JP2007263057A - Exhaust gas channel control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas channel control valve which inhibits run-out and oscillation of a valve element, and thereby hardly generates noise (strike noise) due to contact of the valve element and a housing. <P>SOLUTION: The exhaust channel control valve 10 is provided with: a housing 11 including an exhaust gas channel; the valve element 30 opening and closing the exhaust gas channel; and a pair of torsion coil springs 41, 42. The torsion coil springs 41, 42 are arranged in an opposite side of the housing of the valve element 30. The torsion coil springs 41, 42 includes coil parts 41a, 52a having spring wire wound in a coil shape and arms provided on both ends of the coil, and winding directions of the coil parts 41a, 42a are mutually opposite, and wind axis lines are roughly in parallel with a valve element surface. The torsion coil springs 41, 42 are provided symmetrically in left and right. When the coil parts 41a, 42a are bent in relation to the arms, the valve element is energized to a close side by repulsion force thereof. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an exhaust passage control valve disposed in an exhaust passage of an internal combustion engine (for example, an automobile engine). Specifically, the present invention relates to an exhaust passage control valve that opens when the pressure of exhaust gas flowing through the exhaust passage becomes a predetermined value or more.

An exhaust passage control valve that opens when the pressure of the exhaust gas exceeds a predetermined value is disposed in the exhaust passage of the internal combustion engine. For example, in the case of an automobile engine, a bypass passage for reducing ventilation resistance is provided in the silencer of the exhaust device, and an exhaust passage control valve is disposed in the bypass passage. When the exhaust gas pressure is high, the exhaust passage control valve opens to increase the engine output. When the pressure of the exhaust gas is low, the exhaust flow path control valve is closed to improve the silencing performance.
Conventionally, a butterfly valve has been used for this type of exhaust passage control valve. In the butterfly valve, the spring load increases in proportion to the valve opening. Therefore, even if the pressure of the exhaust gas reaches a predetermined value and the butterfly valve starts to open, the pressure of the exhaust gas needs to be considerably higher than the predetermined value in order to fully open the butterfly valve. Therefore, an exhaust flow control valve is proposed that allows the valve opening load to increase gradually with respect to the increase in the valve opening, opens quickly when the exhaust gas pressure exceeds a predetermined value, and obtains a sufficient valve opening. (Japanese Patent No. 3326746).

The exhaust flow path control valve includes a housing through which exhaust gas of the engine flows, a valve body attached to the housing, and a torsion coil spring that biases the valve body toward the closing side. The torsion coil spring is disposed on the opposite side of the valve body from the housing. The coil portion of the torsion coil spring is supported by a spring receiving portion provided in the approximate center of the valve body. The winding axis of the coil portion is substantially parallel to the valve body surface. The arm of the torsion coil spring is supported by the spring mounting member. The arm of the torsion coil spring is slidable in the axial direction with respect to the spring mounting member. When these parts are assembled, the arm of the torsion coil spring is rotationally displaced. When the arm is rotationally displaced, the coil portion is bent with respect to the arm. The valve element is biased toward the closing side by the bending reaction force of the coil portion.
In this exhaust flow path control valve, when the valve element is shifted to the open side, the arm of the torsion coil spring slides in the axial direction with respect to the spring mounting member. When the arm slides with respect to the spring mounting member, the distance from the center of the coil portion to the arm mounting position (effective length of the arm) changes. When the effective length of the arm is increased, the bending reaction force of the coil portion is also reduced. Since this exhaust flow control valve is set so that the effective length of the arm becomes longer as the valve element moves to the opening side, the increase in the valve opening load with respect to the increase in the valve opening can be kept low. it can. As a result, when the pressure of the exhaust gas exceeds a predetermined value, it is fully opened quickly, and a sufficient valve opening can be obtained.

Japanese Patent No. 3326746

  In the exhaust flow control valve of Patent Document 1, the coil portion of the torsion coil spring is held by the spring receiving portion in a state where a certain amount of movement is allowed, and when the contact load is increased by the action of an external force, the coil portion is bent. The arm is rotationally displaced. The torsion coil spring is not a left-right symmetrical shape because the spring wire is wound in either the left or right winding direction. When the arm is rotationally displaced, the load on the left and right arm support points (two-point support state) increases, and a deviation occurs in the magnitude and direction of the load, which easily distorts the coil portion. The present inventors have confirmed the movement of the torsion coil spring to rotate around the axis perpendicular to the winding axis (movement of the valve body rotating horizontally) as the valve opening increases. In this way, if the torsion coil spring is distorted and the coil portion moves in an unnecessary manner in the lateral direction, the valve body becomes unstable, causing rattling or abnormal noise (sounding sound).

  An object of the present invention is to suppress the lateral shaking and swinging of the valve body due to unnecessary movement of the torsion coil spring, and it is difficult for abnormal noise (sounding sound) due to contact between the valve body and the housing to occur. An object is to provide an exhaust passage control valve.

The first exhaust flow path control valve of the present invention includes a housing having an exhaust flow path through which exhaust gas from the internal combustion engine flows, a valve body that opens and closes the exhaust flow path of the housing, and a torsion coil spring. The torsion coil spring includes a coil portion having a winding axis substantially parallel to the valve body surface and arms provided at both ends of the coil portion. The arm of the torsion coil spring is supported by a spring mounting portion provided in the housing, while the coil portion is supported by the valve body. When the coil portion is bent with respect to the arm, the valve body is biased toward the closing side by the reaction force. The exhaust flow path control valve includes a plurality of the torsion coil springs. These torsion coil springs are arranged symmetrically about a predetermined center line on the valve body surface as an axis of symmetry.
This exhaust flow path control valve includes a plurality of torsion coil springs, and these are arranged symmetrically with respect to a predetermined center line on the valve body surface. For example, a right-handed torsion coil spring and a left-handed torsion coil spring are arranged symmetrically. For this reason, even if the torsion coil spring is distorted as the valve opening increases, the load deviation exerted on the support point (spring mounting portion) is offset. In addition, the force that the torsion coil spring tries to rotate the valve element also acts in the opposite direction, and is canceled out. Therefore, the valve body is hardly shaken regardless of the valve opening (stroke position), and the movement of the valve body is stabilized. Thereby, generation | occurrence | production of the noise (hit) by contact with a valve body and a housing is prevented.

Here, “substantially parallel to the valve body surface” means that the valve body is substantially parallel to the surface that closes the exhaust passage of the housing.
The term “provided with a plurality of torsion coil springs” as used in the present invention includes substantially providing a plurality of torsion coil springs. For example, a plurality of torsion coil springs having different winding directions may be connected from one spring element wire.
It is preferable to provide an even number of torsion coil springs.

The second exhaust flow path control valve of the present invention includes a housing having an exhaust flow path through which exhaust gas from the internal combustion engine flows, a valve body that opens and closes the exhaust flow path of the housing, and a torsion coil spring. The torsion coil spring includes a coil portion having a winding axis substantially parallel to the valve body surface and arms provided at both ends of the coil portion. The arm of the torsion coil spring is supported by a spring mounting portion provided in the housing, while the coil portion is supported by the valve body. When the coil portion is bent with respect to the arm, the valve body is biased toward the closing side by the reaction force. And the means which controls that the coil part of a torsion coil spring deform | transforms in a winding axis direction is provided.
In this exhaust flow path control valve, the coil portion of the torsion coil spring is restricted from being deformed in the winding axis direction. For this reason, generation | occurrence | production of the force which tries to rotate the valve body by a torsion coil spring is suppressed. As a result, the movement of the valve body is stabilized, and abnormal noise (sounding sound) due to contact between the valve body and the housing is prevented.

The main features of the techniques described in the following examples are listed.
(Mode 1) An arm of a torsion coil spring is supported by a spring mounting portion so as to be slidable in the longitudinal direction of the arm. The support position of the arm is adjusted so that the effective length of the arm becomes longer as the valve body shifts to the opening side.
(Form 2) The coil part is arrange | positioned in the approximate center of the valve body.
(Mode 3) Two torsion coil springs are arranged. The winding direction of one torsion coil spring of the two torsion coil springs is opposite to the winding direction of the other torsion coil spring. The two torsion coil springs are arranged symmetrically with respect to the center line of the valve body.

  Next, the exhaust passage control valve of the first embodiment will be described in detail with reference to the accompanying drawings. As shown in FIGS. 1 and 2, the exhaust flow path control valve includes a cylindrical housing 11. An exhaust gas flow path (exhaust pipe) through which gas discharged from an engine such as an automobile flows is connected to the lower end (exhaust pipe connection port) of the housing 11. The exhaust gas flowing through the exhaust gas passage is guided into the housing 11. The upper end (exhaust port) of the housing 11 is closed by a valve body 30 so as to be opened and closed.

  The upper end (exhaust port) of the housing 11 is expanded in diameter to form a flange 11a. A metal mesh sheet 20 is placed on the flange 11a. A welded portion 20b extending downward from the seal portion 20a of the metal mesh sheet 20 and an enlarged diameter portion 11b of the housing 11 are fixed by spot welding or the like. The metal mesh sheet 20 is a mesh formed by braiding metal wires, and has a certain degree of elasticity. As the metal mesh sheet, for example, a knitted stainless steel wire can be used. In addition, a sintered porous metal plate, a composite of graphite and metal wire, a sheet made of ceramic fibers, or the like can be used. When the valve body 30 closes the upper end (exhaust port) of the housing 11, the metal mesh sheet 20 comes into contact with the sealing surface of the housing 11. Since the metal mesh sheet 20 has elasticity, the metal mesh sheet 20 improves the sealing performance and prevents the sound of the valve body 30 and the housing 11 from being generated when the valve body 30 is closed. . Spring mounting portions 12 and 13 are provided upright at opposing positions on the outer periphery of the housing 11.

  The valve body 30 is a plate molded product manufactured by press molding or the like. The valve body 30 has a spring receiving portion 31 formed at the center thereof and a pair of grooves 32 and 33 formed at opposing positions on the outer periphery thereof. The spring receiving portion 31 is formed in a recess on the housing side. The spring receiving portion 31 has a shape that can accommodate and hold the lower half of the coil portion in a state in which a pair of torsion coil springs 41 and 42 described below are arranged in series.

  Torsion coil springs 41 and 42 having different winding directions are arranged on the side opposite to the housing of the valve body 30. The torsion coil spring 41 (42) includes a coil part 41a (42a) obtained by winding a spring element in a coil shape, an arm 41b (42b) formed at one end of the coil part 41a (42a), and a coil part 41a ( 42a) and an arm 41c (42c) formed at the other end. The torsion coil springs 41 and 42 are arranged symmetrically with respect to the center line of the valve body 30 as an axis of symmetry, and the two coil portions 41 a and 42 a are held by the spring receiving portion 31 of the valve body 30. In a state where the outer peripheral lower portions of the coil portions 41a and 42a are supported by the spring receiving portion 31, the winding axis of the coil portions 41a and 42a is substantially parallel to the valve body 30 (the upper surface of the valve body 30). The torsion coil springs 41 and 42 have the same spring specifications other than the winding direction.

One arm 41 b (42 b) of the torsion coil spring 41 (42) is inserted into a mounting hole 14 b (15 b) formed in the spring mounting portion 12, and the other arm 41 c (42 c) is connected to the spring mounting portion 13. It is inserted into the formed mounting hole 14c (15c). The arms 41b, 41c, 42b, 42c are supported so as to be slidable in the longitudinal direction with respect to the respective mounting holes 14b, 14c, 15b, 15c.
The spring mounting portions 12 and 13 include guide portions 12a and 13a that guide the valve body 30, and locking portions 12b and 13b that are wider than the guide portions 12a and 13a.
The valve body 30 moves from the valve closing state shown in FIG. 3A to the valve opening state shown in FIG. 3B with the grooves 32 and 33 being guided by the guide portions 12a and 13a. In the valve open state, the upper surface of the valve body 30 comes into contact with the locking portions 12b and 13b, and the further movement of the valve body 30 in the valve opening direction is restricted.

When the torsion coil springs 41 and 42 are attached to the spring attachment portions 12 and 13, the arms 41b, 41c, 42b and 42c are bent by a predetermined amount in the rotation direction, and the valve reaction is caused by the bending reaction force of the coil portions 41a and 42a. The body 30 is biased toward the closing side. That is, the torsion coil springs 41 and 42 can urge the valve body 30 with a predetermined set load. Thus, the valve body 30 can be opened when a desired exhaust gas pressure is reached. In FIG. 3A, the initial position before mounting (free state) of the arms 41b and 41c is indicated by an imaginary line.
In addition, when the characteristics of the torsion coil springs 41 and 42 have manufacturing variations, it is preferable to have a structure in which the initial rotation amount of each arm 41b to 42c can be adjusted. Specifically, a plurality of mounting holes 14b to 15c are formed in the vertical direction at predetermined intervals so that the insertion positions of the arms 41b to 42c can be selected. Further, the mounting portions 12 and 13 are configured separately from the housing 11, and the mounting positions of the mounting portions 12 and 13 on the housing 11 are determined while measuring the pressing force P acting on the valve body 30 from the torsion coil springs 41 and 42. The method may be used.

  In the exhaust flow path control valve described above, when the pressure of the exhaust gas flowing in the housing 11 is lower than a predetermined value, the valve body 30 closes the exhaust port of the housing 11 (see FIG. 3A). When the pressure P ′ of the exhaust gas becomes higher than a predetermined value, the valve body 30 opens the exhaust port of the housing 11 (see FIG. 3B). When the valve body 30 moves in the opening direction, the arms 41b, 41c, 42b, 42c of the torsion coil springs 41, 42 are bent in the rotational direction with respect to the coil portions 41a, 42a and slid with respect to the spring mounting portion 12, The load acting radius of 41b, 41c, 42b, 42c becomes longer. For this reason, the increase rate of the valve opening load can be kept low with respect to the increase in the movement amount (valve opening degree) of the valve body. Here, the load acting radius refers to the distance from the coil center to the mounting position.

  Now, when the torsion coil spring 41 alone is viewed, a contact load is applied upward to the coil portion 41a supported by the spring receiving portion 31, and the spring mounting portion 12, according to the rotational position of the arms 41b and 41c. There is a load deviation at 13 arm support points (hole edges of the mounting holes 14b and 14c). For this reason, the rotational force around the axis orthogonal to the winding axis acts on the coil portion 41a, and the coil portion 41a tries to rotate the valve body 30 substantially horizontally. Similarly, a rotational force in the opposite direction acts on the coil portion 42 a of the torsion coil spring 42. In the exhaust flow path control valve of the present embodiment, the torsion coil springs 41 and 42 having different winding directions are disposed symmetrically with respect to the central axis, so that the above-described rotational force (load deviation) is substantially canceled out. be able to.

FIG. 4 is a schematic diagram for explaining the rotational force generated by the contact load acting on the torsion coil springs 41 and 42, and FIG. 5 shows the valve opening degree (lift amount) and the valve rotation angle (rotation) of the exhaust flow control valve described above. It is a graph of the measurement result which shows the relationship of quantity. In FIG. 5, as a comparative example, a measurement result of an exhaust passage control valve (see FIG. 10) configured with a single torsion coil spring, and a measurement result of using the single torsion coil spring with increased rigidity Is also shown. As is clear from FIG. 5, the exhaust flow control valve of the present embodiment has a low rate of increase in the valve rotation angle with respect to the valve opening (slightly negative), and that of the comparative example. In comparison, it was confirmed that the valve rotation amount can be reduced by about 90% at the maximum.
In addition, it was found that the maximum swing angle of the valve body when the valve body is moved is suppressed to be smaller in the exhaust flow path control valve of the present embodiment than in the comparative example. If the oscillating angle is large and the valve body is unstable, the exhaust gas pressure escapes and does not act effectively on the valve body, so that rapid movement of the valve body is hindered. In this respect, the exhaust passage control valve of this embodiment has good valve body movement characteristics and can be expected to operate stably.
Furthermore, it was found that the frequency and volume of hitting sound when external vibration was input were kept low.

As is apparent from the above description, in the exhaust flow control valve of the first embodiment, the torsion coil springs 41 and 42 are arranged symmetrically, so that the valve body 30 is not easily shaken regardless of the valve opening degree. The movement becomes stable. Therefore, the contact between the valve body 30 and the housing 11 can be suppressed to prevent the generation of abnormal noise (sounding sound).
In the present embodiment, since the spring receiving portion 31 for receiving the torsion coil springs 41 and 42 is provided on the valve body 30, the number of parts can be reduced and the manufacturing can be performed at low cost.
Furthermore, since the torsion coil springs 41 and 42 are disposed on the opposite side of the valve body 30 from the housing, the torsion coil springs 41 and 42 are prevented from being directly exposed to high-temperature exhaust gas, and the heat settling of the springs is suppressed. The

Hereinafter, an exhaust passage control valve according to another embodiment will be described with reference to schematic views.
(Other Embodiment 1) FIG. 6 is a diagram for explaining another example of a torsion coil spring. The torsion coil spring 51 shown in the figure is a double torsion type torsion coil spring formed from one spring element wire. The torsion coil spring 51 is formed symmetrically. Therefore, the number of parts can be reduced by replacing the torsion coil spring 51 with the torsion coil springs 41 and 42 described above. The exhaust flow path control valve equipped with the torsion coil spring 51 can obtain the same effects as the exhaust flow path control valve described above.

(Other Embodiment 2) FIG. 7 shows an example in which three torsion coil springs 61, 62, 63 are arranged on three sides of an equilateral triangle. In this case, there are six arm support points, and there are three coil support portions where the valve body receives a pressing force (biasing force) from the coil portion. Since these arm support points and coil support portions are both equally distributed in the circumferential direction, the valve element is operated more in comparison with the exhaust flow control valve using two torsion coil springs. Is stable. If the number of torsion coil springs is an odd number, the left-right symmetry is not achieved. However, if the number of torsion coil springs is increased, the point of action of the load is dispersed and the load deviation can be reduced.

(Other Example 3) In order to suppress the lateral shaking and swinging of the valve body and stabilize the operation, the displacement of the torsion coil spring in the winding axis direction is restricted to prevent the coil portion from buckling or distorting. It is possible. FIG. 8 shows an exhaust flow path control valve provided with a single torsion coil spring 71, and a rectangular frame (spring guide) 73 is provided upright on the upper surface of the valve body 72. The coil portion of the torsion coil spring 71 is surrounded by a frame 73 around the circumference. Since the inner surface of the frame body 73 is in contact with both end portions of the torsion coil spring 71, displacement in the winding axis direction is restricted, so that it is effective that the coil portion is distorted as the valve body opens and closes. Can be prevented.
As shown in FIG. 9, if the gap is not set between the inner wall surface of the spring receiving portion 81 provided on the valve body 80 and both end portions of the torsion coil spring 82, the coil portion is buckled or distorted. It is possible to prevent the lateral displacement of the valve body 80 and to stabilize the operation.

As mentioned above, although the specific example of this invention was demonstrated in detail, this is only an illustration and does not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
In addition, the technical elements described in the present specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

The perspective view at the time of valve closing of the exhaust passage control valve concerning an embodiment. The disassembled perspective view of the exhaust flow path control valve which concerns on embodiment. It is a front view of the exhaust-flow-path control valve which concerns on embodiment, (a) shows the time of valve closing, (b) shows the time of valve opening. The schematic diagram explaining the contact load and rotational force which act on a torsion coil spring. The diagram which shows the relationship between the valve opening degree of an exhaust flow path control valve, and a valve rotation angle. The figure explaining the torsion coil spring which concerns on another example. The figure explaining the torsion coil spring which concerns on another example. The figure explaining the torsion coil spring which concerns on another example. The figure explaining the torsion coil spring which concerns on another example. The perspective view at the time of valve closing of the exhaust-flow-path control valve which concerns on a comparative example.

Explanation of symbols

11: Housing 12, 13: Spring mounting portion 30: Valve body 41, 42: Torsion coil spring 41a, 42a: Coil portion 41b, 41c, 42b, 42c: Arm

Claims (2)

A housing having an exhaust passage through which exhaust gas from the internal combustion engine flows, a valve body that opens and closes the exhaust passage of the housing, a spring mounting portion provided in the housing, and a winding axis that is substantially parallel to the valve body surface A coil part and a torsion coil spring comprising arms provided at both ends of the coil part, and the valve part is closed by bending of the coil part supported by the valve part with respect to the arm supported by the spring mounting part. In the exhaust flow path control valve biased to the side,
An exhaust flow path control valve comprising a plurality of torsion coil springs, wherein the torsion coil springs are arranged symmetrically about a predetermined center line on the valve body surface as an axis of symmetry. A housing having an exhaust passage through which exhaust gas from the internal combustion engine flows, a valve body that opens and closes the exhaust passage of the housing, a spring mounting portion provided in the housing, and a winding axis that is substantially parallel to the valve body surface A coil part and a torsion coil spring comprising arms provided at both ends of the coil part, and the valve part is closed by bending of the coil part supported by the valve part with respect to the arm supported by the spring mounting part. In the exhaust flow path control valve biased to the side,
An exhaust passage control valve, further comprising means for restricting deformation of the coil portion of the torsion coil spring in the winding axis direction.

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