Throttle device

Abstract

To prevent a gear side end part of a coil spring from being completely detached from a gear side spring locking part in the middle of assembling to a rotating member.SOLUTION: One embodiment is a throttle device including a rotating member coupled to a throttle shaft and rotated by a drive source, and a coil spring interposed between a throttle body and the rotating member and biasing a throttle valve toward a default position. The coil spring has a first spring portion, a second spring portion, and an intermediate hook connecting the first and second spring portions. The intermediate hook can be engaged with a first stopper provided on the rotating member and a second stopper provided on the throttle body, the rotating member has a holding hole at least partially surrounding the first end portion of the first spring portion locked to the first spring locking portion, the first spring locking portion has a locking groove, and the first end portion is fitted to the locking groove.SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] The present technology relates to a throttle device. [Background technology]

[0002] Automotive throttle devices that adjust the amount of intake air supplied to the engine typically open and close an intake passage formed in the body by rotating a shaft fixed to a throttle valve (disk) with an electric motor. In many cases, such throttle devices are equipped with a mechanism that moves the throttle valve to a specified default position so that some intake air volume can be ensured even when the motor is de-energized. For example, in the throttle device disclosed in JP 2020-033942 A, a coil spring (torsion spring) biases the throttle valve toward the default position.

[0003] Specifically, this coil spring is attached between the final gear of a gear train that transmits rotation of an electric motor to a shaft and the body of the throttle device. This coil spring is composed of an opener spring portion and a return spring portion wound in opposite directions, connected by a U-shaped intermediate hook. The intermediate hook is engaged with only one of the gear and the body, so that either the return spring portion or the opener spring portion exerts a biasing force toward the default position. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-033942 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, the coil spring is attached with a preload applied by twisting the opener spring portion in the radial direction to bias the throttle valve toward the default position. As a result, the gear-side end of the coil spring may become completely disengaged from the gear-side spring locking portion during assembly due to this preload. [Means for solving the problem]

[0006] One aspect of the present technology is a throttle device including a throttle body that defines an intake passage, a throttle valve that opens and closes the intake passage, a throttle shaft connected to the throttle valve, and a rotating member that is connected to the throttle shaft and rotated by a drive source. The throttle device further includes a coil spring that is interposed between the throttle body and the rotating member and biases the throttle valve toward a default position. The coil spring has a first spring portion including a first end, a second spring portion including a second end, and an intermediate hook that connects the first spring portion and the second spring portion. The first end is engaged with a first spring engaging portion provided on the rotating member, and the second end is engaged with a second spring engaging portion provided on the throttle body. The intermediate hook is capable of engaging with a first stopper provided on the rotating member and a second stopper provided on the throttle body. The rotating member has a retaining hole that at least partially surrounds the first end of the first spring portion engaged with the first spring engaging portion, the first spring engaging portion has an engaging groove, and the first end is fitted into the engaging groove.

[0007] In some embodiments, the throttle device further includes a support pillar forming the first spring locking portion and a support pillar forming the first stopper, and the retaining hole is formed by a bridge portion spanning between these support pillars.

[0008] In some embodiments, the first spring locking portion is formed as an inner wall of the retaining hole. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a throttle device according to an embodiment; [Figure 2] 1 is a cross-sectional view of the throttle device taken along a plane passing through the motor and throttle shaft, with the hatched surface indicating the cross section. [Figure 3] FIG. [Figure 4] FIG. 2 is a perspective view showing the throttle gear alone. [Figure 5] FIG. 10 is a side view of the coil spring alone, showing the intermediate hook tilted relative to the central axis. [Figure 6] This is a diagram showing the state in which the opener spring portion of the coil spring is attached to the throttle gear, and the coil spring is cut at the intermediate hook. [Figure 7] FIG. 10 is a view showing the housing of the throttle device with the cover open when the throttle valve is in the default position. [Figure 8] FIG. 2 is a view showing the housing of the throttle device with the cover open when the throttle valve is in a fully closed position. [Figure 9] FIG. 2 is a view showing the housing of the throttle device with the cover open when the throttle valve is in a fully open position. [Figure 10] 10 is a view showing an eccentric opener spring portion and an outer peripheral support portion acting thereon as viewed in the axial direction. FIG. [Figure 11] 10 is a side view showing a state in which the opener spring portion is eccentric in a direction different from that of the return spring portion due to being pressed by the outer peripheral support portion. FIG. [Figure 12] 10 is a view of an eccentric opener spring portion when there is no outer peripheral support portion, as viewed in the axial direction. FIG. [Figure 13] FIG. 10 is a side view of an eccentric opener spring portion when there is no outer peripheral support portion. [Figure 14] FIG. 10 is a side view showing a gear-side stopper inclined with respect to the central axis of the throttle gear, as another embodiment. [Figure 15] FIG. 10 is a perspective view showing the coil spring attempting to fit inside the outer peripheral support portion during attachment to the throttle gear. [Figure 16] FIG. 2 is a perspective view showing a coil spring attached to a throttle gear. DETAILED DESCRIPTION OF THE INVENTION

[0010] Various embodiments will be described below with reference to the drawings.

[0011] [Throttle device] 1 to 3 show a throttle device 10 as one embodiment that is mounted on a vehicle such as an automobile and adjusts the amount of air intake into the engine. The throttle device 10 includes a throttle body 12 that forms an intake passage 13. The throttle body 12 can be made of metal or resin. The throttle device 10 also includes a rotatable, disc-shaped throttle valve (disk) 15 that adjusts the flow rate passing through the intake passage 13. The throttle valve 15 is fixed to a throttle shaft 17 that is rotatably supported via bearings 18 and 19 attached to the throttle body 12 on both sides of the intake passage 13. The throttle valve 15 is rotatable between a fully closed position (FIG. 8) that is approximately perpendicular to the intake passage 13 and a fully open position (FIG. 9) that is approximately parallel to the intake passage 13. The throttle valve 15 opens and closes as the throttle shaft 17 rotates. Both the throttle valve 15 and the throttle shaft 17 can be made of metal.

[0012] [Motor and transmission mechanism] The throttle device 10 includes a motor 22 as a drive source for driving the throttle valve 15. Rotation output by the motor 22 is transmitted to the throttle shaft 17 via a transmission mechanism. The motor 22 and the transmission mechanism are housed in a housing portion formed in the throttle body 12, and the throttle body 12 includes a lid 29 for closing this housing portion. In one embodiment, the transmission mechanism includes a drive gear 24 fixed to an output shaft 23 of the motor 22, an intermediate gear 26 rotatably supported on the throttle body 12 via an intermediate shaft 27, and a throttle gear 20, which is a driven gear coaxially fixed to the throttle shaft 17. The intermediate gear 26 has a large-diameter toothed portion 26a and a small-diameter toothed portion 26b coaxially fixed to the intermediate shaft 27. The large-diameter toothed portion 26a meshes with the drive gear 24, and the small-diameter toothed portion 26b meshes with the teeth 28 of the throttle gear 20. The throttle gear 20 may be made of resin. The throttle shaft 17 is inserted into a mounting hole 21 provided in the throttle gear 20 and fixed by caulking the end. The motor 22 is controlled by an external electronic control unit (ECU). The opening of the throttle valve 15 is adjusted by controlling the direction and amount of rotation of the motor 22.

[0013] [Coil spring] As shown in Figures 2, 3, and 5, the throttle device 10 is equipped with a coil spring 30 that biases the throttle valve 15 from a fully closed position (Figure 8) toward a predetermined default position (Figure 7), which is a slightly open position. This coil spring 30 functions as a torsion spring. When the motor 22 is energized (i.e., when the output shaft 23 can be controlled), the throttle valve 15 can be rotated to any position between the fully closed position (Figure 8) and the fully open position (Figure 9) against the biasing force of the coil spring 30. When the motor 22 is de-energized, the biasing force of the coil spring 30 automatically rotates the throttle valve 15 to the default position, allowing a small amount of air to be supplied to the engine through the intake passage 13.

[0014] Specifically, the coil spring 30 is configured by connecting a return spring portion 35 (e.g., approximately six turns) and an opener spring portion 37 (e.g., approximately two turns) wound in opposite directions, and is interposed between the throttle body 12 and the throttle gear 20. Both end portions 31, 32 of the coil spring 30 are bent so as to protrude radially outward, with one end portion 31 being engaged with a body-side spring engaging portion 40 (see FIG. 7) provided on the throttle body 12 and the other end portion 32 being engaged with a gear-side spring engaging portion 42 provided on the throttle gear 20. The end portion 31 engaged with the throttle body 12 is also the end portion of the return spring portion 35, and the end portion 32 engaged with the throttle gear 20 is also the end portion of the opener spring portion 37.

[0015] 3, 5, 6, and 16, the connection between the return spring portion 35 and the opener spring portion 37 is a U-shaped folded portion that is bent so as to protrude radially outward. This bent folded portion is configured as an intermediate hook 33 to be engaged with at least one of a gear-side stopper 44 provided on the throttle gear 20 and a body-side stopper 46 provided on the throttle body 12. When the throttle gear 20 is in the default position (FIG. 7), the intermediate hook 33 is engaged with both the gear-side stopper 44 provided on the throttle gear 20 and the body-side stopper 46 provided on the throttle body 12. At this time, both the return spring portion 35 and the opener spring portion 37 are twisted in a radially contracting direction from their natural states and are in a preloaded state (a state in which elastic energy is stored).

[0016] When the motor 22 drives the throttle gear 20 to rotate from the default position (FIG. 7) toward the fully closed position (FIG. 8), the intermediate hook 33 of the coil spring 30 engages with a body-side stopper 46 provided on the throttle body 12, thereby disabling the return spring portion 35, whose ends are constrained by the throttle body 12. Meanwhile, the throttle gear 20 rotates relative to the throttle body 12 with the intermediate hook 33 still engaged with the body-side stopper 46, so the gear-side stopper 44 of the throttle gear 20 moves away from the intermediate hook 33. Because the throttle gear 20 rotates while holding the end 32 of the coil spring 30, the opener spring portion 37 is further twisted in the direction of reducing its diameter. If the power supply to the motor 22 is cut off when the throttle gear 20 is closer to the fully closed position than the default position, the throttle gear 20 is returned to the default position by the biasing force of the opener spring portion 37.

[0017] When the throttle gear 20 attempts to rotate from the default position (Figure 7) toward the fully open position (Figure 9) due to the drive of the motor 22, the intermediate hook 33 remains engaged with the gear-side stopper 44 of the throttle gear 20, and the opener spring portion 37, both ends of which are constrained by the throttle gear 20, is disabled. Meanwhile, the throttle gear 20 rotates relative to the throttle body 12 with the intermediate hook 33 still engaged by the gear-side stopper 44, and the return spring portion 35 is further twisted in the direction of reducing its diameter. If power to the motor 22 is cut off when the throttle gear 20 is closer to the fully open position than the default position, the urging force of the return spring portion 35 will return the throttle gear 20 to the default position.

[0018] When the throttle gear 20 rotates between the default position and the fully closed position, the opener spring portion 37 twists, but the amount of rotation of each portion of the coil wire of the opener spring portion 37 is not uniform. For example, the portion of the opener spring portion 37 close to the end portion 32 held by the throttle gear 20 rotates following the throttle gear 20, so the amount of rotation relative to the throttle gear 20 is small. On the other hand, the portion of the opener spring portion 37 close to the intermediate hook 33 restrained by the body-side stopper 46 rotates less relative to the throttle body 12, but the amount of rotation relative to the throttle gear 20 is large.

[0019] [Inner circumference support part] As shown in Figures 4 and 6, the throttle gear 20 has an inner support portion 47 that protrudes toward the inside of the coil spring 30 and suppresses eccentricity of the coil spring 30. As an example, the inner support portion 47 is formed as a cylindrical portion that protrudes from a plate-like base portion on which the teeth 28 of the throttle gear 20 are formed. The aforementioned mounting hole 21 for fixing the throttle shaft 17 can be formed in a metal plate that is joined to the inside of this cylindrical inner support portion 47 by insert molding. The inner support portion 47 is formed to a height that at least passes through the opener spring portion 37, and can also be formed to a height that protrudes into the return spring portion 35 (for example, from the intermediate hook 33 to approximately two revolutions of the return spring portion 35).

[0020] As shown schematically in Figures 10 and 11, the opener spring portion 37 is attached with a preload applied by being twisted in the radially contracting direction, so that the orbit 37a on the end 32 side of the opener spring portion 37 tends to become eccentric relative to the central axis of the throttle gear 20 in approximately the same direction (arrow 70) as the reaction force received from the gear-side spring locking portion 42. In response, the inner support portion 47 supports the inner side of the orbit 37a that tends to become eccentric. In addition, the return spring portion 35 is attached with a preload applied by being twisted in the radially contracting direction, so that the orbit 35b of the return spring portion 35 closest to the intermediate hook 33 tends to become eccentric relative to the central axis of the throttle gear 20 in approximately the same direction (arrow 74) as the reaction force received from the gear-side stopper 44 (or body-side stopper 46). In response, the inner support portion 47 supports the inner side of the orbit 35b that tends to become eccentric. The inner peripheral support portion 47 also suppresses eccentricity of the coil spring 30 that may occur when the coil spring 30 is twisted by the rotation of the throttle gear 20 while the throttle device 10 is in operation.

[0021] In another embodiment (not shown), the inner peripheral support portion can be formed on the throttle shaft 17 instead of the throttle gear 20.

[0022] 2, the throttle body 12 has a bearing holder 45 that holds the bearing 18 closer to the throttle gear 20. This bearing holder 45 is formed to a height that protrudes into the return spring portion 35, and can function as an additional inner peripheral support portion for the return spring portion 35. However, in the following description, the term "inner peripheral support portion" simply refers to the inner peripheral support portion 47 formed on the throttle gear 20.

[0023] [Outer support part] As shown in Figures 4 and 6, the throttle gear 20 is provided with at least one outer peripheral support portion 50 that abuts against the outer peripheral side of the opener spring portion 37 of the coil spring 30. The outer peripheral support portion 50 can be formed integrally with the throttle gear 20. In one embodiment, the outer peripheral support portion 50 is formed so as to extend from the base portion 48, on which the teeth portion 28 of the throttle gear 20 are formed, to the same side as the inner peripheral support portion 47. For example, the outer peripheral support portion 50 can be shaped to make point contact with the opener spring portion 37, and can be, for example, a cylindrical shape extending parallel to the axial direction of the throttle gear 20.

[0024] As shown in FIGS. 12 and 13 , when a throttle gear 120 without an outer peripheral support portion 50 is used, the preload applied to the opener spring portion 37 causes the turn 37b of the opener spring portion 37 on the intermediate hook 33 side to be significantly eccentric relative to the central axis of the throttle gear 20 in approximately the same direction (arrow 72) as the reaction force received from the body-side stopper 46 (or gear-side stopper 44). In particular, because the number of turns of the opener spring portion 37 is relatively small (approximately two turns), the reaction force received from the body-side stopper 46 and the gear-side spring locking portion 42 is not easily distributed among the turns, and the amount of eccentricity of each turn of the opener spring portion 37 tends to be large. As a result, the portion of the opener spring portion 37 closest to the intermediate hook 33 (the right side in the drawings) is pressed against the inner peripheral support portion 47, while the portion on the opposite side (the left side in the drawings) is significantly separated from the inner peripheral support portion 47. When the throttle gear 20 rotates from the default position toward the fully closed position, the opener spring portion 37 twists further in the radially contracting direction, increasing the force with which the opener spring portion 37 presses against the inner peripheral support portion 47. When the throttle gear 20 rotates between the default position and the fully closed position, the intermediate hook 33 is restrained by the body-side stopper 46, and as described above, the portion of the opener spring portion 37 close to the intermediate hook 33 rotates more relative to the throttle gear 20. Therefore, if this portion of the opener spring portion 37 is pressed against the inner peripheral support portion 47, friction occurs between the opener spring portion 37 and the inner peripheral support portion 47 when the throttle gear 20 rotates, resulting in rotational resistance of the throttle gear 20.

[0025] In contrast, in the above-described embodiment in which the outer peripheral support portion 50 is provided on the throttle gear 20 as shown in FIGS. 10 and 11 , the outer peripheral support portion 50 abuts against the outer peripheral side of the orbit 37b of the opener spring portion 37 on the middle hook 33 side, suppressing eccentricity. This causes the orbit 37b on the middle hook 33 side to be separated from the inner peripheral support portion 47 of the throttle gear 20. As a result, the inner peripheral side of the orbit 37b of the opener spring portion 37 on the middle hook 33 side is separated from the inner peripheral support portion 47. This eliminates friction that occurs between the opener spring portion 37 and the inner peripheral support portion 47 when the throttle gear 20 rotates between the default position and the fully closed position. This not only reduces wear on the inner peripheral support portion 47 but also reduces the load on the motor 22, making it possible to reduce the size of the motor 22 and the reduction ratio of the transmission mechanism, leading to a more compact throttle device 10.

[0026] In another embodiment (not shown), the outer peripheral support portion 50 can be configured to reduce the force with which the opener spring portion 37 presses against the inner peripheral support portion 47, instead of completely separating the lap 37b of the opener spring portion 37 on the side of the intermediate hook 33 from the inner peripheral support portion 47. In other words, the outer peripheral support portion 50 can be configured to press back against the opener spring portion 37 in the direction opposite to the direction in which the opener spring portion 37 tends to become eccentric (arrow 72 in FIG. 10). This reduces friction that occurs between the opener spring portion 37 and the inner peripheral support portion 47 when the throttle gear 20 rotates.

[0027] 6, the outer peripheral support part 50 can be arranged to abut on the turn 37b of the opener spring part 37 on the side of the intermediate hook 33 at a position within a range of approximately 180° to 360° (for example, approximately 270°) from the intermediate hook 33. This avoids contact at a location where the relative rotation between the opener spring part 37 and the inner peripheral support part 47 is relatively large, thereby effectively reducing friction.

[0028] The distance from the central axis of the throttle gear 20 to the outer peripheral surface of the inner peripheral support portion 47 does not have to be constant. For example, the distance can be set to be large at a portion of the outer peripheral surface of the inner peripheral support portion 47 that should support the turn 37a on the end 32 side of the opener spring portion 37, and small at a portion where the turn 37b on the intermediate hook 33 side of the opener spring portion 37 approaches the outer peripheral surface due to eccentricity.

[0029] 11, the minimum distance d between the inner peripheral support portion 47 and the outer peripheral support portion 50 where the opener spring portion 37 is disposed can be set to less than twice the diameter of the coil wire of the opener spring portion 37. This prevents the coil wires of the opener spring portion 37 from overlapping with each other between the inner peripheral support portion 47 and the outer peripheral support portion 50, thereby stabilizing the posture of the opener spring portion 37.

[0030] [Intermediate hook contact angle] As shown in FIG. 11 , the stopper-facing surface 34 of the intermediate hook 33 of the coil spring 30 is oriented so that the opener spring-side leg 38 of the intermediate hook 33 (the portion closer to the opener spring portion 37 than the turning point 39) abuts against the gear-side stopper 44. The stopper-facing surface 34 of the intermediate hook 33 here refers to the plane formed by the opener spring-side leg 38 and the return spring-side leg 36 of the intermediate hook 33 on the side facing the gear-side stopper 44. When viewed alone (see FIG. 5 ), the above-described orientation can be achieved by tilting the stopper-facing surface 34 of the intermediate hook 33 (by an angle θ) relative to the center axis 76 of the coil spring 30. The return spring-side leg 36 does not need to abut against the gear-side stopper 44, but as another embodiment (not shown), it may abut against the gear-side stopper 44. For example, the stopper-opposing surface 34 of the intermediate hook 33 can be oriented so that the angle α with respect to the abutting surface 49 of the gear-side stopper 44 is 0 to 7 degrees.

[0031] As described above, the opener spring portion 37 is supported from the outer periphery by the outer peripheral support portion 50, so its turn 37b on the middle hook 33 side is separated from the inner peripheral support portion 47. On the other hand, the return spring portion 35 is not supported by the outer peripheral support portion 50, so its turn 35b on the middle hook 33 side is supported by the inner peripheral support portion 47. As a result, the opener spring portion 37 is supported by the outer peripheral support portion 50 at a position about three-quarters of the way around from the middle hook 33 in the circumferential direction, while the return spring portion 35 is supported by the inner peripheral support portion 47 at a position about one-quarter of the way around, so that the initial support points of the two springs are offset. Due to this difference in the length (span) from the middle hook 33 to the initial support point, only one of the opener spring portion 37 and the return spring portion 35 tends to resonate in the axial direction of the coil spring 30. However, as described above, because the opener spring side leg 38 of the intermediate hook 33 abuts against the gear side stopper 44, even if the opener spring portion 37 resonates, the vibration is prevented from being transmitted to the turning point 39 of the intermediate hook 33. Therefore, repeated bending and twisting stresses are prevented from being applied to the turning point 39, improving the durability of the throttle device 10 against vibration.

[0032] As shown in FIG. 14 , in another embodiment, instead of tilting the stopper-facing surface 34 of the intermediate hook 33, the abutment surface 49 of the gear-side stopper 44 can be tilted (by an angle β) with respect to the center axis of the throttle gear 20 or the stopper-facing surface 34 of the intermediate hook 33 so that the opener spring-side leg 38 of the intermediate hook 33 abuts against the gear-side stopper 44. In another embodiment (not shown), not only can the gear-side stopper 44 be tilted, but the abutment surface of the body-side stopper 46 with which the intermediate hook 33 abuts can also be tilted in the same way. In yet another embodiment, the stopper-facing surface 34 of the intermediate hook 33 and the abutment surfaces of the gear-side stopper 44 and the body-side stopper 46 can all be tilted. In these embodiments, when the opener spring portion 37 resonates, the vibration is prevented from being transmitted to the turning point 39 of the intermediate hook 33 for the same reason as described above.

[0033] [Latching groove and retaining hole] As shown in Figures 15 and 16, the gear-side spring locking portion 42 that locks the gear-side end 32 of the coil spring 30 can be provided with a locking groove 43 into which the end 32 can fit. Furthermore, the gear-side spring locking portion 42 can be provided as the inner wall of a retaining hole 64 that surrounds the gear-side end 32 of the coil spring 30. This prevents the gear-side end 32 of the coil spring 30 from completely coming off the gear-side spring locking portion 42 due to vibration during use or during assembly. For example, the retaining hole 64 can be formed by providing a bridge portion 67 between a support post 66 that forms the gear-side spring locking portion 42 and a support post 68 that forms the gear-side stopper 44. The bridge portion 67, in particular, prevents the gear-side end 32 of the coil spring 30 from coming off the gear-side spring locking portion 42. In an embodiment not shown, instead of the bridge portion 67, a protrusion may be provided that extends from the support pillar 66 that forms the gear-side spring locking portion 42 toward the support pillar 68 that forms the gear-side stopper 44. In this way, even if the protrusion does not reach the support pillar 68 of the gear-side stopper 44, it is possible to form a retaining hole that partially surrounds the gear-side end portion 32 of the coil spring 30.

[0034] [Assembling the coil spring to the throttle gear] As shown in Figure 15, to attach the coil spring 30 to the throttle gear 20, the end 32 is engaged with the gear-side spring engaging portion 42, and then the opener spring portion 37 is twisted in the radially contracting direction while the intermediate hook 33 is engaged with the gear-side stopper 44. At this time, care must be taken to ensure that the opener spring portion 37 is securely fitted between the inner peripheral support portion 47 and the outer peripheral support portion 50. Figure 16 shows the coil spring 30 correctly attached to the throttle gear 20.

[0035] [Obstacle structure] As shown in Figures 4, 15, and 16, the throttle gear 20 may be provided with an obstacle structure 60 to prevent the coil spring 30 from being installed in an incorrect position. The obstacle structure 60 may be a block extending from the base 48 of the throttle gear 20 on the same side as the outer circumferential support portion 50. The obstacle structure 60 is preferably disposed between the outer circumferential support portion 50 of the throttle gear 20 and the gear-side spring locking portion 42. As a specific example, the obstacle structure 60 may be an arc-shaped block extending over an angle range of approximately 45° as viewed from the axis of the throttle gear 20. The obstacle structure 60 may also be provided with an inner slope 62 that slopes inward (toward the inner circumferential support portion 47) from the top toward the base 48 of the throttle gear 20.

[0036] [Other embodiments] In an alternative embodiment not shown, the coil spring 30 may be a mirror image of the one shown, depending on the direction of rotation required to open and close the throttle valve 15 and the direction of the throttle shaft 17 extending from the throttle valve 15. Of course, even in such a mirror image configuration, the return spring portion and the coil spring are still wound in opposite directions.

[0037] In still other embodiments, the return spring portion 35 and the opener spring portion 37 of the coil spring 30 may have a different number of turns than those shown. In still other embodiments, the relative diameters of the turns of the return spring portion 35 and the opener spring portion 37 may also be different than those shown.

[0038] In yet another embodiment, of the two spring portions constituting the coil spring 30, the first spring portion engaged with the throttle gear 20 can function as the return spring portion, and the second spring portion engaged with the throttle body 12 can function as the opener spring portion. In this case, the rotation direction of the throttle gear 20 when opening and closing the throttle valve 15 is opposite to the direction shown in FIG. 6. Even in this embodiment, the provision of the outer peripheral support portion as described above can suppress eccentricity of the return spring portion (rather than the opener spring portion). Furthermore, by abutting the return spring side leg of the intermediate hook against the gear side stopper, even if the return spring portion resonates, the vibration can be prevented from being transmitted to the turning point of the intermediate hook.

[0039] Although specific embodiments have been described above, the present technology is not limited to these embodiments, and a person skilled in the art can make various substitutions, improvements, and modifications without departing from the purpose of the present technology. [Explanation of symbols]

[0040] 10 Throttle device 12 Throttle body 13 Intake passage 14 Housing part 15 Throttle valve 17 Throttle shaft 18, 19 Bearings 20 throttle gear 21 Mounting holes 22 Motor 23 Output shaft 24 Drive gear 26 Intermediate gear 26a Large diameter tooth part of intermediate gear 26b Small diameter tooth part of intermediate gear 27 Intermediate shaft 28 Throttle gear teeth 29 Housing lid 30 coil spring 31 Body side end of coil spring 32 Gear side end of coil spring 33 Coil spring middle hook 34 Stopper facing surface of intermediate hook 35 Return spring part 35b The return spring part is the most central hook side circumference 36 Return spring side leg of intermediate hook 37 Opener spring part 38 Opener spring side leg of intermediate hook 39 Middle hook turn point 37a End of opener spring 37b Opener spring part, middle hook side circumference 40 Body side spring locking part 42 Gear side spring locking part 43 Locking groove 44 Gear side stopper 45 Bearing holder 46 Body side stopper 47 Inner circumference support part 48 Throttle gear base 50 Periphery support part 52 Outer slope 60 Obstacle Structure 62 Inner Slope 64 retaining hole 66 Gear side spring locking part support pillar 67 Bridge 68 Gear side stopper support column 76 Coil spring center axis

Claims

1. A throttle device, a throttle body that forms an intake passage; a throttle valve that opens and closes the intake passage; a throttle shaft coupled to the throttle valve; a rotating member coupled to the throttle shaft and rotated by a drive source; a coil spring interposed between the throttle body and the rotary member and biasing the throttle valve toward a default position, the coil spring has a first spring portion including a first end, a second spring portion including a second end, and an intermediate hook connecting the first spring portion and the second spring portion; the first end is engaged with a first spring engaging portion provided on the rotary member, and the second end is engaged with a second spring engaging portion provided on the throttle body, the intermediate hook is adapted to be able to engage with a first stopper provided on the rotary member and a second stopper provided on the throttle body, the rotating member has a retaining hole that at least partially surrounds the first end of the first spring portion that is engaged with the first spring engaging portion; The first spring locking portion has a locking groove, and the first end portion is fitted into the locking groove.

2. 2. The throttle device of claim 1, further comprising a support pillar forming the first spring engaging portion and a support pillar forming the first stopper, and the retaining hole is formed by a bridge portion extending between the support pillars.

3. 3. The throttle device according to claim 1, wherein the first spring engaging portion is formed as an inner wall of the retaining hole.

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