JP2011149346A - Valve device for muffler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a valve opening of a plate-like valve dealing with exhaust pressure of exhaust gas have nonlinear characteristics, and to still more increase a circulation flow rate in a state that the plate-like valve opens, while maintaining miniaturization of the whole device. <P>SOLUTION: A valve device for a muffler includes: a base member 42 having a valve hole 40 through which the exhaust gas circulates and a tilting part 42b; a plate-like valve 44 opening and closing the valve hole 40; and a leaf spring 46 biasing the plate-like valve 44 in a direction where the valve closes. The leaf spring 46 is held in a flexure state between a first holding part 52a provided on one side of the valve hole 40 of the base member 42 and a second holding part 52b provided on the tilting part 42b, and is provided abutting the plate-like valve 44 between the first holding part 52a and the second holding part 52b. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a silencer valve device provided, for example, in an exhaust system of a vehicle engine. More specifically, the present invention relates to a valve opening state from a closed state when the exhaust pressure of exhaust gas in the silencer rises to a predetermined pressure. The present invention relates to a silencer valve device that switches to

  In general, in order to improve the performance at the time of acceleration driving and high speed driving in a vehicle, it is required to ensure the output of the high speed rotation region of the engine, and the quietness (quietness at idling or low speed driving) Therefore, it is required to reduce the exhaust noise in order to ensure the property. That is, it is required to reduce exhaust noise at least in the low-speed rotation region of the engine while sufficiently ensuring the output in the high-speed rotation region of the engine.

  It is known that engine output and exhaust noise are greatly affected by the cross-sectional area of an exhaust passage constituting an exhaust system of a vehicle engine. That is, if the cross-sectional area of the exhaust passage is increased, the engine resistance can be sufficiently ensured by reducing the exhaust resistance, while the exhaust noise is increased by reducing the exhaust resistance, whereas the exhaust passage is opposite to this. If the cross sectional area of the engine is reduced, the exhaust noise can be reduced by increasing the exhaust resistance, but the engine output is reduced by increasing the exhaust resistance.

  For this reason, some silencers provided in the exhaust system of an engine are provided with a bypass passage capable of changing the passage cross-sectional area in the exhaust passage. A valve device is disposed in the bypass passage, and a configuration is adopted in which the cross-sectional area of the exhaust passage is adjusted by opening and closing the valve body of the valve device (see, for example, Patent Document 1).

  In addition, as a valve device that adjusts the cross-sectional area of the exhaust passage by providing such a bypass passage, for example, in Patent Document 2, a bent portion is formed at both side edges of a predetermined range from the tip of the plate valve. Disclosed is a silencer valve device capable of suppressing resonance by increasing rigidity. Further, Patent Document 3 discloses that a valve body portion of a plate-like valve is bent with respect to a base end portion. And the valve apparatus for silencers which can change urging | biasing force easily by attaching to a valve seat part in the direction which reduces the bending is disclosed.

Japanese Patent No. 3430011 JP 2004-124904 A JP 2006-63935 A

  By the way, in the prior art, if it is attempted to increase the flow rate of exhaust gas by increasing the valve opening degree when the plate-like valve of the silencer valve device is opened, the entire device becomes larger and the manufacturing cost increases. There is a problem of doing.

  That is, in the valve device in the prior art, if the valve body portion of the plate-shaped valve formed in a flat plate is bent away from the valve seat portion, the exhaust pressure of the exhaust gas and the valve opening of the plate valve There is a problem that a large flow rate cannot be secured in the actual vehicle exhaust pressure region.

  In other words, in the conventional valve device, the flow rate characteristic of the exhaust gas with respect to the exhaust pressure is determined based on the linear spring characteristic set by the combination of the plate valve and the leaf spring. For this reason, in the valve device in the prior art, in order to achieve high performance that further increases the flow rate of the exhaust gas with respect to the exhaust pressure, each spring characteristic of the plate valve and the leaf spring is set low ( It is conceivable to set a small spring constant), but such setting may cause resonance, and the entire valve device has to be enlarged in order to ensure a large flow rate in the actual vehicle exhaust pressure region ( With the spring constants of the plate valve and leaf spring as they are, the flow rate is secured while suppressing resonance by widening the dimension in the width direction perpendicular to the axis of the valve hole, plate valve or leaf spring), and the manufacturing cost is reduced Soaring.

  For example, in the valve devices disclosed in Patent Documents 2 and 3, when the plate-like valve moves away from the seating portion and gradually moves in the valve opening direction, the contact position of the leaf spring with the plate-like valve is plate-like. The moment (pressing force) in the valve closing direction in which the leaf spring acts on the plate-like valve decreases as the plate-like valve moves toward the valve opening direction and moves toward the valve opening direction. Therefore, in the valve devices disclosed in Patent Documents 2 and 3, the exhaust pressure (the urging force in the valve closing direction by the leaf spring) and the flow rate of the exhaust gas flowing through the valve hole (the valve opening of the valve body of the plate-like valve) Strictly speaking, the non-linear characteristic is due to the displacement of the contact position.

  However, such a decrease in moment (biasing force) in the valve devices disclosed in Patent Documents 2 and 3 is insignificant and the degree of decrease is small. Therefore, when the exhaust pressure reaches a predetermined pressure, it is caused by the leaf spring. The moment (biasing force) in the valve closing direction decreases rapidly, and the plate valve operates in the valve opening direction at once (the valve opening of the plate valve increases rapidly in a nonlinear manner with respect to the exhaust pressure). Snap action status cannot be obtained.

  The present invention has been made in view of the above points, and provides a non-linear characteristic to the valve opening of the plate valve with respect to the exhaust pressure of the exhaust gas so that the plate valve can be opened while maintaining the downsizing of the entire apparatus. It aims at providing the valve apparatus for silencers which can further increase the flow volume in a valve state.

  In order to achieve the above object, the present invention provides a base having a valve hole through which exhaust gas flows, a plate valve for opening and closing the valve hole, and a plate valve closed in the silencer. A silencer valve device that opens when the exhaust pressure of the exhaust gas acting on the plate valve rises, wherein the base is on one side of the valve hole The plate-like valve is supported on the other side of the valve hole and has an inclined portion that is inclined in the valve-opening direction of the plate-like valve, and the leaf spring is located on one side of the valve hole of the base. The holding portion is held in a bent state between the holding portion provided and the holding portion provided in the inclined portion, and is in contact with the plate valve between the both holding portions.

  According to the present invention, the plate-like valve can be urged toward the closing side by the elastic force of the leaf spring held in a bent state between the two holding portions. Therefore, in the present invention, the relationship between the exhaust pressure and the valve opening degree of the plate valve can be made a non-linear characteristic, and the switching response of the plate valve from the closed state to the open state is improved. It is possible to achieve high performance of the valve device by increasing the valve opening of the valve body when the valve is opened and increasing the exhaust gas flow rate without increasing the size and cost. Can do.

  Furthermore, according to the present invention, when the plate-like valve is switched from the closed state to the open state, the leaf spring is bent so that it protrudes toward the valve hole between the two holding portions when viewed from the side. From this state, the relationship between the exhaust pressure and the valve opening of the valve body of the plate valve can be made a non-linear characteristic by elastically deforming into a substantially S-shaped bend between both holding parts. In addition to improving the switching responsiveness from the closed state to the open state of the plate-like valve, the valve opening of the valve body in the open state is increased to increase the exhaust flow rate of the exhaust gas, High performance of the valve device can be achieved without increasing the size and cost.

  In the present invention, the valve opening degree of the plate valve corresponding to the exhaust pressure of the exhaust gas has a non-linear characteristic, and the flow rate in the open state of the plate valve is further increased while maintaining the downsizing of the entire device. Thus, a silencer valve device that can be used can be obtained.

It is a longitudinal section of a silencer in which a valve device concerning a 1st embodiment of the present invention was built. (A) is a perspective view of the valve device shown in FIG. 1, and (b) is a side view of the valve device. It is a disassembled perspective view of the said valve apparatus. The operation of the valve device is described. (A) is a longitudinal sectional view showing a closed state in which a valve body of a plate-like valve of the valve device is seated on a seating portion, and (b) is a view of a valve body. It is a longitudinal cross-sectional view which shows the valve opening state spaced apart from the seating part. It is the characteristic view which showed the relationship between exhaust pressure (biasing force to the closing side by a leaf | plate spring) and flow volume (valve opening degree of a plate-shaped valve). It is a longitudinal cross-sectional view of the valve apparatus which concerns on 2nd Embodiment of this invention, (a) has shown the valve closing state, (b) has shown the valve opening state. It is a longitudinal cross-sectional view of the valve apparatus which concerns on 3rd Embodiment of this invention. It is a longitudinal cross-sectional view of the valve apparatus which concerns on 4th Embodiment of this invention. It is a longitudinal cross-sectional view of the valve apparatus which concerns on 5th Embodiment of this invention.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a longitudinal sectional view of a silencer incorporating a valve device according to a first embodiment of the present invention.

  As shown in FIG. 1, for example, a silencer 1 interposed in the middle of an exhaust system of an internal combustion engine such as an automobile engine has a silencer body 9, and the silencer body 9 has a cylindrical shape. It is comprised by the shell 11 and the edge part side walls 12 and 13 which obstruct | occlude the one end part and other end part of the said shell 11, respectively. The silencer body 9 is divided into three internal spaces by a first separator 14 and a second separator 15, and further by three pipes including an exhaust inflow pipe 21, an inner pipe 22 and an exhaust outflow pipe 23. An exhaust gas passage is formed.

  The first separator 14 and the second separator 15 are disposed substantially parallel to the end side walls 12 and 13 in the silencer body 9 with a predetermined distance therebetween. A first silencing chamber 31 is formed between the first separator 14 and the one end side wall 12, and a second silencing is provided between the first separator 14 and the second separator 15 facing each other. A chamber 32 is formed, and a third silencing chamber 33 is formed between the second separator 15 and the other end side wall 13.

  The exhaust inflow pipe 21 extends substantially parallel to the axis of the shell 11, and sequentially passes through one end side wall 12, the first separator 14, and the second separator 15, and the exhaust passage from the engine (not shown) and the third It is provided so as to communicate with the muffler chamber 33. A plurality of through holes 21 a communicating with the second silencing chamber 32 are formed between the intermediate portions of the exhaust inflow pipe 21 facing the second silencing chamber 32.

  The inner pipe 22 extends between one end side wall 12 and the other end side wall 13 in the silencer body 9, passes through the first separator 14 and the second separator 15, and is connected to one end of the inner pipe 22. The third silencing chamber 33 facing the part and the first silencing chamber 31 facing the other end of the inner pipe 22 are provided to communicate with each other. In addition, a large number of through holes 22 a communicating with the second silencing chamber 32 are formed at an intermediate portion of the inner pipe 22 facing the second silencing chamber 32. As a result, the inner pipe 22 is provided so as to communicate with the exhaust inflow pipe 21 via the third silencing chamber 33, and is provided so as to communicate with the exhaust inflow pipe 21 via the through hole 22a.

  One end of the exhaust outlet pipe 23 along the axial direction faces the first silencing chamber 31, passes through the first separator 14, the second separator 15, and the other end side wall 13, and passes through the first silencing chamber 31 and the outside. Are provided to communicate with each other.

  Due to such a structure of the silencer 1, the exhaust gas flowing into the exhaust inflow pipe 21 flows through the third silencer chamber 33, the inner pipe 22, and the first silencer chamber 31 and flows out from the exhaust outlet pipe 23 to the outside. Through the first path A, the through-hole 21a of the exhaust inflow pipe 21, the second silencing chamber 32, the through-hole 22a of the inner pipe 22, the inner pipe 22, and the first silencing chamber 31, and from the exhaust outflow pipe 23 to the outside. It is discharged to the outside by two systems comprising the second path B that flows out.

  By the way, when a large amount of exhaust gas flows into the exhaust inflow pipe 21 as the engine rotates at high speed, the exhaust in the second silencing chamber 32 and the third silencing chamber 33 can be obtained only by the exhaust gas exhaust passages of the two systems. The pressure increases and eventually the engine output decreases.

  For this reason, the first separator 14 is provided with an opening 14a for the bypass path C that allows the second silencing chamber 32 and the first silencing chamber 31 to communicate with each other, and the exhaust gas exhaust pressure is set to a predetermined pressure with respect to the opening 14a. A valve device 10 is provided that switches from a closed state to an open state when the valve is raised. By providing this valve device 10, a large amount of exhaust gas is discharged to the outside through the three exhaust routes A, B, C in which the bypass route C is added to the above-described two exhaust routes A, B in the high speed rotation region of the engine. To discharge smoothly.

  Next, the valve device 10 according to the first embodiment of the present invention will be described in detail below. 2A is a perspective view of the valve device incorporated in the silencer shown in FIG. 1, FIG. 2B is a side view of the valve device, and FIG. 3 is an exploded perspective view of the valve device. is there.

  As shown in FIGS. 2 and 3, the valve device 10 includes a base member having a valve hole 40 through which exhaust gas flows in (circulates) from the second silencing chamber 32 through the opening 14 a of the first separator 14. (Base) 42, a plate valve 44 that opens and closes the valve hole 40, a plate spring 46 that is formed in a thin plate shape and biases the plate valve 44 in the valve closing direction (closed side), and a flexure. A stopper member 48 that restricts the displacement of the leaf spring 46 by contacting the bent leaf spring 46 is provided.

  The base member 42 is made of a rectangular plate formed thicker than the plate-shaped valve 44, and is fixed to the first separator 14 via fixing means (not shown), and the fixing portion 42a. And an inclined portion 42b that is inclined (bent) at a predetermined angle with respect to the fixed portion 42a.

  A rectangular valve hole 40 that can communicate with the opening 14a of the first separator 14 is formed at the center of the fixed part 42a, and a valve body 44a of a plate-like valve 44 is seated around the valve hole 40. Alternatively, a separable seat portion 42c is provided. In addition, a rectangular outflow hole 50 through which the exhaust gas flowing in from the valve hole 40 flows out is formed at the center of the inclined portion 42b. In addition, without forming the outflow hole 50 in the inclined portion 42b, the exhaust gas flowing in from the valve hole 40 flows out from between the inclined portion 42b and the leaf spring 46 toward the left and right sides of the inclined portion 42b. It may be.

  On one side of the valve hole 40 of the base member 42, a support part 42d for supporting one end 44b of the plate valve 44 is provided, and on the other side of the valve hole 40, the plate valve 44 is opened. An inclined portion 42b that is inclined in the valve direction is provided.

  The plate valve 44 is formed of a thin rectangular plate material (for example, rectangular spring steel) that can be elastically deformed. One end 44 b of the plate-like valve 44 formed in a flat plate shape is provided so as to be fixed to the support portion 42 d of the base member 42. Further, the other end of the plate-like valve 44 is provided with a curved portion 44 c that curves in a circular arc shape and abuts against the leaf spring 46. By making the portion where the plate-like valve 44 abuts against the leaf spring 46 into the curved portion 44c, the plate-like valve 44 can be smoothly slid and displaced along the leaf spring 46 when the plate-like valve 44 is bent. Between the one end portion 44b and the curved portion 44c of the plate-like valve 44, there is a valve body 44a that can be seated on or separated from the seating portion 42c around the valve hole 40 and open and close the valve hole 40. Provided.

  A first holding portion 52 a extending in a direction (width direction) orthogonal to the axis of the base member 42 is fixed to one side of the valve hole 40 of the base member 42, and the valve hole of the base member 42 On the other side of 40, a second holding portion 52b extending in a direction orthogonal to the axis of the base member 42 is fixed. The first holding part 52a and the second holding part 52b have spring receiving parts 54a and 54b each formed of a substantially V-shaped groove part when viewed from the side. One end portion along the axial direction of the leaf spring 46 is held in a state having some play in the groove of the spring receiving portion 54a of the first holding portion 52a, and the other end portion along the axial direction of the leaf spring 46. The part is held in a state having some play in the groove of the spring receiving part 54b of the second holding part 52b.

  The first holding portion 52a is laminated and fixed to the support portion 42d of the base member 42 together with the one end portion 44b of the plate valve 44 by welding or the like, and the second holding portion 52b is welded or the like, for example. It is fixed to the inclined portion 42b of the base member 42. In addition, the thick broken line in FIG. 3 shows a welding site, and as the welding method, for example, any one of arc welding, laser welding, spot welding, seam welding, and the like may be used.

  In this case, the opening angle α of the spring receiving part 54a of the first holding part 52a provided on one side of the valve hole 40 and the spring receiving part 54b of the second holding part 52b provided on the other side of the valve hole 40 are provided. The opening angle β may be set to an acute angle, and the opening angle α may be set to be larger than the opening angle β (α> β). That is, by setting the opening angle β on the second holding portion 52b side to be smaller than the opening angle α on the first holding portion 52a side, the plate on the second holding portion 52b side compared to the first holding portion 52a side. The urging force of the valve-like valve 44 toward the closing side with respect to the valve body 44a can be increased, and when the plate-like valve 44 is opened, the leaf spring 46 is suitably bent into a substantially S shape when viewed from the side. The song can be deformed.

  The leaf spring 46 includes a first holding part 52a (spring receiving part 54a) provided on one side of the valve hole 40 of the base member 42 and a second holding part 52b (spring receiving part 54b) provided on the inclined part 42b. Between the first holding portion 52a and the second holding portion 52b so as to contact the curved portion 44c of the plate valve 44. In the first embodiment, the contact portion of the plate valve 44 (curved portion 44c) with respect to the leaf spring 46 is closer to the first holding portion 52a side than the central portion along the axial direction of the leaf spring 46. However, as will be described later, it may be in contact with the central portion 46a along the axial direction of the leaf spring 46 (see FIG. 6A).

  Both end portions along the axial direction of the stopper member 48 are fixed to the first holding portion 52a and the second holding portion 52b, respectively, by welding or the like, and are spaced apart from the leaf spring 46 in a closed state. An interval is provided. The stopper member 48 is provided so as to regulate the displacement of the flexed and deformed leaf spring 46, and the leaf spring 46 is curved in a convex shape toward the direction away from the valve hole 40 and elastically returns to the original shape. Is to be difficult.

  In this case, the inner surface of the stopper member 48 facing the leaf spring 46 is formed as a flat surface 48a. For example, as shown in FIG. 7 to be described later, the stopper member 48 has a central portion along the axial direction of the stopper member 48. Alternatively, a protruding portion 48b that protrudes toward the leaf spring 46 and presses toward the valve closing direction by abutting against the leaf spring 46 may be formed in a portion close to the second holding portion 52b.

  The valve device 10 according to the first embodiment assembled to the silencer 1 is basically configured as described above. Next, the function and effect will be described. FIG. 4 illustrates the operation of the valve device, and FIG. 4 (a) is a longitudinal sectional view showing a closed state in which the valve body of the plate-like valve of the valve device is seated on the seat, FIG. b) is a longitudinal sectional view showing a valve opening state in which the valve body is separated from the seating portion.

  When the engine (not shown) is driven at a low rotational speed, the exhaust pressure of the exhaust gas in the second silencing chamber 32 of the silencer 1 is low, so that the plate valve 44 of the valve device 10 is bent. The leaf spring 46 is pressed toward the closing side (valve closing direction) by the spring force, and as shown in FIG. 4A, the valve body 44a is in the closed state in which it is seated on the seating portion 42c. Accordingly, the valve hole 40 of the base member 42 is closed by the plate-like valve 44, and the leaf spring 46 is located between the first holding part 52a and the second holding part 52b when viewed from the side. It is in the initial state bent so that it may become convex toward.

  Next, when the rotational speed of the engine (not shown) increases and the exhaust pressure in the second silencing chamber 32 rises to a predetermined pressure, the exhaust pressure applied to the valve body 44a of the plate valve 44 through the valve hole 40. (Pressing force that presses the valve body 44a of the plate-like valve 44 upward) becomes higher, and exceeds the total force of the urging force of the leaf spring 46 toward the closing side and the urging force of the plate-like valve 44 itself. The plate-like valve 44 begins to bend against the urging force of the leaf spring 46 toward the closing side (see the dashed line in FIG. 4B).

  Subsequently, when the exhaust pressure reaches a predetermined pressure, as shown by the solid line in FIG. 4B, the leaf spring 46 bends in a substantially S shape as viewed from the side, thereby causing the leaf spring 46 to The urging force (moment) in the valve closing direction is suddenly decreased and the plate valve 44 operates in the valve opening direction at once (the valve opening degree of the plate valve 44 rapidly increases nonlinearly with respect to the exhaust pressure. ) Can be obtained.

  The substantially S-shaped bending of the leaf spring 46 is convex in a direction in which a part of the leaf spring 46 adjacent to the first holding portion 52a is separated from the valve hole 40, as shown in FIG. And the other portion of the leaf spring 46 adjacent to the second holding portion 52b is set to a curved state that is convex toward the inclined portion 42b. In addition, the valve opening degree of the valve body 44a of the plate valve 44 is regulated by the plate spring 46 coming into contact with the flat surface 48a of the stopper member 48, and the plate spring 46 and the plate valve 44 are bent excessively. Is prevented. Further, when the leaf spring 46 is bent into a substantially S shape, the displacement thereof is restricted by contacting the flat surface 48a of the stopper member 48. However, the leaf spring 46 bent into a substantially S shape has an original shape. It is in a state of being urged toward the closing side of the valve body 44a by the elastic force (restoring force) to return to the position.

  In the present embodiment, when the exhaust pressure rises and reaches a predetermined pressure, the leaf spring 46 abuts against the curved portion 44c of the leaf valve 44 in the intermediate state shown by the one-dot chain line in FIG. As a reaction force is exerted on the part of the plate-like valve 44 toward the side opposite to the valve hole 40, the urging force for pressing the valve body 44a of the plate-like valve 44 toward the closing side is rapidly reduced. As a result, the leaf spring 46 is instantaneously changed from the intermediate state shown by the one-dot chain line in FIG. 4B to a state bent in a substantially S shape, and the leaf spring 46 follows the bent state of the leaf spring 46. The valve opening degree of the valve body 44a of the valve 44 increases instantaneously.

FIG. 5 is a characteristic diagram showing the relationship between the exhaust pressure (the urging force to the closing side by the leaf spring) and the flow rate (the valve opening of the plate valve).
In the characteristic curve according to the present embodiment shown by the solid line in FIG. 5, when the exhaust pressure becomes a predetermined pressure, the flow rate of the exhaust gas flowing through the valve hole 40 increases abruptly in a non-linear manner (curved shape). The flow rate Q2 can be obtained as the maximum flow rate in the exhaust pressure region.

  On the other hand, in the characteristic curve according to Comparative Example 1 using the conventional valve device (not shown) indicated by the broken line in FIG. 5, the flow rate is linear (linear) corresponding to the increase in exhaust pressure. ), The flow rate Q1, which is approximately half of the flow rate Q2, can only be obtained as the maximum flow rate in the actual vehicle exhaust pressure region.

  In other words, in the present embodiment, the flow rate increased from the flow rate Q1 to the flow rate Q2 at the same exhaust pressure with respect to the valve device according to the prior art by providing a nonlinear characteristic as the exhaust pressure-flow rate characteristic of the valve device 10. Can be obtained.

  In addition, the characteristic curve which concerns on the comparative example 2 shown with the broken line in FIG. 5 is a case where the spring force of the leaf | plate spring of the valve apparatus which concerns on the prior art of the comparative example 1 is weakened, and respond | corresponds to the increase in exhaust pressure. Since the flow rate rises relatively abruptly in a linear shape, a large flow rate Q2 can be obtained as in the present embodiment as the maximum flow rate in the actual vehicle exhaust pressure region, but there is a problem that resonance occurs. As a result, the opening / closing operation of the valve body may become unstable.

  Subsequently, in the present embodiment, when the rotational speed of the engine (not shown) is reduced again, the amount of bending of the plate valve 44 is reduced to be equal to or less than the predetermined amount of bending, so that the plate shape by the leaf spring 46 is reduced. The urging force of the valve 44 toward the closing side is increased, and the valve body 44a of the plate valve 44 is immediately seated on the seating portion 42c to be in the closed state, and returns to the initial state.

  As described above, in this embodiment, the valve body 44a of the plate-like valve 44 slightly opens due to the exhaust pressure (the valve body 44a starts to move away from the seating portion 42c), and the exhaust pressure rises to a predetermined pressure. Then, since the increasing rate of the urging force to the closing side of the leaf spring 46 with respect to the rise of the exhaust pressure rapidly decreases, the valve opening degree of the plate-like valve 44 increases at a stroke from that point.

  As a result, in this embodiment, as compared with the valve device according to the prior art, the switching from the closed state to the open state of the plate-like valve 44 can be instantaneously performed to improve the response, and the exhaust pressure The valve opening of the plate-like valve 44 after the pressure reaches a predetermined pressure is increased so that the valve device 10 is not increased in size and maintained in a reduced size, and the cost is not increased. Of high performance (increasing exhaust gas flow rate relative to exhaust pressure) can be achieved.

  Next, a valve device according to another embodiment of the present invention will be described below. The same components as those in the first embodiment are denoted by the same reference numerals, detailed description thereof is omitted, and only differences from the first embodiment will be described. 6A and 6B are longitudinal sectional views of a valve device according to a second embodiment of the present invention, in which FIG. 6A shows a valve closing state, and FIG. 6B shows a valve opening state.

  In the valve device 10a according to the second embodiment, in the valve closing state shown in FIG. 6A, the center along the axial direction of the leaf spring 46 bent so as to be convex toward the valve hole 40 side. The curved portion 44c of the plate-like valve 44 is brought into contact with the portion 46a, and the extension line D1 of the receiving surface 56a in the spring receiving portion 54a of the first holding portion 52a and the spring receiving portion 54b of the second holding portion 52b. Is different from the first embodiment in that the extension line D2 of the receiving surface 56b is set not to be coaxial (straight) but to be substantially V-shaped.

  In this valve device 10a, by setting the extension line D1 of the receiving surface 56a and the extension line D2 of the receiving surface 56b so as to intersect in a substantially V shape, when the plate-like valve 44 is opened, The leaf spring 66 can be suitably bent and deformed in a substantially S shape when viewed from the side.

FIG. 7 is a longitudinal sectional view of a valve device according to a third embodiment of the present invention.
In the valve device 10b according to the third embodiment, the inner surface of the stopper member 48 with which the bent leaf spring 46 abuts in the valve open state does not have a flat surface 48a, and is along the axial direction of the stopper member 48. The second embodiment is different from the first embodiment in that a protrusion 48b bulging in a semicircular cross section is formed on the inner wall displaced from the central portion toward the second holding portion 52b.

  The protrusion 48b is provided so as to extend along a direction (width direction) substantially orthogonal to the axial direction of the stopper member 48, and when the valve body 44a of the plate-like valve 44 is opened, When the leaf spring 46 abuts on the protrusion 48b and urges the leaf spring 46 toward the closing side, the leaf spring 46 can be bent and deformed in a substantially S shape when viewed from the side. it can.

FIG. 8 is a longitudinal sectional view of a valve device according to a fourth embodiment of the present invention.
In the valve device 10c according to the fourth embodiment, one piece 58a of the second holding portion 52b formed by bending in a substantially V-shaped cross section is compared with the other piece 58b by a predetermined length toward the valve hole 40 side. It is different from the first embodiment in that it protrudes. In this case, both pieces on the first holding portion 52a side are set to the same length.

  In the valve device 10c, the one piece 58a on the second holding portion 52b side is expanded compared with the other piece 58b, thereby biasing (pressing) the leaf spring 46 toward the closing side as compared with the first holding portion 52a side. ) Acts greatly, and the leaf spring 46 can be bent and deformed in a substantially S shape when viewed from the side.

FIG. 9 is a longitudinal sectional view of a valve device according to a fifth embodiment of the present invention.
In the valve device 10d according to the fifth embodiment, the first holding portion 52a and the second holding portion 52b that hold both ends of the leaf spring 46 and the stopper member 48 that regulates the displacement of the leaf spring 46 are integrated. The second embodiment is different from the first embodiment in that the member 60 formed in is provided.

  In the fifth embodiment, the stopper member 48, the first and second holding members 52a and 52b in the first embodiment are integrally coupled to form a single member 60, thereby reducing the number of parts and the number of assembly steps. Thus, there is an advantage that the manufacturing cost can be further reduced.

  Next, in consideration of the first to fifth embodiments described above, the conditions for bending and deforming the leaf spring 46 in the valve-opened state in a substantially S shape while maintaining the biasing force toward the closing side are as follows. Consider.

  The substantially S-shaped bending deformation of the leaf spring 46 is a portion of the leaf spring 46 adjacent to the first holding portion 52a that is curved and deformed in a convex shape toward the direction away from the valve hole 40. The other part of the leaf spring 46 adjacent to the second holding part 52b is curved and deformed in a convex shape toward the inclined part 42b.

Examples of the conditions for bending and deforming the leaf spring 46 in a substantially S shape include the following.
I) When the plate-like valve 44 is closed, a contact portion between the curved portion 44c of the plate-like valve 44 and the leaf spring 46 is provided at the central portion 46a along the axial direction of the leaf spring 46 (see FIG. 6). Or provided at a position close to the first holding portion 52a side from the central portion 46a (see FIG. 2).
II) The opening angle α of the spring receiving portion 54a of the first holding portion 52a provided on one side of the valve hole 40 and the opening of the spring receiving portion 54b of the second holding portion 52b provided on the other side of the valve hole 40. Each of the angles β is set to an acute angle, and the opening angle β on the second holding portion 52b side is set to be smaller than the opening angle α on the first holding portion 52a side (α> β) (FIG. 2). (See (b)).
III) The extension line D1 of the receiving surface 56a in the spring receiving portion 54a of the first holding portion 52a and the extension line D2 of the receiving surface 56b in the spring receiving portion 54b of the second holding portion 52b are not coaxial (straight). And set so as to intersect in a substantially V-shape (see FIG. 6A).
IV) The stopper member 48 that restricts the displacement of the leaf spring 46 is provided with a protrusion 48b that urges the leaf spring 46 toward the closing side (see FIG. 7).
V) One piece 58a of the second holding portion 52b formed by bending in a substantially V-shaped cross section is projected by a predetermined length toward the valve hole 40 as compared with the other piece 58b (see FIG. 8).

  In this case, the leaf spring 46 can be suitably bent and deformed in a substantially S shape by appropriately combining any one or more of the above conditions I to V.

1 Silencer 10, 10a to 10d Valve device 40 Valve hole 42 Base member (base)
42b Inclined portion 44 Plate valve 46 Leaf spring 52a, 52b Holding portion

Claims (2)

A base provided in the silencer and having a valve hole through which exhaust gas flows;
A plate-like valve for opening and closing the valve hole;
A valve spring for a silencer, comprising a leaf spring that biases the plate valve in a valve closing direction, and opens when an exhaust pressure of exhaust gas acting on the plate valve rises,
The base supports the plate valve on one side of the valve hole, and has an inclined portion inclined on the other side of the valve hole in the valve opening direction of the plate valve,
The leaf spring is held in a bent state between a holding portion provided on one side of the valve hole of the base and a holding portion provided on the inclined portion, and between the holding portions. A silencer valve device that abuts on the plate valve.   When the plate valve switches from the closed state to the open state, the leaf spring is bent from the bent state so as to protrude toward the valve hole between the two holding portions in a side view. 2. The silencer valve device according to claim 1, wherein the silencer valve device is elastically deformed so as to be bent in a substantially S shape between the two holding portions.

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