Intake charge-regulating apparatus for an internal combustion engine, and engine incorporating same

An intake charge regulating apparatus for a four cylinder engine with first and second banks arranged substantially in a V shape, the intake charge regulating apparatus comprising:

• a first throttle body having a throttle bore formed therein for communicating with an intake port of a first cylinder head, and a throttle valve disposed in the throttle bore for controlling an opening of the throttle bore,
• wherein two throttle bodies including the first throttle body are arranged respectively corresponding to two cylinders in the first bank, and the two throttle bodies are connected to each other so that the two throttle bodies constitute a first throttle body group,
• two other throttle bodies are arranged respectively corresponding to two cylinders in the second bank are connected to each other in order that the two other throttle bodies constitute a second throttle body group;
• a throttle driving mechanism including an electric motor for generating power for driving the throttle valve to open and close, and a transmission mechanism for decelerating a driving force of the electric motor, and for transmitting the driving force to the throttle valve, wherein:
• a camshaft sprocket, which is part of a timing transmission mechanism for transmitting power from a crankshaft is fixed to an end portion of a camshaft included in a valve system for driving an intake valve and an exhaust valve to open and close in the cylinder head;
• wherein the throttle driving mechanism is arranged at a side of the engine which is opposite to the camshaft sprocket in an axis direction of the crankshaft;
• and
• the electric motor is arranged between the first throttle body and the first cylinder head as seen in a top plan view;
• wherein the engine is configured such that a distance between the throttle bores of the two respective throttle bodies in the first throttle body group is set shorter than a distance between the throttle bores of the two throttle bodies in the second throttle body group, and
• the electric motor is situated proximate the first throttle body group.

A four cylinder engine comprising:

• first and second banks arranged substantially in a V shape;
• first and second throttle body groups each comprising a plurality of throttle bodies, and a pair of spaced-apart side plates operatively interconnecting the first and second throttle body groups;
• said first throttle body group comprising a first throttle body having a throttle bore formed therein for communicating with an intake port of a first cylinder head, and a throttle valve disposed in the throttle bore for controlling an opening of the throttle bore,
• wherein two throttle bodies including the first throttle body are arranged respectively corresponding to two cylinders in the first bank, and the two throttle bodies are connected to each other so that the two throttle bodies constitute the first throttle body group,
• two other throttle bodies are arranged respectively corresponding to two cylinders in the second bank are connected to each other in order that the two other throttle bodies constitute the second throttle body group;
• a throttle driving mechanism including an electric motor for generating power for driving the throttle valve to open and close, and a transmission mechanism for decelerating a driving force of the electric motor, and for transmitting the driving force to the throttle valve,
• wherein:
• a camshaft sprocket, which is part of a timing transmission mechanism for transmitting power from a crankshaft is fixed to an end portion of a camshaft included in a valve system for driving an intake valve and an exhaust valve to open and close in the cylinder head;
• the throttle driving mechanism is arranged at a side of the engine which is opposite to the camshaft sprocket in an axis direction of the crankshaft;
• the electric motor is arranged between the first throttle body and the first cylinder head as seen in a top plan view;
• the engine is configured such that a distance between the throttle bores of the two respective throttle bodies in the first throttle body group is set shorter than a distance between the throttle bores of the two throttle bodies in the second throttle body group, and
• the electric motor is situated proximate the first throttle body group.