A throttle device includes 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 configured to bias the throttle valve toward a default position. The coil spring has a first spring portion, a second spring portion, and an intermediate hook portion for connecting the first spring portion and the second spring portion. The rotating member includes an inner periphery supporting portion that supports an inner peripheral side of the first spring portion, an outer periphery supporting portion that supports an outer peripheral side of the first spring portion, and a blocking structure for preventing the first spring portion from being fitted to an outside of the outer periphery supporting portion when assembling the coil spring.

A coil-over throttle return spring device mounts onto the exterior of the carburetor and allows the user to adjust the throttle tension without having to remove the device from the carburetor. The throttle tension is adjusted by moving the ring along the length of the body to lengthen or shorten the spring. A coil-over throttle return spring device kit comprises the device and a bracket and hardware used to easily mount onto various size carburetors. The bracket and hardware allows for adjustability depending on the size of the engine and length of cables. A method of installing a coil-over throttle return spring device kit onto a carburetor and a method of adjusting the throttle tension.

A torsion spring that is used in a throttle valve device increasing and decreasing an opening degree of an intake passage or an exhaust passage of an internal-combustion engine includes: two coil springs connected with each other so that torsion directions are opposite from each other; and a hook disposed between the two coil springs. Of the two coil springs, one side spring arranged at one side in an axial direction biases a valve object to a closing side, and the other side spring arranged at the other side in the axial direction biases the valve object to an opening side. In at least one coil spring of the two coil springs, a dimension of a clearance between the at least one coil spring and the hook connected with each other is larger than an average value of clearances between coil turns of the at least one coil spring.

A throttle valve having: a valve body; an intake duct obtained in the valve body; a throttle plate arranged in the intake duct; a shaft mounted so as to rotate, supporting the throttle plate; an electric motor; a gear transmission, which couples the electric motor to the shaft and has an end gear which is integral with the shaft; a return spring, which is designed to rotate the throttle plate towards a closing position; a striking element, which is obtained in the valve body and establishes an intermediate position of partial opening; and a countering spring, mounted on the end gear, which is designed to rotate the throttle plate towards the intermediate position and has one end which is designed to rest against the striking element during the rotation of the end gear.

A throttle device comprises a throttle body, a throttle gear, and a coil spring. The coil spring comprises an intermediate hook part, a return spring part that is wound in one direction from the intermediate hook part, and an opener spring part that is wound in the opposite direction from the intermediate hook part. A gear-side end part of the opener spring part is connected to the throttle gear. The throttle gear comprises a spring guide part that holds the inner circumferential side of the opener spring part. The throttle gear comprises an outer circumferential support part that abuts the outer circumferential side of the first turn of the opener spring part on the intermediate hook part side.

An excentric pin for an electronic throttle control assembly, which is used to adjust the default position of at least one spring used to control the position of a valve plate, where the valve plate is located in an opening of a housing in the electronic control assembly. The excentric pin is used to adjust the default angle of the valve plate to have an angular tolerance of +/0.10. The excentric pin is slideably pressed into an aperture of the housing of the electronic throttle control assembly, and turned using some type of driver. The electronic throttle control assembly may be a one-spring design, or a two-spring design, where the two-spring design requires only one spring pin and the excentric pin. Also, the excenter pin may be used to adjust the position of the sector gear, e.g., function as the lower mechanical stop to provide a minimum opening angle for low leakage, and a minimum opening angle to avoid throttle plate corking into opening of the housing.

A control system of at least one flap of a fluid duct of an intake system of an internal combustion engine, including: a swivel axis, at least one flap connected off-center to the swivel axis by which the at least one flap can be swiveled within the fluid duct between positions with different degrees of opening, a swivel lever connected to the swivel axis, the swivel lever pivoting the swivel axis, an elastic working return element connected directly or indirectly to the swivel lever and applying a force to the at least one flap to return the at least one flap toward a home position.

A throttle device includes 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 configured to bias the throttle valve toward a default position. The coil spring has a first spring portion, a second spring portion, and an intermediate hook portion for connecting the first spring portion and the second spring portion. The rotating member includes an inner periphery supporting portion that supports an inner peripheral side of the first spring portion, an outer periphery supporting portion that supports an outer peripheral side of the first spring portion, and a blocking structure for preventing the first spring portion from being fitted to an outside of the outer periphery supporting portion when assembling the coil spring.

A coil spring of a throttle valve device around a shaft between a valve and a valve gear has one end rotated together with a first guide, and another end rotated together with a second guide. The both ends of the coil spring contact a holding portion and a driving portion at a valve intermediate position of the shaft. The driving portion pushes the one end of the coil spring while the holding portion holds the other end of the coil spring during movement of the shaft from the valve intermediate position toward a valve fully-open position or a valve fully-closed position. The first guide and the second guide have insertion holes that face each other in an axial direction when the both ends of the coil spring are positioned near the valve intermediate position of the shaft and are not in contact with the holding portion.

A torsion spring that is used in a throttle valve device increasing and decreasing an opening degree of an intake passage or an exhaust passage of an internal-combustion engine includes: two coil springs connected with each other so that torsion directions are opposite from each other; and a hook disposed between the two coil springs. Of the two coil springs, one side spring arranged at one side in an axial direction biases a valve object to a closing side, and the other side spring arranged at the other side in the axial direction biases the valve object to an opening side. In at least one coil spring of the two coil springs, a dimension of a clearance between the at least one coil spring and the hook connected with each other is larger than an average value of clearances between coil turns of the at least one coil spring.