Throttle valve assembly

A throttle valve assembly for displacing the plungers of at least two contiguous throttle valves in correspondence with the degree of throttle opening of an engine includes a first cam rotatably mounted on a stationary bracket fixed to the throttle valve bodies and having a cam face for displacing the plunger of the first throttle valve and an axially extending boss, a second cam rotatably mounted on the bracket and having a cam face for displacing the plunger of the second throttle valve and an axially extending boss, the first and second cams being coupled via coupling means formed on the opposing bosses, and a cable operatively associated with the engine torque demand for rotating the cams. The cam faces of the cams are formed to have a shape capable of providing the desired throttle pressure characteristic, the shapes of the cam faces differing from each other in order to obtain the optimum speed-change performance.

BACKGROUND OF THE INVENTION 
This invention relates to throttle valve means arranged in the hydraulic 
circuit of an automatic transmission and, more particularly, to a throttle 
valve assembly for displacing the pressure regulating means of at least 
two throttle valves in correspondence with the degree of throttle opening 
of an engine. 
The growing popularity of vehicles having an automatic transmission has 
been accompanied by stricter evaluation of the speed change performance of 
such transmissions. In particular, a speed-change shock produced when a 
gear train is changed over to alter the speed-change ratio can only be 
evaluated in terms of "feel", and even a slight shock of this kind is 
annoying. Various methods and apparatus have heretofore been proposed and 
put into practical use in order to mitigate or eliminate such speed-change 
shock. Furthermore, coupled with the trend toward front-engine automotive 
vehicles with front wheel drive, there is a demand for automatic 
transmissions which are smaller and lighter in weight. 
Fundamental in smoothly controlling the speed change of an automatic 
transmission is to adopt a method of varying main pressure, mainly the 
pressure of the fluid which actuates the frictional engaging means that 
administers speed change control in dependence upon the output of the 
engine. Ordinarily, main pressure is varied by a throttle valve assembly 
which generates pressure (throttle pressure) commensurate with the 
throttle opening of the engine. The throttle pressure, in cooperation with 
governor pressure dependent upon vehicle speed, is also used as a signal 
which changes over shift control valves. 
A throttle valve assembly of this type is disclosed in the specification of 
Japanese Utility Model Application Laid-Open No. 58-135547. The disclosed 
throttle valve assembly is adapted to apply a throttle pressure, which is 
produced by a second throttle valve, as back pressure of an accumulator 
for controlling the extent to which pressured oil is supplied to 
frictional engaging means, and to changeover the shift control valve by 
employing throttle pressure, which is produced by a first throttle valve, 
in cooperation with governor pressure. As for the pressure regulation of 
the first and second throttle valves, plungers inside the valves are 
displaced by levers connected to the accelerator pedal, and a load acting 
upon a pressure regulating spring is changed by the plungers. 
Alternatively, rotary cams may be used in place of the levers, in which 
case the cams are made to rotate by cables connected to the engine 
throttle. 
SUMMARY OF THE INVENTION 
When attempting to perform a smoother change of speeds with an automatic 
transmission, it is desirable to use a plurality of throttle valves and 
cause the valves to generate pressures having different throttle pressure 
characteristics corresponding to various conditions, and to control or 
actuate corresponding equipment in the hydraulic pressure circuitry on the 
basis of these throttle pressure characteristics. 
To this end, it is necessary to apply the cam means to the two throttle 
valves and separately set, as required, the displacement of the throttle 
valve pressure regulating means with respect to the rotation of the cam 
means. 
However, this presents a problem in view of the requirement for smaller, 
lighter automatic transmissions for the front-engine, front-wheel drive 
vehicles mentioned above. This requirement is difficult to satisfy because 
the two throttle valve assemblies must be housed in the limited confines 
of the transmission, the cam means must be provided for each of the 
throttle valves, and the engine throttle must be connected to each of the 
cam means. 
Further, in order to mitigate or eliminate the shock sustained when 
changing speeds, it is necessary to design the cam surfaces while taking 
into account differences in engine power(or output torque) or differences 
in vehicle weight. With the conventional throttle valve assembly, however, 
the structure adopted is such that the levers are actuated by a rotary 
shaft journaled at an appropriate position in the transmission case and 
act to displace the plungers of the throttle valves. The levers are 
difficult to replace and this approach does not lend itself to a 
manufacturing process in which a wide variety of items are manufactured in 
small lots. 
The present invention has been devised to satisfy the abovementioned 
requirements and to solve the aforementioned problems, and an object of a 
first aspect of the present invention is to provide a throttle valve 
assembly which can be housed in the limited confines of a transmission, 
which is capable of a design change that takes into account differences in 
engine power (or output torque) and differences in vehicle weight, and 
which is suitable for manufacturing process in which a wide variety of 
items are manufactured in small lots. 
Another problem with the foregoing conventional structure is that since the 
valve bodies and lever means are installed in the transmission case 
individually and independently, the positional relationship between the 
throttle valves and levers cannot be set in accurate fashion, with the 
result that accurate plunger displacement corresponding to throttle 
opening becomes impossible to obtain. 
Furthermore, with the conventional assembly, a stopper abutting against one 
lever determines the position of the lever when the throttle opening is 
zero. However, the position of the stopper is decided solely by the 
position of the throttle valve relative to the plunger, with the result 
that control in the vicinity of zero throttle opening is unstable. Another 
problem is that the speed change characteristic differs from one automatic 
transmission to another depending upon the method used to mount the lever 
means. 
An object of a second aspect of the present invention is to satisfy the 
abovementioned requirements and to solve the aforementioned problems. More 
specifically, a second object of the invention is to provide a throttle 
valve assembly which can be housed in the limited confines of a 
transmission, and in which the mounting method does not cause a major 
change in the position of a shaft for supporting cam means, thereby 
allowing production of an accurate throttle pressure corresponding to 
throttle opening. 
In a known throttle valve assembly, displacement of a cable connected to 
the engine throttle is converted into rotational motion transmitted to cam 
means, and a throttle element of a throttle valve is in turn displaced and 
actuated by the cam means. The assembly uses an ordinary rotary cam as the 
cam means, the cam means is positioned to face a valve bore in which there 
are fitted a throttle valve and a valve element in series with the 
throttle valve, and a shaft disposed at a position perpendicularly 
intersecting an extension of the valve bore is supported by being screwed 
into the valve body. 
In order to mitigate or eliminate speed-change shock, it is necessary to 
actuate the throttle valve in a precise manner. 
With the construction of the conventional throttle valve assembly, however, 
the threaded hole for the shaft supporting the cam means is difficult to 
form in the valve body with good accuracy, and careful positioning is 
essential in order to assure that the position at which the support shaft 
is screwed with respect to the valve bore does not vary from one part to 
another. A further problem with the conventional assembly is the 
possibility that looseness may develop between the valve body and the 
shaft where the two are screwed together, this being caused by frequent 
cam operation. 
An object of third and fourth aspects of the present invention is to 
satisfy the abovementioned requirements and to solve the aforementioned 
problems. More specifically, a third object of the invention is to provide 
a throttle valve assembly which can be housed in the limited confines of a 
transmission, and in which the mounting method does not cause a major 
change in the position of the shaft for supporting cam means, thereby 
allowing production of an accurate throttle pressure corresponding to 
throttle opening. 
According to the first aspect of the present invention, there is provided a 
throttle valve assembly comprising first and second throttle valves 
adjoining each other, cam means rotatably mounted on a fixed member, said 
cam means including a first cam having a cam face for displacing a valve 
element of the first throttle valve and a boss extending in the axial 
direction, and a second cam having a cam face for displacing a valve 
elexent of the second throttle valve and a boss extending in the axial 
direction, the first and second cams being connected via coupling means 
formed on the opposing bosses, and an input member operatively associated 
with an engine torque demand signal for rotating the cams of the cam 
means. 
Since the first and second throttle valves are arranged to adjoin to each 
other, the valve bodies in this case can be integrated into a single 
unitary body. It is preferred that the cams of the cam means rotatably 
mounted on the fixed member be coaxially supported at the bosses on a 
shaft member through the intermediary of a retaining member. A part such 
as a bracket can be used at the fixed member, and the shaft member can be 
secured to the bracket. 
The coupling means formed on the bosses can be cut-outs or gears formed on 
the distal ends of the opposing bosses, or may be spline-like portions 
formed on the inner and outer sides of the bosses. Resilient means for 
applying a restoring force to the cams can be provided. Selecting a 
torsion spring as the resilient means enables the assembly to be made 
small in size. In such case, the torsion spring is wound on the outer 
periphery of the bosses of the first and second cams between these cams. 
One end of the spring is fastened to either the first or second cam, and 
the other end of the spring is fastened elsewhere. 
The input member is connected to either the first or second cam. 
The cam faces of the cams for displacing the pressure regulating means of 
the throttle valves in dependence upon throttle opening are formed to have 
a shape capable of providing the desired throttle pressure characteristic. 
The cam faces can be made to differ from each other in terms of shape in 
order to obtain the optimum speed-change performance. 
According to the second aspect of the present invention, there is provided 
a throttle valve assembly comprising first and second throttle valves 
adjoining each other, a generally U-shaped bracket attached to front sides 
of the first and second throttle valves and having a base portion, two 
generally parallel side portions formed by bending the base portion upward 
from both sides thereof, and mounting portions formed by bending the two 
side portions, cam means accommodated in the generally U-shaped bracket, 
the cam means comprising a support shaft supported on the bracket, a first 
cam rotatably mounted on the support shaft for displacing a valve element 
of the first throttle valve, and a second cam operatively associated with 
the first cam for displacing a valve element of the second throttle valve, 
and an input member operatively associated with an engine torque demand 
signal for rotating the cams of the cam means. 
According to the third aspect of the present invention, there is provided a 
throttle valve assembly comprising throttle valves accommodated in 
respective valve bores formed in a valve body for regulating hydraulic 
pressure to bring said pressure into conformance with a predetermined 
pressure, valve elements for being displaced so as to vary the regulating 
action of the throttle valves, a bracket secured to the valve body and 
having faces perpendicular to the central axes of the respective valve 
bores formed in the valve body, and a face parallel to the central axes of 
the valve bores, cam means rotatably mounted on a support shaft supported 
on the bracket and having cam faces for displacing the valve element of 
the throttle valves, an input member capable of providing an input signal 
for rotating the cam means in response to an engine torque demand signal, 
and resilient means for applying a rotating force to the cam means in 
opposition to the input signal. 
According to the fourth aspect of the present invention, there is provided 
a throttle valve assembly comprising at least first and second throttle 
valves adjoining each other, a bracket of a generally U-shaped 
configuration having a base portion and two generally parallel side 
portions formed by bending the base portion upwardly from both sides 
thereof, the bracket including first mounting portions formed by bending 
the two side portions and having faces perpendicular to the central axes 
of valve bores formed in respective valve bodies, and a second mounting 
portion formed by bending one of the two side portions and having a face 
parallel to a plane containing at least two axes of the valve bores, a 
support shaft supported on the bracket, cam means comprising a first cam 
having a cam face for displacing valve element of the first throttle 
valve, and a second cam connected to the first cam and having a cam face 
for displacing valve element of the second throttle valve, an input member 
capable of providing an input signal for rotating the cam means in 
response to an engine torque demand signal, and resilient means for 
applying a rotating force to the cam means in opposition to the input 
signal. Common through all the aspects, the valve element may be a plunger 
and/or spool or the like. 
The second through fourth aspects of the invention share a number of points 
in common. Specifically, as in the first aspect of the invention, the 
first and second throttle valves are arranged to adjoin each other but the 
valve bodies can be constructed as a single unitary body. The front sides 
of the throttle valves are formed to include a portion to which the 
mounting portions of the bracket are secured. The cam means accommodated 
within the bracket are assembled while being brought into agreement with 
the plungers of the throttle valves. 
The operative association between the first and second cams of the cam 
means can be achieved by coupling means formed on the distal ends of 
opposing bosses of the two cams. In addition, if the cam face of the first 
cam of the cam means is provided with a stopper for abutting against the 
side face of the plunger of the first throttle valve, the angular position 
of the first cam when the throttle opening is zero can be set in a 
reliable manner. The cam means can also be provided with resilient means 
in order to assure the restoration of the cams. 
The cams can be provided with a restoring force, namely a rotating force 
which opposes the input signal, if a torsion spring is provided as the 
resilient means, the torsion spring is wound between the first and second 
cams on the outer periphery thereof, one end of the spring is fastened to 
either the first or second cam, and the other end of the spring is 
fastened to a portion other than the first or second cam. With such an 
arrangement, an effective restoring action can be achieved in a smaller 
space. 
Using a cable connected to the engine throttle as the input member and 
guiding the cable around the periphery of a cam enables the cams to be 
rotated with just a small torque. 
It goes without saying that the cam faces of the cams for displacing the 
pressure regulating means of the throttle valves in dependence upon 
throttle opening are each formed to have a shape that will enable the 
desired throttle pressure characteristics to be obtained. 
To assemble the throttle valve assembly, both of the cams interconnected by 
the coupling means are placed inside the generally U-shaped bracket and 
the support shaft is passed through holes in both cams from one side of 
the bracket so that the cams are rotatably supported on the shaft. Next, 
the mounting portions of the bracket are placed on predetermined portions 
on the front sides of the first and second throttle valves and are secured 
thereto by fixing means such as bolts. Finally, the input member 
operatively associated with the engine throttle, e.g., the cable connected 
to the engine throttle, is wound on the outer periphery of one of the 
cams. 
In the operation of the throttle valve assembly, which is common throughout 
all the aspects of the present invention, the cams are rotated by the 
input member, which is operatively associated with the engine throttle, 
when the accelerator pedal is depressed. The cam faces, which are formed 
such that desired throttle pressure characteristics will be obtained in 
dependence upon throttle opening, displace the plungers, i.e., the valve 
elements, of the throttle valves to vary the pressure regulating means. 
Since the first and second cams are set in correspondence with the first 
and second throttle valves, these valves produce throttle pressures that 
improve the speed-change performance. One of the throttle pressures 
produced in the respective valve in accordance with throttle opening is 
used as back pressure for deciding line pressure, thereby supplying the 
hydraulic equipment with pressured oil in an accurate manner. The other of 
the throttle pressures produced in the respective valve acts upon a shift 
valve as back pressure opposing governor pressure, thereby deciding 
precise changeover timing of the shift valve. When the plungers (valve 
elements) are employed as valves for changing over the hydraulic 
equipment, the hydraulic equipment is operated precisely in dependence 
upon throttle opening. If the amount by which the accelerator pedal is 
depressed is increased, the cams are rotated further; if decreased the 
cams are restored by the pressure regulating means or by the resilient 
means. 
According to the second through fourth aspects of the invention, since both 
valves and the cam means are assembled together in coordination by the 
bracket (in particular, between the valve body and the bidirectional 
mounting portions of the bracket), accurate throttle pressure 
corresponding to throttle opening can be produced even when the degree of 
throttle opening is diminished. This enables the hydraulic equipment to be 
operated in an accurate manner. 
ADVANTAGES OF THE INVENTION 
According to the first aspect of the present invention, the first and 
second cams are connected by the coupling means. Therefore, the cam 
profiles of the cam faces on both cams can be set as desired so that any 
hydraulic pressure characteristic corresponding to a single input 
(throttle opening) can be obtained. In addition, the first and second cams 
can be replaced to alter the hydraulic pressure characteristics in 
accordance with a difference in engine output or vehicle weight. The valve 
assembly therefore readily lends its to an era in which parts of diverse 
types are produced in small lots and, hence, is of great industrial value. 
Furthermore, since resilient means such as the torsion spring can be 
provided between both cams, the overall throttle valve assembly can be 
made compact so that two throttle valves can be arranged in the limited 
space of an automatic transmission case. Cam means can be provided for 
each throttle valve and each cam can readily be coupled to the engine 
throttle. 
According to the second through fourth aspects of the invention, the first 
and second throttle valves are arranged to adjoin each other and the cam 
means are mounted on the front faces of the valve bodies by being received 
in the bracket. Accordingly, the overall throttle valve assembly can be 
made compact so that two throttle valves can be arranged in the limited 
space of an automatic transmission case. Cam means can be provided for 
each throttle valve and each cam can readily be coupled to the engine 
throttle. 
Furthermore, since the bracket can be attached to the valve bodies while a 
direct relation is maintained between the bracket and the valve bodies, 
any error in the set positional relationship between the cam means and the 
plungers is minimized so that each throttle valve can accurately produce a 
throttle pressure corresponding to the throttle opening. Moreover, since 
the positions of the cams at zero throttle opening are limited in terms of 
their relation to the plungers, it is possible to carry out an accurate 
sequence. 
Other features and advantages of the present invention will be apparent 
from the following description taken in conjunction with the accompanying 
drawings, in which like reference characters designate the same or similar 
parts throughout the figures thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Specific embodiments of the present invention will now be described with 
reference to the accompanying drawings, though it should be understood 
that the invention is not limited to the illustrated embodiments. 
FIRST EMBODIMENT 
A first throttle valve 1 illustrated in FIG. 2 is a throttle valve for 
shift control, the valve having an output port connected to one back 
pressure port of a plurality of shift valves. The first throttle valve 
cooperates with governor pressure connected to the other back pressure 
port of each shift valve to actuate the shift valves and suitably select 
friction engaging devices connected to the shift valves, thereby 
performing a speed change conforming to the throttle opening and vehicle 
speed. The first throttle valve 1 also sends a release signal to a lock-up 
relay valve at a throttle opening near zero. In response to the signal 
from the first throttle valve, the lock-up relay valve breaks a direct 
connection between the turbine and the pump of a torque converter. 
The first throttle valve 1 has a spool 4 backed at one end (the left end in 
the figure) by a spring 3, a plunger (valve element) 5 arranged in series 
with the spool 4, and a pressure regulating spring 6 arranged between the 
spool 4 and the plunger 5, these elements being provided in a valve body 
2. The plunger 5 is guided by a sleeve 7, which is secured to the valve 
body 2 by a pin 8. The spool 4 is formed to include three lands 10, 11, 12 
in the order mentioned starting from the side on which the backing spring 
3 is located, and the valve body 2 is formed to include three ports 13, 
14, 15 corresponding to the three lands 10, 11, 12, respectively. In the 
illustrated embodiment, the lands 11, 12 have the same diameter, which is 
larger than that of the land 10. The central port 14 supplies pressured 
oil from the pump. The right port 15 is an output port connected to the 
port 13, which is a back pressure port, via orifice means, and is also 
connected to back pressure ports opposing the governor pressure of the 
shift valves. 
The plunger 5 also is formed to include three lands 16, 17, 18. The valve 
body 2 is formed to include five ports 19a, 19b, 20a, 20b, 20c through the 
sleeve 7 to correspond to the lands. The port 19a on the left side is 
connected to the port 13 on the side of the spool 4. When the throttle is 
approximately fully open, communication is established between the port 
19b and a port of one of the shift valves, e.g., a 3-4 shift valve. The 
output of the port 19b in this case is employed as a kick-down signal. The 
port 20a is provided very close to the land 18 of the plunger 5 and serves 
to introduce pump pressure at a throttle opening near zero. The port 20b 
is an output port connected to the back pressure port of the lock-up relay 
valve. The port 20c is located just to the left of the output port 20b and 
is used as the discharge port of the lock-up relay valve. 
The first throttle valve 1 is arranged between a transmission case 22 and 
an oil pan 23. A lower valve body 26 is arranged below the valve body 2 so 
that a gasket 24 and a plate 25 are sandwiched between the valve bodies. A 
strainer 28 is provided beneath the lower valve body 26. 
A second throttle valve 31 is constructed as shown in FIG. 3. The second 
throttle valve 31 is for control of main pressure and causes hydraulic 
pressure, which is regulated in dependence upon throttle opening, to act 
as back pressure of a regulator valve, whereby the pressured oil from the 
pump is made to conform to throttle opening to regulate the main pressure 
in the oil line. 
The second throttle valve 31 has a spool 34 backed at one end (the left end 
in the figure) by a spring 33, a plunger 35 arranged in series with the 
spool 34, and a pressure regulating spring (pressure regulating means) 36 
arranged between the spool 34 and the plunger 35, these elements being 
provided in a valve body 32 constructed adjacent to and integral with the 
valve body 2 of the first throttle valve 1. The plunger 35 is guided by a 
sleeve 37, which is secured to the valve body 32 by a pin 38. 
The spool 34 is formed to include four lands 39, 40, 41, 42 in the order 
mentioned starting from the side on which the backing spring 33 is 
located. In the illustrated embodiment, the lands 41, 42 have the same 
diameter, which is larger than that of the land 40, with the diameter of 
the latter being larger than that of the land 39. The valve body 32 is 
formed to include four ports 43, 44, 45, 46 corresponding to the four 
lands 39, 40, 41, 42, respectively. The port 45 is an input port for 
receiving an input from the pump. Pressured oil regulated by the land 41 
is delivered from the port 46. The port 46 communicates with a regulator 
valve back pressure port, with a drain port via orifice means, with the 
port 43 via a cut-back valve 105, and with the port 44 via orifice means. 
The cut-back valve 105 is actuated by governor pressure for communicating 
the port 46 with the port 43. 
The plunger 35 also is formed to include two lands 47, 48, the diameter of 
the former being larger than that of the latter. The valve body 32 is 
formed to include one port 49 through the sleeve 37. The port 49 
communicates with the back pressure port 43 on the side of the spool 34. 
Pressured oil which enters from the port 49 acts to move the plunger 35 to 
the left in FIG. 3. 
As shown in FIG. 1, the two throttle valves 1, 31 are arranged in parallel 
and adjacent to each other with the plunger sides thereof in alignment. In 
the figure the second throttle valve 31 is shown to be arranged in front 
of the first throttle valve 1. 
As shown in FIGS. 4 through 7, cam means 50 comprises a first cam 51 for 
displacing the plunger 5 of the first throttle valve 1, and a second cam 
52 operatively associated with the first cam 51 for displacing the plunger 
35 of the second throttle valve 31. 
The first cam 51 has a cam face 53 formed on its outer periphery for 
displacing the plunger 5, and is formed to include an axially extending 
boss 54. It will be appreciated from FIG. 2 that the cam face 53 is 
provided with a stopper 53a which determines the position of the cam 51 by 
abutting against the plunger 5 when the throttle opening is zero. The 
second cam 52 likewise has a cam face 55 formed on its outer periphery for 
displacing the plunger 35, and is formed to include an axially extending 
boss 56. The distal ends of the opposing bosses 54, 56 are provided with 
coupling means 57, shown in FIGS. 4 and 5, in such a manner that the 
second cam 52 can be rotated in operative association with the first cam 
51. In the meshing means 57 of the illustrated embodiment, half of the 
distal end of boss 54 of the first cam 51 is cut away to leave a 
projecting half 58, and half of the distal end of boss 56 of the second 
cam 52 is cut away to leave a projecting half 59. The projecting halves 
58, 59 are fitted into the cut-away portions of the opposing bosses 56, 
54, respectively, so that first and second cams 51, 52 will operate in 
association. Alternatively, the meshing means 57 can be arranged in such a 
manner that teeth formed in the side surfaces of the bosses 54, 56 mesh 
with each other. 
A bracket 60 (FIG. 5) accommodating the cam means 50 comprises a base 
portion 61, generally parallel side portions 62, 63 formed by bending the 
base portion 61 upward from both sides thereof, first mounting portions 
64, 65 and a second mounting portion 66 formed by bending the two side 
portions 62, 63. The overall bracket 60 has a U-shaped configuration. The 
faces of the first mounting portions 64, 65 lie perpendicular to the 
central axes of valve bores 2a, 32a formed in the valve bodies 2, 32, and 
the face of the second mounting portion 66 (FIG. 4) lies parallel to a 
plane containing the two axes. The positions of the first mounting 
portions 64, 65 can be set at a distance X from the central axis of the 
pin 8, as shown in FIG. 2. The position of the second mounting portion 66 
can be set a distance Y from the central axis of the valve bore 2a. The 
pin 8 and valve bore 2a are used as the reference points because this 
facilitates the setting of the positional relationship between the cam 
means and the ports of the throttle valves, and because it is easy to set 
the positions when the throttle opening is zero. The mounting portions 64, 
65, 66 are formed to include respective bolt holes 67, 68, 69. The bracket 
60 is bolted directly to the front side of the valve bodies 2, 32, which 
are constructed to adjoin each other in the form of an integral body, by 
three bolts 70. 
The cam means 50 are supported in the bracket 60 by a support shaft 71 
passed through the two side portions 62, 63 of the bracket 60. On the 
basis of the aforementioned dimensions X and Y, the position of the 
support shaft 71 in the bracket 60 can be set accurately at a distance L 
from the upper faces of the first mounting portions and at a distance M 
from the lower face of the second mounting portion 66, as shown in FIG. 6, 
while correspondence is maintained with respect to the valve bores 2a, 
32a. Bearings 72, 73 are arranged between the support shaft 71 and the cam 
means 50 to facilitate rotation. Fitted into the inner sides of the bosses 
54, 56 between the bearings 72, 73 is a cylindrical retaining member 74 
for retaining the cams 51, 52 in a concentric relationship. In an 
alternative arrangement, it is possible to maintain the concentricity of 
the cams 51, 52 by fitting a retaining member over the outer sides of the 
bosses 54, 56. In such case it would be possible to provide the 
abovementioned meshing means between the bosses 54, 56 of the two cams and 
the retaining member 74, with the meshing means in such a configuration 
being of the spline-fitting type. It should be noted that the support 
shaft 71 is prevented from falling out by a snap ring 75 fitted thereon on 
the outer side of the side portion 62 of bracket 60. 
Resilient means 80 for restoring the cam means 50 are constituted by a 
torsion spring. The torsion spring 80 is wound on the outer periphery of 
bosses 54, 56 of respective cams 51, 52. One end 81 of the torsion spring 
80 is anchored to a suitable portion of the first cam 51, and the other 
end 82 of the torsion spring is anchored to a hook portion 83, which is 
formed in the base portion of the U-shaped bracket in the form of a bent 
ear, in such a manner that the torsion spring 80 itself is torsioned to a 
some extent (FIG. 6). The end 81 of the torsion spring 80 can also be 
anchored to the second cam 52, which operates in concurrence with the 
first cam 51. 
As shown in FIG. 2, a cable 84 can be used as an input member for rotating 
the cam means 50 in dependence upon the throttle opening of the engine. 
One end of the cable 84 is connected to the engine throttle. The other end 
of cable 84 is guided by a groove 85 formed in the outer periphery of the 
first cam 51 at a portion thereof that does not constitute the cam face 
53. An anchor piece 86 at the tip of the cable 84 is fit snugly into a 
recess 87 formed in the outer periphery of the cam 51 at a suitable 
position thereof. 
Rollers 88, 89 are arranged at the distal ends of the plungers 5, 35 that 
contact the cam faces of the first and second cams 51, 52, thereby 
assuring smooth rotation of the first and second cams 51, 52. 
To assemble the throttle valve arrangement having the above-described 
construction, the torsion spring 80 constituting the resilient means is 
wound around the bosses 54, 56 of the first and second cams 51, 52, after 
which the coupling means 57 of both cams 51, 52 are fitted on the 
cylindrical retaining member 74 and brought into engagement. The bearings 
72, 73 are then fitted into the cams 51, 52 from the outer sides thereof 
to be disposed on both sides of the retaining memer 74. The cam means 50 
thus assembled is received in the bracket 60 from the upper part thereof 
in such a manner that both side faces of the cam means lie parallel to the 
side portions 62, 63 of the generally U-shaped bracket 60. The cam means 
50 is supported by the support shaft 71, which is inserted from the side 
portion 63 of the bracket 60 and passed through the bearings 72, 73 and 
the retaining member 74. The support shaft 71 is held in place by the snap 
ring 75 fitted onto the support shaft 71 from the outer side of the side 
portion 62 of bracket 60. The support shaft 71 is prevented from rotating 
by a member 76 inserted from the outer side of the opposing side portion 
63 of bracket 60. Next, one end of the torsion spring 80 is securely 
fastened to the first cam 51 at a suitable location thereon, and the other 
end of the torsion spring 80 is fastened to the hook 83 of the bracket 60 
so as to apply torsion to the spring. The bracket 60 thus assembled is 
fastened to the front side of the integrated valve bodies 2, 32 by bolts 
70, with the first mounting portions 64, 65 lying in a plane perpendicular 
to the central axes of the valve bores 2a, 32a, respectively, and the 
second mounting portion 66 lying in a plane parallel to a plane containing 
at least the two axes of the valve bores 2a, 32a. As shown in FIGS. 1 and 
8, the bracket 60 is secured directly to the valve bodies 2, 32 at three 
points and in two mutually perpendicular planes. This raises positional 
precision and minimizes any error in throttle pressure setting caused by 
the mounting manner. Finally, the locking piece 86 of the cable 84 is 
fitted into the recess 87 of the first cam 51 and the cable is disposed in 
the groove 85 of the first cam 51. The rear end of the cable 84 is 
connected via a support member to a part such as the accelerator pedal 
operatively coupled to the engine throttle. 
OPERATION OF FIRST EMBODIMENT 
When, e.g., the accelerator pedal of a vehicle equipped with the throttle 
valve assembly of the present invention is depressed, the throttle of the 
vehicle engine opens to an extent commensurate with the amount of pedal 
depression and, in operative association with the accelerator pedal, the 
cable 84 guided in the peripheral groove 85 of the first cam 51 is pulled. 
The first cam 51 is rotated by the cable 84 by an amount corresponding to 
the amount of accelerator pedal depression, and the first cam 51 rotates 
the second cam 52 through the coupling means 57 operatively coupling the 
two cams together. 
Owing to the rotation of the cams 51, 52, the plungers 5, 35 are made to 
follow up this motion inside the sleeves 7, 37 via the rollers 88, 89 
abutting against the cam faces 53, 55, thereby separately compressing the 
respective pressure regulating springs 6, 36 to subject them to loads of 
different magnitude. The supplied hydraulic pressure is regulated in 
dependence upon the loads applied to the springs 6, 36, with the 
respective throttle pressures being delivered from the output ports 15, 
46. 
The throttle pressures act respectively upon the back pressure ports 13, 44 
of the valves 1, 31. If the working oil delivered from the output ports 
15, 46 increases and the throttle pressures drop, the spool 4 is moved 
backward to open the valves (lands 11, 41) so that the working oil is 
supplied in a stable manner at the same time that throttle pressures 
corresponding to the throttle opening are approached. Conversely, when the 
amount of working oil diminishes, the spools 4, 34 are advanced to close 
the valves (lands 11, 41) to effect regulation to predetermined throttle 
pressures. 
If the amount of accelerator pedal depression is reduced, the cams 51, 52 
are rotated in the opposite direction by the pressure regulating springs 
6, 36 and torsion spring 80 up to the degree of throttle opening. The 
plungers 5, 35 act by following up this movement of the cams and perform a 
valving operation of the kind described above. 
The operation of the throttle valve assembly of the present invention will 
now be described in conjunction with the hydraulic circuit diagram shown 
in FIG. 9, in which numeral 100 denotes a pump, 101 a regulator valve, 102 
a governor valve, 103 a shift valve, e.g., a 3-4 shift valve, 104 a 
lock-up control circuit and 105 a cut-back valve. 
When the vehicle engine is started, pressured oil from the pump 100 is fed 
via a line L1 to the regulator valve 101, governor valve 102, shift valve 
103, input ports 14, 19a, 20a of the first throttle valve 1, and input 
port 45 of the second throttle valve 31. Main pressure in line L1 applied 
to the port 45 of second throttle valve 31 is regulated by the spring 36 
and is delivered as throttle pressure from the port 46. This throttle 
pressure is fed back to the back pressure port 49 on the side of the 
plunger 35 and through an orifice to the back pressure port 44 on the side 
of the spool 34, thereby subjecting throttle pressure to further 
regulation. The throttle pressure of the second throttle valve 31 acts 
upon a back pressure port of the regulator valve 101 through a line L2, 
and main pressure in the line L1 is regulated to a pressure in conformance 
with the throttle opening by the regulator valve 101. 
Main pressure in line L1 applied to the port 14 of first throttle valve 14 
is regulated by the spring 6 and is delivered as throttle pressure from 
the port 15. This throttle pressure ordinarily is set to a value different 
from that of the throttle pressure of the second throttle valve 31. The 
throttle pressure of the first throttle valve acts upon one back pressure 
port of the shift valve 103 via a line L5. 
The governor valve 102 delivers an output corresponding to vehicle speed to 
a line L3. The output on line L3 acts as governor pressure on the other 
back pressure port of the shift valve 103, namely on the back pressure 
port that opposes the throttle pressure. It also acts upon one back 
pressure port of the cut-back valve 105. 
When the accelerator pedal connected to the cam 51 by the cable 84 is 
depressed by only a small amount so that the throttle opening is 
substantially near zero, the ports 20a, 20b of the first throttle valve 1 
communicate and main pressure in line L1 is delivered to the lock-up 
control circuit 104 via a line L4. During the time that the pressure in 
line L4 is applied thereto, the lock-up control circuit 104 operates the 
torque converter in an ordinary manner. 
When the accelerator pedal is depressed slightly from the condition in 
which the throttle opening is near zero, the cam 51 and the cam 52 
operatively associated therewith are rotated by the cable 84 connected to 
the accelerator pedal, whereby the ports 20b, 20c of the first throttle 
valve are communicated. The pressure in line L4 vanishes owing to the 
communication between these two ports, so that the lock-up control circuit 
104 is directly coupled to the pump and turbine of the torque converter. 
The plunger 5 is displaced by rotation of the cam 51, thereby compressing 
the pressure regulating spring 6 to raise the output from port 15 and 
enlarge the force acting upon the shift valve 103. At the same time, the 
plunger 35 of the second throttle valve 31 is displaced by rotation of the 
cam 52, thereby compressing the pressure regulating spring 36 to increase 
the output from port 46. Though the discharge output of the pump 100 
increases with an increase in the output of the vehicle engine, the output 
from port 46 of the second throttle valve 31 acts upon the regulator valve 
101, so that the main pressure in line L1 is made proportional to the 
throttle opening. With a further increase in throttle opening, the vehicle 
speed rises and the output of the governor valve 102 also rises in an 
abrupt manner. 
Further depression of the accelerator pedal causes an increase in the 
throttle opening, whereupon the governor pressure acting on the shift 
valve 103 overcomes the throttle pressure of the first throttle valve 1 so 
that the shift valve 103 changes over to effect a speed change from L to 
H. 
When the throttle opening reaches the vicinity of 85.degree. owing to 
further depression of the accelerator pedal, the ports 19a, 19b of the 
first throttle valve 1 are communicated by displacement of the plunger 5 
caused by rotation of the cam 51 connected to the accelerator pedal by the 
cable 84. The communication between these ports allows the main pressure 
in line L1 to act, in opposition to governor pressure, on the shift valve 
103 through a line L6. Kick-down is performed as a result. 
In an operation separate from that just described, the cut-back valve 105 
is actuated by governor pressure when a certain vehicle speed is attained, 
and the port 46 of the second throttle valve 31 is brought into 
communication with the port 43 of valve 31. Communication between these 
two ports reduces the output from port 46 and increases the amount of 
leakage at the regulator valve 101, with the result that main pressure in 
line L1 drops and is held at a predetermined value. 
When the amount of accelerator pedal depression is reduced to diminish the 
throttle opening, operation is the reverse of that described above. 
SECOND EMBODIMENT 
FIG. 10 is a sectional view showing a second embodiment of a throttle valve 
assembly according to the invention. A bracket 110 of a generally U-shaped 
configuration has a base portion 111, generally parallel side portions 112 
formed by bending the base portion 111 upwardly from both sides thereof, 
and mounting portions 113 formed by bending the two side portions 112. 
Cam means 120 is constituted by a cylindrical cam having an end face formed 
to include the cam face of a first cam 121 for displacing the plunger 5 of 
the first throttle valve as well as the cam face of a second cam 122 for 
displacing the plunger 35 of the second throttle valve 31. 
A support shaft 130 fixedly secured to the base portion of the cam means 
120 for supporting the cam means is rotatably journaled in the base 
portion 111 of the bracket 110. 
The support shaft 130 is arranged to be rotated in operative association 
with the engine throttle by an input member, which is not shown. 
As many apparently widely different embodiments of the present invention 
can be made without departing from the spirit and scope thereof, it is to 
be understood that the invention is not limited to the specific 
embodiments thereof, the scope being defined in the appended claims.