JP3345393B2 - Electronically controlled throttle valve device for internal combustion engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled throttle valve device for an internal combustion engine.

[0002]

2. Description of the Related Art A conventional electronically controlled throttle valve device is disclosed in
As described in JP-A-62-284932, a motor and a throttle valve are connected in series via a reduction gear, and a throttle valve position sensor as a throttle valve opening detecting means is provided on the opposite side of the motor and the reduction gear. It was engaged with the end of the throttle valve shaft.

[0003]

In this case, since the motor, the throttle valve and the throttle valve position sensor are arranged in series, the dimension in the direction along the axis of the throttle valve shaft becomes longer, and the entire throttle valve controller becomes large. There was a problem.

An object of the present invention is to reduce the size of the entire throttle valve control device by arranging a motor, a reduction gear, and a throttle valve position sensor around the throttle valve in a compact manner.

[0005]

In order to achieve the above object, according to the present invention, a cover member for covering a reduction gear is attached to a throttle body, and the cover member has a position facing an end of a throttle valve shaft. a throttle valve position sensor that is attached to. The input gear is parallel to the throttle valve shaft.
It is configured to rotate integrally with the motor output shaft arranged in the row.
And another reduction gear meshing with the input gear
The motor is connected via the vehicle and the reduction gear fixed to the throttle valve shaft.
Is configured to be transmitted to the throttle valve shaft,
The reduction gear fixed to the throttle valve shaft is separate from the input side gear.
Closer to the throttle body than the meshing position with the reduction gear
To receive the driving force from the motor at the position
Is done.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronically controlled throttle valve device for an internal combustion engine according to the present invention will be described.

1 to 3, reference numeral 1 denotes a throttle valve (throttle valve). The throttle valve 1 is fixed to a throttle valve shaft 3 rotatably supported on a support (throttle body) 2. .

Reference numeral 4 denotes a control unit, and reference numeral 6 denotes a motor serving as an actuator for controlling the throttle valve opening. The control unit 4 provides a throttle valve target opening signal 5 set based on various information indicating the operating state of the engine. Is input, thereby transmitting the drive signal 7 to the motor 6.

Next, reference numeral 8 denotes an electromagnetic clutch, which operates according to an excitation signal 9 from the control unit 4, and controls the throttle valve shaft 3.
And a driving force coupling / disconnecting means for controlling the transmission / disconnection of the driving force between the motor and the motor 6.

The input side reduction gear 8a with a clutch plate of the electromagnetic clutch 8 is rotatable about the motor shaft 6a. When the electromagnetic clutch 8 is excited by the excitation signal 9, it is integrated with the motor shaft 6a. It is configured to rotate. The reduction gear 10a meshed with the reduction gear 8a and the reduction gear 1 fixed to the throttle valve shaft 3
The driving force from the motor 6 is transmitted to the throttle valve shaft 3 via Ob.

The rotating shaft 10c of the reduction gear 10a is rotatably supported at both ends by the cover member 2A and the throttle body 2.

Next, reference numeral 11 denotes a spring driving force transmission mechanism, which includes a control lever 11a attached to the throttle valve shaft 3;
It comprises a throttle lever 11b connected to an accelerator pedal 14 via an accelerator wire 15, and two lost motion springs 11c and 11d. Then, the throttle lever 11b and the control lever 11a
Are these two lost motion springs 11
c, 11d.

On the other hand, a return spring 13 is provided on the throttle lever 11b via a lever 12.
Thereby, the throttle valve 1 is urged in the closing direction.

Reference numeral 16 denotes a throttle valve position sensor, which serves as detecting means for detecting the actual opening of the throttle valve 1, and is attached to the cover member 2A.

Reference numeral 16A denotes a connector of the throttle valve position sensor 16, which protrudes from the cover member 2A.

Reference numeral 17 denotes an accelerator position sensor, which serves as detecting means for detecting the operating position of the throttle lever 11b. 17A is an accelerator position sensor connector.

The throttle lever 11b also engages with the fully open stopper 18 and the fully closed stopper 19 and has a function of defining the rotation range of the throttle valve 1. In FIG. 1, the fully open stopper 18 and the fully closed stopper 19 are not shown.

Next, reference numerals 20 and 21 denote spring receivers, which are made of a material having a small coefficient of friction such as a resin material. By providing lost motion springs 11c and 11d on these spring receivers 20, 21. It works to reduce these sliding resistances.

An accelerator position sensor shaft 22 is rotatably inserted and held in a sensor housing 23.
The lever 24 is attached to this. The lever 24 is connected to the throttle lever 11 b and the connecting pin 2.
4a, the throttle lever 11
b together with the rotation of the throttle lever 11
The rotation of b can be transmitted to the accelerator position sensor 17.

At this time, by providing a return spring 13 on the accelerator position sensor shaft 22, play existing in the rotation transmission system is eliminated.

As shown in FIG. 3, the output voltage signal 25 of the throttle valve position sensor 16 is input to the control unit 4, and the output voltage signal 25 representing the actual opening of the throttle valve 1 and the target opening 5 are calculated. The drive signal 7 is transmitted to the motor 6 by the comparison judgment, whereby the feedback control of the throttle valve 1 is established.

When the control by the motor 6 is interrupted, basically, the output voltage 25 of the throttle valve position sensor 16 and the accelerator position sensor 1
7, there is a certain correlation with the output voltage 26,
These are taken into the control unit 4 and compared and determined, so that fail-safe control is performed to determine whether or not a normal operation is being performed.

However, the failsafe control logic described here is merely an example, and the present invention is not limited to this.

FIG. 2 is a view of the spring driving force transmission mechanism 11 as viewed from P in FIG. 1. The throttle valve 1 is fixed to the throttle valve shaft 3, and the control lever 11a is also fixed to the throttle valve shaft 3.
Therefore, it rotates integrally with the throttle valve 1.

On the other hand, the throttle lever 11b is rotatably supported with respect to the throttle valve shaft 3, and the lost motion springs 11c and 11d are provided with spring supports 20,
The springs 11c, 11c are mounted on top of each other with biasing forces in opposite directions.
d is arranged so as to receive displacements in opposite directions with respect to the throttle lever 11b, and each is configured to be prestressed.

The accelerator wire 15 passes through the wire guide groove 15a of the throttle lever 11b and is fixed to the throttle lever 11b at the slinging portion 11e. When the accelerator pedal 14 is operated, the accelerator wire 15 is throttled against the urging force of the return spring 13. and it is configured to be able to rotate the valve 1 in the arrow theta _a direction.

Next, the operation of the embodiment shown in FIGS. 1 and 2 will be described with reference to the conceptual configuration diagram of FIG.

FIG. 3 shows FIG. 1 for easy understanding.
In this embodiment, the rotation operation is represented by a linear movement in the left-right direction, and the same parts as those in FIG. 1 or the same parts are denoted by the same reference numerals.

In FIG. 3, when the driver turns on a key switch (not shown), an excitation signal 9 is transmitted to the electromagnetic clutch 8 at the same time, and the electromagnetic clutch 8
N state, the preparation in the normal control state is completed, and the drive signal 7 is sent from the control unit 4 to the motor 6.
Is transmitted, and the opening and closing of the throttle valve 1 is controlled.
At this time, the control lever 11a attached to the throttle valve shaft 3 moves (rotates) as shown by a broken line in the figure, integrally with the throttle valve 1 by the rotation of the motor 6. The relative displacement between the control lever 11a and the throttle lever 11b caused by the movement (rotation) of the control lever 11a is caused by one extension and the other contraction of the lost motion springs 11c and 11d (in FIG. Of the accelerator pedal 14).
Irrespective of the operating position of the throttle lever 11b given according to the amount of depression of the throttle valve, the opening and closing control of the throttle valve 1 by the motor 6 can be performed independently of this, and the operation as an electronic throttle mode can be obtained. Become.

Next, it is assumed that an abnormality such as a failure has occurred in the motor drive system for some reason. Then, by the function of the abnormality determination function built in the control unit 4, first, the excitation of the electromagnetic clutch 8 is stopped, the electromagnetic clutch 8 is turned off, and then the throttle valve shaft 3 is disconnected from the motor 6, and Be free.

At this time, the throttle lever 1
If there is a relative displacement between the control lever 11a and the control lever 11a, a difference occurs between the biasing loads of the lost motion spring 11c and the lost motion spring 11d. The position of the control lever 11 is controlled by the action of the springs 11c and 11d until the position where the relative displacement difference becomes zero.
a is moved (rotated), and as a result, the throttle valve 1 is also moved (rotated) to an opening suitable for the operation position of the accelerator pedal 14.

As a result, the throttle valve shaft 3 is connected to the control lever 11a and the lost motion spring 11c,
11d and a state where the throttle valve 1 is coupled to the accelerator pedal 14 via the throttle lever 11b, and the preparation for driving the throttle valve 1 by operating the accelerator pedal 14 is completed.

Thereafter, when the accelerator pedal 14 is depressed, the throttle lever 11b is rotated against the return force of the return spring 13, and the control lever 11 is moved in accordance with the movement (rotation) of the throttle lever 11b.
a has lost motion springs 11c and 11d.
The control lever 11a follows the throttle lever 11b and moves (rotates) in the same phase as the throttle lever 11b, so that the opening control of the throttle valve 1 is obtained, and the limp home The function can be achieved.

FIG. 4 shows the controllable region in this embodiment. The opening control region of the throttle valve 1 by the motor 6 can be controlled to open and close over the entire region. Also,
It can be seen that, even in the limp home mode, the control follows the operation of the accelerator pedal as it is, similarly to the prior art.

Therefore, according to this embodiment, when an abnormality occurs, the motor 6 is disconnected from the throttle valve shaft 3 and automatically shifts to the opening control by the accelerator pedal. Since it is automatically placed under the opening control by the accelerator pedal in a state corresponding to the operation position of the accelerator pedal, the limp home function is provided, and at this time, the throttle valve is returned to the accelerator pedal operation position, The occurrence of serious accidents such as runaway in the limp home state is reliably suppressed, and a complete fail-safe function and high reliability can be achieved.

FIG. 5 is a schematic diagram showing the operation of the spring driving force transmission mechanism 11 in this embodiment when it is controlled by the motor 6 and when it is controlled by operating the accelerator pedal 14. The horizontal axis indicates the opening of the throttle valve 1. The degree TVO and the vertical axis indicate the biasing torque T of the lost motion springs 11c and 11d.

In the drawing, a point O represents a neutral (initial) state, which is assumed to be at a throttle valve opening TVO corresponding to the operation position of the accelerator pedal.

First, the throttle valve 1 is turned by the motor 6 to the angle θ.
Considering a state in which the opening direction is controlled by _M [deg], one lost motion spring 11c is deflected in the winding direction, and the other lost motion spring 11d is deflected in the loosening direction. Therefore, the OA "characteristic shown in FIG. 5 indicates the biasing torque T characteristic of the spring 11c, and the OB" characteristic
It shows the biasing torque T characteristic of 1d. Here, the absolute value of A "-B" represents the required torque to be generated by the motor 6.

This is the description of the case where the throttle valve 1 is controlled in the opening direction, but the same applies to the case where the throttle valve 1 is controlled in the closing direction.

Next, in FIG. 5, consider the case where the limp home mechanism by the spring driving force transmission mechanism 11 operates from the point O.

Assuming that the throttle lever 11b is rotated in the opening direction by the angle θ _A [deg] by the operation of the accelerator pedal 14, the biasing torques T of the springs 11c and 11d are relatively moved in a direction in which they are balanced. . As a result, the control lever 11a is
Following the same direction with the rotation of b, it moves from the point O to the point O 'in FIG. 5, and the throttle valve 1 rotates in the opening direction at the same angle θ _A [deg], As a result, even when an abnormality occurs in the drive system including the motor 6, the limp home mechanism is reliably established.

Normally, as in this embodiment, the accelerator pedal 1
If a clutch or the like is not provided on the side 4, when the throttle valve 1 is controlled by an actuator such as the motor 6, a kickback phenomenon appears on the accelerator pedal 14.

However, in this embodiment, two springs 11c and 11c are used as lost-motion springs.
11d, these biasing torques are assembled so that they are opposite. As a result, according to this embodiment,
By setting the same biasing torque constant of the springs 11c and 11d with respect to the throttle valve shaft 3, each combined torque can be flattened and the characteristic OC of FIG. 5 can be obtained. According to this, there is an effect that the kickback phenomenon can be eliminated.

To realize the ISC (idle speed control) and FIC (fast idle control) functions by such an electronic throttle type throttle valve control device, the stability of the engine speed (idle speed) at the time of control is required. It is essential to increase the control accuracy (resolution) in order to secure.

An embodiment of the present invention in which control accuracy (resolution) is increased will be described below. FIG. 6 shows a throttle valve opening range θ _R (ISC control range, FIC
In the control range), by increasing and amplifying the output characteristic change rate of the throttle valve position sensor 16 that detects the controlled actual opening of the throttle valve 1, the accuracy of feedback control of the throttle valve opening by the actuator is improved. The embodiment shown in FIG.

Numeral 27 indicates the output voltage characteristic of the normal throttle valve position sensor 16. The vertical axis output voltage (V) characteristic with respect to the horizontal axis throttle opening (θ) is a linear characteristic with a constant voltage constant k. ing. In contrast,
Reference numeral 28 denotes an output voltage characteristic of the throttle valve position sensor 16 according to the embodiment of the present invention. The output voltage characteristic is obtained by amplifying the voltage constant by n times only in the ISC and FIC control regions requiring control accuracy (resolution). ing.

The control accuracy (resolution) ΔV _T when the throttle valve opening is feedback-controlled is determined by the output voltage range (V ₁ −
V ₀₎ determined by V and the microcomputer of the A / D conversion processing capacity (BBIT), the _{ΔV T = (V 1 -V 0} ) / B. That is, when the feedback control, the following accuracy [Delta] V _T, throttle valve 1
Is the limit output value that cannot be controlled. Throttle valve position sensor 1 with normal output voltage characteristic 27
When using the 6, control accuracy (resolution) [Delta] V _T corresponding throttle opening is _{(ΔV T / k) [deg} ] . On the other hand, a throttle valve position sensor 16 of the output voltage characteristic 28
When using, control accuracy (resolution) [Delta] V _T corresponding throttle opening becomes _{(ΔV T / nk) [deg} ]. Therefore, by using a throttle valve position sensor whose voltage constant is amplified n times, control accuracy (resolution) can be improved n times, and stability of the engine speed (idle speed) at the time of control is ensured. A good way to do that.

FIGS. 7 and 8 show another embodiment of the present invention. When the throttle valve 1 is controlled in the throttle valve opening range θ _R where control accuracy is required, the output voltage 25 of the throttle valve position sensor 16 for detecting the controlled actual opening of the throttle valve 1 is controlled by the control unit 4.
In this embodiment, an n-fold processing is performed via an amplifier 4c within the circuit to improve the accuracy of the feedback control of the throttle valve opening by the actuator.

FIG. 7 is a schematic block diagram of the present invention, and FIG. 8 is a graph showing the output voltage (V) characteristics read by the vertical axis control unit with respect to the horizontal axis throttle opening (θ) in the present invention. It is. In the throttle valve opening range θ _R , the output voltage 25 of the throttle valve position sensor 16 is read via the n-fold amplifier 4c, so that the read output voltage (V) characteristic is a normal voltage constant such as 28a. The characteristic is obtained by multiplying k by n.

In the high opening range, the output voltage 25 of the throttle valve position sensor 16 is read without passing through the n-fold amplifier 4c, so that the read output voltage (V) characteristic is as shown at 27a. The characteristic has a normal voltage constant k. From the control accuracy (resolution) ΔV _{T at} the time of feedback controlling the throttle valve opening, a throttle opening equivalent to the control accuracy (resolution) ΔV _{T is obtained} as described above.
In the throttle valve opening range θ _R, it becomes (ΔV _T / nk) [deg], and in the throttle valve high opening range, it becomes (ΔV _T / k) [deg].

Therefore, by reading the output voltage 25 of the throttle valve position sensor 16 via the n-fold amplifier 4c, the voltage constant is amplified n times and the feedback control is performed, thereby improving the control accuracy (resolution) to n times. The engine speed during control (idle speed)
This is a good way to ensure the stability of.

[0052]

According to the present invention, it is possible to reduce the size of the entire electronically controlled throttle valve device, and to provide an electronically controlled throttle valve device which can be mounted even in a narrow engine room .

[Brief description of the drawings]

FIG. 1 is an expanded sectional view showing an embodiment of a throttle valve control device for an internal combustion engine according to the present invention.

FIG. 2 is a side view showing an embodiment of a throttle valve control device for an internal combustion engine according to the present invention.

FIG. 3 is a conceptual diagram illustrating a configuration of a principle of an embodiment of the present invention.

FIG. 4 is a characteristic diagram showing a controllable region according to the present invention.

FIG. 5 is a characteristic diagram of a spring driving force transmission mechanism according to the embodiment of the present invention.

FIG. 6 is a characteristic diagram showing a throttle valve position sensor output voltage according to the first embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a control block according to a second embodiment of the present invention.

FIG. 8 is a characteristic diagram showing an output voltage of a throttle valve position sensor according to a second embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Throttle valve, 2 ... Support body (throttle body), 4 ... Control unit, 4a ... Read path at the time of low opening control, 4b ... Read path at the time of high opening control, 4c ... n-fold amplifier, 6 ... Motor , 7: drive signal, 10a, 10b: reduction gear, 16: throttle valve position sensor, 2
5, 26 ... output voltage, 27, 27a, 28, 28a ... output voltage characteristics.

Continuing from the front page (72) Inventor Teruhiko Minegishi 2477 Kashimayatsu, Kataida-shi, Ibaraki Pref. 3 Inside Hitachi Automotive Engineering Co., Ltd. (72) Inventor Tatsuya Yoshida 2520 Takata, Katsuta-shi, Ibaraki Shares Company Hitachi, Ltd.Automotive Equipment Division (72) Inventor: Mitsuru Konoi Okata, Katsuta-shi, Ibaraki Prefecture 2477 Kashima Yatsu Ground 3 Within Hitachi Automotive Engineering Co., Ltd. (72) Inventor: Norihiro Isozaki Katsuta-shi, Ibaraki 2520 Takaba Hitachi, Ltd. Automotive Equipment Division (56) References JP-A-2-5716 (JP, A) JP-A-3-57857 (JP, A) JP-A-64-69725 (JP, A) JP-A-3-50346 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 9/00-11/10

Claims (2)

(57) [Claims] A cover member for covering a reduction gear is attached to a throttle body.
Deceleration fixed to one end of the throttle valve shaft movably supported
Gear and a motor output shaft arranged in parallel with the throttle valve shaft.
A rotating input-side gear, another reduction gear meshing with the input-side gear, and the throttle
From the motor via a reduction gear fixed to the
Is configured to be transmitted to the throttle valve shaft.
And a reduction gear fixed to the throttle valve shaft is provided with the input side teeth.
The throttle body more than the reduction gear meshing with the car
Receiving a transmission of the driving force from the motor at a position over closer, in the cover member have a throttle valve position sensor is mounted in a position facing the end portion of the throttle valve shaft, wherein in the throttle valve position sensor An electronically controlled throttle valve device for an internal combustion engine configured to detect rotation of a throttle valve. 2. An electronically controlled throttle valve device for an internal combustion engine according to claim 1, wherein a connector of said throttle valve position sensor is attached to said cover member.