Throttle valve controller for internal combustion engine

Details Throttle valve controller for internal combustion engine Throttle valve controller for internal combustion engine

1999-12-15

2001-06-19

Yuen, Henry C. (Department: 3747)

Internal-combustion engines

Engine speed regulator

Open loop condition responsive

C123S361000, C123S339140, C251S129010

Reexamination Certificate

active

06247447

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a throttle valve controller and, more particularly, to a throttle valve controller for an internal combustion engine that is used to finely control the intake air quantity when the internal combustion engine is in an idling state.
2. Description of the Prior Art
When an internal combustion engine for an automobile is in an idling state in particular, the intake air quantity is affected considerably by environmental or equipment temperature or other conditions. Therefore, it is necessary to finely control the intake air quantity. Various techniques of finely controlling the intake air quantity have already been proposed.
Examples of the proposed techniques are as follows:
{circle around (1)} Japanese Patent Application Post-Examination Publication No. 5-34518 is an example of a bypass air valve system that controls a bypass air passage provided in parallel to the throttle valve. The publication discloses a system that uses a rotary solenoid valve.
{circle around (2)} Japanese Patent Application Unexamined Publication (KOKAI) No. 3-107544 is an example of a direct-acting system that directly drives the throttle valve only in a small throttle opening range. The publication discloses a system in which the throttle valve is driven by a DC motor.
{circle around (3)} Japanese Patent Application No. 10-69410 is an example of a DBW (Drive By Wire) system in which the throttle valve is driven in the entire throttle opening range by using various actuators. Japanese Patent Application No. 10-69410 employs a torque motor as an actuator.
In the above-described various systems, the bypass air valve system stated in {circle around (1)} generally adopts open-loop control and hence suffers from problems in terms of accuracy. To adopt closed-loop control, a position sensor is additionally needed, resulting in an increase in cost.
The direct-acting system stated in {circle around (2)} drives the throttle valve by a DC motor and therefore requires speed reduction through a gear mechanism to obtain appropriate control resolution owing to the transmission structure thereof. Accordingly, this system suffers from problems in terms of response due to speed reduction as well as an increase in cost.
In the DBW system stated in {circle around (1)}, no matter which actuator is used, i.e. a torque motor, a DC motor, or a stepper motor, the cost of the actuator unavoidably increases to obtain satisfactory driving force and driving range. In addition, higher levels of fail-safe and limp-home capabilities are demanded. Accordingly, the system becomes unfavorably costly.
SUMMARY OF THE INVENTION
In view of the above-described problems associated with the prior art, an object of the present invention is to provide a throttle valve controller for an internal combustion engine that exhibits superior control resolution with a simple structure and is free from runaway due to a circuit failure and obtainable at reduced cost.


REFERENCES:
patent: 4976237 (1990-12-01), Bollinger
patent: 5490487 (1996-02-01), Kato et al.
patent: 5517966 (1996-05-01), Kanazawa et al.
patent: 5624100 (1997-04-01), Bolte et al.
patent: 2000-240474 (2000-05-01), None

Affiliated with

Also associated with

Rating

Throttle valve controller for internal combustion engine does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Throttle valve controller for internal combustion engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Throttle valve controller for internal combustion engine will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2479401