JP3383254B2 - 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 flow control valve is provided with a housing through which engine exhaust gas flows, a valve body mounted on the housing, and a valve spring for urging the valve body toward a closed side, and an exhaust pressure of a predetermined value. The valve is configured to be opened when the above is reached.

Conventionally, as an exhaust passage control valve,
Generally, a butterfly valve that opens and closes by rotation of a valve element around a shaft is used, but this requires a bearing that supports the shaft of the valve element, resulting in high cost. Therefore, JP-A-11-
According to Japanese Patent No. 287118, as a low-cost exhaust flow path control valve that does not require a bearing, a spiral valve body whose outer peripheral portion is seated on an annular valve seat portion of a housing is used, and a valve in the spiral winding axis direction is used. A valve configured to open and close according to the expansion and contraction of the body has also been proposed.

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

[0005]

In the exhaust passage control valve using the spiral valve element as described above, the exhaust pressure corresponds to the set load in the initial state (closed state) of the valve spring (open valve setting). When the pressure rises, the valve body begins to open.
Then, in order to change the valve opening set pressure according to the type of engine, it is necessary to change the set load of the valve spring. Here, in the above-mentioned conventional exhaust passage control valve, the mounting position of the spring bearing with respect to the housing is uniquely determined, and in order to change the valve opening set pressure, valve springs having different spring constants or spring bearings having different dimensions are used. I have no choice but to use. Therefore, the valve spring and the spring bearing are dedicated for each engine type, which causes a cost increase.

In view of the above points, the present invention has an object to provide an exhaust flow passage control valve capable of changing the valve opening set pressure without changing the valve spring or the spring bearing.

[0007]

[Means for Solving the Problems] In order to solve the above problems,
The present invention is provided with 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 closed side, and opens the valve when the exhaust pressure exceeds a predetermined value. In the exhaust passage control valve configured as described above, a spiral valve body having an outer peripheral portion seated on an annular valve seat portion of a housing is used as the valve body, and the valve body in the direction of the spiral winding axis is used. In what is configured to open and close by expansion and contraction of
The spring receiver for the valve spring provided in the housing is composed of a member separate from the housing, and the spring receiver mounting portion extending in the opening / closing direction of the valve body is formed in the housing, and the spring receiver is attached to this mounting portion. Can be freely connected in the open / close direction with overlapping for any length.

According to the present invention, the set length of the valve spring can be changed by changing the overlap length of the spring receiver with respect to the spring receiver mounting portion formed on the housing. Thus, the valve opening set pressure can be changed without changing the valve spring or the spring bearing, and the cost can be reduced.

By the way, as the valve spring, a screw coil spring having a coil-shaped body portion and arm portions at both ends of the body portion is used in place of the compression coil spring as in the conventional example, and both sides around the valve seat portion are used. It is also possible to provide a pair of spring bearings on the housing portion of the housing, engage each arm portion with each spring bearing, and press the valve body toward the closing side via the body portion. In this case, the mounting portion for each spring receiver is composed of a pair of tongue pieces extending in the opening / closing direction of the valve body, which are formed in the housing at intervals in the circumferential direction of the valve seat portion. One piece can be freely joined in the state where it overlaps in the opening and closing direction of the valve body by an arbitrary length.
In this, in the portion of the end of each spring receiver in the closing direction of the valve body located between the tongues, the hypotenuses on both sides obliquely intersecting the inner edges of the tongues are recessed in the opening direction of the valve body. By forming a recessed portion having the above and engaging the respective arm portions with the recessed portion, each arm portion is guided to the oblique sides on both sides of the recessed portion, and is securely positioned in the central portion of the recessed portion. This is advantageous in that the variation of the set load of the valve spring due to the displacement of the engagement position of the arm portion is prevented.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to FIG. 1, reference numeral 1 denotes a silencer provided in an exhaust system of an engine, which has a cylindrical shell 10 and
End walls 11 ₁ and 11 ₂ that close one end and the other end of the shell 10.
The first and second pair of separators 12 ₁ and 12 ₂ are provided in the silencer body constituted by and the space in the body is defined by the first end wall 11 ₁ and the first separator 12 ₁ . 1 silence room 13 ₁
, A second silencing chamber 13 ₂ between the first separator 12 ₁ and the second separator 12 ₂ , a second separator 12 ₂ and the other end wall 1
It is divided into a third silencing room 13 ₃ between 1 ₂ and 1. The silencer 1 further includes an exhaust gas inflow pipe 14 that penetrates the first separator 12 ₁ and the second separator 12 ₂ from the one end wall 11 ₁ to reach the third silencer chamber 13 ₃ , and the other end wall 11 ₂ to the first exhaust wall 14. 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 to 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 that is a bypass valve communicating with ₁ is provided.

A large number of through holes 14a are formed in a portion of the exhaust inflow pipe 14 located inside the second muffling chamber 13 _{2. The} exhaust gas flowing in from the exhaust inflow pipe 14 and the second through holes 14a form a second hole.
Muffler chamber 13 ₂ , first inner pipe 16 ₁ and first muffler chamber 13
₁ to the exhaust outflow pipe 15 so that the expansion silencing effect in the second silencing chamber 13 ₂ and the first silencing chamber 13 ₁ can be obtained. Also, the third silencing chamber 13 of the exhaust inflow pipe 14
_A large number of through holes 14b are also formed in the portion located inside ₃ , so that the resonance silencing effect in the third silencing chamber 13 ₃ can always be obtained.

The exhaust passage control valve 2 is constructed so as to open when the exhaust pressure rises due to the high speed rotation of the engine. When the exhaust passage control valve 2 is opened, the bypass passage from the third silencing chamber 13 ₃ to the first silencing chamber 13 ₁ via the second inner pipe 16 ₂ is opened, and the exhaust inflow pipe 1
The flow path of the exhaust gas from 4 reaches the exhaust outflow pipe 15 through the second silencing chamber 13 ₂ , the first inner pipe 16 ₁ and the first silencing chamber 13 _1, and the third silencing chamber 13 ₂ . There are two systems, that is, a route leading to the exhaust outflow pipe 15 through the bypass passage and the first muffling chamber 13 ₁ , and it is possible to prevent the output of the engine from decreasing due to the increase in exhaust pressure.

As shown in FIGS. 2 to 5, the exhaust passage control valve 2 includes a housing 20 through which exhaust gas from the second inner pipe 16 ₂ flows, and a valve body 2 mounted on the housing 20.
1 and a valve spring 22 that biases the valve body 21 toward 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 (valve closed state). Open the valve.

The housing 20 includes a second inner pipe 16
It is composed of a pipe-shaped member fitted in ₂ . And
The tip of the housing 20 protruding into the first muffling chamber 13 ₁ is expanded in diameter to form a flange, and the flange forms an annular valve seat portion 20a.

The valve body 21 is composed of a spiral valve body in which the outer peripheral portion is seated on the valve seat portion 20a, and the outer peripheral side and the inner peripheral side of the spiral are overlapped with each other in a closed state. Is opened when the valve body 21 extends in the direction of the spiral winding axis. 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 ₂ is combined in a double spiral shape, and both spiral plates 21 ₁ and 21 ₂ are combined.
The semi-circular central portion of the above is butt-welded to the semi-circular chord 21a to form the spiral valve body 21. Then, the outer peripheral portions of both the 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 positions around the valve seat portion 20a are caulked to form the spiral plates 21 ₁ and 21 2. The outer peripheral portion of ₂ is fixed to the valve seat portion 20a.

The valve spring 22 includes a coil-shaped body portion 22a,
It is composed of a torsion coil spring having arm portions 22b and 22b at both ends of the body portion 22a. And the valve seat portion 20a
A pair of first spring bearings 23, 23 are provided in the housing 20 on both sides of the circumference of the housing, and both arm portions 22b, 22b of the valve spring 22 are provided in the first spring bearings 23, 23 in the longitudinal direction of each arm portion 22b. The second spring bearing 24 is provided at the center of the valve body 21 so that the second spring bearing 24 supports the body portion 22a of the valve spring 22. Thus, the valve body 2
1 is pressed toward the closing side via the body portion 22a by the bending reaction force of the arm portions 22b, 22b of the valve spring 22.

By the way, the valve spring 22 has a low spring constant in order to open and close the valve at once when the exhaust pressure reaches a predetermined value and close it at once when the exhaust pressure falls below the predetermined value. Will be needed. Here, according to the present embodiment, the valve spring 22 is extended by the expansion of the valve body 21 toward the opening side.
As the body portion 22a of the is displaced toward 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,
After all, the spring constant becomes low. Further, along with the movement of the valve body 21, sliding friction of the arm portion 22b with respect to the first spring receiver 23 and friction between the coiled wire rods of the body portion 22a are generated, and a vibration damping action due to the friction is obtained. Opening and closing vibrations are effectively prevented.

Further, in this embodiment, both first spring supports 2
3, 23 are provided so as to be in a line-symmetrical relationship with respect to the predetermined first diameter line a of the valve body 21, and the valve spring 22 of the valve spring 22 is viewed from the winding axis direction (opening and closing direction) of the spiral of the valve body 21. The second portion of the valve body 21 in which each arm portion 22b is orthogonal to the first diameter line a
The center line c of the body 22a and the first diameter line a of the body 22a of the valve spring 22 are predetermined by the second spring receiver 24 so that the body 22a of the valve spring 22 obliquely intersects with the diameter line b. It is supported in a state where it crosses at an angle. As shown in phantom lines in FIG. 5, the housing 20 on one side and the other side around the valve seat portion 20a are offset to one side and the other side in the longitudinal direction of the body portion 22a, so that the body portion 22a of the valve spring 22 is offset. A pair of first spring bearings 23 ', 23' along a plane parallel to the center line c of the
And each arm portion 2 of the valve spring 22 is provided in each first spring receiver 23 '.
It may be possible to engage the 2b in an orthogonal state, but with this, the amount of protrusion of the first spring bearing 23 'outward in the radial direction with respect to the valve seat portion 20a becomes large, and the valve becomes large.
On the other hand, in the present embodiment, the first spring receiver 23
The amount of outward protrusion of the valve seat portion 20a in the radial direction is reduced, which is advantageous in achieving a smaller valve.

Further, each first spring receiver 23 is provided in the housing 2
It is composed of a member separate from 0, and each first spring receiver 23 is coupled to a mounting portion 25 for each first spring receiver 23 formed in the housing 20. The mounting portion 25 is a pair of tongue pieces 25 a, 2 formed in the housing 20 with a space in the circumferential direction of the valve seat portion 20 a and extending in the opening / closing direction of the valve body 21.
5a. Then, each first spring receiver 23 is formed so as to be in contact with both the tongue pieces 25a, 25a.
The first spring supports 23 are welded to the 5a and 25a while being overlapped with each other in the opening / closing direction of the valve body 21 by an arbitrary length. When the overlap length of the first spring receiver 23 with respect to the mounting portion 25 composed of both 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, the mounting portion 2
It can be obtained only by changing the overlap length of the first spring receiver 23 with respect to No. 5, so that the parts can be shared and the cost can be reduced.

The portion of each of the first spring bearings 23 located between the tongues 25a, 25a on the edge of the valve body 21 in the closing direction is
A recessed portion 23a that is recessed in the opening direction of the valve body 21 is formed, and each arm portion 22b of the valve spring 22 is formed in the recessed portion 23a.
Are engaged. Here, the recessed portion 23a is formed by the tongue pieces 2
Hypotenuses 23b, 2 on both sides obliquely intersecting the inner edges of 5a, 25a
3b is provided. Therefore, each arm portion 22 of the valve spring 22
b is guided by the oblique side 23b and securely engages with the central portion of the recessed portion 23a, so that the variation of the set load of the valve spring 22 due to the shift of the engagement position of the arm portion 22b is prevented.

The second spring receiver 24 is the body portion 2 of the valve spring 22.
It is formed in a trough-shaped recessed shape for receiving 2a, and the outer peripheral surface of the body portion 22a is seated on the second spring receiver 24. The second spring receiver is composed of a rod-shaped member that is inserted into the body portion 22a and a support member on the side of the valve body 21 that supports the rod-shaped member, and the rod-shaped member is inserted into the body portion 22 at the time of assembly. It is conceivable to connect the member to the support member, but this requires a lot of labor for the assembling work. On the other hand, in the case of the present embodiment, it is only necessary to seat the body portion 22a on the second spring receiver 24, and the assembling work becomes easy. But body 2
If the seat 2a is simply seated on the recessed second spring receiver 24, the body portion 22a is opened and closed by the valve body 21 when the valve body 21 is opened and closed.
Tilt in the opening and closing direction of the
May shift in the lateral direction, which is the extending direction of the arm portion 22b. Therefore, in the present embodiment, both ends of the second spring receiver 24 are provided with tongue-shaped stoppers 24a that prevent the tilting of the body portion 22a from coming into contact with the end surface of the body portion 22a. It is designed so that it can be prevented from standing upside down. Further, the recess depth h of the second spring receiver 24 (see FIG. 7)
Is 1/2 or more of the diameter of the body portion 22a. According to this, even if the body portion 22a is overturned while rolling over,
As long as the whole a does not float from the second spring bearing 24, the body portion 22a does not fall off from the second spring bearing 24, and
2a can be stably supported by the second spring receiver 24. The second
Notches 24b for avoiding interference with each arm 22b are formed at both side edges of the spring receiver 24.

Further, in the housing 20, there is shown a valve opening stopper 26 for restricting the extension of the valve body 21 toward the opening side by a predetermined amount or more by contacting the body portion 22a of the valve spring 22, and FIGS. 6 and 7. As described above, the valve closing stopper 27 for preventing the valve body 21 from bending so as to be recessed toward the closing side by contacting with the central portion of the valve body 21 is provided, and an excessive stress is applied to the valve body 21. 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 receivers 23, 23, and the first spring receivers 23, 23 and the valve opening stopper 26 are formed as an integral part.

The valve closing stopper 27 is constituted by a plate-like member fixed in the housing 20 so as to be along a plane orthogonal to the plane including the valve seat portion 20a, that is, a plane parallel to the flow line of the exhaust gas. Therefore, it is possible to prevent the flow resistance of the exhaust gas from increasing due to the valve closing stopper 27. Then, the abutment portion 2 facing the central portion of the valve body 21 is attached to the valve closing stopper 27.
7a is formed so as to project more toward the open side of the valve body 21 than the surface including the valve seat portion 20a, and the winding portions on the outer peripheral side and the inner peripheral side of the valve body 21 are in a closed state in which they overlap each other. When the valve body 2
The central portion of 1 contacts the contact portion 27a.
The pair of spiral plates 21 ₁ and 21 ₂ forming the valve body 21 are
As described above, the two spiral plates 21 ₁ and 21 ₂ are joined to each other at the semi-circular central chord 21a, so that the joining portion is not separated by the impact received from the valve closing stopper 27.
A valve closing stopper 27 is provided along the surface intersecting the string 21a, which is the joining point.

FIG. 9 shows an exhaust passage control valve 2 according to a second embodiment. The same members as those in the first embodiment are designated by the same reference numerals. The main difference from the first embodiment is that the housing 20 is provided with a dish-shaped first spring bearing 23 facing the opening side of the valve body 21, and the first spring bearing 23 and the central portion of the valve body 21 are provided. That is, the valve spring 22 is configured by the compression coil spring that is interposed between the second spring receiver 24 and the second spring receiver 24. The housing 20 has a valve seat portion 20a.
A tongue-shaped attachment portion 25 extending in the opening / closing direction of the valve body 21 is formed at a plurality of locations around the. Then, the first spring receiver 23 is welded to each mounting portion 25 in a state in which the leg pieces 23c formed at a plurality of locations around the mounting portion 25 overlap in the opening / closing direction of the valve body 21 by an arbitrary length. ing. Thus, also in the second embodiment, the exhaust passage control valve 2 having a different valve opening set pressure does not change the leg spring portion 23c with respect to the mounting portion 25 without changing the valve spring 22 and the first spring receiver 23. It can be obtained only by changing the wrap length, and parts can be shared.

Although the embodiment in which the present invention is applied to the exhaust passage control valve 2 formed of the bypass valve provided in the silencer 1 has been described above, the exhaust passage control valve provided in other parts of the exhaust system of the engine is also described. The present invention can be similarly applied.

[0026]

As is apparent from the above description, according to the present invention, an exhaust passage control valve having a different valve opening set pressure can be attached to a spring bearing mounting portion without changing a valve spring or a spring bearing. It can be obtained only by changing the overlap length of the spring bearing with respect to the above, and the parts can be commonly used, and the cost can be reduced.

[Brief description of drawings]

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

FIG. 2 is an enlarged front view of the exhaust passage control valve seen from the direction of arrow II in FIG.

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

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

5 is a sectional view taken along the line V-V of FIG.

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

7 is a sectional view taken along the line VII-VII in FIG.

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

FIG. 9 is a sectional view of a second embodiment of the exhaust flow control valve.

[Explanation of symbols]

2 Exhaust flow control valve 20 housing 20a valve seat 21 valve 22 valve spring 23 1st spring bearing (housing side spring bearing) 23a recessed portion 23b hypotenuse 25 Mounting part for spring receiver 25a tongue

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masamichi Fujishiro 1-4-1 Chuo, Wako-shi, Saitama Inside the Honda R & D Co., Ltd. (72) Inventor Jun Fukasawa 1069-1 Toyatsuka-cho, Isesaki-shi, Gunma Sankei Giken Industrial Co., Ltd. Gunma Manufacturing Technology Center (56) Reference JP-A-11-287118 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F01N 1/08 F01N 7/08

Claims (2)

(57) [Claims] 1. A housing provided with a housing through which exhaust gas of an engine circulates, a valve body mounted on the housing, and a valve spring for urging the valve body toward a closed side, and opened when exhaust pressure exceeds a predetermined value. An exhaust passage control valve that is adapted to be valved, wherein 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 valve in the spiral winding axis direction is used. In a structure in which the body is opened and closed by expansion and contraction, the spring bearing for the valve spring provided in the housing is composed of a member separate from the housing, and the housing has a spring bearing for extending in the opening and closing direction of the valve body. An exhaust passage control valve, characterized in that a mounting portion is formed, and a spring bearing can be freely coupled to the mounting portion while being overlapped in the opening / closing direction of the valve body by an arbitrary length. 2. The exhaust passage control valve according to claim 1, wherein the valve spring is a torsion coil spring having a coil-shaped body portion and arm portions at both ends of the body portion, and a valve seat. A pair of spring bearings are provided on the housing portions on both sides of the periphery of the housing, each arm portion is engaged with each spring bearing, and the valve body is pressed toward the closing side through the body portion. The mounting part is composed of a pair of tongues formed in the housing at intervals in the circumferential direction of the valve seat and extending in the opening / closing direction of the valve body, and each spring receiver is formed so as to contact both tongues. In addition, each of the spring receivers has a hypotenuse at both ends of the valve body in the closing direction, which is located between the tongues and is recessed in the opening direction of the valve body so as to be oblique to the inner edges of the tongues. The exhaust flow path control according to claim 1, wherein a recessed portion is formed, and each of the arm portions is engaged with the recessed portion. Valve.