Control valve opening control apparatus

A control valve control apparatus includes a pivotally mounted accelerator lever linked to an accelerator operation and having a first engagement member, a drive lever linked to an actuator and having a second engagement member, a pivotally mounted control valve shaft lever assembled integral with a control valve and having a third engagement member, and a link lever for linking together the beforementioned levers. When the actuator 41 is not operated, the link lever 51 turns the control valve shaft 3 by means of the third engagement member 7 and the first engagement member 27 linked to accelerator operation. When the accelerator operation is fixed with the actuator operated, the link lever turns the control valve shaft 3 by means of the third engagement member 7 and the second engagement member 47 linked to the actuator 41. This arrangement provides a control valve control apparatus having few components and low cost.

TECHNICAL FIELD 
The invention relates to a control valve control apparatus for controlling 
a flow rate control valve such as a throttle valve and the like used in an 
automotive engine fuel supply system, when the valve is also driven by a 
device such as a step motor. 
BACKGROUND ART 
Control apparatus for preventing slip of a vehicle on ice bound or snow 
covered roads incorporate a traction controller to control the closing of 
a second throttle valve which is not linked to the accelerator pedal, 
thereby controlling the fuel flow rate to reduce engine torque and drive 
force. 
Preferably, the traction controller should be small and light weight, 
however, with the above apparatus wherein the traction controller is 
arranged separate from and connected in series with the throttle valve, 
the size is increased. 
There is a throttle valve control apparatus which utilizes a single control 
valve with the opening determined by operation of the accelerator pedal 
under normal conditions, and automatically controlled irrespective of 
accelerator pedal operation, under traction control conditions. (For 
example refer to Unexamined Japanese Patent Publication No. 3-61654). 
With this type of apparatus, the throttle shaft incorporating a butterfly 
type throttle valve is turned either by the operation of the accelerator 
pedal through a lost motion mechanism, or by a linkage to an actuator 
drive system. 
This construction for the control valve control apparatus for controlling a 
control valve such as a throttle valve, however, results in an increase in 
cost due to the increased number of components and increased complexity of 
the mechanism. Moreover, the large number of components makes 
intercomponent adjustment during assembly difficult, so that apparatus 
reliability is compromised. 
It is, therefore, an object of the present invention to provide a control 
valve control apparatus which addresses the above situation by having 
fewer components, thereby reducing cost and improving reliability. 
DISCLOSURE OF THE INVENTION 
In view of the above, the control valve control apparatus according to the 
present invention comprises; a pivotally mounted accelerator lever linked 
to an accelerator operation and having a first engagement member disposed 
thereon at a distance from a pivotal axis of its pivotal mount, a drive 
lever linked to an actuator and having a second engagement member, a 
pivotally mounted control valve shaft lever formed integral with a control 
valve and having a third engagement member disposed thereon at a distance 
from a pivotal axis of its pivotal mount, and a link lever having 
engagement portions for engagement with said first, second and third 
engagement members such that at least two of said engagement members allow 
relative movement, for linking together said accelerator lever, drive 
lever and control valve shaft lever. 
With such an arrangement for the present invention, operation of the 
accelerator pedal turns the accelerator lever accordingly, while operation 
of the actuator moves the drive lever linked thereto. Here, the 
accelerator lever, drive lever and control valve shaft lever are linked 
together by engagement of the engagement portions of the link lever with 
the first, second and third engagement members provided respectively on 
the accelerator lever, drive lever and control valve shaft lever, with at 
least two engagement members allowing relative movement. 
Moreover, with the present invention, the construction is such that when 
the actuator is stationary, the link lever is pivoted about the second 
engagement member by the first engagement member, which is pivoted 
together with the accelerator lever by the accelerator operation, thereby 
turning the control valve by way of the third engagement member. Hence, 
when the actuator is stationary, the link lever pivots about the second 
engagement member to turn the control valve in accordance with the 
operation of the accelerator. 
Furthermore, with the present invention, when the actuator is operated with 
the accelerator operation fixed, the link lever is pivoted about the first 
engagement member by the second engagement member linked to the actuator, 
thereby turning the control valve by way of the third engagement member. 
Hence, when the accelerator is not operated, the link lever pivots about 
the first engagement member with movement of the actuator to turn the 
control valve in accordance with the movement of the actuator. 
In addition, a construction is possible wherein a regulator means for 
regulating the control valve opening below a predetermined opening, and 
ensuring a minimum control valve opening under accelerator operation, is 
attached to the drive lever. With provision of such a regulator, since 
this regulates the control valve opening below a pre-determined opening, 
the control valve can be opened/closed within a pre-determined range under 
accelerator operation, and also the minimum limit of control valve opening 
under accelerator operation maintained, thereby ensuring a "limp home" 
function. 
The first, second and third engagement members may comprise respective 
first, second and third engagement pins respectively disposed on the 
accelerator lever, drive lever, and control valve shaft lever. Moreover, 
at least two of the engagement portions provided on the link lever may 
comprise elongated holes for engaging with at least two of the first, 
second or third engaging members. 
The engagement portions which engage the first, second and third engagement 
members in that order with the link lever may be provided on the link 
lever. 
Moreover, the pivotal axis of the accelerator lever and the axis of the 
control valve shaft assembled integral with the control valve may be 
located on the same axis. 
A spring may be interposed between the link lever and the accelerator lever 
so as to urge the link lever in a constant direction relative to the 
accelerator lever. 
Furthermore, a step motor may be used as an actuator with the drive lever 
having an axis parallel to the beforementioned pivotal axis such that when 
the step motor turns, the link lever is pivoted about the first engagement 
member by pivotal rotation of the drive lever, thereby turning the control 
valve by way of the third engagement member. 
Moreover, a linear actuator having a direction of operation approximately 
perpendicular to the beforementioned pivotal axis may be used as an 
actuator such that when the linear actuator is operated, the link lever is 
pivoted about the first engagement member due to movement of the drive 
lever thereby turning the control valve by way of the third engagement 
member. 
In addition, the regulator may comprise an adjustment screw which regulates 
the linkage of the drive lever from the actuator. 
Furthermore, the control valve control apparatus according to the present 
invention may be used in an apparatus wherein a control amount is changed 
by variation of the control valve opening.

BEST MODE FOR CARRYING OUT THE INVENTION 
A more detailed description of the present invention is given below with 
reference to the accompanying drawings. 
The Figures show a control apparatus according to the present invention 
applied to the control of a butterfly type throttle valve used as a 
control valve in a vehicle throttle control apparatus. 
FIGS. 1 to 4 and FIGS. 5 to 11 show a first embodiment wherein a throttle 
shaft 2, to which is fixedly attached a butterfly type throttle valve 3, 
is supported so as to be freely rotatable on a support member such as a 
throttle body 9, and is urged in a direction to close the throttle valve 3 
by means of a spring 4. A control valve shaft lever 5 is fixedly attached 
to a right end portion 2a (right end in FIG. 1) of the throttle shaft 2. A 
third engagement pin 7 is provided on the control valve shaft lever 5 so 
as to protrude therefrom at a distance from and be pivotal about the 
throttle shaft 2. 
A throttle opening detector 71 (opening detector) is fixedly supported on 
the throttle body 9 (or the like) near a left end 2b of the throttle shaft 
2 so as to face the left end 2b of the throttle shaft 2, and is linked to 
a lever 72 fixed to the left end 2b of the throttle shaft 2. Consequently, 
the amount of rotation of the throttle shaft 2, i.e. the opening of the 
throttle valve 3 (control valve) is detected by the throttle opening 
detector 71. 
An accelerator drum shaft 22 is axially supported on the throttle body 9 
with its axis parallel to the axis of the throttle shaft 2. An accelerator 
drum 24, which is linked to the operation of the accelerator pedal (not 
shown in the figure), and which is urged in a direction of non-operation 
of the accelerator pedal by a spring 28, is mounted on the accelerator 
drum shaft 22 so as to be pivotal thereabout and so as to turn an 
accelerator lever 25 (to be described hereafter) about the accelerator 
drum shaft 22. The accelerator lever 25 is fixedly attached to the 
accelerator drum shaft 22 and is provided with a first engagement pin 27 
protruding therefrom at a distance from and pivotal about the accelerator 
drum shaft 22. 
A stopper 85 is provided on the accelerator drum 24 for contacting with the 
accelerator drum 24 when it turns through a pre-determined angle in the 
direction of non-operation of the accelerator pedal under the urging of 
the spring 28, and for enabling adjustment of the angular position of the 
accelerator drum 24. 
The accelerator drum 24 is engaged with a link 32 of a link mechanism 
generally indicated by arrow 31 which is connected to an accelerator drum 
opening detector 74 (opening detector) attached to the throttle body 9. 
The link mechanism 31 in combination with a link 33 transmits a rotation 
of the accelerator drum 24 to the accelerator drum opening detector 74. 
Hence, the amount of rotation of the accelerator drum 24 (i.e. the amount 
of pedal operation by the driver) is detected by the accelerator drum 
opening detector 74. 
An actuator in the form of a step motor 41 is supported on the throttle 
body 9, with an axis of its output shaft 42 parallel to the throttle shaft 
2. A drive lever shaft 44 having an axis parallel to the axis of output 
shaft 42 (i.e. the throttle shaft 2), and to which a drive lever 45 is 
fixedly attached is axially supported on the throttle body 9. A second 
engagement pin 47 is provided on the drive lever 45 so as to protrude 
therefrom at a distance from and be pivotal about the drive lever shaft 
44. A follower gear 48 is provided on an outer peripheral face of the 
drive lever 45 so as to engage with a drive gear 43 which is fixedly 
attached to the output shaft 42 of the step motor 41. The drive lever 45 
thus provides a pivotal linkage with the step motor 41. 
Maximum and minimum angle adjustment screws 81 and 82, which can be 
adjusted to set the pivotal range of the drive lever 45, are provided on 
an opposite side of the drive lever 45 to that of the follower gear 48. 
A link lever 51 is disposed between the right end 2a of the throttle shaft 
2 and the drive lever 45, and is provided with a first hole 52 for 
engagement with the first engagement pin 27 by way of a bearing member, a 
second elongated hole 54 for engagement with the second engagement pin 47 
by way of a bearing member, and a third elongated hole 56 for engagement 
with the third engagement pin 7 by way of a bearing member. The first 
engagement pin 27 is engaged with the first hole 52, while the second and 
third engagement pins 47 and 7 are engaged with the respective second and 
third elongated holes 54 and 56 so as to be movable therein. Consequently, 
the accelerator lever 25, drive lever 45 and control valve shaft lever 5 
are linked together by the link lever 51. 
In the present embodiment, a coil spring 88 which urges the link lever 51 
and the accelerator lever 25 in a constant direction, is disposed around 
the first engagement pin 27 so as to urge the link lever 51 in a constant 
direction relative to the accelerator lever 25. 
With this arrangement, the first engagement pin 27, second engagement pin 
47 and third engagement pin 7 function in effect as first, second and 
third engagement members. 
The operation will now be described with reference to the figures. In FIGS. 
5 to 11, to avoid confusion, only components such as the throttle valve 3, 
accelerator drum 24, accelerator lever 25, drive lever 45 and link lever 
51 are shown, and the control valve shaft lever 5 is indicated by a chain 
double-dashed line. 
FIG. 5 shows a condition wherein the accelerator pedal (which is not shown 
in the figure) is not pressed, and traction control is not operative. 
Pressing the accelerator pedal in this condition strokes the wire 29 wound 
on the accelerator drum 24, and as shown in FIG. 6 or FIG. 9, pivots the 
accelerator drum 24 counter clockwise through a pre-determined angle about 
the accelerator drum shaft 22. 
Pivoting of the accelerator drum 24 through a predetermined angle about the 
accelerator drum shaft 22 pivots the accelerator lever 25 counter 
clockwise about the accelerator drum shaft 22. 
Since the traction control is not operative, the step motor 41 does not 
turn, so that the drive lever 45 remains in a fixed condition. 
Consequently, the second engagement pin 47 engaged with the second 
elongated hole 54 of the link lever 51 also remains in a fixed condition. 
Pivoting of the first engagement pin 27, which is engaged with the first 
hole 52, through a pre-determined angle in a counter clockwise direction, 
pivots the link lever 51 counter clockwise about the second engagement pin 
47. The third engagement pin 7 is engaged with the third elongated hole 56 
by way of a bearing member or bearing when the control valve shaft lever 5 
on which the third engagement pin 7 is mounted pivots, the throttle shaft 
2 which is fixedly attached to the control valve shaft lever 5 turns 
counter clockwise through a pre-determined angle. 
That is to say, when the step motor 41 is stationary and the accelerator is 
operated, the link lever 51 pivots about the second engagement pin 47 to 
turn the throttle valve 3 in accordance with the operation of the 
accelerator. 
In the present embodiment, the throttle shaft 2 and the accelerator drum 
shaft 22 both lie on the same axis. The throttle shaft 2 therefore rotates 
in a predetermined linear angular relationship with a pivotal rotation of 
the accelerator drum 24 so that the driver experiences no difference in 
feel. 
Next is a description with reference to FIGS. 7, 8 and FIGS. 10, 11 of the 
situation wherein a slip condition of the vehicle is detected and a 
traction control request signal is issued to rotate the step motor 41. 
With clockwise rotation of the step motor 41, since the drive gear 43 is 
meshed with the follower gear 48, the drive lever 45 is turned counter 
clockwise about the drive lever shaft 44 through a pre-determined angle, 
thereby pivoting the second engagement pin 47 counter clockwise about the 
drive lever shaft 44 through a predetermined angle. 
When traction control is carried out with the accelerator pedal held 
pressed by a pre-determined amount (i.e. with the accelerator drum 24 in a 
fixed condition), the first engagement pin 27 engaged with the first hole 
52 of the link lever 51 also remains in a fixed condition. Since the 
second elongated hole 54 is elongated, then even with the difference in 
pivot radius of the second pin 47 and second elongated hole 54, the 
difference is absorbed by the slot length of the elongated hole 54. 
Consequently, counter clockwise pivoting of the second engagement pin 47 
engaged with the second elongated hole 54 through a pre-determined angle 
results in the link lever 51 pivoting in a clockwise direction about the 
first engagement pin 27. In this case, since the third engagement pin 7 is 
engaged with the third elongated hole 56 of the link lever 51, the control 
valve shaft lever 5 on which the third engagement pin 7 is mounted pivots, 
thereby turning the throttle shaft 2 fixed to the control valve shaft 
lever 5 through a predetermined angle in a clockwise direction. 
Hence, operation of the step motor 41 without operation of the accelerator 
results in the link lever 51 pivoting about the first engagement pin 27 to 
turn the throttle valve 3 in accordance with the operation of the step 
motor 41. 
With the present embodiment as described above, the third engagement pin 7 
is engaged with the third elongated hole 56 so as to be movable therein, 
the second engagement pin 47 is engaged with the second elongated hole 54 
so as to be movable therein, and the first engagement pin 27 is engaged 
with the first hole 52. Consequently, the accelerator lever 25, drive 
lever 45 and control valve shaft lever 5 are linked together by the link 
lever 51. Thus, by having the second engagement pin 47 as an input end and 
the first engagement pin 27 as a pivot point, or the first engagement pin 
27 as an input end and the second engagement pin 47 as a pivot point, the 
third engagement pin 7 acts as an output end for both cases and can be 
pivoted in opposite directions. In other words, linking each of the levers 
together with the link lever 51 enables pivotal motion in opposite 
directions. Hence, a control valve control apparatus having few 
components, a simplified mechanism and high reliability is possible for 
carrying out control operations such as traction control. 
With the present invention, the maximum angle adjustment screw 81 and 
minimum angle adjustment screw 82 are provided. 
The maximum angle adjustment screw 81 sets the maximum pivotal angle of the 
drive lever 45 when pivoted in a counter clockwise direction (as shown in 
FIG. 1) by the step motor 41. If the drive lever 45 is pivoted by the step 
motor 41 through an angle greater than a predetermined angle in a counter 
clockwise direction, then even with pivoting of the accelerator lever 25 
due to an operation of the accelerator to close the throttle valve 3, the 
throttle valve 3 may not be closed completely due to the large 
displacement of the second engagement pin 47 which acts as the pivot 
point. Since with the present embodiment, the position of the second 
engagement pin 47 is set within a predetermined range by the maximum angle 
adjustment screw 81, the opening of throttle valve 3 is restrained below a 
predetermined opening by the maximum angle adjustment screw 81 so as to 
provide a fail-safe insurance against failure, such as of the step motor 
41. 
Furthermore, the minimum angle adjustment screw 82 sets the maximum pivotal 
angle of the drive lever 45 when pivoted in a clockwise direction (as 
shown in FIG. 1) by the step motor 41. If the drive lever 45 is pivoted by 
the step motor 41 through an angle greater than a predetermined angle in a 
clockwise direction, then even with pivoting of the accelerator lever 25 
due to an operation of the accelerator to open the throttle valve 3, the 
throttle valve 3 may hardly open due to the large displacement of the 
second engagement pin 47 which acts as the pivot point. Since with the 
present embodiment, the position of the second engagement pin 47 is set 
within a predetermined range by the minimum angle adjustment screw 82, the 
opening of throttle valve 3 may be set above a predetermined opening by 
the minimum angle adjustment screw 82. Hence even with failure, such as of 
the step motor 41, a minimum limit of opening of the throttle valve 3 
under accelerator operation is possible so as to ensure a "limp home" 
function. 
The maximum angle adjustment screw 81 and minimum angle adjustment screw 82 
thus function in effect as regulating means. 
Since the stopper 85 is provided adjacent to the accelerator drum 24, then 
when the accelerator drum 24 is returned so as to close the throttle valve 
3 under the urging force of the spring 28 on completion of the accelerator 
operation, it contacts with the stopper 85. Consequently, shock loading 
due to the urging force of the spring 28 is taken by the stopper 85 and is 
prevented from acting on the other components such as the link lever 51, 
so that the life of the link lever 51 and first engagement pin 27 etc. can 
be extended. 
The link lever 51 is urged in a constant direction with respect to the 
accelerator lever 25 by the coil spring 88 provided on the first 
engagement pin 27. Hence, any slack in the engagement of the first 
engagement pin 27 in the first hole 52 and the movable engagement of the 
second engagement pin 47 and third engagement pin 7 in the respective 
second elongated hole 54 and third elongated hole 56 is absorbed by the 
respective pins being forced to one side of the respective holes. 
Next is a description of a second embodiment of the present invention with 
reference to FIG. 12. Components similar to those of the first embodiment 
are indicated with the same symbols and the description is omitted. 
In the second embodiment, a linear actuator 60 is supported on the throttle 
body 9 so that its direction of operation is approximately perpendicular 
to the pivotal axis of the accelerator drum shaft 22 and the longitudinal 
axis of the elongated hole 54, and the second engagement pin 47 is 
protrudingly provided on a drive lever 61 which is moved in the direction 
of operation by the linear actuator 60. 
Maximum and minimum movement adjustment screws 65 and 66 are respectively 
provided to correspond with opposite ends 62 and 63 of the drive lever 61 
so that the movement range of the drive lever 61 can be set by their 
adjustment. 
With the second embodiment, when traction control is not being carried out 
the linear solenoid 60 does not operate. Consequently, the second 
engagement pin 47 engaged with the second elongated hole 54 of the link 
lever 51 also remains in a fixed condition. Thus, when the linear solenoid 
60 does not operate, and the accelerator is operated, the link lever 51 
pivots about the second engagement pin 47 to turn the throttle valve 3 in 
accordance with the operation of the accelerator. 
Next is a description of the situation wherein a slip condition of the 
vehicle is detected and a traction control request signal is issued to 
operate the linear solenoid 60. 
With movement of the linear solenoid 60 towards the maximum movement point 
adjustment screw 65, the second engagement pin 47 moves by only a 
predetermined amount in a counter clockwise direction about the third 
engagement pin 7. 
This movement of the second engagement pin 47, which is engaged with the 
second elongated hole 54, through only a predetermined amount in a counter 
clockwise direction results in the link lever 51 being pivoted in a 
clockwise direction about the first engagement pin 27. In this case, since 
the third engagement pin 7 is engaged in the third elongated hole 56 of 
the link lever 51, the control valve shaft lever 5 to which the third 
engagement pin 7 is attached pivots so that the throttle shaft 2 which is 
fixed to the control valve shaft lever 5 is turned through a predetermined 
angle in a clockwise direction. 
When the accelerator is not operated, the link lever 51 pivots about the 
first engagement pin 27 with movement of the linear solenoid 60 to turn 
the throttle valve 3 in accordance with the drive from the linear solenoid 
60. Hence, operation and results similar to those of the first embodiment 
are also realized in the second embodiment. 
With the embodiments described above, the first hole 52 and two elongated 
holes, namely the second elongated hole 54 and the third elongated hole 56 
are formed in the link lever 51. However, a construction of a link 
mechanism involving the accelerator lever 25, drive lever 45, control 
valve shaft lever 5 and link lever 51 is possible provided that at least 
two of the holes for engaging with the first, second and third engagement 
pins 27, 47 and 7 in that order are elongated. 
Furthermore, a construction of a link mechanism involving the accelerator 
lever 25, drive lever 45, control valve shaft lever 5 and link lever 51 is 
possible without the requirement for the first hole 52, second elongated 
hole 54, and third elongated hole 56 to be formed in that order. 
INDUSTRIAL APPLICABILITY 
With the control valve control apparatus according to the present invention 
as described above, the control valve can be turned through operation of 
the accelerator alone or through operation of the actuator. Consequently, 
the number of components for the control valve control apparatus can be 
reduced, the mechanism simplified and the cost lowered. Moreover, with a 
reduction in the number of components, component adjustment becomes 
simpler, and reliability of the apparatus is improved. Consequently, the 
apparatus is suitable for use in the control of automotive engine fuel 
supply systems, and in controls wherein flow rate is changed through 
control of the opening of a control valve.