JP2013019367A - Air amount control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a valve element at an idle opening even if an over load in a close valve direction is applied on a lever part from an idle opening keeping state.SOLUTION: This air amount control device 1 controls the air amount flowing in a bore 3 by making the opening of the valve element 4 variable. The air amount control device 1 includes a bar-like shaft part 11 including a plate-like fixing part 11a to which the valve element 4 is fixed, the lever part 12 that is formed integrally with the shaft part 11 and to which a driving means for turning the valve element 4 fixed to the fixing part 11a is connected, an arm part 13 that is formed integrally with the lever part 12 and abuts on a stopper 24 to keep the valve element 4 at the idle opening. The shaft part 11 and the arm part 13 are arranged in the lever part 12 so that a fixing plane 11d to which the valve element 4 on the fixing part 11a is fixed is substantially orthogonal to an abutting plane 13a of the arm part 13 in the state where the stopper 24 abuts on the abutting plane 13a of the arm part 13 to keep the valve element 4 at the idle opening.

Description

  The present invention relates to an air amount control device that controls the amount of air flowing through an intake passage of an engine.

  Conventionally, as this type of technology, for example, an air control valve structure described in Patent Document 1 below is known. This air control valve structure is configured such that a plate-like valve (valve element) supported so as to be rotatable with respect to the body is rotated by a driving means. The air control valve structure includes a first plate member that fixes a plate-shaped valve body, a second plate member that is formed integrally with the first plate member and is located on a different plane from the first plate member. The board material which consists of is provided. Both sides of the position where the valve element of the first plate member is attached are covered with a resin material, the resin material on both sides of the first plate member is supported in contact with the body, and the driving means is attached to the second plate member. The second plate member is integrally formed with an abutment plate portion that abuts the idle opening adjustment screw in order to adjust the opening of the valve body to an appropriate idle opening. The first plate member and the second plate member are arranged so that the mounting plane on which the valve body of the first plate member is mounted and the contact plane on which the screw contacts the contact plate portion of the second plate member are substantially parallel. Is placed.

  In the air control valve structure described above, the first plate member to which the valve body is fixed and the second plate member to which the driving means is attached are integrally formed of the same plate material, so that the conventional butterfly valve is fixed. Compared to an air control valve that uses a metal rotating shaft, the weight can be reduced and the number of parts can be reduced.

Japanese Patent Laid-Open No. 9-60737 JP 2007-303357 A

  By the way, in the air control valve structure described in Patent Document 1, the valve element is held at the idle opening degree by the contact of the idle opening degree adjusting screw with the contact plate portion. In this idle opening holding state, a case is assumed in which an overload is applied to the second plate member in a direction (valve closing direction) in which the valve body is rotated to a lower opening side than the idle opening. In this case, the plate thickness of the first plate member is because the contact plane of the contact plate portion with which the screw contacts due to the overload and the mounting plane of the valve body of the first plate member are substantially parallel to each other. The overload acts in the direction, the rigidity of the first plate member against the overload is relatively small, and the first plate member tends to be easily deformed in the plate thickness direction. As a result, the valve element rotates due to the deformation of the first plate member, the idling opening degree decreases, and the idling rotational speed of the engine may decrease.

  The present invention has been made in view of the above circumstances, and its purpose is to provide a valve element even when an overload is applied to the lever portion from the state where the valve element is held at the idle opening degree in the valve closing direction. Is to provide an air amount control device capable of holding the air at an idle opening.

  In order to achieve the above object, according to the first aspect of the present invention, the opening degree of the valve body relative to the bore is adjusted by rotating a plate-like valve body supported to be rotatable with respect to the body by the driving means. An air amount control device that controls the amount of air flowing through a bore as a variable, including a plate-like fixing portion to which a valve body is fixed, and is formed integrally with a rod-shaped shaft portion and a shaft portion. A lever part to which a driving means is coupled to rotate the fixed valve body, and a lever part formed integrally with the lever part and provided on the body to hold the valve body fixed to the fixed part at an idle opening. An arm portion that contacts the stopper, the fixing portion includes a fixed plane that fixes the valve body, the arm portion includes a contact plane that contacts the stopper, and the stopper contacts the contact plane and the valve body In a state where the idle opening is maintained, A constant plane and the abutment plane shaft portion and the arm portion so as to substantially perpendicular to the purpose in that it is positioned relative to the lever portion.

  According to the configuration of the above invention, since the lever portion is formed integrally with the shaft portion and the arm portion is formed integrally with the lever portion, the shaft portion, the lever portion, and the arm portion are formed integrally. Compared to the case where the part, lever part and arm part are formed separately and assembled, the number of parts is reduced. Further, in a state in which the stopper is in contact with the contact plane of the arm portion and the valve body is held at the idle opening, the lever portion rotates the lever portion in the valve closing direction to close the bore. Even if an overload is applied, the fixing plane of the fixing part and the contact plane of the arm part are substantially perpendicular to each other. Therefore, an overload acts on the plate-like fixing part mainly in the width direction of the plate. Compared with the case where an overload acts in the plate thickness direction of the portion, the rigidity of the fixed portion against the overload becomes relatively high.

  In order to achieve the above object, the invention according to claim 2 is directed to the lever portion according to the invention according to claim 1, wherein the valve body rotates the lever portion in a valve closing direction to close the bore. The first distance between the overload force point and the first action point in the fixed portion is set to be larger than the second distance between the second action point where the stopper in the arm portion abuts and the force point. The purpose is that.

  According to the configuration of the invention, in addition to the action of the invention according to claim 1, the first distance centered on the power point is set to be larger than the second distance, so that the overload acting on the fixed portion is not the arm. It becomes relatively smaller than the overload acting on the part.

  In order to achieve the above object, the invention according to claim 3 is the invention according to claim 1 or 2, wherein the shaft portion, the lever portion, and the arm portion are formed by punching one plate material into a predetermined unfolded shape, It is integrally formed by bending, and in the state where one plate material is punched into a predetermined unfolded shape, the shaft portion and the arm portion are arranged on opposite sides with the lever portion as the center, and the shaft The purpose is that the angle formed by the center line of the part and the center line of the arm part is set to be substantially the same as the angle related to the idle opening of the valve body.

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 1 or 2, the shaft portion, the lever portion, and the arm portion are integrally formed by one plate material. The weight can be reduced by setting.

  According to the first aspect of the present invention, the valve body can be held at the idle opening even when the lever portion is overloaded in the valve closing direction from the idle opening holding state of the valve body.

  According to the second aspect of the invention, in contrast to the effect of the first aspect of the invention, the deformation of the fixed portion can be further suppressed, and the valve element is opened to the idle opening degree against an overload in the valve closing direction. Can certainly hold.

  According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, the weight of the air amount control device can be reduced.

The side view which concerns on one Embodiment and shows an air quantity control apparatus. The front view which concerns on the same embodiment and abbreviate | omits and shows a part of air quantity control apparatus. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 with the air amount control device partially omitted according to the same embodiment. The BB sectional drawing of FIG. 3 which concerns on the embodiment and shows an air quantity control apparatus. Sectional drawing which shows the fully open state of the part which concerns on the embodiment and contains the valve body of an air quantity control apparatus. The side view which shows a lever part etc. concerning the embodiment. The side view which concerns on the embodiment and shows a lever cover. The top view which shows the expansion | deployment shape which concerns on the embodiment and the shaft part, the lever part, and the arm part were punched out from one metal plate material. The perspective view which shows the state which bent the shaft part and the arm part from the expansion | deployment shape shown in FIG. 8 from the inner side of a lever part concerning the embodiment. The perspective view which shows the state which bent the shaft part and the arm part from the expansion | deployment shape shown in FIG. 8 from the outer side of a lever part concerning the embodiment. The side view which concerns on the embodiment and shows the principal part of FIG. The side view which expands and shows the inside of the chain line circle | round | yen of FIG. 11 concerning the embodiment. The graph which shows the relationship between the lever forced return overload and valve | bulb return angle in an idle opening holding | maintenance state as contrasted with proportionality in the same embodiment.

  Hereinafter, an embodiment of an air amount control device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side view showing an air amount control device 1 of this embodiment. FIG. 2 is a front view of the air amount control device 1 with a part thereof omitted. FIG. 3 is a sectional view taken along the line AA in FIG. The air amount control device 1 is provided in an intake passage (not shown) of an engine of a two-wheeled vehicle and is used to control the amount of air flowing through the intake passage. The air amount control device 1 includes a metal body 2, a bore 3 having a circular cross section formed in the body 2, and a circular plate shape that is rotatably supported with respect to the body 2 to open and close the bore 3. The valve body 4 is provided. The air amount control device 1 is configured to control the amount of air flowing through the bore 3 by rotating the valve body 4 by driving means so that the opening degree of the valve body 4 with respect to the bore 3 is variable. By controlling the amount of air flowing through the intake passage by the air amount control device 1 during engine operation, the rotational speed of the engine can be controlled.

  As shown in FIG. 3, a shaft hole 5 is formed in the body 2 so as to be perpendicular to the bore 3. In the shaft hole 5, a shaft portion 11 having a rod shape and a plate shape for fixing the valve body 4 is disposed. The shaft portion 11 is assembled so as to be rotatable with respect to the shaft hole 5 through a pair of resin collars 21 and 22 provided on the outer periphery of both end portions thereof. A plate-like fixing portion 11 a for fixing the valve body 4 is provided in the middle of the shaft portion 11. The valve body 4 is fastened and fixed to the fixing portion 11 a by a pair of screws 23. FIG. 4 shows the air amount control device 1 by a cross-sectional view taken along line BB in FIG. As shown in FIG. 4, the shaft portion 11 has a cross-sectional plate shape, and a collar 21 having a circular cross section is provided so as to cover the outer periphery of the shaft portion 11. As shown in FIG. 4, the shaft portion 11 is disposed slightly shifted from the center of the collar 21 to one side. 1 to 3 show a state in which the valve body 4 substantially closes the bore 3, and specifically shows a state in which the valve body 4 is held at the idle opening. On the other hand, FIG. 5 is a portion including the valve body 4 of the air amount control device 1 and shows a fully open state in which the valve body 4 opens the bore 3 to the maximum by a sectional view. As shown in FIG. 5, the shaft portion 11 includes a planar surface 11 b and a back surface 11 c in the plate thickness direction, and the valve body 4 is fixed to the surface 11 b of the fixing portion 11 a by screws 23. A planar surface 11b of the fixed portion 11a is a fixed plane 11d. And as shown in FIG. 5, the center of the plate | board thickness direction of the valve body 4 is arrange | positioned so that it may correspond with the center axis line L1 of both the collars 21 and 22. As shown in FIG.

  As shown in FIGS. 1-3, the lever part 12 with which a drive means is connected in order to rotate the valve body 4 fixed to the fixing | fixed part 11a at one end (left side in FIG. 3) of the shaft part 11, It is formed integrally with the shaft portion 11. FIG. 6 is a side view showing the lever portion 12 and the like. The lever portion 12 has a substantially U shape having a notch portion 12a at the center. The shaft portion 11 is disposed in the notch portion 12 a at the center of the lever portion 12. The shaft portion 11 is bent at a right angle toward the back side of the paper surface of FIGS. In FIG. 6, a pair of retaining holes 12 b are formed on the right side of the lever portion 12 at an interval. In FIG. 6, inclined portions 12 c that are inclined on the upper and lower outer edges of the lever portion 12 are formed in an arc shape. Further, in FIG. 6, on the right side of the lever portion 12, a stopper provided on the bracket 2a of the body 2 as shown in FIG. 1 to hold the valve body 4 fixed to the fixing portion 11a at the idle opening degree. The arm portion 13 that abuts on the lever 24 is formed integrally with the lever portion 12. The arm portion 13 has a belt shape, and the tip end portion thereof is bent at a right angle toward the rear side of the sheet of FIG. The arm portion 13 includes an abutting flat surface 13 a that abuts the stopper 24. In this embodiment, the shaft part 11, the lever part 12, and the arm part 13 are integrally formed from one plate material.

  As shown in FIGS. 1 to 3, the lever cover 14 is fixed to the lever portion 11 by welding or the like outside the lever portion 11. FIG. 7 shows the lever cover 14 in a side view. In FIG. 7, the lever cover 14 has a substantially annular shape having a circular hole 14 a at the center, and a pair of stop holes 14 b corresponding to the pair of stop holes 12 b of the lever portion 11 is formed on the right side thereof. A cutout 14c is formed in a part of these stop holes 14b. In FIG. 7, an inclined portion 14 d that is inclined is formed on the outer peripheral edge of the lever cover 14 except for a portion where the stop hole 14 b is provided.

  Then, by fixing the lever cover 14 to the outer surface of the lever portion 11, as shown in FIGS. 1 and 3, a wire for guiding the opening side wire 31 and the closing side wire 32 between the both 11 and 14. A groove 15 is formed. One end of the opening side wire 31 is locked to the lower stopper holes 12b and 14b in FIGS. On the other hand, one end of the closing side wire 32 is locked to the upper retaining holes 12b and 14c in FIGS. 1 and 3 show the wires 31 and 32, respectively. In this embodiment, these wires 31 and 32 constitute a pull-pull type accelerator device that is connected to and operated by an accelerator grip of a motorcycle. These wires 31 and 32 correspond to the driving means of the present invention.

  As shown in FIGS. 1 and 2, in a state where the valve body 4 is almost fully closed, a contact plane 13 a located at one end (upper end in FIGS. 1 and 2) of the arm portion 13 is provided on the body 2. The valve element 4 is held at the idle opening degree by abutting against the tip of the stopper 24. The idle opening means an opening that the valve body 4 is slightly opened from the fully closed state, and is an opening that is necessary for ensuring idling of the engine. In this embodiment, the stopper 24 is constituted by a screw, and the contact position with the arm portion 13 can be made variable by adjusting the tightening amount with respect to the bracket 2a. By adjusting the position of the stopper 24, the idle opening of the valve body 4 can be adjusted.

  In this embodiment, the shaft part 11, the lever part 12, and the arm part 13 described above are integrally formed by punching one metal plate material into a predetermined developed shape and bending it. FIG. 8 is a plan view showing a developed shape in which the shaft portion 11, the lever portion 12, and the arm portion 13 are punched out from one metal plate material. FIG. 9 is a perspective view of the state in which the shaft portion 11 and the arm portion 13 are bent from the developed shape shown in FIG. FIG. 10 is a perspective view of the shaft 11 and the arm 13 bent from the developed shape shown in FIG. However, in FIG. 9, 10, illustration of the inclined part 12c is abbreviate | omitted. As shown in FIG. 8, the shaft portion 11 and the arm portion 13 are arranged on opposite sides of the lever portion 12 in the state where one metal plate material is punched into a predetermined developed shape. That is, with the lever portion 12 having a substantially U-shape as the center, the direction in which the tip of the shaft portion 11 extends and the direction in which the tip of the arm portion 13 extends are directed substantially opposite to each other. In addition, an angle α formed by the center line L2 of the shaft portion 11 and the center line L3 of the arm portion 13 is set to be substantially the same as an angle θ (see FIG. 12) related to the idle opening of the valve body 4. Then, from the developed shape shown in FIG. 8, the base end portion of the shaft portion 11 is bent at a right angle toward the back side of the paper surface at the center of the lever portion 12, and the base end portion of the arm portion 13 faces the back side of the paper surface. By being bent at a right angle, an integrated part 16 having a final shape is obtained as shown in FIGS. As shown in FIGS. 8 to 10, a pair of screw holes 11 e for fixing the valve body 4 with screws 23 is formed in the fixing portion 11 a of the shaft portion 11.

  Here, FIG. 11 shows the main part of FIG. 1 in a side view. As shown in FIG. 11, in a state where the stopper 24 provided on the body 2 abuts against the abutment plane 13a of the arm portion 13 and the valve body 4 is held at the idle opening degree, the valve body 4 of the fixed portion 11a. The stopper 24 of the arm portion 13 comes into contact with the direction in which the fixing plane 11d (see FIG. 5) to which the arm is fixed extends (the direction indicated by the arrow D1 in FIG. 11 and the same direction as the direction in which the valve body 4 extends). The shaft portion 11 and the arm portion 13 are disposed with respect to the lever portion 12 so that the direction in which the contact flat surface 13a extends (the direction indicated by the arrow D2 in FIG. 11) is substantially orthogonal.

  Here, it is assumed that the closing side wire 32 is forcibly pulled for some reason in the idle opening degree holding state. In this case, an overload is applied to the lever portion 12 so that the valve body 4 rotates the lever portion 12 in the valve closing direction to close the bore 3. For example, it can be assumed that the motorcycle rolls over and the driver unconsciously forcibly operates the accelerator grip in the closing direction in an attempt to cause it to roll over. In this embodiment, in the above assumed state, as shown in FIG. 11, the force point P1 of the overload applied to the lever portion 12 is the center, and the force point P1 and the first action point at the fixing portion 11a of the shaft portion 11 The first distance a between P2 is set to be larger than the second distance b between the second action point P3 where the stopper 24 in the arm portion 13 abuts and the force point P1.

  In addition, in FIG. 3, a return spring 6 is provided between the one end flange portion 21 a of the left collar 21 and the step portion 2 b of the body 2. The return spring 6 is configured to apply a rotational torque to the integrated component 16 in order to bias the valve body 4 toward the idle opening, that is, in the valve closing direction. In FIG. 3, a throttle sensor 7 for detecting the opening degree of the valve body 4 is provided at one end of the right collar 22. The throttle sensor 7 is accommodated in a resin casing 8 attached to the body 2.

  According to the air amount control device 1 of this embodiment described above, the lever portion 12 is formed integrally with the shaft portion 11, and the arm portion 13 is formed integrally with the lever portion 12. 12 and the arm part 13 are integrally formed as an integral part 16. Therefore, compared with the case where the shaft part 11, the lever part 12, and the arm part 13 are formed separately and assembled, the number of parts is reduced and the number of man-hours is also reduced. For this reason, the structure and manufacture of the air quantity control apparatus 1 can be simplified.

  Further, according to the air amount control device 1 of this embodiment, as shown in FIG. 11, in a state where the stopper 24 is in contact with the contact plane 13a of the arm portion 13 and the valve body 4 is held at the idle opening. It is assumed that the lever portion 12 is overloaded so that the closing side wire 32 is forcibly pulled and the valve body 4 rotates the lever portion 12 in the valve closing direction to close the bore 3. In this overload state, a direction D1 in which the fixing plane 11d of the fixing portion 11a of the shaft portion 11 extends and a direction D2 in which the contact plane 13a of the arm portion 13 extends are substantially orthogonal. Accordingly, an overload acts mainly on the plate-shaped fixing portion 11a to which the valve body 4 is fixed, in the width direction of the plate, and compared with a case where an overload acts on the plate thickness direction of the fixing portion 11a. The rigidity of the fixed portion 11a with respect to the load becomes relatively high.

This will be described in detail below. FIG. 12 is an enlarged side view of the chain line circle S1 of FIG. In FIG. 11, the tensile force F <b> 1 of the closing side wire 32 acts on the lever portion 12 and the lever cover 14 via the upper pin 34 as indicated by arrows. At this time, at the force point P1 located between the first action point P2 and the second action point P3, as indicated by an arrow, a force F2 due to the tensile force F1 acts. Therefore, the force F3 acting on the first action point P2 uses the first distance a and the second distance b from the relationship of the arrangement of the force point P1, the first action point P2, and the second action point P3. Then, it can be shown as the following formula.
F3 = F2 × b / (a + b)
Similarly, the force F4 acting on the second action point P3 can be expressed by the following equation using the first distance a and the second distance b.
F4 = F2 × a / (a + b)
Here, in FIG. 12, the force F3 acting on the first action point P2 can be divided into a component force F3a in the plate width direction of the fixed portion 11a and a component force F3b in the plate thickness direction of the fixed portion 11a. . If the inclination angle θ of the fixed plane 11d of the fixed portion 11a corresponding to the idle opening is used, the component forces F3a and F3b can be expressed by the following equations.
F3a = F2 × b / (a + b) × cos θ
F3b = F2 × b / (a + b) × sin θ
Therefore, as shown in FIG. 12, the larger component force F3a of the force F3 acting on the first action point P2 is applied in the plate width direction of the plate-shaped fixing portion 11a, and the smaller component force F3b is applied to the plate. Will be applied in the thickness direction of the fixed portion 11a. That is, the component force F3b which tries to bend the plate-shaped fixing portion 11a in the plate thickness direction is relatively small. On the other hand, since the relatively large component force F3a acts in the plate width direction of the fixed portion 11a, the rigidity of the fixed portion 11a becomes relatively high, and the fixed portion 11a becomes difficult to deform. For this reason, even if an overload is applied to the lever portion 12 in the valve closing direction from the state in which the valve body 4 is held at the idle opening, the valve body 4 can be held at the idle opening.

  FIG. 13 shows the overload in the valve closing direction (lever forced return overload) applied to the lever portion 12 in a state where the valve body 4 is held at the idle opening degree, and the valve body in the air amount control device 1 of this embodiment. The relationship between the return angle at which 4 (valve) returns to the closing side is shown by a graph in comparison with the proportionality. Here, while the plate-like shaft portion is used in the present embodiment, a round bar-like shaft is used in comparison. As shown in FIG. 13, when the lever forcible return overload is changed to “0, 50, 100, 150 (N)”, in this embodiment, the valve return angle is “0, 0.02, 0.0. 04, 0.06 (°) ”. On the other hand, the valve return angle changed to “0, 0.1, 0.2, 0.3 (°)” in contrast. In this embodiment, it can be seen that the valve return angle is as small as “1/5” with respect to the proportionality.

  In this embodiment, the first distance a between the force point P1 of overload applied to the lever portion 12 so as to rotate the lever portion 12 in the valve closing direction and the first action point P2 in the fixing portion 11a. Is set to be larger than the second distance b between the second action point P3 at which the stopper 24 comes into contact with the arm portion 13 and the force point P1. Therefore, as shown in FIG. 11, the force F3 caused by the overload acting on the first action point P2 of the fixed portion 11a is more relative to the force F4 caused by the overload acting on the second action point P3 of the arm portion 13. Become smaller. In this sense as well, the deformation of the fixed portion 11a can be further suppressed, and the valve body 4 can be reliably held by the idle opening against an overload in the valve closing direction.

  Moreover, in this embodiment, since the shaft part 11, the lever part 12, and the arm part 13 are integrally formed by one board | plate material, the weight reduction of the integrated component 16 is attained by the board thickness and material setting of a board | plate material. . In this sense, the air amount control device 1 can be reduced in weight.

  In addition, this invention is not limited to the said embodiment, A part of structure can also be changed suitably and implemented in the range which does not deviate from the meaning of invention.

  In the above embodiment, the entire shaft portion 11 is formed in a plate shape, but only the fixed portion 11a of the shaft portion 11 may be formed in a plate shape, and the other portions may be formed in a round bar shape.

  The present invention can be used for an engine mounted on a vehicle or the like.

DESCRIPTION OF SYMBOLS 1 Air quantity control apparatus 2 Body 3 Bore 4 Valve body 11 Shaft part 11a Fixing part 11d Fixing plane 12 Lever part 13 Arm part 13a Contacting plane 16 Integrated component 24 Stopper 31 Opening side wire (drive means)
32 Closing wire (drive means)
D1 direction in which the fixed plane extends D2 direction in which the contact plane extends P1 force point P2 first action point P3 second action point a first distance b second distance

Claims (3)

An air amount control device for controlling the amount of air flowing through the bore by rotating a plate-like valve body supported to be rotatable with respect to the body by a driving means so that the opening degree of the valve body with respect to the bore is variable. There,
The drive means includes a plate-like fixing portion to which the valve body is fixed, and is formed integrally with the shaft portion, and is fixed to the fixing portion, so as to rotate the valve body. And a lever portion that is formed integrally with the lever portion and that abuts against a stopper provided on the body to hold the valve body fixed to the fixed portion at an idle opening. The fixing portion includes a fixing plane for fixing the valve body, the arm portion includes an abutting plane for abutting the stopper, and the stopper abuts the abutting plane so that the valve body is the idle The air amount control device, wherein the shaft portion and the arm portion are arranged with respect to the lever portion so that the fixed plane and the abutting plane are substantially orthogonal to each other when the opening is held. .   A first point between an overload force point applied to the lever part and a first action point in the fixed part so that the valve body rotates the lever part in a valve closing direction to close the bore. The air amount control device according to claim 1, wherein the distance is set to be larger than a second distance between a second action point at which the stopper in the arm portion abuts and the force point.   The shaft portion, the lever portion, and the arm portion are integrally formed by punching and bending a single plate material into a predetermined unfolded shape, and the single plate member is punched into the predetermined unfolded shape. In the pulled-out state, the shaft portion and the arm portion are arranged on opposite sides with respect to the lever portion, and the angle formed by the center line of the shaft portion and the center line of the arm portion is the valve body. The air amount control device according to claim 1, wherein the air amount control device is set to be substantially the same as an angle related to the idle opening of the air.

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