JPH03225037A - Variable-lever ratio throttle control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To shorten the arithmetic processing time and improve the responsiveness for operation control by setting the optimum level ratio between the first and second levers in response to operation conditions, and calculating the eccentricity necessary for an intermediate lever with an approximate equation to perform drive control. CONSTITUTION:An intermediate lever 11 transferring the rotation of the first lever 10 to the second lever 6 in conjunction with both levers 10, 6 is provided between the first lever 10 relatively rotatable with respect to a throttle shaft 3 and the second lever 6 fixed to the throttle shaft 3. Guide members 14, 15 rotatably coupled and supported with the intermediate lever 11 can be linearly driven in the radial direction of the throttle shaft 3 by a driving mechanism 16, thereby the lever ratio between the first and second levers can be optionally changed. The optimum value of the lever ratio is set in response to operation conditions, and the necessary eccentricity is calculated with a simple approximate equation given as the function of the lever ratio. The driving mechanism 16 can be quickly controlled against the transient change of the operation conditions.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a device for opening and closing the throttle of an internal combustion engine, and in particular, to an apparatus for arbitrarily adjusting the characteristics between the amount of human accelerator pedal operation and the amount of actual throttle opening and closing. The present invention relates to a variable lever ratio throttle control device that can be changed.

(Prior Art) The throttle of an internal combustion engine, for example, the throttle valve of an automobile gasoline engine, is normally directly connected to the accelerator pedal via an accelerator wire, and the amount of operation of the accelerator pedal (depression) by the driver is directly connected to the accelerator pedal. The dust closure of the throttle valve is fixedly determined according to the amount of dust. Therefore, when driving in traffic jams, delicate operation of the accelerator pedal is required, resulting in poor operability.

Therefore, in recent years, various throttle opening and closing devices have been proposed in which a throttle valve of an internal combustion engine is driven to open and close by an electric motor. With this type of device, the amount of operation of the accelerator pedal is detected as an electrical signal by a potentiometer, etc.
Based on this, an output signal from a control circuit drives an electric motor such as a pulse motor or a DC motor, and a throttle valve connected to the electric motor rotates. In other words, the accelerator pedal operated by the driver and the throttle valve are simply electrically connected, and the throttle valve is directly driven by an electric motor (for example, Japanese Patent Laid-Open No. 62-2142
Publication No. 41). Therefore, it is easy to change or correct the characteristics between the accelerator pedal operation amount and the throttle valve opening, and to control the output during slippage.

In addition, the present applicant links a first lever that rotates in conjunction with an accelerator pedal with a second lever fixed to a throttle shaft via an intermediate lever, and changes the rotational center position of this intermediate lever. By doing so, the first.
We have previously proposed a variable lever ratio type throttle opening/closing device that can change the lever ratio between the second lever, that is, the characteristics between the accelerator pedal operation amount and the actual throttle opening/closing amount (patent application 1-108156).

(Problems to be Solved by the Invention) In the above throttle opening/closing device previously proposed by the present applicant, the rotation angle of the first lever is α, the rotation angle of the second lever is β, and the rotation center of both levers is The eccentricity between the center of rotation of the intermediate lever and the center of rotation of the intermediate lever is e, and the first. The actual lever radius of the second lever (
(assumed to be equal for both levers) is represented by r, then there is a relationship β r−e tan −=tan − 2r+e 2 as described later.

Therefore, when trying to give the optimal value for the throttle opening/closing amount (corresponding to β) for a certain accelerator pedal operation amount (corresponding to α), the required eccentricity e is calculated using the above relational expression, and this It is necessary to control the actuator along the eccentricity fle.

However, calculating the amount of eccentricity e sequentially using a complicated relational expression including trigonometric functions as described above takes a considerable amount of time, and the responsiveness of the control to transient changes in operating conditions may become unstable. There is a possibility that it will be sufficient.

(Means for Solving the Problems) Therefore, the present invention focuses on the fact that the amount of eccentricity e can be expressed approximately as a function of the lever ratio (β/α), and calculates the amount of eccentricity e using this approximate expression. By doing so, the processing time is shortened. That is, the variable lever ratio throttle control device for an internal combustion engine according to the present invention is mechanically connected to a throttle shaft linked to a throttle of the internal combustion engine and an accelerator pedal, and has a rotation center substantially coaxial with the throttle shaft. a first lever rotatable relative to the throttle shaft as the accelerator pedal is operated, a second lever fixed to the throttle shaft, and linked to both the first lever and the second lever; an intermediate lever that transmits the rotation of the first lever to the second lever; a guide member that defines the rotational center position of the intermediate lever; a drive mechanism that moves the guide member in the radial direction of the throttle shaft; Rotation angle α and second
means for setting a target value of the lever ratio (β/α) between the lever rotation angle β and the lever ratio (β/α) according to engine operating conditions;
α), a means for calculating an eccentricity e of the intermediate lever corresponding to the target value using an approximate expression given as a function of α), and a means for controlling the drive mechanism in accordance with the eccentricity e. has been done.

(Operation) When the driver operates the accelerator pedal, the first lever rotates, this rotation is transmitted to the second lever via the intermediate lever, the throttle shaft also rotates, and the throttle opens. At this time, for example, if the rotation centers of the first lever and the intermediate lever coincide with the axial center of the throttle shaft, the rotation angle α of the first lever and the rotation angle β of the second lever are equal.

On the other hand, if the center of rotation of the intermediate lever is eccentric from the center of the throttle shaft axis, the rotation angle α of the first lever and the rotation angle β of the second lever will be different, and the correlation between the two will be The lever ratio (β/α) changes depending on the eccentricity e.

That is, by appropriately moving the guide member using the drive mechanism, the characteristic between the accelerator pedal operation amount and the throttle opening degree can be varied.

Here, the above characteristic, that is, the lever ratio (β/α), is controlled according to engine operating conditions such as the amount of operation of the accelerator pedal.

Specifically, the target value of the lever ratio (β/α) is set according to engine operating conditions. Then, using a simple approximation formula given as a function of the lever ratio (β/α), the necessary eccentricity ff1
e is calculated, and the drive mechanism is controlled in accordance with this.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

Fig. 1 is a configuration explanatory diagram showing a control system of a variable lever ratio throttle control device according to the present invention, and Fig. 2 is an exploded perspective view showing a variable lever ratio type throttle opening/closing mechanism l used in this embodiment in an exploded state. , FIG. 3 is a sectional view showing the opening/closing mechanism 1 in an assembled state.

First, the throttle opening/closing mechanism 1 will be explained with reference to FIGS. 2 and 3.

In the figure, reference numeral 2 denotes a throttle chamber (not shown in FIG. 2) attached to the inlet of an intake collector (not shown), and a throttle shaft 3 passes through the throttle chamber 2 so as to cross the intake passage 2a. A disk-shaped throttle valve 4 is fixed to the throttle shaft 3. Further, one end of the throttle shaft 3 projects from the side wall of the throttle chamber I, and a second lever 6 having a pin 5 at its tip is fixed to the base of the projecting part.

The throttle shaft 3 is always biased in one direction of rotation, specifically in the closing direction of the throttle valve 4, by a return spring 7 made of a coil spring, so that in the free state, the throttle valve 4 moves through the intake passage 2. It has become completely occluded.

As shown in FIG. 1, a throttle valve opening sensor 20 for detecting the actual opening β of the throttle valve 4 is attached to the other end of the throttle shaft 3.

A fan-shaped throttle drum 8 is rotatably fitted into the tip of the protruding portion of the throttle shaft 3, and is prevented from being removed by an E-ring 19. The throttle drum 8 includes an accelerator pedal 21
The end of the accelerator wire 22 (see FIG. 1) linked to the accelerator wire 22 (see FIG. 1) is fixed, and the accelerator wire 22 is wound around the concave groove 8a, and the It is designed to rotate.

Then, on the side of the throttle drum 8, there is a bottle 9 at the tip.
A first lever 10 is fixed. Therefore, in this embodiment, the first rotation center 10 coincides with the axial center of the throttle shaft 3.

11i, t, an intermediate lever located between the first lever lO and the second lever 6;
has a short cylindrical bearing part 11a in the center, and can be played from two locations 180 degrees apart) 111b, llc
is formed in an extended manner, and each plate portion 11b, ll
Elongated engagement holes 12 and 13 are respectively formed in c. The pin 9 at the tip of the second lever 6 is engaged with one engagement hole 12, and the pin 5 at the tip of the second lever 6 is engaged with the other engagement hole 13.

Further, the intermediate lever 11 is rotatably supported by its bearing portion 11a fitting into the outer periphery of a cylindrical guide ring 14 serving as a guide member. The guide ring 14 is formed integrally with a flange portion 15a at the tip of the control rod 15, and the intermediate lever l ] is maintained. The control rod 15 is linearly driven by an actuator 16 constituting a drive mechanism in the radial direction of the throttle shaft 3, specifically in a direction substantially along the longitudinal direction of the intermediate lever 11 when the throttle valve 4 is fully closed. It is now possible to do so. The actuator 16 is
For example, it has a built-in electric motor such as a pulse motor, and is configured to convert its rotational motion into linear motion using a screw or the like, and is fixed by a bracket 17. In addition, the flange portion 1 of the control rod 15
5a, an elongated shaft through hole 18 through which the throttle shaft 3 passes is formed along the moving direction of the control rod 15.

As shown in FIG. 1, the actuator 16 is driven and controlled by a control unit 23 consisting of, for example, a microcomputer system. The control unit 23 receives a detection signal from the throttle valve opening sensor 20 that detects the opening β of the throttle valve 4 described above. Further, in FIG. 1, 24 is the operation amount (depression angle) α of the accelerator pedal 21. 25 is a crank angle sensor that detects the engine speed N, and these detection signals are also input to the control unit 23.

Note that the operation amount α of the accelerator pedal 21 is. is the first lever 1
It uniquely corresponds to the rotation angle α of 0.

Next, the operation of the above configuration will be explained.

First, the principle of changing characteristics by the throttle opening/closing mechanism 1 will be explained with reference to FIG. 4.5.

In the above configuration, the second lever 6 is naturally centered around the throttle shaft 3 (its rotation center is 0 as shown in Fig. 4.5).
(shown as a point), and the first lever 10 similarly rotates around the throttle shaft 3, that is, the above-mentioned 0 point. Further, the intermediate lever 11 is rotatable about the center point of the guide ring 14 (shown as point 01 in FIG. 4.5). Note that while the 0 point is a fixed point, the 01 point, which is the center of the intermediate lever 11, is movable in the radial direction of the throttle shaft 3.

Therefore, when the accelerator pedal 21 is operated, the first lever l
When O rotates by an angle α corresponding to the amount of operation (depression amount), the intermediate lever 11 rotates in the same direction via the pin 9. The rotation of the intermediate lever 11 is transmitted to the second lever 6 via the pin 5, and the throttle valve 4 rotates together with the throttle shaft 3.

Here, if the center point 01 of the guide ring 14 coincides with the 0 point which is the center of the throttle shaft 3 as shown in FIG.
The three members in 1 rotate by exactly the same angle. For example, in FIG. 4, the first lever IO is at the minimum opening position A. The state in which the first lever 10 is rotated from (the position where the amount of depression is 0) to the maximum opening position A (the maximum depression position) is shown.
rotation angle α and the corresponding minimum opening position B of the second lever 6. The rotation angles β from to the maximum opening position B1 are equal to each other.

Therefore, the opening characteristic is the same as when the throttle drum 8 is directly attached to the throttle shaft 3.

On the other hand, if the center OI of the guide ring I4 is eccentric to one side with respect to the 0 point as shown in FIG.
The rotation angle α of the lever 10 and the rotation angle β of the second lever 6 have different values. For example, FIG. 5 shows an example in which point 01 is moved toward the bottle 5 when the throttle valve 4 is fully closed, and the first lever 10 is moved to the minimum opening position A as in FIG. The figure shows the change when rotating from the maximum opening position A+.
The lever 6 is at the minimum opening position B as shown. It can only be rotated from 1 to the maximum opening position B, and the rotation angle β is smaller than the rotation angle α of the first lever IO.

Therefore, compared to the amount of operation of the accelerator pedal, the actual throttle valve 4
The change in the opening degree becomes smaller, resulting in characteristics suitable for driving in traffic jams, for example.

Figure 6 is a schematic representation of the above configuration, and for ease of understanding, the lever radii from the center of rotation O to the pin 5°9 are equal to each other, and point 01 connects point A0 and point 0. It is assumed that it moves along a line. As can be understood from this figure, if the lever radius is r and the eccentricity of the 01 point from the 0 point is e, then the rotation angle β of the second lever 6 (approximately equal to the opening degree of the throttle valve 4) can be shown as . Note that in the actual layout, the first lever 10. Even if the lever radius of the second lever 6 is slightly different, or if the 01 point moves in a direction slightly deviated from the line passing through the Ao point and the 0 point, a similar relationship holds true. Further, the eccentricity ff1e can be in both positive and negative directions.

Therefore, if the eccentricity e is appropriately variably controlled by the actuator 16, the lever ratio (β/α), that is, the opening characteristic between the accelerator pedal operation amount and the actual throttle valve 4 opening degree can be arbitrarily changed. I can do it.

Next, FIG. 7 is a main flow chart showing an outline of the control of the eccentricity e, that is, the control of the actuator 16, executed in the control unit 23. The control of the actuator 16 will be explained with reference to this figure.
First, in step l, the operating conditions at that time, specifically, the rotation angle α of the first lever 10 (corresponding to the operation amount of the accelerator pedal 21), the actual opening degree β of the throttle valve 4, and the engine speed N are determined. Loaded. In step 2, the optimum lever ratio (β/α), that is, the target lever ratio (β/α), is set according to these operating conditions. Furthermore, this target lever ratio is
It is set by a lookup method referring to a predetermined data map or by calculation using a predetermined arithmetic expression.

Then, in step 3, the necessary eccentricity e corresponding to the target lever ratio (β/α) is approximately determined. Here, an approximate expression is given in advance in the form of a function of the lever ratio (β/α), that is, e#f (β/α), and the eccentricity e is successively calculated using this approximate expression.

For example, if lever radius r is 40xz, e#30(1
−β/α)°°■ It can be approximated by the −order number of (β/α).

The graph in Figure 8 shows the relationship between the specific lever ratio (β/α) and the amount of eccentricity e when r = 40xx, and the solid line (A) shows the characteristics according to the approximate formula (■) mentioned above. . In addition, the dashed line (b), -dotted chain line (c), and -dotted chain line (d) are all the characteristics obtained from the relational expression (■) mentioned above, and the dashed line (b) is α
The characteristic when the angle is −5°, the dashed line (c) shows the characteristic when the angle is α−45°, and the dashed double dotted line (d) shows the characteristic when the angle is α−90°. As is clear from FIG. 8, a practically sufficient approximation can be obtained using the above approximation formula (2).

After approximately calculating the necessary eccentricity e in this way, in step 4, the actuator 16 is driven with this eccentricity e as a target value. The current position of the actuator 16 at that time can be determined from the actual relationship between α and β, or if a step motor is used, it can be determined from the number of steps.

Therefore, in the embodiment described above, since the required eccentricity e is calculated by the approximation formula (2) consisting of a simple linear function, the calculation processing time is extremely short, and the responsiveness of the control can be improved accordingly.

It should be noted that the above approximate equation is just an example, and it goes without saying that it will vary depending on the lever radius r, etc.

(Effects of the Invention) As is clear from the above explanation, in the variable lever ratio throttle control device for an internal combustion engine according to the present invention, there is a difference between the first lever linked to the accelerator pedal and the second lever linked to the throttle. The target value of the lever ratio (β/α) is set according to the engine operating conditions, and the required eccentricity e is calculated using an approximate formula given as a function of the lever ratio (β/α). The calculation processing time is much shorter than when calculation is performed without using an approximation formula, and the responsiveness of control to transient changes in operating conditions can be improved.

[Brief explanation of drawings]

Fig. 1 is a configuration explanatory diagram showing one embodiment of a variable lever ratio throttle control device according to the present invention, Fig. 2 is an exploded perspective view of a throttle opening/closing mechanism used in this embodiment, and Fig. 3 is an exploded perspective view of the throttle opening/closing mechanism used in this embodiment. 4 is an explanatory diagram of the operation when the amount of eccentricity of the throttle opening/closing mechanism is 0, FIG. 5 is an explanatory diagram of the operation when an appropriate amount of eccentricity is given, and FIG. 6 is the operating principle. An explanatory diagram for explaining, FIG. 7 is a flowchart showing an example of actuator control, and FIG.
The figure is a characteristic diagram showing a comparison of the relationship between the lever ratio and the amount of eccentricity based on a predetermined relational expression and its approximate expression. 1... Throttle opening/closing mechanism, 3... Throttle shaft, 4... Throttle valve, 6... Second lever 10...
First lever II... Intermediate lever 14... Guide ring, 16... Actuator, 20... Throttle valve opening sensor, 21... Accelerator pedal, 23... Control unit, 24... Accelerator Step angle sensor, 25
...Crank angle sensor. 0 1-111 slot LL/1g! ! Opening mechanism 16---
Dried: L eta 20 --- 1 comparison Ff + fl hiro (Nza 21 --- Aku < Lumadaru 23 --- Control loss Nizutsu 24 --- Eku < Lu Kaf! e Enkiri 25 ----Kufunk angle (Figure 8) 0 0.2 0.4 06 o8 Lever ratio (-L) 0 2 4

Claims (1)

[Claims] (1) A throttle shaft that is connected to the throttle of the internal combustion engine, is mechanically connected to the accelerator pedal, and has a rotation center approximately coaxial with the throttle shaft, and when the accelerator pedal is operated, the throttle shaft is connected to the accelerator pedal. a first lever that is relatively rotatable; a second lever fixed to the throttle shaft;
an intermediate lever that is linked to both levers and transmits the rotation of the first lever to the second lever; a guide member that defines the rotational center position of the intermediate lever; and a guide member that moves the guide member in the radial direction of the throttle shaft. The drive mechanism and the lever ratio (β) between the first lever rotation angle α and the second lever rotation angle β
/α) according to the engine operating conditions and an approximate expression given as a function of the lever ratio (β/α) to calculate the eccentricity e of the intermediate lever corresponding to the above target value. A variable lever ratio throttle control device for an internal combustion engine, comprising means for controlling the drive mechanism in accordance with the eccentricity e.