Title: System for controlling an automatic transmission throttle valve and method of use
Abstract: A system for controlling a transmission throttle valve allows the transmission response to be quickly adjusted. The system includes an adapter assembly which is mounted on the rotatable throttle member of a fuel management device. A cam assembly is selectively positionable on the adapter assembly so as to adjust the rate of throttle valve cable pull. The cam assembly has guide pins which move within guide slots on the adapter assembly. The cam assembly also has an adjustment slot which receives an adjustment screw connected to the adapter assembly. The cam assembly is positioned on the adapter assembly so that the adjustment screw occupies a desired location along the adjustment slot, and then the adjustment screw is tightened to lock the cam assembly in place.
Patent Number: 6,855,091 Issued on 02/15/2005 to Holmes
| Inventors:
|
Holmes; Stephen G. (13176 Red Cedar St., Victorville, CA 92392)
|
| Appl. No.:
|
434120 |
| Filed:
|
May 9, 2003 |
| Current U.S. Class: |
477/121; 123/342; 123/396; 123/400; 123/403 |
| Intern'l Class: |
F16H 059//30 |
| Field of Search: |
477/121
123/342,396,400,403
|
References Cited [Referenced By]
U.S. Patent Documents
| 4411845 | Oct., 1983 | Tanahashi et al. | 261/65.
|
| 4631983 | Dec., 1986 | Morisawa et al. | 477/156.
|
| 5078111 | Jan., 1992 | McCann | 123/400.
|
| RE34138 | Dec., 1992 | Flaig et al. | 123/400.
|
| 5542313 | Aug., 1996 | McCarthy | 74/513.
|
| 5964203 | Oct., 1999 | Sato et al. | 123/396.
|
| 6575875 | Jun., 2003 | Holmes | 477/121.
|
| 2003/0196638 | Oct., 2003 | Matsuda et al. | 123/342.
|
| Foreign Patent Documents |
| 02238138 | Sep., 1990 | JP | .
|
| 02308932 | Dec., 1990 | JP | .
|
| 03225036 | Oct., 1991 | JP | .
|
| 04005439 | Jan., 1992 | JP | .
|
Primary Examiner: Rodriguez; Saul
Assistant Examiner: Le; David D.
Attorney, Agent or Firm: Tyson; Timothy Thut, Masters; Ted
Freilich, Hornbaker & Rosen
Claims
I claim:
1. A system for controlling a transmission throttle valve in a vehicle
having a fuel management device which includes a rotatable throttle member
having an idle state and a wide open throttle state, the transmission
throttle valve connected to a transmission throttle valve cable, said
system comprising:
a cam assembly attachable to the rotatable throttle member;
the transmission throttle valve cable connectable to said cam assembly,
wherein when the rotatable throttle member is rotated from the idle state
to the wide open throttle state, said cam assembly pulls the transmission
throttle valve cable a correct cable pull distance;
said cam assembly selectively positionable on the rotatable throttle
member, wherein the position of said cam assembly determines a rate at
which the transmission throttle valve cable is pulled said correct cable
pull distance; and,
wherein as the transmission throttle valve cable is pulled said correct
cable pull distance said rate being one of (1) increasing as the rotatable
throttle member is rotated from the idle state to the wide open throttle
state, and (2) decreasing as the rotatable throttle member is rotated from
the idle state to the wide open throttle state.
2. A system according to claim 1, further including:
as the rotatable throttle member is rotated from the idle state to the wide
open throttle state, said cam assembly pulling the transmission throttle
valve cable said correct cable pull distance for any selected position of
said cam assembly on the rotatable throttle member.
3. A system for controlling a transmission throttle valve in a vehicle
having a fuel management device which includes a rotatable throttle member
having an idle state and a wide open throttle state, the transmission
throttle valve connected to a transmission throttle valve cable, said
system comprising:
an adapter assembly attachable to the rotatable throttle member;
said adapter assembly including at least one guide slot;
a cam assembly having at least one guide pin, a throttle valve cable guide,
and a holder for holding the throttle valve cable;
a retaining mechanism for selectively locking said adapter assembly and
said cam assembly in fixed relationship;
wherein said cam assembly may be placed in contact with said adapter
assembly so that said at least one guide pin is received by said at least
one guide slot; and,
wherein said cam assembly may be moved so that said at least one guide pin
assumes a desired position along said at least one guide slot, and said
cam assembly locked in said desired position with said retaining
mechanism; and,
the transmission throttle valve cable connectable to said cam assembly,
wherein when the rotatable throttle member is rotated from the idle state
to the wide open throttle state, said cam assembly pulls the transmission
throttle valve cable a correct cable pull distance for any selected
position of said cam assembly with respect to said adapter assembly, and,
wherein said locked desired position of said cam assembly determines a rate
at which said transmission throttle valve cable is pulled said correct
cable pull distance as the rotatable throttle member is rotated from the
idle state to the wide open throttle state.
4. A system according to claim 3, further including:
said at least one guide slot being curved.
5. A system according to claim 3, further including:
a throttle valve cable mounting bracket for holding the throttle valve
cable; and,
said throttle valve cable mounting bracket mountable beneath the fuel
management system.
6. A system according to claim 3, further including:
said retaining mechanism including:
said adapter assembly including a threaded hole;
said cam assembly having an adjustment slot;
an adjustment screw which threadably engages said threaded hole in said
adapter assembly;
wherein said adjustment screw passes through said adjustment slot and
engages said threaded hole, so that when said adjustment screw is
tightened, said cam assembly and said adapter assembly are forced
together;
said adjustment slot being curved;
said adapter assembly having a pocket for receiving the rotatable throttle
member, so that said adapter assembly may be mounted on the rotatable
throttle member;
said adapter assembly including two said guide slots;
said cam assembly including two said guide pins, wherein one said guide pin
is received by each of said guide slots; and,
said two guide slots being curved.
7. A system according to claim 3, further including:
wherein as the transmission throttle valve cable is pulled said correct
cable pull distance said rate being one of (1) increasing as the rotatable
throttle member is rotated from the idle state to the wide open throttle
state, and (2) decreasing as the rotatable throttle member is rotated from
the idle state to the wide open throttle state.
8. A system according to claim 3, further including:
said retaining mechanism including:
said adapter assembly including a threaded hole;
said cam assembly having an adjustment slot;
an adjustment screw which threadably engages said threaded hole in said
adapter assembly; and,
wherein said adjustment screw passes through said adjustment slot and
engages said threaded hole, so that when said adjustment screw is
tightened, said cam assembly and said adapter assembly are forced
together.
9. A system according to claim 8, further including:
said adjustment slot being curved.
10. A system according to claim 3, said system further including:
said adapter assembly having a pocket for receiving the rotatable throttle
member, so that said adapter assembly may be mounted on the rotatable
throttle member.
11. A system according to claim 10, further including:
said adapter assembly including a front plate having said threaded hole and
said at least one guide slot, a pocket plate contoured to at least a
portion of the rotatable throttle member, and a rear plate.
12. A system according to claim 3, further including:
said adapter assembly including two said guide slots; and,
said cam assembly including two said guide pins, wherein one said guide pin
is received by each of said guide slots.
13. A system according to claim 12, further including:
said two guide slots forming an angle of between about 75.degree. and
105.degree..
14. A method for controlling a transmission throttle valve, comprising:
(a) providing a fuel management device which includes a rotatable throttle
member having an idle state and a wide open throttle state,
(b) providing a transmission throttle valve connected to a transmission
throttle valve cable;
(c) providing a system for controlling said transmission throttle valve,
including:
a cam assembly attachable to said rotatable throttle member,
said transmission throttle valve cable connectable to said cam assembly,
wherein when said rotatable throttle member is rotated from said idle
state to said wide open throttle state, said cam assembly pulls said
transmission throttle valve cable a correct cable pull distance;
said cam assembly selectively positionable with respect to said rotatable
throttle member, wherein the position of said cam assembly determines a
rate at which said throttle valve cable is pulled, said rate being one of
(I) increasing as said rotatable throttle member is rotated from said idle
state to said wide open throttle state, and (2) decreasing as said
rotatable throttle member is rotated from said idle state to said wide
open throttle state, and,
a retaining mechanism for locking said cam assembly in a fixed position
with respect to said rotatable throttle member;
(d) position said cam assembly to a desired position with respect to said
rotatable throttle member;
(e) using said retaining mechanism to lock said cam assembly in said
desired position;
(f) attaching said transmission valve throttle cable to said cam assembly;
and,
(g) causing said rotatable throttle member to rotate from said idle state
to said wide open throttle state thereby pulling said transmission
throttle valve cable said correct cable pull distance: and,
(h) observing that said rate at which said transmission throttle valve
cable is pulled said correct cable pull distance results in a desired
transmission shift timing, firmness, and feel.
15. A system according to claim 14, further including:
(i) observing that said cam assembly pulls said transmission throttle valve
cable said correct cable pull distance for any selected position of said
cam assembly with respect to said rotatable throttle member in step (d).
Description
TECHNICAL FIELD
The present invention pertains generally to automobiles having automatic
transmissions, and particularly to a system for selectively controlling
the actuation rate of the automatic transmission throttle valve.
BACKGROUND OF THE INVENTION
The throttle valve, which is slidably movable in a bore, regulates the flow
of transmission oil through the transmission's valve body. A linkage
couples the position of the accelerator pedal to the throttle valve, and
causes the throttle valve to move between an idle or low throttle position
and a full or wide open throttle position. Throttle valve controlled
transmissions utilize a cable running from the vehicle's fuel management
system whether a fuel injector or carburetor to the transmission's valve
body. The cable linkage between a modern fuel injector/carburetor system
provides a signal method for proper transmission function. The cable
connection is commonly known as the throttle valve (TV) cable. The TV
cable connects the throttle mechanism to the transmission hydraulic
control valve. The throttle valve reciprocates in a common bore in the
transmission valve body, and is typically composed of a plunger, spring,
and throttle valve. The positioned relationship of these components
determines how the transmission will operate.
The TV cable is used to connect the carburetor linkage at one end, to a
swinging lever at the other end. The swinging lever moves the throttle
valve. Any movements of the carburetor linkage, during normal driving,
results in a corresponding movement of the TV cable. Carburetors have a
range of movement from idle to wide open throttle (W.O.T.). As normal
carburetor linkage movement pulls the TV cable, the swinging lever rotates
thereby pushing the throttle valve plunger down its bore. This plunger has
a designed operating range from its engineered starting point to a fully
inwardly depressed position, wherein the range of motion is specific to a
particular make and model. Even slight movement of the throttle valve
linkage results in a corresponding movement of the throttle valve. As the
throttle valve moves, it will adjust the shift timing, feel, and firmness
of the transmission.
For the throttle valve system to function properly, actuation of the
throttle valve must be proper for the particular vehicle. Just because the
plunger (and therefore the TV) is mechanically made to move through its
engineered spectrum of movement, does not mean the transmission will
perform in the desired manner. The rate of movement at any given point can
be altered by the dynamics of the carburetor linkage, and can dramatically
affect transmission performance characteristics. When new cars are
designed, the correct linkage relationship is established for each
particular vehicle. This is done to satisfy the different transmission
operating responses needed for the different types of vehicles. For
example, a luxury car's TV system is not designed the same way as a
performance car's TV system, nor as a pickup truck's TV system.
Mechanisms for controlling transmission throttle valves are well known in
the art. For example, U.S. Pat. No. 4,631,983 shows a lever mechanism for
a cable linkage including a control lever mounted on a rotary shaft for
rotation therewith, a base plate mounted on the rotary shaft and fixed to
the control lever for rotation therewith, and a lever plate adjustably
assembled with the base plate and connected at one side of its outer
peripheral portion to one end of the cable linkage. The lever plate is
provided at its outer peripheral portion with a semicircular guide surface
having a center located substantially at a rotation fulcrum of the lever
plate. The cable linkage is supported on the semicircular guide surface of
the lever plate. And the lever plate is displaceable on the base plate.
During the assembly process, the distance between the semicircular guide
surface and the rotation fulcrum is adjustable. U.S. Pat. No. 4,711,140
illustrates an improved throttle valve regulating system for automatic
transmissions for motor vehicles. The throttle valve reciprocates in a
bore as a result of the action of a plunger and a throttle valve spring to
control the flow and pressure of transmission fluid or oil to effect gear
shifting. A rigid spacing element of predetermined length received within
the throttle valve spring is provided for urging the valve towards a full
throttle position in the event that the valve sticks in the bore in a
lower throttle position. The system further includes a high rate spring
located in the full throttle position in the bore to prevent sticking of
the valve in that position, and a low rate spring similarly positioned in
the bore to counteract the force of the throttle valve spring for
returning the throttle valve to a low throttle or zero position. The
reciprocating throttle valve includes at least one land or circumferential
flange having sharpened edges for shearing large particles or other
impurities introduced into the bore with the transmission fluid which
might otherwise become wedged between the valve and the bore and cause
sticking of the valve in a fixed position in the bore.
U.S. Pat. No. 5,046,380 defines a throttle valve operating cam of an
automatic transmission and an output control member of an automotive
engine that are interconnected so as to cooperate with each other by a
cable consisting of an outer tube and an inner cable. The inner cable is
connected to the throttle valve operating cam and the output control
member. One end of the outer tube is connected first to the automatic
transmission. The other end of the outer tube is regulated in position
relative to a cable fitting member secured to the automotive engine and
then fixed to the cable fitting member secured to the automotive engine.
U.S. Pat. No. 5,727,425 comprises a method for adjusting the throttle valve
cable in an automatic transmission. In a motor vehicle automatic
transmission, for example a GENERAL MOTORS THM 700-R4 automatic
transmission, the TV cable forms part of the mechanical link between the
throttle pedal, the throttle valve linkage on a fuel delivery system
(e.g., a carburetor or electronic fuel injector), and the throttle valve.
The TV cable is adjusted using a sleeve and spring installed at the distal
end of the TV cable between the cable end clamp and a teardrop shaped
cable end fitting on the TV cable. The spring opposes the movement of the
cable end fitting toward the distal end of the TV cable so that the cable
end fitting is at its maximum distal position only at fully open throttle.
This gives the vehicle operator the shift feel of a shorter TV cable at
most throttle openings. The sleeve and spring are installed only on TV
cables in automatic transmissions that do not have TV cable end fittings
permanently attached to a throttle cam.
Providing a system which pulls the TV cable the correct distance while the
carburetor linkage rotates from engine idle to wide open throttle is a
relatively simple engineering exercise. However, just because the TV cable
provides the correct cable pull distance as the linkage rotates from idle
to wide open throttle does not automatically mean the transmission will
behave correctly or appropriately. For example, because a transmission
performs a second gear to first gear downshift doesn't mean it will do so
at the appropriate time or with the correct firmness. The real issue is
"behavior". To further exacerbate the situation, each individual driver
defines what he or she believes is proper and correct behavior. Vehicles
receiving these transmissions can vary tremendously from one another. Many
of these differences can have an effect on the behavior of a transmission.
A few factors which effect transmission performance are (1) more or less
powerful engines, (2) vehicles of different weights, and (3) tires sizes
and rear end ratios.
In view of the above, a method is needed for providing the required TV
cable pull distance and allowing adjustment of the rate of cable pull. The
present invention accomplishes this by always providing the correct cable
pull distance, and by also allowing the installer to quickly adjust the
rate of TV cable pull per degree of carburetor linkage rotation.
SUMMARY OF THE INVENTION
The present invention is directed to a system and method for controlling
the throttle valve of automatic transmissions, and more particularly to a
system and method which permits selective adjustment, or "Ming", of the
rate at which the throttle valve is activated to adjust shift timing,
firmness, and feel. This allows the installation of a modern throttle
valve controlled automatic transmission into a vehicle for which it was
not designed. Specifically, the linkage on older carburetors was never
designed to provide the proper signal to newer throttle valve
transmissions. The present invention provides a means of insuring not only
the correct cable pull distance, but also of adjusting the characteristics
of transmission operation. The present invention offers a user the ability
to accomplish both a correct cable pull distance which is a requirement
fixed by the travel of the throttle valve, while concurrently offering
different cable pull rates to "tune" the transmission response to a
desired shift timing, firmness, and feel.
The present invention allows the throttle valve cable pull characteristics
to be altered using a uniquely designed cam. The cam is attached to the
carburetor or fuel injection system's rotatable throttle linkage via a
specially designed adapter assembly, and is also attached to the throttle
valve cable. The position of the cam with respect to the linkage may be
quickly and easily changed, thereby changing the rate of throttle valve
cable pull, and therefore the behavior of the transmission.
In accordance with a preferred embodiment of the invention, a system for
controlling a transmission throttle valve in a vehicle having a fuel
management device which includes a rotatable throttle member having an
idle state and a wide open throttle state, the transmission throttle valve
connected to a throttle valve cable, said system comprising:
a cam assembly attachable to the rotatable throttle member;
the transmission throttle valve cable connectable to the cam assembly,
wherein when the rotatable throttle member is rotated from the idle state
to the wide open throttle state, the cam assembly pulls the transmission
throttle valve cable a fixed distance; and,
the cam assembly selectively positionable on the rotatable throttle member,
wherein the position of the cam assembly determines the rate at which the
throttle valve cable is pulled.
In accordance with an aspect of the invention, the cam assembly pulls the
throttle valve cable the fixed distance for any selected position of the
cam assembly with respect the rotatable throttle member.
In accordance with another aspect of the invention, the system further
includes:
an adapter assembly attachable to the rotatable throttle member;
the adapter assembly including at least one guide slot;
a cam assembly having at least one guide pin, a throttle valve cable guide,
and a holder for holding the throttle valve cable;
a retaining mechanism for selectively locking the adapter assembly and the
cam assembly in fixed relationship;
wherein the cam assembly may be placed in contact with the adapter assembly
so that the at least one guide pin is received by the at least one guide
slot; and,
wherein the cam assembly may be moved so that the at least one guide pin
assumes a desired position along the at least one guide slot, and the cam
assembly locked in the desired position with the retaining mechanism.
In accordance with another aspect of the invention, the retaining mechanism
includes an adjustment screw which rides along an adjustment slot in the
cam assembly. The desired transmission response is chosen by positioning
the cam assembly so that the adjustment screw occupies a desired location
along the adjustment slot, and then tightening the adjustment screw to
lock the cam assembly to the adapter assembly.
In accordance with another aspect of the invention, the adapter assembly
includes two guide slots and the cam assembly includes two corresponding
guide pins.
Other features and advantages of the present invention will become apparent
from the following detailed description, taken in conjunction with the
accompanying drawings, which illustrate, by way of example, the principles
of the invention.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a side elevation view of a prior art fuel management device in an
idle state;
FIG. 2 is a side elevation view of the prior art fuel management device in
a wide open throttle state;
FIG. 3 is a side elevation view of a throttle linkage member in an idle
state showing a nominal arc of cam pull for a throttle valve cable;
FIG. 4 is a side elevation view of the throttle linkage member in a wide
open throttle state showing the nominal arc of cam pull for a throttle
valve cable;
FIG. 5 is a side elevation view of the throttle linkage member in an idle
state showing a passive arc of cam pull for a throttle valve cable;
FIG. 6 is a side elevation view of the throttle linkage member in a wide
open throttle state showing the passive arc of cam pull for a throttle
valve cable;
FIG. 7 is a side elevation view of the throttle linkage member in an idle
state showing an aggressive arc of cam pull for a throttle valve cable;
FIG. 8 is a side elevation view of the throttle linkage member in a wide
open throttle state showing the aggressive arc of cam pull for a throttle
valve cable;
FIG. 9 is a side elevation view of a system for controlling an automatic
transmission throttle valve in accordance with the present invention
mounted on the throttle linkage member shown in an idle state;
FIG. 10 is a side elevation view of the system and throttle linkage member
of FIG. 9 rotated to the wide open throttle state;
FIG. 11 is a side elevation view of the system for controlling an automatic
transmission throttle valve with the system set to a passive position;
FIG. 12 is a side elevation view of the system and throttle linkage member
of FIG. 11 rotated to the wide open throttle state;
FIG. 13 is a side elevation view of the system for controlling an automatic
transmission throttle valve with the system set to an aggressive position;
FIG. 14 is a side elevation view of the system and throttle linkage member
of FIG. 13 rotated to the wide open throttle state;
FIG. 15 is a side elevation view of a cam assembly;
FIG. 16 is a edge view of the cam assembly;
FIG. 17 is an opposite side elevation view of the cam assembly;
FIG. 18 is an enlarged side elevation view of an adjustment screw;
FIG. 19 is a side elevation view of a front plate;
FIG. 20 is a side elevation view of a pocket plate;
FIG. 21 is a side elevation view of a rear plate;
FIG. 22 is an exploded perspective view showing how the front plate, pocket
plate, and rear plate fit together to form an adapter assembly;
FIG. 23 is a side elevation view of a throttle valve cable mounting
bracket;
FIG. 24 is a side elevation view of the system mounted on the fuel
management device;
FIG. 25 is a graph showing cable pull distance in relation to rotatable
throttle member rotation for both passive and aggressive throttle valve
responses;
FIG. 26 is a graph showing the calculation of guide slots; and,
FIG. 27 is a graph showing the calculation of an adjustment slot.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates a side elevation view of a prior art fuel management
device, generally designated as 500, in an idle state. The fuel management
device 500 shown is a carburetor. The fuel management device 500 could
also be a fuel injection system. Fuel management device 500 includes a
rotatable throttle member. In the shown embodiment the rotatable throttle
member is a throttle linkage member 504 which is connected to and rotates
throttle shaft 502. A transmission throttle valve (not shown) is connected
to fuel management device 500 by a throttle valve cable 506 (refer to FIG.
24).
Fuel management device 500 is mounted on an intake manifold 508 of a
vehicle. In a typical embodiment, fuel management device 500 includes two
butterfly valves which control the intake of air to the engine of the
vehicle. The butterfly valves are connected to a throttle shaft 502. In
the shown idle or low throttle position state, butterfly valves are
oriented so as to block air from entering the air intake of the engine.
When throttle linkage member 504 is rotated by an accelerator pedal
linkage (not shown), throttle shaft 502 rotates and thereby rotates the
butterfly valves increasing the intake of air to the engine.
FIG. 2 illustrates a side elevation view of the prior art fuel management
device 500 in a wide open throttle state. Throttle linkage member 504 has
been rotated through angle A causing throttle shaft 502 to rotate and open
the butterfly valves increasing the intake of air to the engine. In the
shown embodiment, the rotation angle A from idle to wide open throttle is
75.18.degree.. This angular rotation applies to the "Pro-Flo 3500"
aftermarket fuel injection system throttle body linkage available from
Edelbrock Corporation of Torrance, Calif., and is used in the description
of the present invention. However, it may be appreciated that other fuel
management devices 500 will have a different angle A of rotation from idle
to wide open throttle, yet the principles of the present invention
disclosed herein may also be applied to these devices.
FIG. 3 is a side elevation view of throttle linkage member 504 in an idle
state. The throttle valve cable 506 is connected to the throttle valve of
an automatic transmission. For the purposes of this illustration, the
throttle valve requirements of a Th-700R4 transmission available from
General Motors Corporation of Detroit, Mich., are used. As with the fuel
management device 500, it may be appreciated that other transmissions will
have different requirements, to which the principles of the present
invention may be applied. The throttle valve cable 506 used with a
Th-700R4 transmission must be pulled a fixed distance D of 1.610" to move
the throttle valve plunger in the transmission from a starting point at
idle to a fully buried position at wide open throttle.
The correct throttle cable pull distance may be implemented by providing a
75.180 (A.degree.) cam having an arc length of 1.610" (D). The cam will
have first R1 and second R2 radiuses of 1.227". Such a cam will have an
arc length D of exactly 1.610", which is equal to the desired fixed pull
distance. This design will provide 0.02142" of cable pull for each degree
of throttle linkage member 504 rotation, ultimately pulling the throttle
valve cable the required 1.610" (D) during the 75.180 (Al) of throttle
linkage member 504 rotation from idle to wide open throttle. This design
provides a constant steady pulling action throughout the entire throttle
linkage member 504 rotation.
FIG. 4 is a side elevation view of throttle linkage member 504 in a wide
open throttle state showing the nominal arc of cam pull for a throttle
valve cable 506. Throttle linkage member 504 has been rotated 75.180. This
results in a throttle valve cable 506 pull of the desired 1.610" (D).
While the cam design depicted in FIGS. 3 and 4 provides the correct cable
pull of 1.610", the transmission may not shift at the desired time during
light and medium throttle driving. It may feel too soft or too firm or the
downshift characteristics may be too aggressive or not aggressive enough.
To provide a different rate of cable pull, the same cam can be positioned
on the throttle linkage differently.
FIGS. 5 and 6 are side elevation views of throttle linkage member 504 in
idle and wide open throttle states, respectively, showing a passive arc of
cam pull for throttle valve cable 506. The cam arc having a length of D
inches (1.610") has been moved up along R1 and out along R2. In this
position the end of the cam are furthest from the cable housing is
positioned with a starting radius R1 of only 0.977" from the centerline of
the throttle shaft 502. The other end of the cam arc is positioned with a
starting radius R2 of 1.4113" from the centerline of the throttle shaft
502. The cam positioned in this manner will still pull the throttle valve
cable 506 the required 1.610" while the throttle linkage is rotated
75.18.degree. from idle to wide open throttle. However, the rate of
throttle valve cable 506 pull will be slower at first due to the shorter
R1 distance and more rapid at the end of the pull due to the longer R2
distance. The throttle valve cable 506 will be pulled only 0.0174" during
the first degree of linkage rotation compared to 0.02142" of the constant
rate cams in FIGS. 3 and 4. As the throttle is rotated towards wide open
throttle, each successive degree will pull the cable a little greater
distance. The final degree of throttle linkage rotation will pull the
throttle valve cable 0.0246". Positioning the cam on the throttle linkage
in this manner will cause the throttle valve cable to pull slowly at first
but progressively more rapidly as the throttle is rotated towards wide
open throttle. The transmission will shift noticeably quicker and softer
with most accelerator pedal settings especially during light to medium
accelerator pedal applications. The downshifting characteristics will be
less aggressive requiring a greater application of throttle to perform
downshifts. Wide open throttle performance will remain the same.
FIGS. 7 and 8 are side elevation views of throttle linkage member 506 in
idle and wide open throttle states, respectively, showing an aggressive
arc of cam pull for throttle valve cable 506. The cam arc having a length
of D (1.610") has been moved down along R1 and in along R2. In this
position the end of the cam arc furthest from the cable housing is
positioned with a starting radius R1 of 1.477" from the centerline of the
throttle shaft 502. The other end of the cam arc is positioned with a
starting radius R2 of 0.8273" from the centerline of the throttle shaft
502. The cam positioned in this manner will still pull the throttle valve
cable 506 the required 1.610" while the throttle linkage is rotated
75.18.degree. from idle to wide open throttle. However, the rate of
throttle valve cable 506 pull will be faster at first due to the longer R1
distance and more slowly at the end of the pull due to the shorter R2
distance. The throttle valve cable 506 will be pulled 0.0257" during the
first degree of linkage rotation compared to 0.02142" of the constant rate
cams in FIGS. 3 and 4. As the throttle is rotated towards wide open
throttle, each successive degree will pull the cable a little lesser
distance. The final degree of throttle linkage rotation will pull the
throttle valve cable 506 only 0.0165". Positioning the cam on the throttle
linkage in this manner will cause the throttle valve cable 506 to pull
rapidly at first but then progressively more slowly per degree of throttle
rotation. The transmission will shift noticeably later and firmer with
most light to medium throttle settings. Downshifting will be more active
requiring less accelerator pedal to accomplish. Wide open throttle
performance will remain the same.
FIGS. 9 and 10 are side elevation views of a system for controlling an
automatic transmission throttle valve in accordance with the present
invention, generally designated as 20, shown in an idle state and wide
open throttle state, respectively. System 20 is mounted on the rotatable
throttle member, which is throttle linkage member 504 in the shown
embodiment. System 20 includes an adapter assembly 22 which is attachable
to the throttle linkage member 504. Adapter assembly 22 has a pocket 24
(see FIGS. 20 and 22) for receiving throttle linkage member 504, so that
adapter assembly 22 may be fixedly mounted on throttle linkage member 504
and rotated thereby. Adapter assembly 22 also has a hole 26 for accepting
throttle shaft 502 (see FIGS. 19 and 22).
A cam assembly 30 is slidably mounted on adapter assembly 22. Cam assembly
30 has a throttle valve cable guide 34 which receives throttle valve cable
506, a receptacle or holder 36 for holding the bulbous end 505 of throttle
valve cable 506 (see FIGS. 15-17), and at least one guide pin 32. In the
shown embodiment, cam assembly has two guide pins 32.
Adapter assembly 22 has at least one guide slot 28 (refer also to FIGS. 19
and 22). In the shown embodiment, adapter assembly 22 has two slightly
curved guide slots which form an angle B.degree. of between 75.degree. and
1050 with respect to each other. One guide pin 32 of cam assembly 30 is
slidably received by each of the guide slots 28. The guide pins and guide
slots limit the range of motion of the cam assembly with respect to
adapter assembly 22.
A retaining mechanism selectively locks cam assembly 30 in a fixed
relationship to adapter assembly 22. The retaining mechanism includes
adapter assembly 22 having a threaded hole 38 (see FIGS. 19-22), cam
assembly 30 having a curved adjustment slot 40, and an adjustment screw
42. Adjustment screw 42 passes through adjustment slot 40 and engages
threaded hole 38 so that when adjustment screw 42 is tightened, cam
assembly 30 and adapter assembly 22 are forced together locking the cam
assembly at a particular location with respect to the adapter assembly.
Two guide slots 28 substantially perpendicular to each other and two guide
pins 32 are preferred over one slot and one guide pin to hold the cam
assembly 30 to the adapter assembly 22. At least one pin will then always
be against the side of a slot to prohibit movement of the cam assembly 30
with respect to the adapter assembly 22 in most directions. This makes the
cam assembly better able to resist forces applied in most directions which
might otherwise cause it to become loose.
The position of cam assembly 30 with respect to adapter assembly 22
determines the desired shift timing, firmness, and feel. In FIG. 9,
throttle linkage member 504 is in the idle position. Cam assembly 30 is
rotated so that adjustment screw 42 assumes a mid position along
adjustment slot 40, and then adjustment screw 42 is tightened locking cam
assembly 30 in place on adapter assembly 22. In FIG. 10, throttle linkage
member 504 has been rotated to a wide open throttle position, thereby
pulling throttle valve cable 506 the desired distance. This mid position
of cam assembly 30 on adapter assembly 22 will result in a constant steady
pulling action throughout the entire throttle linkage member 504 rotation,
as was depicted in FIGS. 3 and 4.
FIGS. 11 and 12 are side elevation views at idle and wide open throttle,
respectively, of system 20 set to a passive throttle valve position. Cam
assembly 30 has been positioned on adapter assembly 22 so that the left
and right guide pins 32 have been moved to their extreme up and right
positions respectively, and adjustment screw 42 has been moved to the
leftmost position along adjustment slot 40. Adjustment screw 42 has been
tightened to lock cam assembly 30 in place along guide slot 40 on adapter
assembly 22. This position of cam assembly 30 results in the passive
throttle valve cable 506 pull previously described in the discussion of
FIGS. 5 and 6.
FIGS. 13 and 14 are side elevation views at idle and wide open throttle,
respectively, of system 20 set to an active throttle valve position. Cam
assembly 30 has been positioned on adapter assembly 22 so that the left
and right guide pins 32 have been moved to their extreme down and left
positions, respectively, and adjustment screw 42 has been moved to the
rightmost position along adjustment slot 40. Adjustment screw 42 has been
tightened to lock cam assembly 30 in place along guide slot 40 on adapter
assembly 22. This position of cam assembly 30 results in the aggressive
throttle valve cable 506 pull previously described in the discussion of
FIGS. 7 and 8.
FIGS. 15-17 are side elevation, edge, and opposite side elevation views,
respectively, of cam assembly 30, showing guide pins 32, throttle valve
cable guide 34, holder 36, and adjustment slot 40.
FIG. 18 is an enlarged side elevation view of adjustment screw 42.
FIG. 19 is a side elevation view of a front plate 44 of adapter assembly
22. Front plate 44 includes guide slots 28, and threaded hole 38 which
receives adjustment screw 42. Angle B is between about 750 and
105.degree..
FIG. 20 is a side elevation view of a pocket plate 46 of adapter assembly
22. Pocket plate 46 has a contoured pocket 24 for receiving at least a
portion of throttle linkage member 504 (rotatable throttle member).
FIG. 21 is a side elevation view of a rear plate 48 of adapter assembly 22.
When front plate 44, pocket plate 46, and rear plate 48 are bolted
together, they form a "sandwich" around throttle linkage member 504 and
are rigidly held thereto.
FIG. 22 is an exploded perspective view showing how the front plate 44,
pocket plate 46, and rear plate 48 fit together to form adapter assembly
22.
FIG. 23 is a side elevation view of a throttle valve cable mounting bracket
50. Throttle valve cable mounting bracket 50 holds throttle valve cable
housing 507, and is mountable beneath fuel management device 500 (usually
between fuel management device 500 and intake manifold 508), (refer also
to FIG. 24).
FIG. 24 is a side elevation view of system 20 mounted on fuel management
device 500. Throttle valve cable housing 507 has an adjustment feature
which permits longitudinal movement as described in U.S. Pat. No.
5,295,408.
FIG. 25 is a graph showing cable pull distance D" in relation to rotatable
throttle member rotation A.degree. for both passive and aggressive
throttle valve responses. The passive connection shown in FIGS. 11 and 12
results in a lesser cable pull response at the start of rotatable throttle
member rotation. Conversely, the aggressive connection shown in FIGS. 13
and 14 results in a greater cable pull response at the start of rotatable
throttle member rotation. This difference in the rate of cable pull causes
the transmission throttle valve to change the performance characteristics
of the transmission.
FIG. 26 is a graph showing one method of determining guide slot 28 position
and shape. Two lines along which cam radiuses R1 and R2 are measured
define rotation angle A. Starting at the aggressive position, one end of
cam arc length D is placed at radius R1 and the other end of cam arc
length D is placed at radius R2. The position of guide pin 32 with respect
to cam arc length D is defined by line L. The R1 end of cam arc length D
is then progressively moved up along radius R1 and cam arc length D
rotated so that the other end of cam arc length D touches radius R2. The
upward movement is continued until cam arc length D reaches the R1 and R2
values which correspond to the passive position. As the upward movement is
made, the progressive positions of guide pins 32 (dots) are mapped onto
front plate 44 of adapter assembly 22, thereby resulting in guide slots 28
(dashed line). It may be appreciated that the principles of trigonometry
could also be used to calculate the position of guide slots 28.
It is noted that the above cited technique is generic in nature, and can be
utilized to calculate the guide slot 28 position for any fuel manage
device and associated transmission throttle valve, depending upon the
particular parameters of these devices.
FIG. 27 is a graph showing the calculation of adjustment slot 40 position
and shape. The positions of cam arc length D are as illustrated in FIG. 26
above. The relative position of threaded hold 38 on front plate 44 of
adapter assembly 22 with respect to each cam arc length D position is
indicated by lines 1, 2 and 3. The three cam arc length D positions are
then superimposed to result in adjustment slot 40. Again, trigonometry
could be used to perform this calculation.
In terms of use, a method for controlling a transmission throttle valve,
includes:
(a) providing a vehicle having a fuel management device 500 which includes
a rotatable throttle member 504 having an idle state and a wide open
throttle state;
(b) providing a transmission throttle valve connected to a throttle valve
cable 506;
(c) providing a system 20 for controlling the transmission throttle valve,
including:
a cam assembly 30 attachable to rotatable throttle member 504;
transmission throttle valve cable 506 connectable to cam assembly 30,
wherein when rotatable throttle member 504 is rotated from the idle state
to the wide open throttle state, cam assembly 30 pulls transmission
throttle valve cable 506 a fixed distance;
cam assembly 30 selectively positionable with respect to rotatable throttle
member 504, wherein the position of cam assembly 30 determines the rate at
which throttle valve cable 506 is pulled; and,
a retaining mechanism for locking cam assembly 30 in a fixed position with
respect to said rotatable throttle member 504;
(d) positioning cam assembly 30 to a desired position with respect to
rotatable throttle member 504;
(e) using the retaining mechanism to lock cam assembly 30 in the desired
position;
(f) attaching transmission valve throttle cable 506 to cam assembly 30;
(g) causing rotatable throttle member 504 to rotate from the idle state to
the wide open throttle state; and,
(h) observing that cam assembly 30 pulls throttle valve cable 506 the fixed
distance.
The method further including:
in step (h), cam assembly 30 pulling throttle valve cable 506 the fixed
distance for any selected position of cam assembly 30 with respect to
rotatable throttle member 504 in step (d).
The preferred embodiments of the invention described herein are exemplary
and numerous modifications, dimensional variations, and rearrangements can
be readily envisioned to achieve an equivalent result, all of which are
intended to be embraced within the scope of the appended claims.
*
