JPH09250654A - Hydraulic device, pressure control valve, and fluid control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ease a problem such as a low frequency response and a low reliability generated when a contaminated operation oil whose viscosity is changed in a low hydraulic pressure system is used. SOLUTION: This hydraulic device 10 has a single stage of electrohydraulic clevis type pressure control valve 40, which outputs a compensation signal of the control pressure corresponding to the control pressure in a control pressure chamber 60, and has a control piston 106 to convert the pressure control valve 40 from an integral controller to a proportional controller, and thereby, the stability of the control system is improved. The compensation to the variation of the viscosity generated resulting from the temperature variation of the operation oil can be realized by manufacturing the forked part 98 of the pressure control valve 40 and/or a regulation bridge part 62 with materials of different thermal expansion coefficients.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates generally to hydraulic systems, and more particularly to a fluid control valve for rapid actuation and stable operation of a pressure actuation system in the event of changes in hydraulic oil viscosity or contamination. A hydraulic system that needs to be provided.

[0002]

BACKGROUND In vehicle related uses such as transmissions and braking systems, hydraulic systems must function controllably, responsively and reliably to achieve their function.
The same is true for hydraulically actuated clutches and other power transmission devices used, for example, in fixed emergency generators to power computers and hospitals in the event of a power failure in the local electrical grid.

Typical hydraulic systems in these uses include pumps or other sources of pressurized hydraulic fluid, low pressure tanks, control signal sources, fluid actuating devices, and fluid control valves. These components are connected to form a hydraulic circuit in which the fluid control valve receives the flow of pressurized hydraulic fluid from the pump. The fluid control valve converts a portion of its pressurized hydraulic fluid flow to a controlled flow or pressure which is then provided to the fluid actuated device in response to a control signal or control signal received from a control signal source. The remaining small leak in the pressurized hydraulic fluid stream passes through the fluid control valve and returns to the low pressure tank.

[0004] Such a hydraulic system is available when it is needed, despite the fact that the hydraulic fluid can have a high viscosity associated with exposure to very low ambient temperatures during long periods of inactivity. You must be able to respond quickly. However, such high viscosity hydraulic fluids do not flow easily, thus making it difficult to achieve a rapid response. Further, once the hydraulic system is activated, the hydraulic fluid begins to warm up due to frictional and operational losses in the hydraulic circuit and becomes less viscous. This change in viscosity causes considerable difficulty in maintaining stable control. Therefore, in order to maintain stable control, the components of the hydraulic system should ideally have compensating characteristics that will allow the hydraulic system to operate satisfactorily over a wide range of hydraulic fluid temperatures and viscosities. In addition, hydraulic control systems in both vehicle and stationary use are subject to contamination. Such contamination can jam or stick control elements in the hydraulic circuit, which prevents the valve from working properly.

In the past, hydraulic system designers have been forced to employ high hydraulic pressures, two-stage valves, or hydraulic heating / cooling systems in such systems as there are no acceptable alternatives. I didn't get it. Heating / cooling devices have been used to maintain the temperature and viscosity of hydraulic fluid within a narrow range in order to alleviate the control problems associated with varying hydraulic fluid viscosity as described above. High hydraulic pressure is not desirable because it requires excessive pump power and increases operating costs. The two-stage valve and heater / cooler add undesired equipment complexity and initial cost. Heaters / coolers that require external power also increase operating costs. Dedicated heating
In other conventional hydraulic systems that do not have a cooler, it is necessary to run the pump for a certain amount of time before attempting to activate the fluid actuating device in order to warm the fluid to a temperature where the valve can provide stable response control. Sometimes it becomes. This warm-up period is a waste of fuel. In addition, the warm-up time often results in an unacceptable delay in the ease of operation of the hydraulic system.

The fluid actuating device in a typical hydraulic system of the type described above is a clutch or brake used to controllably start and stop mechanical loads such as drive trains and wheels. Generally, the drive system and the wheels are mechanical loads having inertial members, fluctuating torque, and viscous force. Inertial loading results in a device that has an integral time relationship between working torque and output speed. For example, using a simple flow control valve would reduce the overall control algorithm to 2
It results in multiple integration, which makes stability difficult to achieve. Specifically, this double integration occurs because the relationship between the flow control valve and the clutch creates a second time integral relationship between the control valve input and the generated torque provided by the clutch. The combined effect of these two time integration relationships makes it difficult to keep the system stable. On the other hand, if a pressure control valve with control pressure feedback is used,
The valve / clutch characteristic is proportional rather than integral. No double integrals occur, and in this way stability can be achieved more easily.

What is needed there is a hydraulic system having a low pressure, single stage pressure control valve with internal feedback of control pressure. The valve must be able to operate over a wide range of viscosities without the need for heating and cooling equipment in the hydraulic circuit. The valve must also operate reliably in the presence of contamination in the hydraulic fluid. A hydraulic controller would also be highly desirable if it could provide a constant relationship between the value of the control input and the acceleration of the drive. Previously known pressure servo controlled valves cannot meet these requirements. Generally, the previously known pressure servo control valve is of the two-stage hydraulic amplification type. These valves have a tightly fitted movable spool and a small flapper / orifice type valve. These valves tend to fail due to contamination and tend to be slow to respond as the viscosity of the hydraulic fluid increases.

Harvey Bee, one of the co-inventors of the present invention. U.S. Pat. No. 3,80 granted to Janssen
No. 5,835 describes a fluid flow control valve that uses a bifurcated clevis member that can move across a pair of opposed adjustment ports to precisely control the flow rate of the fluid. Due to its configuration, the control valve of the Janssen 3,805,835 patent is more resistant to contaminated hydraulic fluid than other types of flow control valves. The bifurcated clevis has a tendency to scrape off contaminant deposits which may block the adjusting port or which may stick the movable adjusting member in other types of flow control valves. Also Janssen No. 3,805
The structure of the invention of the '835 patent minimizes mechanical hysteresis in the valve and requires less actuation power than other types of flow control valves. Janssen 3,805,83
The frequency response of the 5's valve is also excellent at high operating frequencies.

However, Janssen's No. 3,805,
The valve of the '835 patent is a flow control valve rather than a pressure control valve that requires solving the problems addressed by the present invention. Janssen 3,805,83
Despite the fact that the valve of the '5 patent is a flow control valve, the inventor of the present invention has found that Janssen's 3,805,83
If those desirable features of the flow control valve of the '5 patent were incorporated into a remotely controllable pressure control valve, then some of the structure of that valve would be encountered in a hydraulic control device of the type discussed herein. We have recognized that it may be well suited for use with oils that are viscous and can be contaminated. In addition to incorporating the desirable features of the flow control valve of the Janssen 3,805,835 patent into the pressure control valve,
Feedback of control pressure is desired to achieve optimum responsiveness and stability of the hydraulic system.

[0010]

SUMMARY OF THE INVENTION Our invention overcomes the above problems and exhibits improved pollution resistance and can be operated with hydraulic oils of varying viscosities and is suitable for use in either vehicles or stationary hydraulics. And provide a hydraulic device that responds quickly. According to one aspect of the invention, a hydraulic system includes a source of pressurized hydraulic oil, a low pressure tank, a control signal source, a pressure actuator and a clevis type fluid pressure control valve. The clevis type fluid pressure control valve exhibits inherent contamination resistance. The clevis-type fluid pressure control valve also has improved stability and frequency response compared to conventional hydraulic systems that use a flow control valve with a tightly fitted spool, needle, flapper or movable control member. Provide sex. The clevis-type fluid pressure control valve further allows our hydraulic system to operate at lower differential pressures than conventional hydraulic systems, thereby reducing operating power requirements. According to another aspect of the invention, the clevis-type fluid pressure control valve improves system stability by providing a control valve whose response is proportional rather than integrated with respect to the input signal. Includes internal feedback of control pressure. In the preferred embodiment of our invention, this feedback is contrasted with the valve outlet pressure.

According to yet another aspect of our invention, the clevis type fluid pressure control valve is characterized in that it compensates for changes in hydraulic fluid viscosity due to changes in operating temperature of the hydraulic fluid. This compensation is provided in a straightforward manner by constructing certain members of the clevis type fluid pressure control valve from materials having different coefficients of thermal expansion. With this configuration, leakage flow from the inlet pressure port to the outlet pressure port can be minimized at high hydraulic fluid temperatures while still maintaining an acceptable hydraulic clearance at low hydraulic fluid temperatures, thus providing a rapid system response over a wide range. Provided over hydraulic oil temperature and viscosity.

In the preferred embodiment of the present invention, both inlet and outlet regulators are provided as components of the clevis type fluid control system to improve the frequency response of the valve.
A portion of a clevis-type device for selectively providing an initial valve position having 1) closed inlet and closed outlet, 2) open inlet and closed outlet, or 3) closed inlet and open outlet. Is also biased preferentially. These and other forms and advantages of our invention will be apparent to those skilled in the art in view of the following drawings and detailed description of various embodiments of our invention. Let's do it.

[0013]

DESCRIPTION OF THE INVENTION FIG. 1 shows an embodiment of our invention in the form of a hydraulic system, generally designated 10, for a vehicle 11 or a fixed power conversion plant 12. The example hydraulic system 10 includes a source of pressurized hydraulic oil in the form of a pump P, a low pressure tank 14, a control signal source C, a pressure actuator in the form of a clutch 16, and a clevis type fluid pressure control valve 40. Although we have decided to use the clutch 16 as the pressure actuating device in the embodiment illustrated here, we would particularly like to emphasize that our invention is not limited to the hydraulic device controlling the clutch. . Our invention provides a number of other types of pressure actuating devices used to stop vehicles, including movable control members of power transmissions such as anti-lock or other types of brakes and automatic transmissions. Is equally applicable to hydraulic systems that control

The clutch 16 has an input shaft 18 and an output shaft 20 supported by bearings 22 and 24, respectively, for rotation about a common axis 26. The input shaft 18 is in operative communication with a prime mover, such as an engine or electric motor, and receives power from it to rotate the input shaft 18 about an axis 26. The output shaft 20 is operatively coupled to the driven device D such that the output shaft 20 drives the driven device D when the output shaft 20 is rotated about the axis 26. The term driven device as used herein encompasses a wide variety of devices including gear trains, generators, compressors and pumps, among others.

The operative connection between the input shaft 18 and the output shaft 20 is provided by a series of alternating interleaved annular drive plates 28 and driven plates 30. The drive plate 28 is slidable along the spline 29 in the axial direction by the spline 29, but the drive plate 28 is rotated together with the input shaft 18 so that the input shaft 1
It is attached to 8. In a similar manner, the driven plate 3
0 is attached to the output shaft 20 by a spline 31 so that it can slide in the axial direction along the spline 31 but can be rotated together with the output shaft 20. The input shaft 18 further has an integral flange 36 at the left shaft end as shown in FIG. 1 and axially slides within a cylinder 34 defined by the input shaft 18 at the right shaft end. It has a piston 32 which is movably supported. The driving plate 28 and the driven plate 30 sandwiched between each other are sandwiched between the flange 36 and the piston 32, so that when the hydraulic pressure is supplied to the cylinder 34, the piston 32 moves to the left. When the piston 32 moves to the left, the drive plate 28 and the driven plate 30 fit together and are compressed against the flange 36, thereby causing the clutch to function and transmit torque from the prime mover PM to the driven device D. . When the hydraulic pressure is released from the cylinder 34, a return spring (not shown) causes the piston 32, the driving plate 28 and the driven plate 3 to move.
0 is moved away from the flange toward the right, thereby releasing the prime mover PM from the driven device D.

As shown in FIG. 1, the fluid pressure control valve 4
0 is a hydraulic oil inlet passage 44 having an inlet port 46 for receiving the pressurized hydraulic oil from the pressurized hydraulic oil source P, and a hydraulic oil outlet having an outlet port 50 for sending the pressurized hydraulic oil to the low pressure tank 14. It has a body 42 that defines a passage 48. The valve 40 also has a control pressure passage 52 having a control pressure port 54 for transmitting control pressure to the cylinder 34 of the clutch 16. This control pressure is controlled by the control pressure port 54 and the inlet means 58 of the clutch 16.
Are in fluid communication with the cylinder 34 and are communicated to the clutch 16 via a conduit 56 connected therebetween. The valve body 42 also includes an inlet passage 44 and an outlet passage 4 of the valve 40.
8 and a control pressure passage 52 to define a control pressure cavity 60 that provides fluid communication.

As shown in FIGS. 1-3, the body 42
Is a regulating bridge portion 6 extending through the control pressure cavity 60
2 The adjustment bridge portion 62 is essentially rectangular in cross section and defines a pair of substantially flat, opposed, laterally spaced, exposed surfaces 64a, 64b to the control pressure cavity. are doing. As shown in the examples of Figures 1 and 4, the term "laterally spaced" is understood to be spaced in a direction generally perpendicular to the plane of the paper. A pair of opposed inlet adjustment ports 66a, which extend through the adjustment bridge portion 62 and open to the control pressure cavity 60 via laterally spaced surfaces 64a, 64b.
66b establishes fluid communication between the control pressure cavity 60 and the hydraulic oil inlet passage 44 described above. In a similar manner, the control pressure cavity 60 and the hydraulic fluid outlet passage 4 previously described.
Fluid communication therewith extends through the adjustment bridge portion 62 and is open to the control pressure cavity 60 via laterally spaced surfaces 64a, 64b, and a pair of opposed inlet adjustment ports 68a. , 68b.

As seen in FIG. 3, the inlet adjustment port 66
a, 66b are arranged around a common centerline 67 that runs generally perpendicular to a plane extending generally parallel to the spaced surfaces 64a, 64b of the adjustment bridge portion 62 of the body 42. Similarly, the outlet adjustment orifices 68a and 68b are
Common center line 67 of inlet adjustment orifices 66a, 66b
At a point laterally away from the adjustment bridge portion 62 at surface 8
It is arranged around a common centerline 69 that runs generally vertically through 0. As shown in FIGS. 1, 3 and 4, the lateral direction is a generally horizontal movement within or parallel to the plane of the paper.

Movable adjustment member 90 is substantially pivotally attached to body 42 at one end thereof in control pressure cavity 60 and extends substantially along surface 80, as shown at 94 in FIG. It has a rigid elongated arm 92. The tip 96 of the elongated arm 92 is attached to the forked portion 98 of the movable adjusting member 90. The forked portion 98 is
It has legs 98 a and 98 b that straddle the adjustment bridge 62. Leg 98
a and 98b are outwardly separated from the surfaces 64a and 64b of the adjusting bridge 62, and a pair of gaps 100a and 10 are provided between the legs 98a and 98b and the respective surfaces 64a and 64b of the adjusting bridge 62.
0b is formed. Due to the structure and pivotal mounting of the movable adjustment member 90, the elongated arm 92 is moved from the body 42 to the surface 80.
Pivoting along, the forked portion 98 moves laterally along the spaced apart surfaces 64a, 64b of the adjustment bridge 62 of the body 42.

As shown in FIGS. 1 and 3, the legs 98a, 98b of the bifurcated portion 98 of the movable adjustment member 90 are generally laterally oriented along the spaced surfaces 64a, 64b of the bifurcated portion 98. It is formed so as to at least partially overlap the inlet adjusting ports 66a and 66b when it moves to. Adjusting this overlap causes a pressure drop change in the hydraulic fluid flow entering the control pressure cavity 60 from the inlet adjustment ports 66a, 66b through the gaps 100a, 100b. Legs 98a, 98b of this embodiment
Are the inlet adjustment ports 66a, 66b and the outlet adjustment ports 68a,
It has a lateral length sufficient to substantially completely cover 68b at the same time. Therefore, when the bifurcated portion is in the equilibrium position as shown in FIG. 3 and the legs 98a, 98b of the present embodiment completely cover the adjustment ports 66a, 66b, 68a, 68b, the inlet and outlet adjustments are made. Mouth 66a, 66b, 68
The hydraulic fluid flow into and out of the control pressure cavity via a, 68b is reduced to a minimum value, i.e. substantially blocked. However, those skilled in the art will appreciate that fork 40 controls the hydraulic pressure at control port 54 rather than the flow rate through control port 54 by positioning bifurcated portion 98 as shown in FIG. Also the gaps 100a, 100b so that a controlled flow of hydraulic oil flows through the valve 40.
It will be appreciated that the dimensions of can be determined. With this arrangement, our invention provides a fluid pressure control valve 40 having a single clevis type control stage.

In this embodiment, the bifurcated portion 98 of the movable adjustment member 90 is responsive to the control signal along the spaced surfaces 64a, 64b and the adjustment ports 66a, 66b, 6.
The actuating means for moving laterally across 8a, 68b comprises an electromechanical torque motor 101. The torque motor 101 has an elongated arm 92 and an electric coil 102, which function as an armature and a stator of the torque motor 101, respectively. The coil is connected to and receives a control signal from a control signal source C as shown diagrammatically in FIG. The arm 92 is at least partially made of magnetic material so that the electromagnetic field generated by the coil 102 causes the arm to pivot laterally about the XX axis as shown in FIG. Laterally through the pivotal mount at. The torque motor 101 has a general structure, and when a predetermined electric control signal is applied to the coil 102, the arm 92 is operable so that the control signal is converted into the increase or decrease of the hydraulic oil pressure in the control pressure cavity 60. It is connected.

As seen in FIG. 1, the valve 40 of the present embodiment.
The actuating means in FIG.
2 has a pressure feedback means in the form of a control piston 106 operatively connected thereto. The control piston 106 is provided in a bore 108 that is in fluid communication with the hydraulic oil inlet passage by a return signal passage 110. The control piston thus constitutes a movable wall between the control pressure cavity and the second hydraulic fluid cavity formed by the hole 108. With this configuration, the differential pressure acting on the control piston 106 produces a net force on the control piston 106. This net force is transmitted to the arm 92 by the control link 112 and causes the forked portion 98 to move the forked surface 6 of the adjustment bridge 62.
4a, 64b and adjusting ports 66a, 66b, 68
Move laterally across a and 68b. Since the control piston 106 is exposed on one side to the control pressure within the control pressure cavity 60, the net force that causes the lateral movement of the bifurcated portion 98 acts on the arm 92 and the control pressure of the control pressure cavity 60. The return pressure corresponding to is generated.

The torque motor 101 and the pressure feedback means of this embodiment, operatively coupled to each other as described above, are responsive to a control signal requesting an increase in pressure in the control pressure cavity 60 to provide leg 98a of the bifurcated portion 98. , 98b to expose most of the inlet adjustment ports 66a, 66b. Entrance adjustment port 6
Most of the exposed portions 6a and 66b are exposed to the inlet adjustment ports 66a and 6b.
It reduces the pressure drop caused by hydraulic fluid as it flows into the control pressure cavity 60 through 6b and the gaps 100a, 100b. As the pressure drop through the inlet adjustment ports 66a, 66b and the gaps 100a, 100b decreases, the hydraulic fluid pressure in the control pressure cavity 60 increases.
Rising towards the inlet pressure in.

Conversely, the torque motor 101 and the pressure feedback means of this embodiment, operatively coupled to each other, are responsive to a control signal requesting a decrease in pressure in the control pressure cavity 60, the leg 98a of the bifurcated portion 98. , 98b, and inlet adjustment port 6
Most of 6a and 66b are covered. Inlet adjustment port 66a, 66
When most of b is covered, the control pressure cavity 60 passes through the inlet adjusting ports 66a, 66b and the gaps 100a, 100b.
Increases the pressure drop caused by hydraulic fluid as it flows into. Inlet adjustment ports 66a, 66b and gap 100
As the pressure drop through a, 100b increases, the hydraulic oil pressure in control pressure cavity 60 decreases from the inlet pressure in inlet passage 44.

The control piston 106, as described above,
An increase in hydraulic fluid pressure in the control pressure cavity 60 causes lateral movement of the inlet adjustment ports 66a, 66b so that the bifurcated portion 98 covers it, and a decrease in hydraulic fluid pressure in the control pressure cavity 60 causes A link 112 is operatively connected to the arm 92 for lateral movement of most of the inlet adjustment apertures 66a, 66b such that the bifurcated portion 98 is exposed. Therefore, the pressure feedback means of the valve 40 of the present embodiment provides a negative feedback to the arm 92 in response to the control pressure so as to switch the valve 40 from an integral controller to a proportional controller. The operating characteristics of the valve 40 are such that the control pressure at the port 54 is proportional to the control current from C.
By providing a proportional rather than an integral relationship between the control current from C and the control pressure at the control port, the stability of hydraulic system 10 is improved.

As shown in FIG. 1, the valve 40 of the present embodiment.
1 further comprises means for returning the bifurcated portion to the initial position shown in FIG. 8 and shown in dashed lines in FIG. 1 from the equilibrium operating position shown in solid lines in FIGS. In the initial position shown there, the inlet adjustment ports 66a, 66
The hydraulic fluid flow through b is substantially blocked, and the outlet adjustment ports 68a, 68b are completely exposed. The example return means is provided in the form of a spring 114 operatively connected between the body 42 and the arm 92 and a stop pin 116 projecting from the adjusting bridge 62. The spring 114 is moved to the right in FIG.
6 to position the pin 116 for lateral movement of the arm 92 to a desired initial position that prevents further lateral movement of the forked portion 98.

The valve 40 of this embodiment is also characterized in that it compensates for changes in the viscosity of the hydraulic oil due to changes in the operating temperature of the hydraulic oil. This compensation is provided in a straightforward manner by at least partially making the bifurcated portion 98 and the adjusting bridge 62 from materials having different coefficients of thermal expansion. A suitable material combination of the bifurcated portion 98 and the adjustment bridge 62 is a steel or cast iron bifurcated portion 98 and a brass or bronze adjustment bridge 62, or a carbon fiber reinforced composite bifurcated portion 98 and a carbon fiber reinforced type. Includes composite conditioning bridge.

By making the bifurcated portion 98 of a material having a smaller coefficient of thermal expansion than the regulating bridge 62, the bifurcated portion 98 expands faster than the regulating bridge as the hydraulic oil temperature rises or falls, respectively. Or contract. As a result, the legs 98a, 98b and the surfaces 64a, 64 of the adjusting bridge 62 are
The gaps 100a, 100b with b are maximum at low hydraulic oil temperatures and minimum at high hydraulic oil temperatures. The expansion of the gap at low temperatures reduces the fluid resistance created in the bifurcated portion 98 by the cold, viscous hydraulic oil passing through the gaps 100a, 100b, thereby reducing the gaps 100a, 1b.
If 00b is kept constant over all temperatures, it partially offsets the frequency response degradation due to the resistance that would otherwise occur. Conversely, when the hydraulic oil warms and its viscosity decreases, the gaps 100a, 100b correspondingly decrease due to the difference in the thermal coefficients, which causes the width of the gaps 100a, 100b to increase as the hydraulic oil temperature increases. The leakage flow from the inlet adjusting ports 66a, 66b to the outlet adjusting ports 68a, 68b, which would otherwise occur if held constant during the operation, is reduced. Since the fluid resistance generated in the bifurcated portion by the hydraulic oil flowing in the gaps 100a, 100b is a function of the viscosity, the gaps 100a, 1 at the increased hydraulic oil temperature are formed.
This reduction in the width of 00b does not adversely affect the frequency response of valve 40. By minimizing the leakage flow at high temperatures, and by maintaining the tolerance of the gaps 100a, 100b at lower temperatures, our inventive valve 40 provides a fast response over a wide range of fluid temperatures and viscosities. provide.

Alternatively, compensation for changes in hydraulic oil viscosity due to changes in hydraulic oil temperature may be provided by laminating the legs 98a, 98b of the bifurcated portion 98 with members having different coefficients of thermal expansion, as shown in FIG. It is produced by making it as a structure.
By forming legs 98a, 98b as a laminated structure having a transverse outer ply 120 of a material having a high coefficient of thermal expansion integrally joined to transverse inner ply 122, legs 98a, 98b are exposed to high temperatures. When exposed, legs 98a, 98b, as shown in exaggerated form in FIG.
Bend inward toward the surfaces 64a, 64b of the adjustment portion 62. Conversely, when the legs 98a, 98b are exposed to low temperatures, the legs 98a, 98b of the bifurcated portion 98 bend inwardly as shown in an exaggerated manner in FIG.
Increase 0b. Therefore, the advantageous results of this embodiment of our invention are the same as in the previous embodiment using a forked portion 98 and a tuning bridge 62 made from materials of different coefficients of thermal expansion. Legs 98a of this embodiment of our invention,
Acceptable material combinations for the laminates 120, 122 at 98b are cited above with respect to the above-described embodiment using, among other things, a forked portion 98 and a tuning bridge 62 made from materials having different coefficients of thermal expansion. Includes things.

To operate the hydraulic system of the above-described embodiment, the operator of the vehicle 11 or the power plant 12 first causes the control flow of pressurized hydraulic oil from the pump P to flow through the valve 10 into the low pressure tank 14. Specifically, the control flow includes the hydraulic oil inlet passage 44, the inlet adjusting ports 66a and 66b, the gap 100.
a, 100b and control pressure cavity 60, continued flow through outlet adjustment ports 68a, 68b, and finally through the hydraulic oil outlet passage 48 and out of the valve. Coil 1
02 is not yet excited and the bifurcated portion 98 is in the initial position shown in FIG. Entrance adjustment port 6 in the initial position
6a and 66b are completely covered, and the outlet adjustment port 68
Since a and 68b are completely exposed, the inlet adjustment port 6
The pressure drop through 6a, 66b and the gaps 100a, 100b is at a maximum. Therefore, the control pressure cavity 60
The control pressure within is at a minimum value. When the control pressure is at the minimum value, the return spring of the clutch 16 keeps the drive plate 28 and the driven plate 30 of the clutch 16 separated, thereby disconnecting the prime mover PM from the driven device D.

To engage the clutch 16, the driver causes the control signal source C to apply an electrical signal to the coil 102 of the torque motor 101 of the valve 10. The coil 102 produces an electromagnetic force that tends to move the arm 92 to the left, generally towards the equilibrium position shown in solid lines in FIGS. 1 and 3, thereby causing the legs 98a, 98b of the bifurcated portion 98 to be deflected. A part of the inlet ports 66a, 66b is exposed to expose the outlet adjusting ports 68a, 68b. By exposing the inlet port, the inlet adjusting ports 66a and 66b and the gaps 100a and 10 are formed.
The pressure drop caused by hydraulic fluid entering the control pressure cavity 60 through 0b is reduced. Inlet adjustment port 66a,
When 66b is open and the outlet adjusting ports 68a and 68b are covered, the control pressure in the control pressure cavity 60 increases toward the inlet pressure in the hydraulic oil inlet passage 44. This increase in control pressure is transmitted to clutch 16 via conduit 56 and causes piston 32 to clamp drive plate 28 and driven plate 30 together, thereby coupling clutch 16 in the manner previously described.

To disengage the clutch 16, the driver causes the control signal source C to leave the coil 102 uncharged or reverse the current passing through it. The spring 114 and / or the opposite polarity coil then drives the bifurcated portion 98 back to its initial position with the inlet adjustment ports 66a, 66b open and the outlet adjustment ports 68a, 68b completely covered. The hydraulic oil pressure drop entering the control pressure cavity 60 again reaches a maximum. The control pressure in the control pressure cavity 60 is controlled by the outlet adjusting port 68.
It is released through a and 68b. When the control pressure reaches a point in the clutch where the force exerted by the return spring exceeds the force exerted by the piston 32, the spring 114 causes the drive plate 28 and the driven plate 30 to separate, thereby releasing the clutch. .

Although the operation of the embodiment has been described above based on a simple on-off type control, those skilled in the art will appreciate that the valve 40 of our invention is preferred when the control pressure in the cavity 60 is the coil 102. It will be readily appreciated that it is operated as a regulated control valve that is adjusted in proportion to the control signal applied to it. The ability to use such proportional control is provided by the feedback means of our invention which operates over the entire operating cycle of the hydraulic system.

Specifically, when the pressure in the control cavity 60 rises in response to the action of the coil 10 on the arm 92, the increase in control pressure acting on the control piston 106 opposes the action of the coil 102. A force acting on 92 is generated. This force from the control piston 106, together with the force generated by the spring 114, causes the bifurcated portion 98 to assume the equilibrium position essentially shown in FIG.
In this position, the force from coil 102 is balanced by the force generated by spring 114 and control piston 106. By adjusting the control signal to coil 102, the position of bifurcated portion 98 is controlled around the equilibrium position of FIG. In this way, the control pressure in the control pressure cavity is precisely and quickly adjusted in an essentially proportional relationship with the current supplied to the coil 102.

The ability to precisely control pressure is of particular utility in many devices, such as antilock brakes and clutches, where it is desirable to allow a limited amount of slip between the components of such brakes and clutches. Easily find gender and benefits. By rapidly adjusting the control signal to the coil 102, the valve 40 of our invention allows the clamping force in the brakes and clutches to vary rapidly or to be controlled in proportion to the control signal. A preferred embodiment of the valve 40 of our invention is shown in FIGS. 4 and 5, where the same reference numerals designate substantially the same parts as the previous embodiments. In this preferred embodiment of valve 40, the pivotal attachment of arm 92 to body 42 is provided by flexible hinge 118 shown in FIGS. Flexible hinge 118 has an associated spring constant and has sufficient lateral stiffness to also function as a leaf or finger spring, thereby eliminating the need for a separate return means such as spring 114. .

As shown in FIGS. 8 and 4, the bifurcated portion 98 of the preferred valve embodiment is also laterally offset and in a preferentially biased initial position. Specifically, the initial position of the bifurcated portion 98 in the preferred embodiment is:
The inlet adjusting ports 66a and 66b are completely covered in the initial position, and the outlet adjusting ports 68a and 68b are biased so as to be completely exposed. This arrangement facilitates the release of the controlled pressure within the controlled pressure cavity 60, thereby allowing a quick release of the driven device D. The minimum control pressure is also reduced to essentially the pressure of the low pressure tank. Due to this arrangement, the spring constants of the spring 114 to the flexible hinge 118 and the coil 102 are designed so that the arm 92 and the bifurcated portion assume the positions shown in FIGS. 4 and 8, respectively, when no current flows through the coil 102. To be done. When the coil 102 is excited, the coil 102, the piston 106, the spring 1
The balance force between 14 or the flexible hinge 118 moves the bifurcated portion 98 to the equilibrium position as shown in FIG. 3 and described above. Therefore, adjusting the control signal entering coil 102 results in a proportional control of pressure to control cavity 60.

In addition to the initial position depicted in FIG. 8, the spring 114 or flexible hinge 118 and coil 10 of our invention is used.
2 also includes inlet adjustment port 66a, as shown in FIG. 9, if our hydraulic system 10 requires such an arrangement.
While 66b is entirely exposed, outlet adjustment ports 68a, 68b
It will also be understood that can be formed to bias the bifurcated portion 98 in an initial position where it is entirely covered. When the coil 102 of such an embodiment is energized, the coil 102 of the valve 40,
Spring 114 or flexible hinge 118 and control piston 1
The force balance between 04 causes the bifurcated portion 98 to move to the equilibrium position depicted in FIG. 3 and described above, thereby establishing a proportional adjustment of the control pressure in response to the control signal applied to the coil 102. . Alternatively, an initial position similar to that shown in FIG. 3 is selected for use where it is desirable to cover the inlet adjustment ports 66a, 66b and the outlet adjustment ports 68a, 68b when the coil 102 is not energized. Will be able to be done.

From the foregoing description, those skilled in the art have found that the problem our invention encounters in conventional hydraulic systems is the use of contaminated hydraulic fluid of varying viscosity in vehicle or stationary hydraulic systems. It will be readily appreciated that any of the above can be overcome by providing a stable, fast responding hydraulic system that offers significant advantages. The increase in current in coil 102 results in an essentially proportional increase in pressure in cavity 60 and clutch piston 32 and a consequent proportional increase in clutch clamping force and transfer torque. By this means, the torque transmitted through the clutch 16 can be controlled in an essentially proportional relationship in response to the current supplied to the coil 102.

Those skilled in the art will further appreciate that, although we have described our invention herein with reference to some particular embodiments and applications, our invention as set forth in the appended claims has been described. It will be appreciated that numerous other implementations and applications are possible within the scope. For example, the electric torque motor 101 of the embodiment presented here could be replaced by a pneumatic or hydraulic device. Control piston 106 and link 112 could alternatively be configured to push arm 92 rather than pull in response to an increase in control pressure in control pressure cavity 60. The return means could also use some device other than the piston 106, such as a bellows or a flexible diaphragm, to form the movable wall.
Further, the reference pressure may be something other than the inlet pressure. For example, an aneroid bellows or atmospheric pressure port would be used as the reference pressure in other implementations and applications of our invention. Therefore, it is to be understood that the spirit and scope of the appended claims should not be limited to the particular embodiments described and illustrated herein.

[Brief description of drawings]

FIG. 1 is a schematic diagram depicting an embodiment for a vehicle or fixed power plant according to the invention, including a cross-sectional view of a fluid control valve and a hydraulic clutch that are parts of the hydraulic system.

FIG. 2 is an auxiliary drawing showing various components and features of the fluid control valve shown in FIG.

FIG. 3 is an auxiliary drawing showing various components and features of the fluid control valve shown in FIG.

FIG. 4 is a cross-sectional view of a preferred embodiment of the control valve of the hydraulic system of FIG.

5 is an auxiliary drawing showing various components and features of the preferred embodiment of the valve shown in FIG.

FIG. 6 is an auxiliary drawing showing various components and features of the fluid control valve shown in FIG.

FIG. 7 is an auxiliary drawing showing various components and features of the fluid control valve shown in FIG.

8 is an auxiliary drawing showing various components and features of the preferred embodiment of the valve shown in FIG.

9 is an auxiliary drawing of an alternative embodiment of the valve shown in FIG. 1 or FIG.

Claims (40)

[Claims] 1. A pressure-actuated hydraulic device, a pressurized hydraulic oil source, a low-pressure tank, a control signal source, and a clevis-type pressure control valve, wherein the clevis-type control valve flows from the pressurized hydraulic oil source to the pressurized hydraulic oil. Means for receiving and directing the flow to the low pressure tank, and converting a portion of the flow to a predetermined control pressure in response to a control signal received from the control signal source,
And a means for applying the control pressure to the pressure-actuated hydraulic device, wherein the conversion means has a clevis-type hydraulic oil pressure control stage. 2. The clevis-type control includes feedback means operably connected to the clevis-type hydraulic oil control stage for controlling the clevis-type hydraulic oil pressure control stage in response to the control pressure. The hydraulic device according to item 1. 3. The hydraulic system according to claim 1, wherein the clevis type fluid pressure control valve has compensating means for compensating for a change in viscosity of a flow of the pressurized hydraulic oil. 4. The hydraulic system of claim 3, wherein said compensating means is responsive to temperature changes in the flow of pressurized hydraulic fluid. 5. A pressure-actuated hydraulic device, a pressurized hydraulic oil source, a low pressure tank, a control signal source, and a pressure control valve, wherein the pressure control valve receives a flow of pressurized hydraulic oil from the pressurized hydraulic oil source. And means for directing the flow to the low pressure tank, and converting a portion of the flow to a predetermined control pressure in response to a control signal received from a control signal source, the control pressure being the pressure actuated hydraulic system. The clevis-type fluid pressure control stage for controlling the single clevis-type fluid pressure control stage and the single clevis-type fluid pressure control stage in response to the control pressure. A hydraulic system having a return means operably connected to the stage. 6. The hydraulic system of claim 5 wherein said means for converting a control signal comprises electromechanical means and said control signal is an electrical signal. 7. The hydraulic system of claim 5, wherein the pressurized hydraulic fluid has a viscosity of about 1000 centistokes or greater. 8. A means for receiving a flow of pressurized hydraulic oil from a source of pressurized hydraulic oil and delivering the flow to a low pressure tank, and predetermining a portion of said flow in response to a control signal received from a control signal source. A pressure control valve having means for converting to a controlled control pressure, said conversion means having a single clevis-type fluid pressure control stage with feedback of said control pressure. 9. The pressure control valve of claim 8 wherein said means for converting a control signal comprises electromechanical means and said control signal is an electrical signal. 10. The pressure control valve of claim 8, wherein the pressurized hydraulic fluid has a viscosity of about 1000 centistokes or greater. 11. A single clevis-type fluid pressure control stage is a first and a second adjusting member, at least one of which is movable with respect to the other, wherein the first and the second adjusting member are between them. Said first and second adjusting members defining one or more gaps apart from each other for flowing a portion of said flow of pressurized hydraulic fluid therethrough, and said pressurized actuation flowing therethrough 9. The pressure control valve according to claim 8, further comprising viscosity compensating means for increasing or decreasing the gap to compensate for a change in oil viscosity. 12. The viscosity compensating means is provided by first and second adjusting members made of materials having different coefficients of thermal expansion, and the first and second adjusting members are provided when the temperature of the flow of the pressurized hydraulic oil changes. The second member expands or contracts to different degrees, thereby increasing or decreasing the gap between them so as to compensate for changes in hydraulic viscosity resulting from changes in temperature of the hydraulic fluid flowing through the gap. The pressure control valve according to claim 11, wherein 13. The clevis-type control valve has a moveable adjustment member, and the return of control pressure is provided by means exposed to the control pressure and operably coupled to the moveable adjustment member. 9. The pressure of claim 8, wherein the control pressure acting on the means exposed to the control pressure causes movement of the movable adjustment member to adjust the control signal in a proportional relationship to the control signal. Control valve. 14. The pressure control valve of claim 8 wherein said means for converting a control signal further comprises compensating means for compensating for changes in hydraulic oil viscosity. 15. The pressure control valve of claim 14 wherein said compensating means includes temperature responsive means for adjusting said means to convert a control signal in response to changes in the temperature of hydraulic fluid within said control valve. 16. A hydraulic fluid control device having a pressurized hydraulic fluid source, a low pressure tank, a control signal source, and a pressure hydraulic fluid system, wherein the pressure control valve includes a hydraulic fluid inlet passage, a hydraulic fluid outlet passage, a control pressure passage, and the operation. A body defining a control pressure cavity in fluid communication with the oil inlet passage, the hydraulic oil outlet passage, and the control pressure passage, wherein the hydraulic oil inlet passage receives the pressurized hydraulic oil therefrom. A hydraulic fluid source has an inlet port connected to it, and the hydraulic fluid outlet passage has an outlet port connected to the low pressure tank for returning hydraulic fluid to it;
The control pressure cavity then has a control port in communication with the pressure actuator for transmitting a control pressure signal, wherein a portion of the body is substantially flat, opposed, laterally spaced. A pair of surfaces defining a pair of surfaces exposed to the control pressure cavity and opening to the control hydraulic cavity to provide fluid communication between the control pressure cavity and the hydraulic fluid inlet passage. The pair of surfaces have opposing adjustment ports so that the pressurized hydraulic fluid enters the control pressure cavity through the adjustment port and exits the cavity through the outlet passage. A body adapted to generate a flow of pressurized hydraulic fluid through the control pressure cavity, the body being mounted within the control pressure cavity of the body;
A forked portion straddling a portion of the body defining the spaced surface, the bifurcated portion being generally laterally moved along the spaced surface. A movable adjusting member in which the bifurcated portion is formed so as to at least partially overlap the adjustment opening, wherein a partial overlap of the adjustment opening by the bifurcated portion from the adjustment opening to the control pressure cavity. The movable pressure adjusting member adapted to cause a pressure drop in an incoming flow of the pressurized hydraulic oil to selectively control the hydraulic oil pressure in the control pressure cavity by changing the overlap; The bifurcated portion of the adjustment member along the spaced surface for selectively controlling the overlap in response to a control signal received from a control signal source; Actuating means for moving generally laterally across the adjustment port, the actuating means generally responsive to hydraulic fluid pressure in the controlled pressure cavity to cause the bifurcated portion to follow the spaced surface and across the adjustment port. Consisting of said actuating means having pressure feedback means operatively connected between said control pressure cavity and said adjusting port for lateral movement, said pressure control valve thereby receiving from said control signal source A pressure control valve for converting the controlled control signal into a control pressure signal to be applied to the pressure actuating device. 17. An increase in hydraulic fluid pressure in the control pressure cavity causes lateral movement of the bifurcated portion to cover a majority of the adjustment port, and a reduction in hydraulic fluid pressure in the control pressure cavity is achieved. The fluid control valve of claim 16, wherein the return means is operably connected to laterally move the bifurcated portion to expose a majority of the adjustment port. 18. The fluid control valve of claim 16, wherein the pressurized hydraulic fluid has a viscosity of about 1000 centistokes or greater. 19. A means for receiving a flow of pressurized hydraulic oil from said source of pressurized hydraulic oil and sending said flow to said low pressure tank, and a portion of said flow corresponding to a control signal received from a control signal source. A conversion means into a predetermined control pressure, the conversion means comprising a single clevis type fluid pressure control stage and the single clevis type fluid pressure control stage in response to a temperature change of the pressurized hydraulic oil. Pressure control valve operatively communicating with the clevis-type fluid pressure control stage to control the pressure control valve. 20. Control pressure feedback means operatively connected between said control pressure and said clevis-type fluid pressure control stage for adjusting said control pressure in a substantially proportional relationship to said control signal. 20. The pressure control valve of claim 19 having. 21. The single clevis-type fluid pressure control stage is a first and second adjustment member, at least one of which is movable with respect to the other, the first and second adjustment members passing therethrough. The first and second adjusting members spaced apart from each other to define a gap or spaces therebetween for flowing a portion of the flow of the pressurized hydraulic fluid, and the pressurized actuation flowing therethrough. 20. Viscosity compensating means operative to increase or decrease the gap to compensate for changes in oil viscosity.
Pressure control valve. 22. The viscosity compensating means is provided by making the first and second adjusting members from materials having different coefficients of thermal expansion, so that when the temperature of the flow of the pressurized hydraulic oil changes, The gap between the first and second members expands or contracts to different degrees, thereby compensating for changes in hydraulic fluid viscosity resulting from changes in temperature of the hydraulic fluid flowing through the gap. 22. The pressure control valve of claim 21, adapted to increase and decrease. 23. The viscosity compensating means is provided by making at least one of the first and second adjusting members from an integrally bonded laminate of materials having different coefficients of thermal expansion, resulting in When the temperature of the flow of the pressurized hydraulic oil changes, at least one of the first and second members bends toward or away from the other of the first or second adjusting members, thereby causing the 22. The pressure control valve of claim 21, adapted to increase or decrease the gap therebetween to compensate for changes in hydraulic oil viscosity resulting from changes in the temperature of hydraulic oil flowing through the gap. 24. A hydraulic oil inlet passage having an inlet port for receiving pressurized hydraulic oil from a pressurized hydraulic oil source, a hydraulic oil outlet passage having an outlet port for returning the hydraulic oil to a low pressure tank, and a pressure sensitive device. A control pressure passage having a control pressure port for transmitting control pressure to and a body defining a control pressure cavity communicating with the inlet passage, the outlet passage, and the control pressure passage, a portion of the body being substantially Electrically flat, opposed, laterally spaced apart, defining a pair of surfaces exposed in the control pressure cavity and providing fluid communication between the control pressure cavity and the hydraulic fluid inlet passage. A body having a pair of opposed adjusting openings that open into the control hydraulic cavity for mounting the body in the control pressure cavity of the body. And having a bifurcated portion straddling a portion of the body defining the spaced surface, the bifurcated portion being moved generally laterally along the spaced surface. A movable part which is formed with a forked portion at least partially overlapping the adjusting port, thereby producing a fluctuating pressure drop in the flow of hydraulic oil entering the control pressure cavity from the adjusting port. Adjustment member,
And responsive to a control signal to move the bifurcated portion of the adjustment member generally laterally along the spaced surfaces and across the adjustment port, in response to hydraulic fluid pressure in the control pressure cavity. A pressure feedback means operatively connected between the control pressure cavity and the adjustment port for moving the bifurcated portion generally laterally along the spaced surface and across the adjustment port; A fluid control valve comprising actuating means. 25. An increase in hydraulic fluid pressure in the control pressure cavity causes lateral movement of the bifurcated portion to cover a majority of the adjustment port, and a reduction in hydraulic fluid pressure in the control pressure cavity is achieved. 25. The fluid control valve of claim 24, wherein the return means is operably connected to laterally move the bifurcated portion to expose a majority of the adjustment port. 26. A second hydraulic fluid cavity, wherein the pressure feedback means is isolated from the control pressure cavity by a movable wall, and is in fluid communication with the hydraulic fluid outlet passage, and a force to the movable wall. 25. The fluid control of claim 24 including means for loading the movable wall operably in communication with the movable adjustment member to move the bifurcated portion laterally along the spaced surfaces. valve. 27. The pressure difference between the hydraulic oil in the control pressure cavity and the hydraulic oil in the outlet passage generates a force acting on the movable wall, and the pressure feedback means causes the pressure feedback means to operate in the control pressure cavity. By moving the bifurcated portion laterally to cover most of the adjusting port as the hydraulic fluid pressure increases relative to the hydraulic fluid pressure in the outlet passage, and in the control pressure cavity. Formed to respond to the force by laterally moving the bifurcated portion to expose a majority of the adjustment port as the oil pressure decreases relative to the hydraulic oil pressure in the outlet passage. 27. The fluid control valve of claim 26. 28. The actuating means includes control means operably connected to the movable adjustment member and responsive to a control signal requesting an increase in hydraulic fluid pressure in the control pressure cavity. The control means is configured to expose the majority of the adjusting port by making the forked portion of the movable adjusting member pass through the adjusting port so as to increase the pressure of the hydraulic oil in the control pressure cavity. The control means controls the bifurcated portion of the movable adjustment member to cause most of the adjustment port in response to a control signal to reduce pressure drop and to reduce the pressure of hydraulic fluid in the control pressure cavity. Is adapted to increase the pressure drop through the adjusting port so as to reduce the pressure of hydraulic oil in the control pressure cavity, and the pressure feedback means is operable on the movable adjusting member. And an increase in hydraulic fluid pressure in the control pressure cavity moves the bifurcated portion generally laterally to cover most of the adjustment port, and a decrease in hydraulic fluid pressure in the control pressure cavity causes 25. The fluid control valve according to claim 24, wherein the bifurcated portion is moved laterally so as to expose most of the adjustment port. 29. The actuating means includes electromechanical control means for translating a predetermined electrical control signal into a lateral movement of the bifurcated portion, the predetermined electrical control signal being in the controlled pressure cavity. 25. The fluid control valve of claim 24, which is adapted to produce a predetermined increase or decrease in hydraulic pressure. 30. The pair of adjustment ports that provide fluid communication with the hydraulic oil inlet passage are inlet adjustment ports, the spaced surfaces opening into the control pressure cavity and the control pressure cavity. And a second pair of opposed outlet adjustment openings for providing fluid communication between the inlet adjustment opening and the hydraulic oil inlet passage, the outlet adjustment openings being transverse to the inlet adjustment opening along the spaced wall. Spaced apart and formed such that the bifurcated portion of the movable adjustment member at least partially overlaps the outlet adjustment opening when the bifurcated portion moves laterally along the spaced surface. 25. The fluid control valve of claim 24, which is provided. 31. The inlet adjustment opening and the outlet adjustment opening are substantially completely such that hydraulic fluid flow into and out of the control pressure cavity through the inlet adjustment opening and the outlet adjustment opening is substantially blocked. 31. The fluid control valve of claim 30, wherein the bifurcated portion has a lateral length sufficient to simultaneously cover. 32. The fluid control valve of claim 31, further comprising means for returning the bifurcated portion to an initial position in which hydraulic fluid flow through the inlet adjustment opening and the outlet adjustment opening is substantially blocked. 33. Means for returning the bifurcated portion to an initial position in which hydraulic fluid flow through the inlet adjustment port is substantially blocked, but hydraulic fluid flow through the outlet adjustment port is not substantially blocked. Item 31. The fluid control valve of Item 31. 34. The bifurcated portion forms a pair of gaps between the bifurcated portion and the spaced surface away from the spaced surface, and the bifurcated portion has different coefficients of thermal expansion. Made from a material having a bifurcated portion that bends inward toward the spaced surfaces to reduce the gap when exposed to high temperatures, and the bifurcated portion when exposed to low temperatures. Bend outwards to increase the gap, thereby joining the materials together to form a laminated structure so as to provide compensation for viscosity changes due to temperature changes of hydraulic fluid flowing through the gap. 25. The fluid control valve of claim 24. 35. The adjustment port is disposed about a common centerline that extends substantially perpendicularly to a surface extending generally parallel to the spaced surfaces of the body, and the movable adjustment member includes the surface. Having a substantially rigid elongate arm generally located along the elongate arm, the elongate arm pivotally attached to the body at one end, and the elongate arm pivoted from the body along the surface. 25. The bifurcated portion is sometimes attached to the bifurcated portion of the movable adjustment member at a tip such that the bifurcated portion moves laterally along the spaced apart surfaces of the portion of the body. Fluid control valve. 36. An electric machine wherein said actuating means is operably communicated between said body and said arm for pivotally moving said arm along said surface in response to said control signal. 36. The fluid control valve of claim 35, having an electronic control means. 37. The fluid control valve of claim 36, further comprising position recovery means operably connected between the body and the arm for returning the arm to a predetermined initial position along the surface. . 38. The adjustment port is disposed about a common centerline that extends substantially perpendicularly to a surface extending generally parallel to the spaced surfaces of the body, and the movable adjustment member includes the surface. Has an elongate arm generally positioned along the elongate arm, the elongate arm being fixedly attached to the body at one end by a flexible hinge member, and the bifurcated when the hinge member bends along the surface. 25. The fluid control valve of claim 24, wherein a portion is attached at the tip to the bifurcated portion of the movable adjustment member for lateral movement along a spaced surface of the portion of the body. 39. Between the body and the arm for causing the arm to exert a bending force on the flexible hinge member so as to bend the flexible hinge member along the surface in response to the control signal. 39. The fluid control valve of claim 38, wherein the actuation means has electromechanical means operably connected to the. 40. The flexible hinge member is formed as a spring means for resisting a bending force applied thereto and for returning the arm to a predetermined initial position along the surface when the bending force is applied to the arm. 39. The fluid control valve of claim 38.