Internal-combustion engines – Engine speed regulator – Open loop condition responsive
Reexamination Certificate
1999-10-29
2001-08-28
Argenbright, Tony M. (Department: 3747)
Internal-combustion engines
Engine speed regulator
Open loop condition responsive
Reexamination Certificate
active
06279535
ABSTRACT:
FIELD OF THE INVENTION
The present invention generally relates to vehicle throttles. More particularly, the present invention pertains to a throttle control device associated with internal combustion engines for adjusting the amount of opening of a throttle valve by driving a motor connected to the throttle in response to the amount of depression of the acceleration pedal.
BACKGROUND OF THE INVENTION
Japanese Patent Laid-Open Publication No. Hei. 6-264779 published on Sep. 20, 1994 without examination discloses a known throttle control device that includes a throttle valve for adjusting the amount of air passing through the intake passage of an internal combustion engine and a throttle body in which is accommodated the throttle valve. The throttle body rotatably supports a throttle shaft to which the throttle valve is fixed. A motor is coupled to the throttle valve via a power transmission mechanism for open/close driving of the throttle valve, and a throttle sensor determines the opening amount of the throttle valve. A cover is also secured to the throttle body for accommodating the power transmission mechanism in a space between the cover and the throttle body.
In this known throttle control device, when the acceleration pedal is depressed, the resultant depression amount is determined by a throttle sensor. A signal indicative of the depression amount of the acceleration pedal is issued from the throttle sensor and the motor is driven to rotate the throttle valve through an angle in response to the signal. Thus, the amount of air to be taken into the internal combustion engine is adjusted. Such an adjustment is established with well-known feedback control or PID control (Proportion-Integration-Differential Control) in such manner that the actual opening amount of the throttle valve which is indicated by the signal from the throttle sensor is compared to a target opening amount of the throttle valve which is indicated by the signal of the acceleration sensor for converging the deviation between the two values to zero.
However, with the above-construction, the cover and the throttle sensor are provided separately, thus requiring an independent fixation mounting of each of the cover and the throttle sensor to the throttle body. Thus, the number of parts is increased, with the result that the production cost is increased and the assembly of the device is more complicated.
Accordingly, a need exists for a throttle control device that is not as susceptible to the foregoing disadvantages and drawbacks.
It would thus be desirable to provide a throttle control device possessing a simpler construction and capable of being more easily assembled and with a lower production cost.
SUMMARY OF THE INVENTION
According to one aspect of the invention, a throttle control device includes a throttle body, a throttle shaft journalled on the throttle body, a throttle valve accommodated in the throttle body and mounted on the throttle shaft for adjusting an amount of air passing through the intake passage of the internal combustion engine, a motor coupled via a power transmission mechanism to the throttle shaft for driving the throttle valve in a closing direction and an opening direction to adjust the amount of opening of the throttle valve, and a cover connected to the throttle body and enclosing the power transmission mechanism. The cover includes a built-in throttle sensor for determining the amount of opening of the throttle valve. A connecting member connects the throttle sensor and the throttle shaft.
According to the present invention, the cover forms the body of the throttle sensor and only one portion is required for connecting the cover to the throttle body. This advantageously decreases the number of parts, thereby reducing the production cost of the throttle control device and simplifying the assembly. In addition, the concentration or integration of parts brings about a reduction in the overall size of the throttle control device.
The present invention also provides an integral connecting portion on the cover which is provided with terminals to be electrically coupled to the motor and the throttle sensor, respectively. The electric coupling operations to the throttle control device are thus significantly improved, thereby facilitating or making easier the mounting operation of the throttle valve control device on the internal combustion engine.
Also, according to the present invention, the throttle sensor includes a sensor shaft journaled in the cover and biased toward a direction of closing the throttle valve, the sensor shaft is fixed with the connecting member in order that the connecting member is engagible with a projection formed at an end of the throttle shaft in the direction of closing the throttle valve, and a guide member is provided at either the connecting member or the projection for rotating the sensor shaft in the direction of opening the throttle valve when the cover is mounted to the throttle body. The guide portion allows the connecting member to engage the throttle shaft in the direction of closing throttle valve and this ensures a reliable transmission of rotation from the throttle shaft to the sensor shaft without rattling, thereby deriving a voltage signal from the throttle sensor which is in response to the opening amount of the throttle valve. Moreover, in the event the sensor shaft fails to rotate, the throttle sensor issues a higher voltage signal than a voltage signal indicative of the actual opening amount of the throttle valve, with the result that the motor is driven in the direction of closing the throttle valve so as to decrease the voltage signal from the throttle sensor. Thus, the output power of the internal combustion engine is decreased, thereby ensuring vehicle safety.
According to another aspect of the invention, a throttle control device includes a throttle body, a throttle shaft journalled on the throttle body, a throttle valve accommodated in the throttle body and mounted on the throttle shaft for adjusting the amount of air passing through the intake passage of the internal combustion engine, a motor coupled via a power transmission mechanism to the throttle shaft for driving the throttle valve in a closing direction and an opening direction to adjust the amount of opening of the throttle valve, and a cover secured to the throttle body to enclose the power transmission mechanism. A throttle sensor is mounted on the cover so that connecting the cover to the throttle body results in mounting of the throttle sensor on the throttle. The throttle sensor is operatively connected to the throttle shaft body for determining the amount of opening of the throttle valve.
In accordance with another aspect of the invention, a throttle control device for a vehicle includes a throttle body, a throttle shaft journalled on the throttle body, a throttle valve accommodated in the throttle body and mounted on the throttle shaft for adjusting the amount of air passing through the intake passage of the internal combustion engine, a motor coupled via a power transmission mechanism to the throttle shaft for driving the throttle valve in a closing direction and an opening direction to adjust the amount of opening of the throttle valve, and a cover connected to the throttle body to enclose the power transmission mechanism. A throttle sensor is operatively connected to the throttle shaft for determining the amount of opening of the throttle valve. The cover includes an integrally formed connecting portion at which are exposed a plurality of terminals that are electrically connected to the motor and the throttle sensor.
REFERENCES:
patent: 6000377 (1999-12-01), Sato et al.
patent: 19540323 (1997-04-01), None
patent: 19704012 (1998-08-01), None
patent: 6-264779 (1994-09-01), None
Aisin Seiki Kabushiki Kaisha
Argenbright Tony M.
Burns Doane , Swecker, Mathis LLP
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