Engine intake control apparatus
View Patent ↗In an engine intake control apparatus, a cover is made of synthetic resin, a motor support plate is made of metal, a positioning boss is integrally formed on the cover, a first positioning hole arranged on a motor support plate is fitted on an outer peripheral surface of the positioning boss, and the positioning boss is positioned and fitted with a throttle valve body each other. With such an engine intake control apparatus, it is possible to perform with high accuracy the mutual positioning between the three components, i.e. the motor support plate, the cover and the throttle valve body, and it is possible to effectively improve the opening and closing accuracy for the opening and closing of the throttle valve by the motor.
1. An engine intake control apparatus comprising:
a throttle valve body including an intake passage opened and closed by a throttle valve, the throttle valve body supporting a valve shaft of the throttle valve for opening and closing the intake passage;
a cover joined to one side of the throttle valve body to define a speed reduction chamber therebetween, wherein the speed reduction chamber includes:
a motor,
a motor support plate joined to the cover and supporting a stator of the motor, the stator being joined to the motor support plate, and
a reduction gear row for decelerating and transferring rotation of a rotor shaft of the motor to the valve shaft, the rotor shaft being parallel with the valve shaft,
wherein the cover is made of synthetic resin, the motor support plate is made of metal,
the cover includes a positioning boss integrally formed thereon, the positioning boss projecting from the cover toward the one side of the throttle valve body,
the motor support plate includes a first positioning hole fitted on an outer peripheral surface of the positioning boss such that the positioning boss is inserted into the first positioning hole, and
the positioning boss is positioned with respect to the throttle valve body,
wherein the engine intake control apparatus further comprises a positioning shaft extending in parallel with the valve shaft from the one side of the throttle valve body, and
wherein the positioning boss includes a second positioning hole inside thereof extending parallel with the rotor shaft and receiving the positioning shaft.
2. The engine intake control apparatus according to claim 1 ,
wherein the reduction gear row includes:
a pinion gear provided on the rotor shaft,
an intermediate gear block, and
an output gear,
wherein the intermediate gear block includes:
a large-diameter intermediate gear engaging with the pinion gear, and
a small-diameter intermediate gear integrally formed on one side face of the large-diameter intermediate gear,
wherein the output gear is provided on the valve shaft and engaged with the small-diameter intermediate gear, and the intermediate gear block is supported by the positioning shaft.
3. The engine intake control apparatus according to claim 2 , wherein the positioning shaft is a rotational axis of the intermediate gear block.
4. The engine intake control apparatus according to claim 2 , wherein one end of the positioning shaft is received by the second positioning hole and the other end of the positioning shaft is attached to the one side of the throttle valve body.
5. The engine intake control apparatus according to claim 3 , wherein one end of the positioning shaft is received by the second positioning hole and the other end of the positioning shaft is attached to the one side of the throttle valve body.
6. The engine intake control apparatus according to claim 2 , wherein the pinion gear and the output gear are configured such that respective side faces of the pinion gear and the output gear face each other.