JP2962818B2 - Engine throttle valve controller - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine throttle valve control device for electrically controlling the opening of an engine throttle valve.

[Prior Art] Generally, in this type of device, a throttle valve is constantly biased in a fully closed direction by a biasing force of a back spring. Since the biasing force of the back spring is usually set to be larger than the torque when the control motor is not energized, the energization to the motor is stopped even if the control circuit breaks down while controlling the opening of the throttle valve. Thus, the throttle valve is operated in the fully closed direction. Incidentally, as this kind of prior art, Japanese Patent Application Laid-Open No. 56-14834
And JP-A-51-138235 have been proposed.

However, in the throttle valve control device, when the engine is stopped, the throttle valve is always fully closed, so that the throttle valve or the throttle shaft freezes in a cold region or at extremely low temperatures (so-called freezing). If it is fixed, the opening of the throttle valve becomes impossible, and there is a possibility that a problem that the engine cannot be operated satisfactorily may occur. Also, when sticky substances such as combustion products accompanying the combustion in the engine adhere to the throttle valve, there is a possibility that the same problem as in the case of freezing may occur.

Therefore, in order to cope with such a problem, for example, Japanese Patent Application Laid-Open No. 63-150449 proposes opening a throttle valve by a predetermined amount when the engine is stopped. In the engine throttle valve control device of this publication,
In addition to the first urging means for urging the throttle valve in the closing direction, a second urging means for urging the throttle valve in the opening direction is provided. The throttle valve is opened to a predetermined opening in a balanced relationship.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, the first and second
The opening degree (opening amount) of the throttle valve is determined by the balance position of the two urging means, so that not only the accuracy of the opening position of the throttle valve is not obtained, but also the throttle valve opening position due to the aging of the urging means. May change.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to allow a throttle valve to be accurately opened to a predetermined opening position when an engine is stopped, and the like. An object of the present invention is to provide an engine throttle valve control device capable of holding an opening position without change over time.

[Means for Solving the Problems] A throttle valve control device for an engine according to the present invention for solving the above problems is provided with a throttle valve provided in an intake pipe of the engine for adjusting a flow rate of combustion air, and driving the throttle valve. A driving means for driving the throttle valve, a first urging means for urging the throttle valve in the closing direction, and a second urging means for urging the throttle valve in the opening direction with an urging force larger than the urging force of the first urging means. And a stopper for regulating the bias of the throttle valve to a predetermined opening degree or more.

According to the above-mentioned means, during the operation of the engine, the throttle valve is opened and closed by the driving force of the driving means against the urging force of the first urging means when the opening degree is equal to or larger than the predetermined opening degree. Hereinafter, it is opened and closed against the urging force of the second urging means.

When the driving force by the driving means is cut off, the throttle valve is opened by the urging force of the second urging means to a predetermined opening position where the urging is restricted by the stopper, and the passage in the intake pipe is opened by a predetermined amount. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1 showing a side view of a throttle valve control device of an engine and FIG. 2 showing a plan sectional view thereof, a throttle valve 2 is provided in an intake pipe 1 of the engine so as to be rotatable by a throttle shaft 3. ing. The throttle valve 2 adjusts the flow rate of combustion air flowing through the intake passage 1a in the intake pipe 1 by its rotation.

One end (the upper end in FIG. 2) of the throttle shaft 3 penetrates the wall of the intake pipe 1, and a driven gear 20 is fixed to the end. A drive motor 4 composed of a step motor is externally attached to the intake pipe 1. A drive gear 21 fixed to the output shaft of the drive motor 4 is meshed with the driven gear 20. Therefore, by controlling the rotation of the drive motor 4, the opening of the throttle valve 2 can be adjusted.

The drive motor 4 is provided with a control device 7 that determines the rotation amount of the throttle valve 2 in accordance with a signal from an accelerator sensor 6 or the like that detects the depression amount of an accelerator pedal operated by a driver, similarly to the above-described conventional device. Is driven by the electric signal of.

The other end (the lower end in FIG. 2) of the throttle shaft 3 also penetrates the wall of the intake pipe 1, and a lever 8 is inserted and fixed to this end. The lever 8 is mounted vertically to the throttle shaft 3, and its front and rear ends extend along the front and rear direction of the intake pipe 1.

A stopper 16 is provided on the side wall of the intake pipe 1 so as to face the left end of the lever 8 in the figure. The stopper 16 includes an adjusting bolt 18 screwed to a mounting piece 19 mounted on the side wall,
An adjustment nut 17 screwed to the bolt 18 is provided.

Further, both ends of a coiled back spring 15 are mounted on a left extension of the lever 8 and a stay 15a externally attached to the intake pipe 1, respectively. This backspring 15
Of the throttle valve 2, the throttle valve 2 is urged in the closing direction of the throttle valve 2, that is, the direction in which the end of the lever 8 comes into contact with the tip of the adjusting bolt 18 of the stopper 16 (clockwise direction in FIG. 1). I have. When the lever 8 comes into contact with the adjustment bolt 18 of the stopper 16, the throttle valve 2 is fully closed (idling state). This state is shown in a side view in FIG. 3, and the throttle valve 2 is shown by a two-dot chain line in FIG. The fully closed position of the throttle valve 2 can be adjusted by adjusting the degree of screwing of the adjusting bolts / nuts 18 and 17 of the stopper 16.

In FIG. 1, a bent piece 8a is provided at the right end of the lever 8 in the drawing.
Is provided. An adjusting bolt 10 is screwed to the bent piece 8a, and an adjusting nut 9 is screwed to the bolt 10.

On the side wall of the intake pipe 1, a second urging means 9 is provided to face an adjustment bolt 10 provided at an end of the lever 8. The second biasing means 9 includes a case 14 screwed to a bracket 9 a provided on a side wall of the intake pipe 1, and a plate 12 which is housed in the case 14 so as to be able to move up and down and can contact the adjustment bolt 10. And the plate stored in the case 14
1 and a spring 13 for urging the same upward in FIG. The plate 12 is prevented from coming off by the stopper 14a of the case 14.

By the urging force of the spring 13, the throttle valve 2
Is urged in the opening direction (counterclockwise in FIG. 1).
Further, the position of the throttle valve 2 when the adjustment bolt 10 abuts on the plate 12 is not fully closed but at a predetermined opening degree θ1 that slightly opens the intake passage 1a. The predetermined opening θ1 is determined by the adjustment bolt / nuts 10 and 11 and the case 14 of the second urging means 9.
Can be adjusted according to the degree of screwing.

Thus, the urging force F1 of the back spring 15 and the second
And the urging force F2 of the spring 13 of the urging means 9 is set to satisfy the relationship of F1 <F2. The torque generated by the drive motor 4 is determined by the urging force F1 of the back spring 15.
And the biasing force F2 of the spring 13 is set larger. Therefore, when the drive motor 4 is driven, the throttle valve 2
Is opened and closed against the urging force of the back spring 15 and the second urging means 9.

In the throttle valve control device for the engine, when the accelerator pedal 5 is depressed and a signal corresponding to the depression amount is input from the accelerator sensor 6 to the control device 7,
A drive signal is output from the control device 7 to the drive motor 4 to drive the drive motor 4. The rotation of the output shaft of the drive motor 4 is transmitted to the throttle shaft 3 via a drive gear 21 and a driven gear 20, and the throttle valve 2
Is adjusted to an opening degree corresponding to the depression amount of the pedal.

Specifically, when the engine is stopped, as shown in FIG. 1, the adjustment bolt 10 of the lever 8 is brought into contact with the plate 12 of the second urging means 9 by the urging force of the back spring 15. In state. At this time, since the urging force (set load) F2 of the spring 13 of the second urging means 9 is larger than the urging force F1 of the back spring 15, the throttle valve 2 has a predetermined opening (hereinafter, this opening is (It will be referred to as an initial opening.) It will be held at the position of θ1.

In this way, the throttle valve 2 is set to the initial opening position, and a state of waiting for engine start is established. By maintaining this state, sticking of the throttle valve 2 due to sticky substances such as combustion products generated between the intake pipe 1 and the throttle valve 2 or freezing of the throttle valve 2 at extremely low temperatures is prevented. Can be prevented.

Furthermore, when the engine is started from this state,
The opening degree of the throttle valve 2 is controlled by the drive motor 4 according to the operating state of the engine. Here, the warming-up of the engine is completed and the released state of the accelerator pedal 5 will be described. The opening of the throttle valve 2 is controlled by the drive motor 4 to an initial opening θ1 or less as shown in FIG. You. At this time, the lever 8 is rotated by pushing the plate 12 against the urging force F2 of the spring 13 of the second urging means 9, and the amount of rotation is adjusted by the lever 8 coming into contact with the adjustment bolt 18 of the stopper 16. Get restrained.

Further, when the accelerator pedal 5 is depressed from the above state, the throttle valve 2 is opened via the initial opening degree θ1.
At this time, the throttle valve 2 is opened and closed against the urging force F1 of the back spring 15 at the initial opening degree θ1 or more.

When the ignition key switch is turned off and the engine is stopped, the power supply to the drive motor 4 is also cut off.
Then, as shown in FIG.
Is opened to the initial opening θ1 position by the urging force of the urging means 9 to open the passage 1a in the intake pipe 1 by a predetermined amount.

According to the throttle valve control device of the engine, when the driving force of the driving motor 4 is cut off, the throttle valve 2 is held at the initial opening degree θ1 position by the urging force of the second urging means 9, so that the conventional throttle valve control device is used. The throttle valve 2 can be opened to the predetermined opening θ1 with higher accuracy than the throttle valve having the predetermined opening based on the balance of the first and second urging means, and the predetermined opening position changes with time. Can be held without.

By the way, in the above embodiment, the drive motor 4 constitutes the drive means of the present invention, and the back spring 15 constitutes the first biasing means of the present invention.

Note that the present invention is not limited to the above embodiment,
Changes can be made without departing from the spirit of the present invention. For example, the spring 13 of the second urging means 9 can obtain the same operation and effect as the embodiment by using an elastic body such as a leaf spring or elastic rubber in addition to the coil spring.

According to the present invention, in addition to the first urging means for urging the throttle valve in the opening direction, the throttle valve has an urging force larger than the urging force of the first urging means. A second urging means for urging the throttle valve in the opening direction, the second urging means being provided with a stopper for restricting the throttle valve from being biased to a predetermined opening degree or more; When the driving force is cut off, the throttle valve is held at a predetermined opening position where the bias is regulated by the stopper by the biasing force of the second biasing means. The throttle valve can be opened to the predetermined opening with higher accuracy than the throttle valve having the predetermined opening based on the balance of the biasing means, and the predetermined opening position can be maintained without change over time.

[Brief description of the drawings]

1 is a side view of an engine throttle valve control device, FIG. 2 is a plan sectional view thereof, and FIG. 3 is a side view of the throttle valve when the throttle valve is fully closed. . DESCRIPTION OF SYMBOLS 1 ... Intake pipe 2 ... Throttle valve 4 ... Drive motor (drive means) 7 ... Control device (control means) 9 ... 2nd urging means 15 ... Back spring (1st urging means)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F02D 9/00-11/10

Claims (1)

(57) [Claims] 1. A throttle valve provided in an intake pipe of an engine for adjusting a flow rate of combustion air, a driving means for driving the throttle valve, and a first bias for biasing the throttle valve in a closing direction. Means, and second urging means for urging the throttle valve in the opening direction with an urging force larger than the urging force of the first urging means, wherein the second urging means comprises A throttle valve control device for an engine, further comprising a stopper for restricting biasing of a throttle valve to a predetermined opening degree or more.