formed in the housing 20 at intervals in the circumferential direction of the valve seat portion 20a and extending in the opening and closing direction of the valve body 21.
5a. Each first spring receiver 23 is formed so as to be in contact with both tongue pieces 25a, 25a.
Each of the first spring supports 23 can be welded and connected to each of the first and second spring supports 5a and 25a in a state where the first spring supports 23 are overlapped by an arbitrary length in the opening and closing direction of the valve body 21. When the overlap length of the first spring receiver 23 with respect to the mounting portion 25 formed by the tongue pieces 25a, 25a is changed, the amount of deflection of the arm portion 22b of the valve spring 22 in the initial state, that is, the set load of the valve spring 22 changes. . Therefore, the exhaust passage control valves 2 having different valve opening set pressures are
Without changing the valve spring 22 or the first spring receiver 23,
5 can be obtained only by changing the overlap length of the first spring receiver 23, and the parts can be shared, thereby reducing the cost.

The portion of each first spring receiver 23 located between the tongues 25a, 25a at the end in the closing direction of the valve body 21 includes:
A concave portion 23a is formed to be recessed in the opening direction of the valve body 21. Each arm portion 22b of the valve spring 22 is formed in the concave portion 23a.
Are engaged. Here, the concave notch 23a is
Oblique sides 23b, 2 on both sides oblique to the inner edges of 5a, 25a
3b. Therefore, each arm 22 of the valve spring 22
b is guided by the oblique side 23b and securely engages with the central portion of the concave portion 23a, thereby preventing the set load of the valve spring 22 from being varied due to the displacement of the engagement position of the arm 22b.

The second spring receiver 24 is provided on the body 2 of the valve spring 22.
It is formed in a gutter-like concave shape for receiving 2a, and the outer peripheral surface of the trunk portion 22a is seated on the second spring receiver 24. The second spring receiver is composed of a rod-shaped member inserted into the body 22a and a support member on the valve body 21 side supporting the rod-shaped member. It is conceivable to connect the member to the support member, but this requires time and labor for the assembling operation. On the other hand, in the case of the present embodiment, only the trunk portion 22a needs to be seated on the second spring receiver 24, and the assembling work is facilitated. But the torso 2
If the valve body 2a is simply seated in the recessed second spring receiver 24, the body 22a is opened and closed by the opening and closing operation of the valve body 21.
Tilting in the opening and closing direction of
May be shifted in the lateral direction, which is the direction in which the arm 22b extends. Therefore, in the present embodiment, tongue-shaped stoppers 24a are provided at both end portions of the second spring receiver 24 to abut against the end surface of the body portion 22a to prevent the tilting of the body portion 22a. It is designed to be able to prevent an inverted state. Further, the depth h of the recess of the second spring receiver 24 (see FIG. 7).
Is set to １ ／ or more of the diameter of the body 22a. According to this, even if the torso 22a rolls over and rolls over,
As long as the entire body a does not float from the second spring receiver 24, the body 22a does not fall off the second spring receiver 24, and the body 2
2a can be stably supported by the second spring receiver 24. The second
Notches 24b are formed on both side edges of the spring receiver 24 to avoid interference with the arms 22b.

The housing 20 has a valve-opening stopper 26 for restricting the expansion of the valve body 21 to the opening side by a predetermined amount or more by abutting the body 22a of the valve spring 22, as shown in FIGS. 6 and 7. As described above, the valve body 21 is provided with the valve closing stopper 27 that abuts on the central portion of the valve body 21 to prevent the valve body 21 from bending so as to be recessed toward the closing side. The stoppers 26 and 27 can prevent the durability from being adversely affected. The valve-opening stopper 26 is formed in a bridge shape connecting the first spring supports 23, 23, and the first spring receivers 23, 23 and the valve-opening stopper 26 are integrally formed.

The valve closing stopper 27 is formed of a plate-like member fixed in the housing 20 along a plane perpendicular to the plane including the valve seat 20a, that is, a plane parallel to the exhaust gas streamline. Thus, it is possible to prevent an increase in exhaust gas flow resistance due to the valve closing stopper 27. Then, the contact portion 2 facing the central portion of the valve body 21 is
7a is formed so as to protrude more toward the opening side of the valve body 21 than the surface including the valve seat portion 20a, so that the winding portions on the outer peripheral side and the inner peripheral side of the valve body 21 are in a closed state where they overlap each other. When the valve body 2
The central portion of 1 is in contact with the contact portion 27a.
The pair of spiral plates 21 ₁ and 21 ₂ that constitute the valve body 21 are
As described above, the two spiral plates 21 ₁ and 21 ₂ are joined at the chord 21 a at the center of the semicircle, so that this joint is not separated by the impact received from the valve closing stopper 27.
A valve-closing stopper 27 is provided along a plane intersecting with the string 21a serving as a joint.

While the embodiment in which the present invention is applied to the exhaust flow path control valve 2 comprising a bypass valve provided in the muffler 1 has been described above, the exhaust flow path control valve provided in another part of the exhaust system of the engine is also applicable. Similarly, the present invention can be applied.

[0026]

As is apparent from the above description, according to the present invention, the amount of the first spring support projecting outward in the radial direction with respect to the valve seat portion is reduced as much as possible, and the valve is reduced in size. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a muffler including an exhaust passage control valve according to the present invention.

FIG. 2 is an enlarged front view of the exhaust passage control valve as viewed from the direction of arrow II in FIG. 1;

FIG. 3 is a side view of the exhaust passage control valve viewed from the direction of arrow III in FIG. 2;

FIG. 4 is a side view of the exhaust passage control valve viewed from the direction of arrow IV in FIG. 2;

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 is a rear view of the exhaust passage control valve viewed from the direction of arrow VI in FIG. 3;

FIG. 7 is a sectional view taken along the line VII-VII of FIG. 6;

FIG. 8 is a view showing a method of assembling the valve body.

[Description of Signs] 2 Exhaust flow path control valve 20 Housing 20a Valve seat 21 Valve body 22 Valve spring 23 First spring receiver 24 Second spring receiver a First diameter line b Second diameter line c Center of body line

Continued on the front page (72) Inventor Masamichi Fujishiro 1-4-1 Chuo, Wako-shi, Saitama Pref. In Honda R & D Co., Ltd. (72) Inventor Jun Fukasawa 1069-1 Toyatsukacho, Isesaki-shi, Gunma Sankei Giken Kogyo Co., Ltd. (56) References JP-A-7-54658 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01N 1/08 F01N 7/08

Claims (1)

(57) [Claims] An exhaust system includes a housing through which exhaust gas of an engine flows, a valve body mounted on the housing, and a valve spring for urging the valve body toward a closing side, and opens when an exhaust pressure becomes a predetermined value or more. An exhaust flow path control valve that is configured to be valved, wherein a spiral-shaped valve element having an outer peripheral portion seated on an annular valve seat portion of a housing is used as a valve element, and a valve is provided in a spiral axis direction. The valve spring is constituted by a torsion coil spring having a coiled body and arms at both ends of the body, and the valve spring is configured to be opened and closed by expansion and contraction of the body. The arms at both ends are slidably engaged in the longitudinal direction of each arm with a pair of first spring receivers provided at a portion of the valve body, and the body is supported at a second spring receiver provided at the center of the valve body. And pressing the valve body toward the closing side via the body portion, wherein the first and second spring receivers are connected to the valve body. And a valve body in which each arm is orthogonal to the first diameter line when viewed from the direction of the winding axis of the spiral of the valve body. The center line of the body and the first diameter line are obliquely formed at a predetermined angle by the second spring receiver so that the center line of the body is oblique to the second diameter line of the first spring receiver. An exhaust passage control valve, wherein the exhaust passage control valve is supported in a state in which the exhaust passage is controlled.