EP0136005A1 - Servo actuator control/damping mechanism - Google Patents
Servo actuator control/damping mechanism Download PDFInfo
- Publication number
- EP0136005A1 EP0136005A1 EP84305122A EP84305122A EP0136005A1 EP 0136005 A1 EP0136005 A1 EP 0136005A1 EP 84305122 A EP84305122 A EP 84305122A EP 84305122 A EP84305122 A EP 84305122A EP 0136005 A1 EP0136005 A1 EP 0136005A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- ram
- servo
- valve
- fluid
- electro
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B18/00—Parallel arrangements of independent servomotor systems
Definitions
- This invention relates generally to servo systems and, more particularly, to aircraft flight control servo systems. More specifically, the invention relates to a servo actuator control/damping mechanism and method which utilize and combine the functions of an electro-mechanically driven servo valve to achieve fluid flow and actuator (ram) load control even after loss of fluid power.
- Fluid servo systems are used for many purposes, one being to position the flight control surfaces of high performance aircraft.
- the servo system desirably should provide for control and damping of flight control surface displacements or flutter after loss of fluid power. Otherwise, aircraft damage or loss of control may result.
- electro-hydraulic valves have been used in conjunction with servo valve actuators to effect position control of the main control servo valve.
- the servo actuators in redundant systems operate on opposite ends of a linearly movable valve element in the main control valve and are controlled by the electro-hydraulic valves located elsewhere in the system housing.
- Such systems also have used bypass/damping valves which operate upon loss of fluid power to bypass flow to and from the main ram or actuator through fixed metering orifices which damp and control the rate of ram and flight surface movements.
- bypass/damping valves have been located in the system housing remote from the main control valve.
- such systems have utilized electronic differential pressure sensors to provide dynamic ram load feed-back information to the aircraft electronic control system which supplies command signals to the electro-hydraulic valves.
- An alternative approach to the electro-hydraulic control system is an electro-mechanical control system wherein a force motor is coupled directly and mechanically to the main control servo valve.
- These systems also have used remotely located bypass/damping valves which bypass ram flow through fixed metering orifices upon loss of fluid power for damping and controlling the rate of ram and flight surface movements.
- the force motor is coupled directly and mechanically to a pilot valve plunger which controls a hydraulically powered servo valve actuator for driving the main control servo valve.
- a shut-off valve sleeve concentric with the pilot valve plunger can be used to direct ram flow through fixed metering orifices upon loss of fluid power for damping and rate control of ram and flight surface movements.
- each of the foregoing systems uses added valves or valve components to achieve some degree of control over ram and flight surface movements after loss of fluid power.
- valves or valve components are shuttled between system on and off (bypass) positions with the latter serving to direct actuator flow through the fixed metering orifices. Consequently, there has been no provision for active damping or flutter control in response to changing conditions at the ram or flight control surface.
- ram pressure relief flow through the fixed metering orifices may under some circumstances be insufficient to prevent overload of the ram and flight control surface and resultant damage.
- the present invention provides a fluid servo actuator control/ damping mechanism and method which utilize and combine the functions of an electro-mechanically driven servo valve to achieve ram or actuator fluid flow and load control even after loss of fluid power as well as the main ram position control function under normal operating conditions.
- the mechanism is particularly useful in an aircraft flight control servo system wherein reduced package size and weight is desired along with active or regulated damping control and overload relief functions, and eliminates the need for separate bypass valves or valve components heretofore utilized to meter bypass ram flow through fixed orifices.
- the mechanism comprises a servo valve including a positionable valve element for selective application of fluid power to a ram, a sensor connectable to the ram for providing ram load feed-back information, and an electro-mechanical drive operable independently of fluid power for selectively positioning the valve element under normal operating conditions for controlled actuation of the ram and, upon loss of fluid power, for providing variable orifices to controllably meter bypass fluid flow across the ram by utilizing the existing metering pattern of the servo valve and modulating the valve element thereof in response to feed-back information received from the sensor, for actively controlled damping of the ram.
- a servo valve including a positionable valve element for selective application of fluid power to a ram, a sensor connectable to the ram for providing ram load feed-back information, and an electro-mechanical drive operable independently of fluid power for selectively positioning the valve element under normal operating conditions for controlled actuation of the ram and, upon loss of fluid power, for providing variable orifices to controllably meter bypass fluid flow across
- a servo mechanism comprises a servo valve including a valve element selectively positionable therein to provide variable orifices for metering fluid flow to and from the opposed pressure surfaces of the ram, means for connecting a source of high pressure fluid to the servo valve for metered passage to either ram pressure surface through the variable orifices, means for directing bypass fluid flow from either pressure surface to the other through such variable orifices in the event of a loss of such high pressure fluid, and electro-mechanical drive means operative independently of such high pressure fluid to controllably position the valve element to effect controlled metering of such high pressure fluid to either pressure surface of the ram for controlled actuation thereof and, in the event of a loss of such high pressure fluid, to effect controlled metering of bypass fluid flow across the ram for active or regulated damping and load control.
- a dual hydraulic servo system is designated generally by reference numeral 10 and includes two similar hydraulic servo actuators 12 and 14.
- the actuators 12 and 14 are connected to a common output device such as a dual tandem cylinder actuator or ram 16 which in turn may be connected to a control member such as a flight control element of an aircraft.
- a common output device such as a dual tandem cylinder actuator or ram 16 which in turn may be connected to a control member such as a flight control element of an aircraft.
- the two servo actuators normally are operated simultaneously to effect position control of the ram 16 and hence the flight control element.
- each servo actuator preferably is capable of properly effecting such position control independently of the other so that the control is maintained even when one of the servo actuators fails or is shut down. Accordingly, the two servo actuators in the overall system provide a redundancy feature that increases safe operation of the aircraft.
- the servo actuators 12 and 14 are similar and for ease in description, like reference numerals will be used to identify corresponding like elements of the two servo actuators.
- Each servo actuator 12, 14 has an inlet port 20 for connection with a source of high pressure hydraulic fluid and a return port 22 for connection with a hydraulic reservoir.
- the respective inlet and return ports of the servo actuators are connected to separate and independent hydraulic systems in the aircraft, so that in the event one of the hydraulic systems fails or shuts down, the servo actuator coupled to the other still functioning hydraulic system may be operated to effect the position control function.
- the hydraulic systems associated with the servo actuators 12 and 14 will respectively be referred to as the forward and aft hydraulic systems.
- an inlet passage 24 connects the inlet port 20 to a common main control servo valve designated generally by reference numeral 26.
- Each inlet passage 24 may be provided with a suitable filter 27 and a check valve 28 which blocks reverse flow through the inlet passage from the servo valve to the inlet port.
- Each servo actuator also is provided with a return passage 30 which connects the return port 22 to the servo valve 26 via a damping mode accumulator or compensator 32 which serves to maintain pressure in the servo actuator sufficient to prevent cavitation across damping restrictions during damping mode operation as described hereafter.
- the main control servo valve 26 includes a plunger or spool 34 longitudinally shiftable in a cylindrical bore 36 which may be formed by a sleeve (not shown) in an overall system housing.
- the plunger has two fluidically isolated valving sections indicated generally at 38 and 40, which valving sections are associated respectively with the actuators 12 and 14 and the passages 24 and 30 thereof.
- the plunger may be selectively shifted from its illustrated neutral or centered position for selective connection of the passages 24 and 30 of each servo actuator to passages 42 and 44 in the same servo actuator.
- the passages 42 and 44 of both servo actuators 12 and 14 are connected to the ram 16 which includes a pair of cylinders 46 having respective pistons 48 connected to ram output rod 50 for common movement therewith. More specifically, the passages 42 and 44 of each servo actuator are connected to a corresponding one of the cylinders of opposite sides of the piston.
- the passages 42 and 44 also are connected by respective branch passages 52 and 54 to a common passage 56 which in turn is connected to the corresponding return passage 30.
- the branch passages 52 and 54 are respectively provided with anti cavitation check valves 58 and 60 which block fluid flow from the passages 42 and 44 to the common passage 56 but permit free flow from common passage 56 to passages 42 and 44.
- each valving section 38, 40 of the plunger 34 has a pair of longitudinally [axially) spaced apart lands 60 and 62 which are locatable, as when the plunger is in its neutral position, to block flow through respective metering ports 64 and 66 that respectively connect the passages 42 and 44 to the interior of the plunger bore 36.
- the lands 60 and 62 define therebetween a supply groove 68 which is in communication with the inlet passage 24 and outwardly thereof respective return grooves 70 and 72 which are interconnected by passage 74 and in common communication with return passage 30.
- Controlled selective movement of the valve plunger 34 is desirably effected by an electric force motor 78 which may be located closely adjacent one end of the plunger.
- the force motor may be of linear or rotary type and operative connection of the force motor to the valve plunger may be obtained by a link member 80 such as in the manner described in the aforementioned U.S. application Serial No. 463,631.
- the force motor 78 is responsive to command signals received from an electronic control or command system indicated at 82 which may be located, for example, in the aircraft cockpit, whereby the force motor serves as a control input to the valve plunger 34. Also, the force motor preferably has redundant multiple parallel coils so that if one coil or its associated electronics should fail, its counterpart channel or channels will maintain control. Moreover, suitable failure monitoring circuitry is preferably provided to detect when and which channel has failed, and to uncouple or render passive the failed channel.
- Feed-back information to the command system 82 is obtained by position transducers or sensors 84 and 86 which are desirably operatively connected to and monitor the positions of the valve plunger 34 and ram output rod 50, respectively.
- electronic load sensors 88 or equivalent devices are desirably operatively connected to respective cylinders 46 of the ram 16 for monitoring ram load and providing load feed- back information to the command system 82 controlling the force motor 78.
- each load sensor 88 may be in the form of a differential pressure sensor including a position transducer 92 connected to a longitudinally shiftable spring centered piston 94.
- Opposite sides or pressure surfaces of the piston 94 are respectively connected by passages 96 and 98 to respective opposite sides or pressure surfaces of the piston 48 in the corresponding cylinder 46 of the ram whereby the position of the piston 94 and corresponding output of the transducer will be indicative of the direction and magnitude of differential pressure forces acting on the piston 48.
- each electronic load sensor 88 may be used during normal operation to provide dynamic load feed-back information to the command system 82 for implementation of damping and over-pressure relief functions in conventional manner. Further, each electronic load sensor 88 may be used during normal operation to provide surface hinge moment control and hinge moment limiting. This would allow the servo to become a torque or force servo rather than a positional servo.
- the command system 82 automatically implements damping mode operation.
- the check valves 28 and compensators 32 serve to maintain positive pressure in the system 10 after such loss of hydraulic power by checking fluid loss through the inlet and return ports 20 and 22.
- the compensators' fluid storage volume can be selected such that damping may be met for a specified minimum period of time.
- active or regulated damping control of the ram 16 is effected by modulating the valve plunger 34 to provide variable orifices which direct and meter bypass flow across each ram piston 48.
- the electro-mechanically driven servo valve 26 is not dependent on hydraulic power for valve plunger positioning whereby the valve plunger will continue to respond to system commands as long as at least one channel of the motor 78 and associated electronics survives and remains operative.
- the valve plunger 34 is modulated in response to ram load feed-back information from the load sensors 88 which monitor the direction and amplitude of differential pressure across the pistons 48.
- each ram piston 48 may be bypassed across the ram to the retract (right) side of each piston by moving the valve plunger 34 to the right of its neutral position to provide a metering orifice connecting passage 42 to return passage 30.
- This establishes correspondingly metered bypass flow across each piston, such flow passing through passage 42 and the provided orifice to return passage 30 which directs the flow to the retract side of the piston via bypass passage 56 and branch passage 54.
- moving the valve plunger to the left of its neutral position will establish and meter bypass flow in the opposite direction across each piston.
- the provided orifices may be controllably varied in size to provide desired damped bypass flow by selective positioning of the valve plunger in response to command signals dictated by sensed ram conditions, i.e., ram position monitored by position sensors 86 and ram load monitored by load sensors 88.
- Such active or regulated damping control in response to ram load feed-back further may have associated therewith an overload relief function in the damping mode.
- an appropriate command signal may be provided to position the valve plunger 34 at a location providing a desired orifice size sufficient to effect rapid relief of such overload condition in order to prevent damage to the actuator and the controlled element connected thereto.
- bypass flow across the ram 16 may be controlled by utilizing the existing flow metering pattern of the main control servo valve 26 and modulating the valve plunger 34 thereof to provide variable orifices for active damping and overload relief control. It also is noted that such active control is even more desirable in redundant systems as shown. If the ram 16 continues to be operated by high pressure fluid supplied to only one of the servo systems, the other servo system operates to effect by pass of the inactive portion of the ram 16. Therefore, the need in such instance for a separate bypass valve is eliminated by such implementation because the main control valve 26 is operated to permit fluid transfer across the respective piston 48 as in normal operation.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fluid-Pressure Circuits (AREA)
- Servomotors (AREA)
Abstract
Description
- This invention relates generally to servo systems and, more particularly, to aircraft flight control servo systems. More specifically, the invention relates to a servo actuator control/damping mechanism and method which utilize and combine the functions of an electro-mechanically driven servo valve to achieve fluid flow and actuator (ram) load control even after loss of fluid power.
- Fluid servo systems are used for many purposes, one being to position the flight control surfaces of high performance aircraft. In such an application, the servo system desirably should provide for control and damping of flight control surface displacements or flutter after loss of fluid power. Otherwise, aircraft damage or loss of control may result.
- In conventional electro-hydraulic systems, electro-hydraulic valves have been used in conjunction with servo valve actuators to effect position control of the main control servo valve. Typically, the servo actuators in redundant systems operate on opposite ends of a linearly movable valve element in the main control valve and are controlled by the electro-hydraulic valves located elsewhere in the system housing. Such systems also have used bypass/damping valves which operate upon loss of fluid power to bypass flow to and from the main ram or actuator through fixed metering orifices which damp and control the rate of ram and flight surface movements. Like the electro-hydraulic valves, such bypass/damping valves have been located in the system housing remote from the main control valve. In addition, such systems have utilized electronic differential pressure sensors to provide dynamic ram load feed-back information to the aircraft electronic control system which supplies command signals to the electro-hydraulic valves.
- An alternative approach to the electro-hydraulic control system is an electro-mechanical control system wherein a force motor is coupled directly and mechanically to the main control servo valve. These systems also have used remotely located bypass/damping valves which bypass ram flow through fixed metering orifices upon loss of fluid power for damping and controlling the rate of ram and flight surface movements.
- In hybrid electro-mechanical systems, the force motor is coupled directly and mechanically to a pilot valve plunger which controls a hydraulically powered servo valve actuator for driving the main control servo valve. A shut-off valve sleeve concentric with the pilot valve plunger can be used to direct ram flow through fixed metering orifices upon loss of fluid power for damping and rate control of ram and flight surface movements.
- As indicated, each of the foregoing systems uses added valves or valve components to achieve some degree of control over ram and flight surface movements after loss of fluid power. This results in increased package size especially in plural redundant systems where redundant valves or valve components are required for multiple hydraulic actuator systems. Furthermore, such valves or valve components are shuttled between system on and off (bypass) positions with the latter serving to direct actuator flow through the fixed metering orifices. Consequently, there has been no provision for active damping or flutter control in response to changing conditions at the ram or flight control surface. Also ram pressure relief flow through the fixed metering orifices may under some circumstances be insufficient to prevent overload of the ram and flight control surface and resultant damage.
- With the foregoing in mind, it would be advantageous and desirable to provide for active and more precise load and damping control in an aircraft flight control servo system. Furthermore, it would be desirable to provide for such active or regulated control while minimizing system package size such as by attributing multiple functions to servo system components.
- The present invention provides a fluid servo actuator control/ damping mechanism and method which utilize and combine the functions of an electro-mechanically driven servo valve to achieve ram or actuator fluid flow and load control even after loss of fluid power as well as the main ram position control function under normal operating conditions. The mechanism is particularly useful in an aircraft flight control servo system wherein reduced package size and weight is desired along with active or regulated damping control and overload relief functions, and eliminates the need for separate bypass valves or valve components heretofore utilized to meter bypass ram flow through fixed orifices.
- According to the present invention, in one aspect, the mechanism comprises a servo valve including a positionable valve element for selective application of fluid power to a ram, a sensor connectable to the ram for providing ram load feed-back information, and an electro-mechanical drive operable independently of fluid power for selectively positioning the valve element under normal operating conditions for controlled actuation of the ram and, upon loss of fluid power, for providing variable orifices to controllably meter bypass fluid flow across the ram by utilizing the existing metering pattern of the servo valve and modulating the valve element thereof in response to feed-back information received from the sensor, for actively controlled damping of the ram.
- According to another aspect of the invention, a servo mechanism according to the invention comprises a servo valve including a valve element selectively positionable therein to provide variable orifices for metering fluid flow to and from the opposed pressure surfaces of the ram, means for connecting a source of high pressure fluid to the servo valve for metered passage to either ram pressure surface through the variable orifices, means for directing bypass fluid flow from either pressure surface to the other through such variable orifices in the event of a loss of such high pressure fluid, and electro-mechanical drive means operative independently of such high pressure fluid to controllably position the valve element to effect controlled metering of such high pressure fluid to either pressure surface of the ram for controlled actuation thereof and, in the event of a loss of such high pressure fluid, to effect controlled metering of bypass fluid flow across the ram for active or regulated damping and load control.
- An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, in which the sole figure thereof is a schematic illustration of a redundant servo system embodying a preferred form of servo actuator control/damping mechanism according to the invention.
- Referring now in detail to the drawing, a dual hydraulic servo system is designated generally by
reference numeral 10 and includes two similarhydraulic servo actuators actuators ram 16 which in turn may be connected to a control member such as a flight control element of an aircraft. It will be seen below that the two servo actuators normally are operated simultaneously to effect position control of theram 16 and hence the flight control element. However, each servo actuator preferably is capable of properly effecting such position control independently of the other so that the control is maintained even when one of the servo actuators fails or is shut down. Accordingly, the two servo actuators in the overall system provide a redundancy feature that increases safe operation of the aircraft. - The
servo actuators - Each
servo actuator inlet port 20 for connection with a source of high pressure hydraulic fluid and areturn port 22 for connection with a hydraulic reservoir. Preferably, the respective inlet and return ports of the servo actuators are connected to separate and independent hydraulic systems in the aircraft, so that in the event one of the hydraulic systems fails or shuts down, the servo actuator coupled to the other still functioning hydraulic system may be operated to effect the position control function. Hereinafter, the hydraulic systems associated with theservo actuators - In each of the
servo actuators inlet passage 24 connects theinlet port 20 to a common main control servo valve designated generally byreference numeral 26. Eachinlet passage 24 may be provided with asuitable filter 27 and acheck valve 28 which blocks reverse flow through the inlet passage from the servo valve to the inlet port. Each servo actuator also is provided with areturn passage 30 which connects thereturn port 22 to theservo valve 26 via a damping mode accumulator orcompensator 32 which serves to maintain pressure in the servo actuator sufficient to prevent cavitation across damping restrictions during damping mode operation as described hereafter. - The main
control servo valve 26 includes a plunger orspool 34 longitudinally shiftable in acylindrical bore 36 which may be formed by a sleeve (not shown) in an overall system housing. The plunger has two fluidically isolated valving sections indicated generally at 38 and 40, which valving sections are associated respectively with theactuators passages passages passages - The
passages servo actuators ram 16 which includes a pair ofcylinders 46 havingrespective pistons 48 connected toram output rod 50 for common movement therewith. More specifically, thepassages passages respective branch passages 52 and 54 to acommon passage 56 which in turn is connected to thecorresponding return passage 30. As shown, thebranch passages 52 and 54 are respectively provided with anticavitation check valves passages common passage 56 but permit free flow fromcommon passage 56 topassages - With particular reference to the main
control servo valve 26, eachvalving section 38, 40 of theplunger 34 has a pair of longitudinally [axially) spaced apartlands respective metering ports 64 and 66 that respectively connect thepassages lands supply groove 68 which is in communication with theinlet passage 24 and outwardly thereof respective return grooves 70 and 72 which are interconnected bypassage 74 and in common communication withreturn passage 30. Accordingly, movement of the plunger to either side of its neutral position will connect theinlet passage 24 to one of thepassages passage 30 through respective metering orifices defined by the position of thelands respective ports 64 and 66. Moreover, such metering orifices may be varied in size by selective positioning of the valve plunger in the manner hereinafter described for controlled metering of flow to and from thepassages - From the foregoing, it will be apparent that selective movement of the
plunger 34 simultaneously controls both valvingsections 38 and 40 which selectively connect one side of eachpiston 48 to a high pressure hydraulic fluid source and the other side to fluid return for controlled metering of flow to and from theram 16 which in turn effects controlled movement of theoutput rod 50 either to the right or left. In the event one of theservo actuators - Controlled selective movement of the
valve plunger 34 is desirably effected by anelectric force motor 78 which may be located closely adjacent one end of the plunger. The force motor may be of linear or rotary type and operative connection of the force motor to the valve plunger may be obtained by alink member 80 such as in the manner described in the aforementioned U.S. application Serial No. 463,631. - The
force motor 78 is responsive to command signals received from an electronic control or command system indicated at 82 which may be located, for example, in the aircraft cockpit, whereby the force motor serves as a control input to thevalve plunger 34. Also, the force motor preferably has redundant multiple parallel coils so that if one coil or its associated electronics should fail, its counterpart channel or channels will maintain control. Moreover, suitable failure monitoring circuitry is preferably provided to detect when and which channel has failed, and to uncouple or render passive the failed channel. - Feed-back information to the
command system 82 is obtained by position transducers orsensors valve plunger 34 andram output rod 50, respectively. In addition,electronic load sensors 88 or equivalent devices are desirably operatively connected torespective cylinders 46 of theram 16 for monitoring ram load and providing load feed- back information to thecommand system 82 controlling theforce motor 78. As shown, eachload sensor 88 may be in the form of a differential pressure sensor including aposition transducer 92 connected to a longitudinally shiftable springcentered piston 94. Opposite sides or pressure surfaces of thepiston 94 are respectively connected bypassages piston 48 in thecorresponding cylinder 46 of the ram whereby the position of thepiston 94 and corresponding output of the transducer will be indicative of the direction and magnitude of differential pressure forces acting on thepiston 48. - During normal operation of the
servo system 10, high pressure fluid from the forward and aft hydraulic systems is supplied viarespective inlet passages 24 to the maincontrol servo valve 26. Through selective positioning of thevalve plunger 34 in response to command signals received from thecommand system 82, high pressure fluid from each hydraulic system is controllably metered to either side of therespective piston 48 of theram 16 to effect controlled movement of theram output rod 50 with return flow from the opposite side of the piston being simultaneously directed by the valve plunger to return via thepassage 30. Further, eachelectronic load sensor 88 may be used during normal operation to provide dynamic load feed-back information to thecommand system 82 for implementation of damping and over-pressure relief functions in conventional manner. Further, eachelectronic load sensor 88 may be used during normal operation to provide surface hinge moment control and hinge moment limiting. This would allow the servo to become a torque or force servo rather than a positional servo. - Should a loss of hydraulic power occur from both the forward and aft hydraulic systems, the
command system 82 automatically implements damping mode operation. In the damping mode, thecheck valves 28 andcompensators 32 serve to maintain positive pressure in thesystem 10 after such loss of hydraulic power by checking fluid loss through the inlet and returnports - With positive pressure maintained in the system, active or regulated damping control of the
ram 16 is effected by modulating thevalve plunger 34 to provide variable orifices which direct and meter bypass flow across eachram piston 48. In this regard, it is noted that the electro-mechanically drivenservo valve 26 is not dependent on hydraulic power for valve plunger positioning whereby the valve plunger will continue to respond to system commands as long as at least one channel of themotor 78 and associated electronics survives and remains operative. Further, thevalve plunger 34 is modulated in response to ram load feed-back information from theload sensors 88 which monitor the direction and amplitude of differential pressure across thepistons 48. - In an exemplary situation, over pressure existing or developed on the extend (left) side of each
ram piston 48 may be bypassed across the ram to the retract (right) side of each piston by moving thevalve plunger 34 to the right of its neutral position to provide a meteringorifice connecting passage 42 to returnpassage 30. This establishes correspondingly metered bypass flow across each piston, such flow passing throughpassage 42 and the provided orifice to returnpassage 30 which directs the flow to the retract side of the piston viabypass passage 56 and branch passage 54. Conversely, moving the valve plunger to the left of its neutral position will establish and meter bypass flow in the opposite direction across each piston. Moreover, the provided orifices may be controllably varied in size to provide desired damped bypass flow by selective positioning of the valve plunger in response to command signals dictated by sensed ram conditions, i.e., ram position monitored byposition sensors 86 and ram load monitored byload sensors 88. - Such active or regulated damping control in response to ram load feed-back further may have associated therewith an overload relief function in the damping mode. When excessive load on the
ram 16 is sensed by theload sensors 88, an appropriate command signal may be provided to position thevalve plunger 34 at a location providing a desired orifice size sufficient to effect rapid relief of such overload condition in order to prevent damage to the actuator and the controlled element connected thereto. - From the foregoing, it can be seen that bypass flow across the
ram 16 may be controlled by utilizing the existing flow metering pattern of the maincontrol servo valve 26 and modulating thevalve plunger 34 thereof to provide variable orifices for active damping and overload relief control. It also is noted that such active control is even more desirable in redundant systems as shown. If theram 16 continues to be operated by high pressure fluid supplied to only one of the servo systems, the other servo system operates to effect by pass of the inactive portion of theram 16. Therefore, the need in such instance for a separate bypass valve is eliminated by such implementation because themain control valve 26 is operated to permit fluid transfer across therespective piston 48 as in normal operation. - Although the invention has been shown and described with respect to a certain preferred embodiment, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications, and is limited only by the scope of the following claims.
Claims (10)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US52911583A | 1983-09-02 | 1983-09-02 | |
US529115 | 1995-09-15 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0136005A1 true EP0136005A1 (en) | 1985-04-03 |
EP0136005B1 EP0136005B1 (en) | 1988-01-20 |
Family
ID=24108588
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP84305122A Expired EP0136005B1 (en) | 1983-09-02 | 1984-07-27 | Servo actuator control/damping mechanism |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0136005B1 (en) |
JP (1) | JPS6073102A (en) |
CA (1) | CA1210306A (en) |
IL (1) | IL72551A (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7757896B2 (en) | 2006-03-06 | 2010-07-20 | The Coca-Cola Company | Beverage dispensing system |
US7913879B2 (en) | 2006-03-06 | 2011-03-29 | The Coca-Cola Company | Beverage dispensing system |
US8162176B2 (en) | 2007-09-06 | 2012-04-24 | The Coca-Cola Company | Method and apparatuses for providing a selectable beverage |
US8251258B2 (en) | 2007-09-06 | 2012-08-28 | The Coca-Cola Company | Systems and methods of selecting and dispensing products |
US8960500B2 (en) | 2006-03-06 | 2015-02-24 | The Coca-Cola Company | Dispenser for beverages including juices |
US9415992B2 (en) | 2006-03-06 | 2016-08-16 | The Coca-Cola Company | Dispenser for beverages having a rotary micro-ingredient combination chamber |
US9821992B2 (en) | 2006-03-06 | 2017-11-21 | The Coca-Cola Company | Juice dispensing system |
US10280060B2 (en) | 2006-03-06 | 2019-05-07 | The Coca-Cola Company | Dispenser for beverages having an ingredient mixing module |
US10631558B2 (en) | 2006-03-06 | 2020-04-28 | The Coca-Cola Company | Methods and apparatuses for making compositions comprising an acid and an acid degradable component and/or compositions comprising a plurality of selectable components |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6441498A (en) * | 1987-08-07 | 1989-02-13 | Teijin Seiki Co Ltd | Controller for rudder surface |
US8739840B2 (en) | 2010-04-26 | 2014-06-03 | The Coca-Cola Company | Method for managing orders and dispensing beverages |
US8757222B2 (en) | 2010-04-26 | 2014-06-24 | The Coca-Cola Company | Vessel activated beverage dispenser |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2826896A (en) * | 1954-12-17 | 1958-03-18 | Hobson Ltd H M | Manually controlled electro-hydraulic system for aircraft |
US4351357A (en) * | 1981-03-27 | 1982-09-28 | The Bendix Corporation | Fail safe compensator used in a hydraulic servo control system |
-
1984
- 1984-07-18 CA CA000459140A patent/CA1210306A/en not_active Expired
- 1984-07-27 EP EP84305122A patent/EP0136005B1/en not_active Expired
- 1984-07-31 IL IL72551A patent/IL72551A/en unknown
- 1984-08-23 JP JP59174201A patent/JPS6073102A/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2826896A (en) * | 1954-12-17 | 1958-03-18 | Hobson Ltd H M | Manually controlled electro-hydraulic system for aircraft |
US4351357A (en) * | 1981-03-27 | 1982-09-28 | The Bendix Corporation | Fail safe compensator used in a hydraulic servo control system |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9821992B2 (en) | 2006-03-06 | 2017-11-21 | The Coca-Cola Company | Juice dispensing system |
US7913879B2 (en) | 2006-03-06 | 2011-03-29 | The Coca-Cola Company | Beverage dispensing system |
US8162181B2 (en) | 2006-03-06 | 2012-04-24 | The Coca-Cola Company | Beverage dispensing system |
US10631560B2 (en) | 2006-03-06 | 2020-04-28 | The Coca-Cola Company | Methods and apparatuses for making compositions comprising an acid and an acid degradable component and/or compositions comprising a plurality of selectable components |
US7757896B2 (en) | 2006-03-06 | 2010-07-20 | The Coca-Cola Company | Beverage dispensing system |
US10631558B2 (en) | 2006-03-06 | 2020-04-28 | The Coca-Cola Company | Methods and apparatuses for making compositions comprising an acid and an acid degradable component and/or compositions comprising a plurality of selectable components |
US10280060B2 (en) | 2006-03-06 | 2019-05-07 | The Coca-Cola Company | Dispenser for beverages having an ingredient mixing module |
US10029904B2 (en) | 2006-03-06 | 2018-07-24 | The Coca-Cola Company | Beverage dispensing system |
US8960500B2 (en) | 2006-03-06 | 2015-02-24 | The Coca-Cola Company | Dispenser for beverages including juices |
US9415992B2 (en) | 2006-03-06 | 2016-08-16 | The Coca-Cola Company | Dispenser for beverages having a rotary micro-ingredient combination chamber |
US8251258B2 (en) | 2007-09-06 | 2012-08-28 | The Coca-Cola Company | Systems and methods of selecting and dispensing products |
US8851329B2 (en) | 2007-09-06 | 2014-10-07 | The Coca-Cola Company | Systems and methods of selecting and dispensing products |
US10046959B2 (en) | 2007-09-06 | 2018-08-14 | The Coca-Cola Company | Method and apparatuses for providing a selectable beverage |
US8814000B2 (en) | 2007-09-06 | 2014-08-26 | The Coca-Cola Company | Method and apparatuses for providing a selectable beverage |
US8434642B2 (en) | 2007-09-06 | 2013-05-07 | The Coca-Cola Company | Method and apparatus for providing a selectable beverage |
US8162176B2 (en) | 2007-09-06 | 2012-04-24 | The Coca-Cola Company | Method and apparatuses for providing a selectable beverage |
Also Published As
Publication number | Publication date |
---|---|
IL72551A (en) | 1989-02-28 |
EP0136005B1 (en) | 1988-01-20 |
CA1210306A (en) | 1986-08-26 |
IL72551A0 (en) | 1984-11-30 |
JPS6073102A (en) | 1985-04-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7200993B2 (en) | Electro-hydraulic steering control system | |
US4201052A (en) | Power transmission | |
EP0136005B1 (en) | Servo actuator control/damping mechanism | |
EP0251172B1 (en) | Hydraulic control system | |
US4407122A (en) | Power transmission | |
WO1996027051B1 (en) | Electrohydraulic proportional control valve assemblies | |
EP3514394A1 (en) | Pressure compensated hydraulic system having differential pressure control | |
EP1504195B1 (en) | Integrated three function valve | |
US4555974A (en) | Servo actuator control/damping mechanism and method | |
US5615593A (en) | Method and apparatus for controllably positioning a hydraulic actuator | |
US4611528A (en) | Power transmission | |
US4472998A (en) | Redundant control actuation system-concentric direct drive valve | |
US4437388A (en) | Dual input pressure compensated fluid control valve | |
US4753157A (en) | Power transmission | |
US4521060A (en) | Hydraulic asymmetry detector | |
US5020322A (en) | Accumulator blow-back hydraulic circuit | |
US4534273A (en) | Control actuation system including staged direct drive valve with fault control | |
US3580139A (en) | Control apparatus | |
EP0276221A4 (en) | Compensated fluid flow control valve. | |
EP0080135B1 (en) | Hydraulic control system for a hydraulic actuator | |
RU2484314C2 (en) | Two-mode electrically-driven hydraulic drive with irreversible pump | |
JP2667880B2 (en) | Hydraulic control system | |
US20020121086A1 (en) | Hydraulic logic cross-coupling between physically-separate redundant servoactuators | |
EP0276222B1 (en) | Compensated fluid flow control valve | |
CA1203145A (en) | Control actuation system including staged direct drive valve with fault control |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Designated state(s): FR GB SE |
|
17P | Request for examination filed |
Effective date: 19850924 |
|
17Q | First examination report despatched |
Effective date: 19861103 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: PNEUMO ABEX CORPORATION |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): FR GB SE |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19880131 |
|
ET | Fr: translation filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19890727 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19900330 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |