JP5570272B2 - Exhaust flow control valve - Google Patents

Description

  The present invention relates to an exhaust flow rate control valve provided in an exhaust passage of an internal combustion engine (engine) and capable of controlling the flow rate of exhaust gas flowing through the exhaust passage.

  Conventionally, for example, an on-off valve is disposed in an exhaust passage of an automobile engine, and the flow rate of exhaust gas flowing through the exhaust passage is controlled by the on-off valve urged in the valve closing direction by an elastic member. Has been done. As an exhaust flow control valve of this type, for example, in Patent Document 1, a movable arm (movable end) of a torsion coil spring, which is an elastic member, is connected to a valve body via a connector made of a cylindrical roller. An exhaust flow control valve engaged with a hook member fixed to a shaft is disclosed.

  Further, in Patent Document 2, a torsion coil spring that biases the open / close valve toward the closing side is disposed in a space formed between the outer pipe of the exhaust pipe and the recess of the inner pipe. An exhaust flow control valve is disclosed in which a movable arm (movable end) is engaged with a hook member fixed to a valve shaft that is linked to a valve body via a connector made of a cylindrical roller.

JP 2007-205180 A JP 2006-322357 A

  Incidentally, in the exhaust flow control valve disclosed in Patent Document 1, a spring support member provided with a curved portion having a C-shaped cross section is fixed to the wall surface of the inner tube in a cantilever state, and the coil portion of the torsion coil spring is The torsion coil spring is held by being gripped by the curved portion of the spring support member. In the exhaust flow control valve disclosed in Patent Document 2, a cylindrical support tube is fixed in a state of protruding from the wall surface of the inner tube, and the coil portion of the torsion coil spring is inserted into the support tube. Thus, the torsion coil spring is held.

  In this case, in the exhaust flow control valves disclosed in Patent Document 1 and Patent Document 2, the valve body biased to the closing side by the torsion coil spring is switched from the valve closed state to the valve open state by the pressure of the exhaust gas. When an attempt is made, a force (a component of the force exerted by the hook member on the connector) that presses the coil portion of the torsion coil spring in a direction substantially perpendicular to the axial direction acts via the movable arm of the torsion coil spring. . Therefore, when the valve body switches from the valve closed state to the valve open state and opens and closes, the coil portion of the deformed torsion coil spring interferes (contacts) with the spring support member or the support tube, and abnormal noise is generated. There is a risk that smooth opening / closing operation of the valve body may not be obtained.

The present invention has been made in view of the above points, and an exhaust flow rate control capable of suitably escaping a force acting on a coil portion through a movable end of a torsion coil spring that urges a valve body to a valve closed state. The purpose is to provide a valve.

In order to achieve the above-mentioned object, the present invention is provided in an exhaust system that exhausts exhaust gas discharged from an internal combustion engine to the outside, and the flow rate of the exhaust gas flowing through the exhaust passage is controlled by opening and closing the valve body. In the exhaust flow control valve to be controlled, a valve body, a torsion coil spring that urges the valve body disposed inside the valve body to a valve closed state, a fixed to the valve body, and the torsion coil spring A torsion coil spring having a coil portion formed of a spiral body, a fixed end provided at one end portion of the coil portion, and a movable end provided at the other end portion of the coil portion. , the support member may escape portion for releasing the deformed when the coil portion is deformed so as to interfere with the support member by a force acting on the coil portion through said movable end is provided with the escape portion Is A part of the outer peripheral surface on one end side along the axial direction of the support member is formed by a notch portion, and the valve body is biased to a valve closed state by a spring force of the movable end. It is, when the valve body is opened and closed, a portion of the coil portion of the moving end is characterized that you deformed along the notch.

According to the present invention, the relief member is provided in the support member that supports the torsion coil spring, and the coil portion and the support member are brought into contact with each other by a force (for example, compression force) acting on the coil portion via the movable end of the torsion coil spring. Interference can be prevented by the escape portion . Accordingly, in the present invention, interference (contact) between the coil portion of the torsion coil spring and the support member can be prevented, and abnormal noise can be suitably prevented, and a smooth opening / closing operation of the valve body is also ensured. it can.
Further, the present invention is characterized in that the valve body has a recess recessed toward the inside of the valve body, and the escape portion is disposed in the recess.
Furthermore, the present invention is characterized in that when the valve body is switched from the valve closed state to the valve open state, a part of the coil portion on the movable end side is deformed along the notch portion.

  In the present invention, it is possible to obtain an exhaust flow control valve capable of suitably absorbing the force acting on the coil portion through the movable end of the torsion coil spring that urges the valve body to the valve closed state.

FIG. 3 is an exploded perspective view in which an exhaust flow control valve according to an embodiment of the present invention is incorporated in an exhaust system of an automobile engine and a cover member is removed from the exhaust flow control valve. (A) is a schematic perspective view of the exhaust flow control valve in which the cover member is omitted, and (b) is a longitudinal sectional view taken along line II-II in (a). (A) is the perspective view seen from the diagonal direction of the front side, (b) is the transparent perspective view seen from the diagonal direction of the rear side. It is a principal part disassembled perspective view which abbreviate | omitted the inner pipe | tube. It is a side perspective view which shows the positional relationship of a spring mechanism and a valve body. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. It is operation | movement explanatory drawing of the exhaust flow control valve which concerns on this embodiment, Comprising: (a) shows the valve closed state of a valve body, (b) and (c) have shown the valve open state of the valve body. . (A)-(c) is explanatory drawing which shows the state which absorbs the force which acts on the coil part of a torsion coil spring via a movable arm in this embodiment and its modification. (A)-(c) is explanatory drawing which shows the state which interferes between a coil part and a supporting member with the force which acts on the coil part of a torsion coil spring in a comparative example.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is an exploded perspective view in which an exhaust flow control valve according to an embodiment of the present invention is incorporated in an exhaust system of an automobile engine, and a cover member is removed from the exhaust flow control valve.

  As shown in FIG. 1, the exhaust system 10 is connected to an exhaust port of an automobile engine (internal combustion engine) (not shown) and is provided so as to extend along the front-rear direction of the automobile 11. A first silencer 12, a pair of second silencers 14a and 14b, and a pair of third silencers 16a and 16b are disposed along the downstream side from the upstream side of the exhaust system 10, respectively. The third silencers 12, 14a, 14b, 16a, 16b are integrally connected via a plurality of pipe members. An exhaust flow control valve 30 according to an embodiment of the present invention is provided in front of the second silencers 14a and 14b and on the output side of the first silencer 12.

  In the present embodiment, the exhaust system 10 in which the exhaust flow control valve 30 is disposed between the first silencer 12 and the second silencers 14a and 14b is illustrated, but the present invention is not limited to this. The exhaust flow control valve 30 may be disposed at another part of the exhaust system 10.

  2A is a schematic perspective view of an exhaust flow control valve in which a cover member is omitted, FIG. 2B is a longitudinal sectional view taken along line II-II in FIG. 2A, and FIG. FIG. 3B is a perspective view seen from the front oblique direction, FIG. 3B is a perspective view seen from the rear oblique direction, FIG. 4 is an exploded perspective view of the main part with the inner tube omitted, and FIG. FIG. 6 is a side perspective view showing the positional relationship between the spring mechanism and the valve body, and FIG. 6 is a cross-sectional view taken along line VI-VI in FIG.

  As shown in FIG. 2, the exhaust flow control valve 30 has an inlet port 32a connected to the first silencer 12 and an outlet port 32b connected to a branched pipe member on the second silencer 14a, 14b side. An inner pipe (valve body) 34 to be formed, and a pair of cover members 36a and 36b (see FIG. 1) that are formed of a rectangular body formed in a pair of upper and lower parts and surround the inner pipe 34 are included.

  The inner tube 34 is formed of a substantially oval cylindrical body in which a through hole 38 is formed. The inner tube 34 is an intermediate portion of the inner tube 34 along the inlet port 32a and the outlet port 32b, and the inner tube 34 is perpendicular to the axis. Concave portions 40 that are recessed inward are formed on both sides.

  Further, as shown in FIG. 3, the inner pipe 34 includes a valve mechanism 44 having a valve body 42 for controlling the flow rate of exhaust gas introduced from the inlet port 32a and led out from the outlet port 32b, and the valve A spring mechanism 48 including a torsion coil spring (coil spring) 46 that urges the body 42 to the valve closed state, and an urging force (spring force) of the torsion coil spring 46 that urges the valve body 42 toward the valve closed state. ) Is transmitted to the valve body 42. The urging force (spring force) of the torsion coil spring 46 refers to a force that causes the valve body 42 to rotate in a direction in which the valve body 42 abuts against the stopper member 60 with a valve shaft 52 described later as a rotation fulcrum.

  The valve mechanism 44 extends in a direction orthogonal to the axis connecting the inlet port 32a and the outlet port 32b, and is pivotally supported through a pair of support holes so as to pass through both side portions of the inner tube 34. The shaft 52 and a valve body 42 made of a rectangular plate body as viewed from the axial direction of the inner pipe 34 (see FIG. 2B) and provided so as to be rotatable at a predetermined angle with the valve shaft 52 as a fulcrum, And a weight member 56 fixed to a portion in the vicinity of one long side of the rectangular valve body 42.

  In this case, the valve shaft 52 is provided with a connecting portion 52a that extends along the axial direction and is formed by cutting out a part of the outer periphery in a planar shape (FIG. 3B, FIG. 4, FIG. 6). The other long side vicinity part of the valve body 42 which consists of a rectangular-shaped board body is fixed to the valve shaft 52 via the screw member 58 by making the said connection part 52a into a mating surface. Further, an annular flange portion 52b that protrudes along the radially outward direction is provided on one end portion side of the valve shaft 52.

  Further, the valve mechanism 44 is composed of a member having a substantially L-shaped cross section fixed to the inner wall of the inner pipe 34, and a valve member 42 which comes into contact with the valve member 42 to be in a closed state. A buffer member 62 that cushions an impact when the body 42 abuts against the stopper member 60, and a metal that is provided on both sides of the valve shaft 52 and outside the inner tube 34, and rotatably supports the valve shaft 52. A bearing member 64 made of a mesh is provided, and a ring body 66 for preventing deformation of the bearing member 64 (see FIG. 6). When the valve body 42 is in the valve closed state in contact with the stopper member 60, it is formed by a gap 67 between the inner wall of the inner tube 34 and the outer surface of the valve body 42 as shown in FIG. The exhaust gas passage area is the most constricted (minimum area).

  Both end portions of the valve shaft 52 projecting outward from the inner tube 34, the torsion coil spring 46, and the like are disposed in a recess 40 that is recessed inwardly outside the inner tube 34 formed of a substantially elliptical cylindrical body. (See FIGS. 2 and 6). For this reason, even if the inner pipe 34 is covered with the pair of upper and lower cover members 36a and 36b, the torsion coil spring 46 and the like do not get in the way, and the exhaust flow control valve 30 in a state where the cover members 36a and 36b are mounted. The overall shape is configured in a substantially rectangular parallelepiped shape.

  As shown in FIG. 6, the spring mechanism 48 includes a torsion coil spring 46, and the torsion coil spring 46 includes a coil portion 46 a formed of a substantially cylindrical spiral body and a coil portion 46 a that is separated from the inner tube 34. A fixed side arm 46b which is provided on one side and extends in a direction substantially orthogonal to the axial direction of the coil part 46a and which is a fixed end; and the coil part provided on the other side of the coil part 46a adjacent to the inner tube 34 The movable arm 46c includes a movable end that extends in a direction substantially orthogonal to the axial direction of 46a.

  Further, the spring mechanism 48 is fixed to the outer wall of the intermediate portion along the axial direction of the inner tube 34 by welding or the like, and is fixed to the plate 68 having a rectangular shape when viewed from the side, and the torsion coil spring 46. A cylindrical support member 70 that supports the coil portion 46 a from the inner peripheral side and a bolt 71 that is screwed into a screw hole of the support member 70 are attached to the support member 70, and And a disc-shaped pressing plate 72 that prevents the torsion coil spring 46 from being detached.

  In this case, on one end portion side of the support member 70 close to the plate 68, from a cutout portion 73a formed by cutting out a part of the outer peripheral surface along the axial direction into a substantially arcuate cross section in plan view. A deformation absorbing portion 73 is provided. The deformation absorbing portion 73 is movable when the valve element 42 is about to switch from the valve closed state (initial state) in which the valve body 42 contacts the stopper member 60 to the valve open state due to the pressure of the exhaust gas flowing through the inner pipe 34. A force (compression force) applied to the coil portion 46a of the torsion coil spring 46 through the side arm 46c is absorbed. In addition, the shape of the deformation | transformation absorption part 73 is not limited to the notch part 73a of a cross-section substantially circular arc shape, Various shapes are possible so that it may mention later.

  As shown in FIGS. 2 to 6, the biasing force transmission mechanism 50 is formed on one end side along the axial direction of the valve shaft 52 exposed to the outside from the inner tube 34, and from the fixed end of the torsion coil spring 46. An annular groove 74 to which the fixed arm 46b is locked, a C clip 76 attached to an annular step adjacent to the annular groove 74, and a folding of the movable arm 46c comprising the movable end of the torsion coil spring 46. A sphere 78 that is rotatably mounted on the curved portion 46d, and a holding surface 80a that holds the sphere 78 in a point contact state are provided at a linear intermediate portion that is continuous with one end and one end of the valve shaft 52. A stay member 80 having a fixing portion 80b having a substantially arc-shaped cross section fixed to the valve shaft 52 at the other end and rotating integrally with the valve shaft 52 with the valve shaft 52 as a fulcrum is provided.

  The annular groove 74 functions as a locking portion (groove portion) that locks the fixed end of the torsion coil spring 46. In the present embodiment, the annular groove 74 is formed to circulate along the outer peripheral surface of the valve shaft 52. However, the present invention is not limited to this. For example, the annular groove 74 may be formed by a flat surface or a recess formed by cutting out the lower side of the outer surface of the valve shaft 52 with a flat surface. . A disc member 82 is fixed to the other end portion along the axial direction of the valve shaft 52 through a hole portion, and the disc member 82 prevents the valve shaft 52 from coming off from the support hole of the inner pipe 34. Is made.

  In this case, as shown in FIG. 6, a fixed side arm 46 b of the torsion coil spring 46 that is locked in the annular groove 74 of the valve shaft 52 and a fixed portion 80 b of the stay member 80 that is fixed to the valve shaft 52. A C clip 76 is interposed therebetween, and the C clip 76 functions as a partition wall, so that the non-contact state between the fixing portion 80b of the stay member 80 and the fixing side arm 46b of the torsion coil spring 46 is preferably maintained. Is done. As a result, even if the stationary arm 46 of the torsion coil spring 46 is locked by the annular groove 74 of the valve shaft 52, the smooth rotation operation of the stay member 80 that rotates integrally with the valve shaft 52 is achieved. Can be secured.

  The C clip 76 prevents the stationary arm 46 b of the torsion coil spring 46 locked in the annular groove 74 of the valve shaft 52 from moving toward the stay member 80 along the axial direction of the valve shaft 52. It also has a stopper function. Further, an annular flange portion 52b is interposed between the fixed portion 80b of the stay member 80 fixed to the valve shaft 52 and the bearing member 64, so that the stay member 80 and the inner portion adjacent to the stay member 80 are disposed. The side wall of the pipe 34 is brought into a non-contact state, and the smooth rotation operation of the stay member 80 can be ensured.

  The fixed side arm 46b of the torsion coil spring 46 extends linearly and engages the lower side of the annular groove 74 formed in the valve shaft 52, and the fixed side arm 46b of the torsion coil spring 46 has its spring force. To prevent displacement upward.

The exhaust system 10 in which the exhaust flow control valve 30 according to the present embodiment is incorporated is basically configured as described above. Next, the function and effect will be described.
FIG. 7 is an explanatory view of the operation of the exhaust flow control valve according to the present embodiment. FIG. 7 (a) shows the valve closed state of the valve body, and FIG. 7 (b) and FIG. The valve state of the valve body is shown.

  When an engine (not shown) is driven (operated), exhaust gas discharged from the engine is introduced into the exhaust system 10 of FIG. After the exhaust gas flow rate is controlled through the first silencer 12 and the exhaust flow rate control valve 30, the exhaust gas is exhausted by the second silencer 14a, 14b and the third silencer 16a, 16b on the downstream side. The sound is muted and discharged to the outside.

  At this time, for example, when the engine rotation speed including idling operation and start operation is in a low speed region, the combustion pressure of the engine (combustion chamber) is low, and the exhaust pressure of the exhaust gas discharged from the engine also decreases. Therefore, the exhaust pressure of the exhaust gas introduced into the exhaust system 10 is also low.

  Therefore, as shown in FIG. 7A, the exhaust flow control valve 30 is held in the valve closed state in which the valve element 42 abuts against the stopper member 60 by the urging force (spring force) of the torsion coil spring 46. Therefore, the exhaust gas passage area formed by the gap 67 (see FIG. 2B) between the inner wall of the inner pipe 34 and the outer surface of the valve body 42 is the most constricted state (minimum area). As a result, the exhaust flow control valve 30 reduces the exhaust energy of the exhaust gas exhausted from the output side of the first silencer 12 and preliminarily silences the exhaust noise before the second silencers 14a and 14b. And the filling efficiency of the engine is increased.

  In other words, in the exhaust flow control valve 30 according to the present embodiment, even if the valve body 42 is biased to the closing side by the biasing force of the torsion coil spring 46, the exhaust passage of the inner pipe 34 is the valve. The exhaust gas having a reduced flow rate flows through a gap 67 formed between the inner wall of the inner pipe 34 and the outer surface of the valve body 42 without being completely sealed by the body 42.

  On the other hand, when the combustion state of the engine becomes a complete explosion state and the engine rotation speed reaches the high speed region, the combustion pressure of the engine (combustion chamber) increases and the exhaust pressure of the exhaust gas discharged from the engine also increases. Become. Therefore, the exhaust gas dynamic pressure introduced into the exhaust flow control valve 30 from the inlet port 32a in the exhaust system 10 also increases, and the force that presses the valve element 42 against the biasing force of the torsion coil spring 46 increases. As a result, the force that presses the valve body 42 overcomes the urging force of the torsion coil spring 46, whereby the valve body 42 rotates counterclockwise by a predetermined angle with the valve shaft 52 as a rotation fulcrum (FIG. 7 ( b), the valve body 42 is switched from the valve closed state in which the valve body 42 is in contact with the stopper member 60 to the valve open state in which the valve body 42 is tilted by a predetermined angle in a direction away from the stopper member 60.

  That is, when the valve body 42 is pressed by the pressing force of the exhaust gas dynamic pressure introduced from the inlet port 32a of the inner pipe 34, the valve body 42 is in the direction of arrow A (counterclockwise direction) with the valve shaft 52 as a fulcrum. The stay member 80 fixed to the valve shaft 52 integrally rotates in the direction of arrow A (counterclockwise direction) with the valve shaft 52 as a fulcrum. In this case, the sphere 78 pivotally supported by the bent portion 46d of the movable arm 46c of the torsion coil spring 46 rolls along the holding surface 80a of the stay member 80, as shown in FIG. 7B. Move while. The fixed arm 46 b of the torsion coil spring 46 is held in a state of being locked in the annular groove 74 of the valve shaft 52.

  The valve body 42 is switched from the valve closed state to the valve open state, and the exhaust gas passage area of the exhaust gas flowing through the inner pipe 34 gradually increases. As shown in FIG. When is fully opened, the exhaust gas passage area becomes the maximum area. Therefore, the exhaust pressure loss when the engine speed is in the high speed region is reduced by appropriately controlling the exhaust gas flow rate by the exhaust flow rate control valve 30.

Next, FIGS. 8A to 8C show a state in which the force acting on the coil portion of the torsion coil spring is absorbed by the deformation absorbing portion via the movable arm in the present embodiment and its modification. FIGS. 9A to 9C are explanatory views showing a state in which interference occurs between the coil portion and the support member due to the force acting on the coil portion of the torsion coil spring in the comparative example.
8 (a) to 8 (c) and FIGS. 9 (a) to 9 (c), the diagrams on the left side in the respective partial views show that a force acts on the coil portion 46a from the movable arm 46c. The state before the deformation is shown, and the diagrams on the right side in the respective drawings show the state after the deformation in which a force is applied from the movable arm 46c to the coil portion 46a.

First, the force acting on the coil portion 46a of the torsion coil spring 46 via the movable arm 46c will be described with reference to FIG.
A stay member 80 that rotates integrally with the valve body 42 when the valve body 42 shown in FIG. 7A attempts to open and close in an attempt to switch from the valve closed state to the valve open state. Applies a force F (force F exerted on the sphere 78 by the stay member 80) to the sphere 78 rotatably held at one end of the movable arm 46c. It acts on the coil part 46a of the torsion coil spring 46 via the movable arm 46c. In this case, the component force Fa acting on the coil part 46a via the movable arm 46c is a force (compression) in a direction of pressing the coil part 46a toward the coil part 46a having the movable arm 46c in a side view. Force), and acts as a force that presses one end of the coil portion 46a of the torsion coil spring 46 in a direction substantially orthogonal to the axial direction in plan view.

  In the present embodiment, a support member 70 made of a cylindrical body is fitted into the inner periphery of the coil portion 46 a of the torsion coil spring 46, and one end side (side close to the sphere 78) along the axial direction of the support member 70. A deformation absorbing portion 73 is provided that is cut out in a circular arc shape in plan view. For this reason, as shown in FIG. 8A, the component force Fa tries to deform the one end portion of the coil portion 46a through the movable arm 46c, but the one end portion side of the coil portion 46a is a cross-sectional circle. Deformation occurs along the arc-shaped cutout portion 73 a, and the deformation force of the coil portion 46 a is absorbed by the deformation absorption portion 73. As a result, in this embodiment, the coil portion 46a of the torsion coil spring 46 and the outer peripheral surface of the support member 70 can be prevented from interfering (contacting), and the occurrence of abnormal noise can be suitably avoided. The stay member 80 that rotates integrally with the valve body 42 can ensure a smooth rotation operation.

  FIG. 8B shows a modification of the deformation absorbing portion 73 provided on the support member 70 a that holds the outer peripheral surface of the torsion coil spring 46. The support member 70 a is an outer peripheral surface of the torsion coil spring 46. Is different from the support member 70 that holds the inner peripheral surface. In this case, when the component force Fa acts on one end portion side of the coil portion 46a of the torsion coil spring 46 through the movable arm 46c, the outer peripheral surface on the one end portion side of the coil portion 46a tends to be deformed in the direction of expanding the diameter. . In this case, the supporting member 70a that holds the outside of the coil portion 46a is recessed in a direction away from the outer peripheral surface of the coil portion 46a, and the deformation absorbing portion 73 is formed of a concave portion 73b having a gently curved cross section. Therefore, the outer peripheral surface on the one end portion side of the coil portion 46a and the support member 70a are preferably prevented from interfering with each other.

  FIG. 8C shows another modification of the deformation absorbing portion 73 provided on the thin plate-like support member 70 b that holds the outer peripheral surface of the torsion coil spring 46. Also in this case, as in FIG. 8B, the support member 70b that holds the outside of the coil portion 46a is recessed in a direction away from the outer peripheral surface of the coil portion 46a, and the cross section is formed in a gently curved shape. Since the deformation absorbing portion 73 including the recessed portion 73b is provided, the outer peripheral surface on the one end portion side of the coil portion 46a and the support member 70b are preferably prevented from interfering with each other.

  Next, comparative examples in which the deformation absorbing portion is not provided on the support member that holds the coil portion of the torsion coil spring are shown in FIGS. 9A to 9C, respectively. 9A to 9C, the state where the coil portion 46a and the support member interfere (contact) is depicted in a state where a part of the coil portion 46a and the support member overlap each other.

  In Comparative Example 1 in which the support member that holds the inner peripheral side of the coil portion 46a of the torsion coil spring 46 is provided, as shown in FIG. 9A, when the component force Fa is applied, the spring is applied to the support member. Since no escape portion is formed, one end side along the axial direction of the support member on the side close to the sphere 78 functioning as a connector interferes with (is contacted with) one end side of the coil portion 46a. In addition, abnormal noise may occur, and the smooth rotation of the stay member 80 that rotates integrally with the valve body 42 may be obstructed.

  Further, in Comparative Examples 2 and 3 in which the support member that holds the outer peripheral side of the coil portion 46a of the torsion coil spring 46 is provided, as shown in FIGS. 9B and 9C, the component force Fa acts. Sometimes, the support member is not formed with any spring escape portion, so that the inner side of the support member on the side away from the sphere 78 functioning as a connector interferes with (is contacted with) one end of the coil portion 46a. However, as described above, there is a possibility that abnormal noise may occur, and there is a possibility that the smooth rotation operation of the stay member 80 that rotates integrally with the valve body 42 may be disturbed.

  Thus, in the present embodiment, when the component force Fa acts on the coil portion 46a of the torsion coil spring 46 via the movable arm 46b, the coil portion 46a will deform in the support member 70 (70a, 70b). By providing a spring escape portion (flank face) deformed in the direction (deformation direction of the coil portion 46a), interference by the spring can be suitably avoided.

  In the present embodiment, a deformation absorbing portion 73 is provided on the support member 70 that supports the torsion coil spring 46, and a force (compression force) acting on the coil portion 46 a via the movable arm 46 c (movable end) of the torsion coil spring 46. ) Can be suitably absorbed by the deformation absorbing portion 73. Therefore, in the present embodiment, interference (contact) between the coil portion 46a and the support member 70 can be prevented, generation of abnormal noise can be prevented, and a smooth opening / closing operation of the valve body 42 can be ensured.

  In other words, in the present embodiment, the component force Fa of the force exerted on the sphere 78 that the stay member 80 functions as a connector is applied to one end portion along the axial direction of the coil portion 46a through the movable arm 46c of the torsion coil spring 46. Although it is transmitted as a displacement force, the displacement force acting on the coil portion 46a can be released to the deformation absorbing portion 73 formed by notching the support member 70, and the coil portion 46a is caused by the displacement force. Deformation can be suitably absorbed.

  The force acting on the coil portion 46a (displacement force) is from the valve closed state (initial state) in which the valve body 42 is biased to the closing side by the torsion coil spring 46, and the valve body 42 by the pressure of the exhaust gas. Is given when the valve is opened and closed to switch to the valve open state.

  As a result, in the present embodiment, the opening / closing resistance of the valve body 42 when rotating integrally with the stay member 80 is suppressed, and a smooth opening / closing operation of the valve body 42 can be ensured.

  In the present embodiment, the deformation absorbing portion 73 is provided with a columnar support member 70 that protrudes laterally from the side wall of the inner tube 34 and holds the inner peripheral surface of the torsion coil spring 46. The notch 73a formed by notching one end along the direction is illustrated, but is not limited to this. For example, the outer peripheral surface of the torsion coil spring 46 is held on the side wall of the inner tube 34. The supporting members 70a and 70b to be fixed are fixed, and the deformation absorbing portion 73 including the concave portion 73b is provided on the supporting members 70a and 70b to absorb the deformation of the coil portion 46a between the outer peripheral surface of the coil portion 46a of the torsion coil spring 46. A clearance may be formed.

  Furthermore, in the present embodiment, as a force acting on the coil portion 46a of the torsion coil spring 46 via the movable arm 46c, a force that presses one end portion along the axial direction of the coil portion 46a toward the coil portion 46a side. Although the compression force is described, for example, in the fully open state of the valve body 42 shown in FIG. 7C, the force acting on the coil portion 46 a of the torsion coil spring 46 is changed by the stay member 80 to the compression force. The deformation member 73 may be formed on the support member 70 to absorb the pulling force (pulling force) that is pulled in the opposite direction.

10 Exhaust system 30 Exhaust flow control valve 34 Inner pipe (valve body)
42 Valve body 46 Torsion coil spring 46c Movable arm (movable end)
70, 70a, 70b Support member 73 Deformation absorbing portion 73a Notch portion 73b Recessed portion 80 Stay member

Claims (3)

In an exhaust flow control valve that is provided in an exhaust system that exhausts exhaust gas discharged from an internal combustion engine to the outside and controls the flow rate of exhaust gas that flows through the exhaust passage by opening and closing the valve body,
A valve body;
A torsion coil spring that biases the valve body disposed inside the valve body to a valve closed state;
A support member fixed to the valve body and supporting the torsion coil spring;
With
The torsion coil spring has a coil portion made of a spiral body, a fixed end provided at one end portion of the coil portion, and a movable end provided at the other end portion of the coil portion,
The support member is provided with an escape portion for releasing the deformation when the coil portion is deformed so as to interfere with the support member by a force acting on the coil portion via the movable end.
The escape portion comprises a cutout portion formed by cutting out a part of the outer peripheral surface on one end side along the axial direction of the support member,
The valve body is biased to a valve closed state by a spring force of the movable end,
When the valve body is opened and closed, the exhaust flow control valve portion of the coil portion of the movable end side, characterized that you deformed along the notch. The exhaust flow control valve according to claim 1,
The valve body has a recess that is recessed toward the inside of the valve body;
The exhaust flow rate control valve , wherein the escape portion is disposed in the recess .   In the exhaust flow control valve according to claim 1 or 2,
  An exhaust flow rate control valve, wherein when the valve body is switched from a valve closed state to a valve open state, a part of the coil portion on the movable end side is deformed along the notch portion.

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