JP2807033B2 - Throttle valve control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a throttle valve control device (also referred to as a throttle valve device) that electrically controls a throttle valve of an engine.

[Prior Art] Generally, in this type of throttle valve control device,
The throttle valve that opens and closes the intake passage of the engine is constantly biased in the fully closed direction by the biasing force of the back spring (for example, Japanese Patent Application Laid-Open Nos. 56-14834 and 51-13823).
No. 5). Normally, the biasing force of the back spring is set to be larger than the torque when the control motor for controlling the opening and closing of the throttle valve is not energized. Therefore, when the control circuit breaks down or the engine is stopped during the operation of the engine, and the power supply to the control motor is stopped, the throttle valve is held at the fully closed position by the biasing force of the back spring.

However, in the above-described configuration, if the power supply to the control motor is stopped (non-conductive state), the throttle valve is fully closed. For this reason, when the throttle valve or the throttle shaft freezes in a low temperature such as a cold region, the opening of the throttle valve becomes impossible, and satisfactory engine operation cannot be performed. is there. A similar problem also occurs when sticky substances such as combustion products generated between the intake cylinder and the valve during engine operation adhere to the throttle valve.

To cope with such a problem, Japanese Patent Laid-Open No. 63-15 / 1988 discloses a throttle valve control device in which the throttle valve is held at a position opened by a predetermined amount instead of the fully closed position when the engine is stopped.
No. 0449 has proposed this.

In this prior art publication, the balance position of the biasing force of the first biasing means for biasing the throttle valve in the closing direction and the second biasing means for biasing the throttle valve in the opening direction is such that the throttle valve is balanced. It is set at a position to open by a predetermined amount.

[Problems to be Solved by the Invention] According to the above-mentioned conventional publication, although the problem caused by the icing or the sticky substance is solved, depending on the balance position between the first urging means and the second urging means. Since the opening of the throttle valve, the so-called opening, is determined, the opening of the throttle valve when the engine is stopped is unstable,
Further, it is conceivable that a problem that the opening degree of the throttle valve changes due to a change over time of the biasing means or the like may occur.

Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to maintain a state in which a throttle valve is opened at a predetermined opening when a control motor is not energized, and It is an object of the present invention to provide a throttle valve device capable of accurately and stably maintaining a throttle valve opening for a long period of time.

Means for Solving the Problems In order to solve the above problems, a throttle valve control device of the present invention includes a throttle valve that opens and closes an intake passage of an engine, a control motor that controls the opening and closing of a throttle valve, and a throttle valve. A relief lever rotatably provided on the throttle shaft, a throttle lever fixed on the throttle shaft of the throttle valve, and first biasing means for biasing the relief lever in the same direction as the throttle valve closing direction; An engagement means for interlocking the relief lever with the rotation of the throttle lever at a predetermined opening degree or more of the throttle valve; and a rotation of the relief lever in the closing direction by the first urging means so that the throttle valve has the predetermined opening degree. A stopper for stopping the throttle valve in the same direction as the opening direction of the throttle valve when the throttle valve is below the predetermined opening degree. The second biasing
And urging means.

[Operation] According to the above means, when the engine is started, the control motor is energized. The amount of intake air flowing through the intake passage is adjusted by controlling the opening of the throttle valve according to the operating state of the engine by the control motor.

By the way, when the throttle valve is at a predetermined opening degree, the relief lever is urged in the same direction as the closing direction of the throttle valve by receiving the urging force of the first urging means (simply called the closing direction), and is stopped by the stopper. It has been stopped. The throttle lever receives the urging force of the second urging means with respect to the relief lever and is engaged with the relief lever in an interlockable manner via the engaging means.

When the opening of the throttle valve is equal to or more than a predetermined opening, the relief lever that is interlocked with the throttle lever through the engagement of the engagement means is first biased as the throttle lever is rotated by the control motor. The follower is turned against the urging force of the means. At this time, since the throttle lever is engaged with the relief lever via the engagement means, the throttle lever does not receive the urging force of the second urging means.

When the throttle valve is below a predetermined opening degree, the throttle lever is rotated by the control motor against the urging force of the second urging means while the relief lever is kept stopped by the stopper. . At this time, since the relief lever is stopped by the stopper, the throttle lever does not receive the urging force of the first urging means.

Further, when the power supply to the control motor is stopped at a predetermined opening degree or more of the throttle valve, the throttle lever is rotated in the closing direction by receiving the urging force of the first urging means together with the relief lever. When the relief lever returns to the state stopped by the stopper, the throttle valve is positioned at the predetermined opening. Further, when the power supply to the control motor is stopped at a predetermined opening degree or less of the throttle valve, the throttle lever receives the urging force of the second urging means so as to be in the same direction as the opening direction of the throttle valve. ), And the throttle lever is returned to the state of being engaged with the relief lever via the engagement means, whereby the throttle valve is positioned at the predetermined opening.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 showing a cross-sectional view of a throttle valve device, and FIG.
In FIG. 3 showing a sectional view taken along the line III-III,
Is formed in a cylindrical shape having an intake passage 15 therein. The intake passage 15 forms a part of an intake passage in the engine.

At a predetermined position of the intake pipe 1, both ends of the throttle shaft 4 are supported so as to be rotatable and their tips project outward. A throttle valve 5 for opening and closing the intake passage 15 is attached to the throttle shaft 4. In addition, the throttle valve 5 opens the intake passage 15 by rotating counterclockwise in the state of FIG. 3, and closes the intake passage 15 by rotating clockwise from this state.

The driven gear 3 is fixed to one end of the throttle shaft 4 (the left end in FIG. 1). A control motor 2 composed of, for example, a step motor is attached to the side surface of the intake pipe 1. A drive gear 2 a is provided on an output shaft of the control motor 2. This drive gear 2a is meshed with the driven gear. The control circuit 20 of the control motor 2 outputs a drive signal to the control motor 2 by inputting a signal corresponding to the depression amount of the accelerator pedal of the engine, thereby performing the drive control of the motor 2. The rotation of the output shaft driven by the control motor 2 is transmitted to the throttle shaft 4 via the drive gear 2a and the driven gear 3, and the throttle valve 5
Is opened and closed (so-called opening degree adjustment), whereby the intake air amount of the engine is adjusted.

A boss 1a for supporting the other end (the right end in FIG. 1) of the throttle shaft 4 and a housing 1b surrounding the boss 1a are integrally formed on a side surface of the intake pipe 1.

A substantially disk-shaped relief lever 6 is rotatably provided on the boss 1a. The relief lever 6 has a support portion 6a formed in a cylindrical shape and rotatably fitted to the boss portion 1a, an engagement piece 6b protruding from an outer peripheral portion (a lower portion in FIG. 3), and It has a contact piece 6c protruding at a position opposite to the engaging piece 6b, and an engaging pin 6d protruding on the outer surface thereof.

An adjusting screw 9 for a relief lever is screwed to the housing portion 1b substantially in the radial direction. When the relief lever 6 rotates in the same direction as the closing direction of the throttle valve 5 (clockwise direction in FIG. 3), the adjusting screw 9 is rotated by the abutment piece 6c abutting on the screw tip. The stopper is used to constitute the stopper of the present invention. The adjusting screw 9 is disposed so that its axis is substantially along the tangential direction of the relief lever 6. The contact position of the contact piece 6c can be adjusted by advancing or retreating the adjusting screw 9.

A back spring 8 made of a coil spring is fitted around the outer periphery of the support portion 6a of the relief lever 6. One end 8a of the back spring 8 is engaged with the hole 16 of the intake pipe 1, and the other end 8b is engaged with the contact piece 6c of the relief lever 6. By the back spring 8, the relief lever 6 is always urged in the same direction as the closing direction of the throttle valve 5. Note that the back spring 8 constitutes a first urging means of the present invention.

A small diameter shaft portion 4a is formed at the shaft end of the throttle shaft 4. The small diameter shaft portion 4a has a substantially oval cross section having a thread on the outer circumference and a width across flats, and a substantially disc-shaped throttle lever 7 is fixed to the shaft end of the throttle shaft 4. I have. Specifically, a mounting hole corresponding to the small-diameter shaft portion 4a is formed in the center of the throttle lever 7, and the throttle lever 7 is caulked to the shaft portion 4a in a state where the mounting hole is fitted to the small-diameter shaft portion 4a. Alternatively, it is fixed by a nut or the like.

The throttle lever 7 has an engaging piece 7a protruding from the outer peripheral portion (the lower part in FIG. 3) and a contact piece 7b protruding at a position opposite to the engaging piece 7a. The engagement piece 7a comes into contact with the engagement piece 6b of the relief lever 6 when the throttle valve 5 rotates in the opening direction by a predetermined opening degree or more.
When the opening is equal to or more than the predetermined opening, the engagement piece 7a receives the urging force from the back spring 8 via the engagement piece 6b, so that the throttle valve 5 is urged in the closing direction. Conversely, when the opening is less than the predetermined opening, the rotation of the relief lever 6 is stopped by the adjusting screw 9, so that the throttle valve 5 does not receive the urging force of the back spring 8. The two engagement pieces 6b and 7a constitute the engagement means of the present invention.

An adjusting screw 11 for a throttle lever is screwed to the housing portion 1b in a substantially radial direction. When the throttle lever 7 rotates in the closing direction of the throttle valve 5 (clockwise direction in FIG. 3), the adjusting screw 11 stops the rotation by the contact piece 7b abutting on the screw tip. The adjusting screw 11 is disposed so that its axis is substantially along the tangential direction of the throttle lever 7. By screwing or retreating the adjusting screw 11,
The contact position of the contact piece 7b, that is, the minimum opening of the throttle valve 5 can be adjusted.

A pair of left and right spring guides 12 located between the boss 1a of the intake pipe 1 and the throttle lever 7 are fitted to the throttle shaft 4.

A relief spring 10 composed of a coil spring is wound around the outer periphery of the spring guide 12. One end 10a of the relief spring 10 is engaged with the engagement piece 7a of the throttle lever 7, and the other end 10b is
Is locked to the engaging pin 6d. By the urging force of the relief spring 10, the levers 6, 7 are urged in a direction in which the engagement piece 6b of the relief lever 6 and the engagement piece 7a of the throttle lever 7 come into contact. The urging force of the relief spring 10 is set smaller than the urging force of the back spring 8. Further, the urging force of the back spring 8 and the relief spring 10 is set to be smaller than the driving torque of the control motor 2 on the throttle shaft 4 and larger than the stop torque when the motor 2 is not energized. In addition, the relief spring 10 constitutes the second urging means of the present invention.

A throttle sensor 13 is fixed to an end surface of the housing portion 1b of the intake pipe 1 so as to cover the inside thereof. A detection piece (not shown) of the throttle sensor 13 includes an interlocking piece 7c extending from the tip of the contact piece 7b of the throttle lever 7.
Are engaged. The throttle sensor 13 detects the opening of the throttle valve 5 as is well known. FIG. 2 is a side view in which the throttle sensor 13 is mounted.

In the throttle valve control device described above, when the control motor 2 is not energized when the engine is stopped or the like, the first and third throttle valves are controlled.
As shown in the figure, the relief lever 6 receives the urging force of the back spring 8, the abutment piece 6c abuts on the adjustment screw 9, and its rotation is stopped. On the other hand, the throttle lever 7 receives the urging force of the relief spring 10, and its engagement piece 7a comes into contact with the engagement piece 6b of the relief lever 6, and its rotation is stopped. Therefore, the opening of the throttle valve 5 in this state (hereinafter referred to as an initial opening) is
The rotation position of the throttle lever 7 is determined based on the stop position of the relief lever 6 set by the relief lever adjusting screw 9. With the initial opening of the throttle valve 5, the engine waits for starting.

By maintaining this state, it is possible to prevent the throttle valve 5 or the throttle shaft from freezing in a cold region or the like and fix the throttle valve 5 due to adhesion of combustion products and the like, and to prevent poor starting of the engine. it can.

In addition, when the engine is started from the above state, the opening degree of the throttle valve 5 is controlled by the control motor 2 according to the operating state of the engine, and the amount of intake air flowing through the intake passage 15 is adjusted. More specifically, in an idling state (released state) in which the accelerator pedal is not depressed, the throttle valve 5 is closed by the control motor 2 to an initial opening degree or less (an opening degree corresponding to an idle speed). That is, as shown in FIG. 5, with the relief lever 6 stopped as described above, the throttle lever 7
Is rotated against the urging force of the relief spring 10, and the locking piece 7 a is separated from the engaging piece 6 b of the relief lever 6. When the contact piece 7b of the throttle lever 7 contacts the adjustment screw 11 for the throttle lever, the rotation of the throttle lever 7 in the closing direction is stopped. The opening of the throttle valve 5 in this state (hereinafter referred to as idling opening) is determined by the stop position of the throttle lever 7 set by the throttle lever adjusting screw 11.

Subsequently, when the accelerator pedal is depressed, the control motor 2 is driven in accordance with the depressed amount, whereby the throttle valve 5 is adjusted to a predetermined opening. At this time, when the throttle valve 5 is not more than the initial opening degree, the throttle lever 7 is rotated against the urging force of the relief spring 10 while the relief lever 6 remains stopped as described above. When the throttle valve 5 is at or above the initial opening, the engagement piece 7a comes into contact with the engagement piece 6b of the relief lever 6 with the rotation of the throttle lever 7, so that the relief lever 6 is attached to the back spring 8. It is made to follow and rotate against the power. FIG. 4 shows the fully opened state of the throttle valve 5.

Also, when the power to the control motor 2 is stopped due to the stop of the engine or the like during the operation of the engine, the throttle valve 5 has the initial opening as shown in FIGS.
It is in a state of waiting for the start of the engine. More specifically, when the power supply to the control motor 2 is stopped when the throttle valve 5 is at or above the initial opening, the relief lever 6 receives the biasing force of the back spring 8 and moves in the same direction as the closing direction of the throttle valve 5. By being rotated, the throttle lever 7 is caused to rotate following the engagement of the locking pieces 6b and 7a, and the throttle valve 5 is held at the initial opening position. Further, when the power supply to the control motor 2 is stopped when the throttle valve 5 is at or below the initial opening, the throttle lever 7 is released from the relief spring.
The throttle valve 5 is held at the initial opening position by being rotated in the opening direction by receiving the urging force of 10. The rotation of the throttle lever 7 is transmitted to the throttle shaft 4, the driven gear 3, and the drive gear 2a in this order, so that the control motor 2 receives reverse drive.

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.

[Effects of the Invention] As described above, according to the throttle valve control device of the present invention, when the control motor for opening and closing the throttle valve is not energized, the urging force of the relief lever and the first urging means is reduced. And the throttle lever receives the urging force of the second urging means with respect to the relief lever and engages with the engaging means while being urged in the same direction as the closing direction of the throttle valve and stopped by the stopper. , The throttle valve can be maintained at a predetermined opening degree. For this reason, it is possible to prevent engine start failure due to freezing in a cold region or the like and adhesion of combustion products and the like.

Further, since the opening of the throttle valve when the control motor is not energized is determined based on the stop position of the relief lever by the stopper, the valve opening can be accurately, stably maintained over a long period of time.

[Brief description of the drawings]

1 is a cross-sectional view of a throttle valve device, FIG. 2 is a side view thereof, FIG. 3 is a cross-sectional view taken along line III-III of FIG. 1, and FIG. Is an operation explanatory view of the fully opened state, and FIG. 5 is an operation explanatory view of the idling state. 2; control motor 4; throttle shaft 5; throttle valve 6; relief lever 6b; engaging piece (engaging means) 7; throttle lever 7a; engaging piece (engaging means) 8; back spring (first attachment Biasing means) 9; adjusting screw (stopper) 10; relief spring (second biasing means)

Claims (1)

(57) [Claims] 1. A throttle valve for opening and closing an intake passage of an engine, a control motor for opening and closing the throttle valve, a relief lever rotatably provided on a throttle shaft of the throttle valve, and a throttle shaft for the throttle valve. A throttle lever fixed to the throttle valve, first biasing means for biasing the relief lever in the same direction as the closing direction of the throttle valve, and interlocking the relief lever with rotation of the throttle lever at a predetermined opening degree or more of the throttle valve. Engaging means, a stopper for stopping the rotation of the relief lever in the closing direction by the first urging means so that the throttle valve has the predetermined opening, and a throttle valve which is not more than the predetermined opening of the throttle valve. A second urging means for urging in the same direction as the opening direction of the throttle valve control device.