JP2010065530A - Exhaust flow control valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce manufacturing cost, and to improve productivity, by reducing the number of component items. <P>SOLUTION: This exhaust flow control valve includes a shaft 20 fixed to a valve element 18 and integrally rotating with the valve element 18, an arm 28 extending from the shaft 20 and integrally rotating with the shaft 20, a support part 36 fixed to an inner pipe 12, and a thin plate spring 30 held between the arm 28 and the support part 36 while having elastic force, and is arranged so as to bias the arm 28 toward the closing side of the valve element 18 by restoring force of the thin plate spring 30 deflected in a substantially S shape from the closing side when the valve element 18 operates to the opening side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exhaust flow control valve provided in an exhaust system through which exhaust gas discharged from an engine flows.

  Conventionally, an exhaust valve through which exhaust gas discharged from an engine flows is provided with an on-off valve that is urged to the closing side by an elastic member, and the on-off valve resists the urging force of the elastic member by the action of the pressure of the exhaust gas. There is known an exhaust flow control valve that opens and closes an exhaust passage constituting the exhaust system or changes the flow passage cross-sectional area of the exhaust gas by switching to the open side.

  With regard to this type of exhaust flow control valve, the present applicant uses the same type of torsion coil spring and can easily change the setting of the open / close characteristics of the open / close valve according to the output characteristics of the engine. A valve has been proposed (see Patent Document 1).

In the exhaust flow control valve disclosed in Patent Document 1, a valve body fixed to a shaft to open and close an exhaust passage, a U-shaped member attached to the shaft, and a flange portion of the U-shaped member are engaged. And a torsion coil spring (torsion bar spring) whose one end is engaged with the roller bush and whose other end is locked to a fixing member.
JP 2007-205180 A

  However, the exhaust flow control valve disclosed in Patent Document 1 is configured by a plurality of members such as a shaft, a valve body, a U-shaped member, a roller bush, a torsion coil spring (torsion bar spring), and a fixing member. Therefore, the number of parts is large, which is disadvantageous in terms of manufacturing cost.

  Moreover, in the exhaust flow control valve disclosed in Patent Document 1, since the number of parts is large, there is a possibility that the valve opening accuracy of the valve body may be affected by the variation (manufacturing error) of each part size, Since it is necessary to improve the dimensional accuracy and assembly accuracy of each component, there is a problem that the difficulty of productivity increases when mass production is performed.

  The present invention has been made in view of the above points, and has an exhaust flow rate control valve capable of reducing the number of parts and manufacturing costs and improving productivity by adopting a simple structure. The purpose is to provide.

  In order to achieve the above object, the present invention provides a closed side which is provided in an exhaust pipe for exhausting exhaust gas from an engine and reduces a flow passage sectional area of a flow passage through which the exhaust gas flows, and the flow passage sectional area. And an elastic member that urges the valve body toward the closing side, and an urging force of the elastic member due to an increase in pressure of exhaust gas acting on the valve body In the exhaust flow control valve for switching the valve body from the closed side to the open side against the above, a rotating shaft fixed to the valve body and rotating integrally with the valve body, and extending from the rotating shaft An arm that rotates integrally with the rotation shaft, a support portion fixed to the exhaust pipe, and used as the elastic member, is held in a state having an elastic force between the base portion of the arm and the support portion. A leaf spring, and the valve body is moved to the open side. When the said arm by the restoring force of the plate spring being elastically deformed from the closed side is characterized in that it is urged toward the closing side of the valve body.

  According to the present invention, the number of parts is reduced by adopting a simple structure in which the valve body is opened and closed by the elastic force of a leaf spring interposed between the arm extending from the valve body and the support portion. Thus, the manufacturing cost can be reduced and the productivity can be improved.

  Further, according to the present invention, when the valve body is moved to the opening side, the leaf spring is provided so as to bend in a substantially S shape when viewed from the side, and the restoring force of the leaf spring elastically deformed from the closing side. Since the arm is biased toward the closing side of the valve body, the valve body can be switched reliably and quickly from the opening side to the closing side (adjustment of the opening degree of the valve body).

  In the present invention, an exhaust flow rate control valve capable of reducing the number of parts and reducing the manufacturing cost and improving the productivity can be obtained by adopting a simple structure.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a schematic side view in which an exhaust flow control valve according to an embodiment of the present invention is applied to an exhaust system of an automobile engine, and FIG. 2A is a partially broken enlarged plan view of the exhaust flow control valve. 2 (b) is a longitudinal sectional view taken along line BB in FIG. 2 (a), and FIG. 3 (a) is a part when the valve body of the exhaust flow control valve is in the initial state on the closed side. FIG. 3 (b) is a sectional side view, FIG. 3 (b) is a partial sectional side view of the exhaust flow control valve on the open side, and FIG. 3 (c) is an open side of the exhaust flow control valve. FIG.

  As shown in FIG. 1, an engine 2 mounted on an automobile 1 is provided with an exhaust system 3 for discharging exhaust gas discharged from the engine 2 to the atmosphere. The exhaust system 3 is connected to an exhaust manifold 4 connected to the exhaust port of the engine 2, an exhaust gas purification catalyst 5 connected to the downstream side of the exhaust manifold 4, and a downstream side of the catalyst 5. A plurality of exhaust pipes 6, an exhaust flow control valve 10 according to this embodiment disposed in the middle of the exhaust pipe 6, a pre-chamber 7 and a muffler sequentially disposed downstream of the exhaust flow control valve 10 8.

  Exhaust gas discharged by driving the engine 2 is purified by the catalyst 5 and then passes through the exhaust flow control valve 10 according to the present embodiment, and is temporarily silenced by the prechamber 7. Further, the silencer 8 Is secondarily muted and discharged into the atmosphere.

  As shown in FIG. 1, the exhaust flow control valve 10 according to this embodiment includes an upstream exhaust pipe 6 connected to the outlet side of the catalyst 5 and a downstream exhaust pipe connected to the inlet of the pre-chamber 7. 6 is interposed.

  As shown in FIG. 2, the exhaust flow control valve 10 includes an inner pipe 12 that functions as a flow passage through which exhaust gas discharged from the exhaust port of the engine 2 circulates, and an inner gap via an annular gap 14. And an outer outer tube 16 surrounding the tube 12.

  Inside the inner pipe 12, a valve body that switches the opening degree by an opening / closing operation between a closed side that reduces the flow passage cross-sectional area of the inner pipe 12 through which the exhaust gas flows and an open side that increases the flow passage cross-sectional area. 18 is arranged. A shaft 20 (rotating shaft) that rotates integrally with the valve body 18 is fixed to the upper portion of the valve body 18, and the shaft 20 is a pair of bearing members fixed to the outer peripheral surface of the inner tube 12. It is pivotally supported via 22a and 22b.

  The shaft 20 penetrates the inner tube 12 in a direction orthogonal to the axial direction, and one end portion 20a of the shaft 20 penetrating the inner tube 12 projects to the outer tube 16 side by a predetermined length and is a space portion described later. 24 is provided. The shaft 20 is prevented from coming off by a pair of ring bodies attached to the outer peripheral surface thereof.

  In this case, the valve body 18 has a shape corresponding to the longitudinal cross-sectional shape orthogonal to the axial direction of the inner tube 12, and becomes wider toward the lower side away from the narrow portion adjacent to the shaft 20. It is formed.

  A portion of the inner tube 12 adjacent to the shaft 20 is formed with a recessed portion 26 that extends by a predetermined length along the axial direction of the inner tube 12 and is recessed toward the inner diameter side (see FIG. 2B). ), A space 24 is formed between the recess 26 of the inner tube 12 and the outer tube 16. One end portion 20 a of the shaft 20 facing the space portion 24 extends along a direction substantially orthogonal to the axial direction of the shaft 20 (parallel to the axial direction of the inner tube 12), and rotates integrally with the shaft 20. A moving arm 28 is provided. In the present embodiment, the arm 28 is configured separately from the shaft 20, but is not limited thereto, and the arm 28 may be configured integrally with the shaft 20.

  As shown in FIGS. 3A to 3C, one end (free end) along the axial direction of the arm 28 has an L-shaped cross section that engages with a thin leaf spring (elastic member) 30 described later. The other end portion (base portion of the arm) along the axial direction of the arm 28 holds one end portion 30a of a thin plate spring 30 which is expanded in a substantially V-shaped cross section and will be described later. A first spring receiving portion 34a to be locked is provided.

  Further, as shown in FIG. 2, the side portion of the inner tube 12 that is separated from the shaft 20 by a predetermined distance along the axial direction of the inner tube 12 projects in a direction substantially orthogonal to the axial direction of the inner tube 12. The supporting part 36 to be fixed is fixed. The support portion 36 is provided with a second spring receiving portion 34b that expands into a substantially V-shaped cross section and holds (locks) the other end portion 30b of the thin plate spring 30 described later (see FIG. 3).

  Between the first spring receiving portion 34a of the arm 28 and the second spring receiving portion 34b of the support portion 36, as shown in FIGS. 2 and 3, the elastic force that biases the valve body 18 toward the closing side. A thin leaf spring (leaf spring) 30 that functions as a member is held (locked) in a state having an elastic force (a state in which the elastic force can be exerted).

  That is, as shown in FIG. 3A, in the initial state, the thin leaf spring 30 faces upward between the first spring receiving portion 34a of the arm 28 and the second spring receiving portion 34b of the support portion 36. The valve body 18 is urged toward the closing side by the elastic force (spring force) of the thin leaf spring 30. In this case, in order to prevent the thin leaf spring 30 from being bent downward, a protrusion (not shown) may be provided.

  The thin plate spring 30 is formed in a long strip shape having a predetermined thickness, and in the present embodiment, a single plate spring formed by a single metal plate is illustrated.

  In this case, the thin leaf spring 30 is not limited to a metal material, and may be formed of a member having elastic force such as a rubber material, a resin material, or a shape memory alloy (super elastic alloy). Good. Further, instead of one single plate, for example, a plurality of plate springs of different materials may be integrally coupled (adhered). Furthermore, a laminated leaf spring constituted by laminating a plurality of leaf springs may be used. Furthermore, the thin plate spring 30 may have a constant spring constant (linear characteristics) or a spring constant that changes (nonlinear characteristics).

  The exhaust flow control valve 10 according to the present embodiment is basically configured as described above. Next, its operation and effects will be described.

  In the initial state, as shown in FIG. 3A, a clockwise force is applied from the thin plate spring 30 to the arm 28 by the elastic force exerted by bending the thin plate spring 30 upward. As a result, the valve body 18 is biased to the closing side (clockwise direction) with the shaft 20 as a fulcrum.

  In such an initial state, when the engine 2 is driven, the exhaust gas flowing through the inner pipe 12 acts on the valve body 18, and as the pressure of the exhaust gas (exhaust pressure) increases, the shaft 20 serves as a fulcrum. The force which presses the valve body 18 in the counterclockwise direction increases. As a result, the valve body 18 rotates counterclockwise by a predetermined angle with the shaft 20 as a fulcrum against the urging force of the thin leaf spring 30, so that the valve body 18 is moved from the closed side (initial state). It is switched to the open side (see FIG. 3B).

  At that time, the valve body 18 is rotated counterclockwise by a predetermined angle from the initial state and switched from the closed side to the open side, whereby the valve body 18, the shaft 20 and the arm 28 are integrally rotated. A pressing portion 32 provided at one end of the arm 28 and bent in a substantially L shape presses an intermediate portion of the thin leaf spring 30 curved upward, as shown in FIG. The thin leaf spring 30 is bent into a substantially S shape when viewed from the side.

  When the valve body 18 of the exhaust flow control valve 10 is located on the open side, the valve is opened, and the exhaust gas that has passed through the gap between the inner pipe 12 and the valve body 18 is discharged downstream through the exhaust pipe 6.

  On the other hand, when the valve body 18 is on the open side, for example, when the engine 2 is in a low speed operation state such as an idling state, and the elastic force of the thin leaf spring 30 overcomes the pressure of the exhaust gas that presses the valve body 18, The restoring force of the thin plate spring 30 causes a force to rotate the arm 28 in the clockwise direction, and the valve body 18 is rotated in the clockwise direction with the shaft 20 as a fulcrum to be in a closed state (initial state). Return to).

  That is, when the valve element 18 is in the open side state (see FIG. 3B), the thin leaf spring 30 that is elastically deformed from the closed side and bent in a substantially S shape as viewed from the side tries to return to the original shape. The arm 28 is urged toward the closing side of the valve body 18 by the elastic force (restoring force), and the plate spring 30 returns to the original shape against the pressure of the exhaust gas that presses the valve body 18 toward the opening side. When the elastic force (restoring force) to be overcome is overcome (see FIG. 3 (c)), the valve body 18 rotates clockwise with the shaft 20 as a fulcrum, and the initial state (FIG. 3 (a) Return to)).

  In the present embodiment, by adopting a simple structure in which the valve body 18 is opened and closed by the elastic force of the thin leaf spring 30 interposed between the arm 28 extending from the valve body 18 and the support portion 36, The number of parts can be reduced to reduce manufacturing costs, and productivity can be improved.

  In other words, in this embodiment, by reducing the number of components of the link mechanism provided between the thin plate spring 30 that is an elastic member and the valve body 18, the number of parts can be reduced and the cost can be reduced. In addition, the productivity can be improved by reducing the quality control items in the assembly accuracy in which each part is assembled.

  Further, in the present embodiment, when the valve body 18 moves to the open side, the thin plate spring 30 is provided so as to bend in a substantially S shape when viewed from the side, and the thin plate spring 30 is elastically deformed from the closed side. Since the arm 28 is biased toward the closing side of the valve body 18 by the restoring force, the valve body 18 can be reliably and quickly switched from the opening side to the closing side.

  In this case, in the thin leaf spring 30 bent in a substantially S shape when viewed from the side, the distance A1 along the horizontal direction of the left first arc portion (curved upward) 31a constituting the S shape and the right side The relationship between the second arc portion (curved downward) 31b and the distance A2 along the horizontal direction may be, for example, A1 = A2, as shown in FIG. 4A, or FIG. As shown in (b), the position of the pressing portion 32 of the arm 28 engaged with the intermediate portion of the thin leaf spring 30 may be adjusted so that A1> A2.

  In the present embodiment, a thin leaf spring 30 made of a long belt-like single plate is used, and is bent so as to be bent in a substantially S shape when viewed from the side when the switching is made from the closed side to the open side. However, the present invention is not limited to this. For example, the arm 28 is urged toward the closing side of the valve body 18 by the restoring force of the overlapping plate spring elastically deformed from the closing side using a not-shown overlapping plate spring. You may make it do.

  Further, as shown in FIG. 5, for example, the bent portion of the pressing portion 32 of the arm 28 that engages with the thin plate spring 30, the opening portion of the first spring receiving portion 34 a, and the second spring receiving portion 34 b of the support portion 36. Damping members 40a to 40c made of stainless mesh may be attached (fixed) to the opening. By providing the damping members 40a to 40c, it is possible to reduce the contact sound with the thin leaf spring 30 and ensure quietness.

  Next, in FIG. 6, the elastic force of the thin plate spring 30 acting in the direction in which the valve body 18 is closed (closed side) is set as a torque on the vertical axis, and the valve opening (opening side) of the valve body 18 is set on the horizontal axis. FIG. As can be understood from FIG. 6, in this embodiment, it is set so as to avoid the elastic force of the thin leaf spring 30 from increasing linearly as the valve opening of the valve body 18 increases. it can. By setting in this way, for example, in the normal use region of the valve opening degree of the valve body 18, the valve body 18 can be switched more quickly between the open side and the closed side.

1 is a schematic side view in which an exhaust flow control valve according to an embodiment of the present invention is applied to an exhaust system of an automobile engine. (A) is a partially broken enlarged plan view of the exhaust flow control valve, and (b) is a longitudinal sectional view taken along line BB in (a). (A) is a partial cross-sectional side view when the valve body of the exhaust flow control valve is in the initial state on the closed side, and (b) is one of the states where the valve body of the exhaust flow control valve is on the open side (C) is a partial cross-sectional side view of a state in which the valve body of the exhaust flow control valve is about to be restored from the open side to the closed side. (A), (b) is the distance A1 along the horizontal direction of the 1st circular arc part of the thin leaf | plate spring which bends in a substantially S shape seeing side view, respectively, and the distance along the horizontal direction of the 2nd circular arc part. It is a partial cross section side view which shows the relationship with A2. FIG. 9 is a partially omitted cross-sectional view showing a modified example in which a damping member is mounted. It is a characteristic view which shows the relationship between a torque and the valve opening degree of a valve body.

Explanation of symbols

10 Exhaust flow control valve 12 Inner pipe 16 Outer pipe 18 Valve body 20 Shaft (rotating shaft)
28 Arm 30 Thin leaf spring (elastic member)
36 Supporting part

Claims (2)

A valve body that is provided in an exhaust pipe that discharges exhaust gas from an engine and switches between a closed side that reduces a flow passage cross-sectional area of a flow passage through which exhaust gas flows and an open side that increases the flow passage cross-sectional area by an opening / closing operation. And an elastic member that urges the valve body toward the closed side, and the valve body is opened from the closed side to the open side against the urging force of the elastic member by increasing the pressure of the exhaust gas acting on the valve body. In the exhaust flow control valve to switch to
A rotating shaft fixed to the valve body and rotating integrally with the valve body;
An arm extending from the pivot shaft and pivoting integrally with the pivot shaft;
A support portion fixed to the exhaust pipe;
A leaf spring that is used as the elastic member and is held in a state having an elastic force between a base portion of the arm and the support portion;
Have
The exhaust flow control valve according to claim 1, wherein when the valve body is moved to the opening side, the arm is biased toward the closing side of the valve body by a restoring force of the leaf spring elastically deformed from the closing side. The exhaust flow control valve according to claim 1,
The said leaf | plate spring is provided so that it may bend in a substantially S shape by side view when the said valve body operate | moves to the open side.

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