JP2000234601A - Servo actuator - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a redundant electro-hydraulic servo actuator suitable for fail-safe. A redundant control system is provided with a logical cross-coupling between independent servo actuators (101A, 101B), each of which has a hydraulic actuator (106).
A, 106B, and control valves 102A, 102B.
B is a logical valve device 103A, B; 104A, B;
5A and 5B are linked, a hydraulic pressure input signal and an electrical input signal are input to a logic valve device, and a mode in which the actuator operates or operates freely in response to a control signal or independently of the control signal, In a mode in which the movement of the load is suppressed as a function of the hydraulic and electrical signals input to the valve, it can be operated appropriately, and the logic valve device emits a hydraulic output signal, which becomes the input signal of another actuator. Configured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a servo actuator for moving a load in response to a control signal, and more particularly to a servo actuator whose output is connected to a common load. An improved redundant control operating system is cross-linked to exchange hydraulic logic information between them.

[0002]

2. Description of the Related Art Modern "fly-by-wire"("FB")
W ") aircraft use hydraulic power-electrically controlled dual redundant servo actuators to activate control wing surfaces and, more recently, thrust vectoring control of the engine. Many, especially designed for military aircraft, employ tandem piston actuators integrated into a single mechanical package, which may include one or more integrated electrical fluids. Redundant servo valves have the redundancy to supply pressurized hydraulic fluids independently, whereas in commercial aircraft, redundant servo actuators are physically independent of each other. And it is generally desired that the independent pressure source and fluid return tube be individually connected to each other.

In each case, these redundant servo actuators typically operate cooperatively in either an active-active mode or an active-standby mode. In particular,
The servo valves are typically connected to respective actuators, and a logic valve is provided for each servo actuator to allow operation in three different modes of operation. The first of these modes is active control, where a servo valve is used to actively control fluid flow with respect to the associated actuator. The second mode is known as the free bypass mode, in which the actuator is substantially separated (ie, "feathered") from its associated servo valve (e.g., its control element or power supply). Another actuator allows the load to continue to be controlled and operated (e.g., because the supply has failed or is in standby mode). The third mode is known as a fail-safe mode, in which the servo valve is disconnected from the associated actuator and the chambers on either side of the disconnected actuator are in communication with each other via a constraining orifice. In addition, the load fluctuation can be maintained.

[0004]

Previous cross-coupling techniques for redundant servo actuators have been performed through the exchange of electrical and / or hydraulic signals. Generally, these prior art devices incorporate a pilot-operated solenoid valve and a fail-safe valve to switch modes in response to certain conditions. Certain devices also employ a bypass valve connected to a failsafe valve. These prior art systems have been employed based on information and belief in compromising weight, size, or cost characteristics.

Accordingly, it is generally desirable to provide an improved redundant control operating system and servo actuators for use therein without compromising the prior art.

[0006]

Means for Solving the Problems Parts, parts or surfaces in the embodiment shown in FIG. 4 will be described, but these are merely for the purpose of explanation of the invention,
It is not to limit the invention. The present invention broadly provides an improved servo actuator 101A for use in the redundant control operating system 100, and an improved redundant control operating system employing such a servo actuator.

[0007] The improved servo actuator is arranged to provide a hydraulic output in response to a control signal and to move a load in response to the hydraulic output from the control valve. Hydraulic actuator 106
A and logic valves 103A, 104A, 105A operatively associated with the control valves and actuators and adapted to receive hydraulic and electrical input signals. The logic valve device is operatively disposed between the control valve and an actuator, and (a) enables the control operation of the actuator in response to the control signal; and (b) freely and controls the actuator. Allowing movement independent of the signal, or (c) suppressing movement of the load independently of the control signal. These selection modes are a function of the supplied hydraulic and electrical input signals. Furthermore, the logic valve arrangement is characterized in that it is arranged to provide a hydraulic output signal.

[0008] The improved redundant control operation system 100 comprises:
First and second servo actuators 101A, 101
1B, wherein each of the servo actuators is arranged to provide a hydraulic output in response to the control signal and a load in response to a hydraulic output from the associated control valve. Actuators 106A, 106B arranged to move the valve and a logic valve device 103 operatively associated with the control valve and actuator
A, 104A, 105A, 103B, 104B, 105
B. The logic valve device is supplied with hydraulic and electrical input signals. The logic valve device is operatively disposed between the associated control valve and an actuator, (a) enabling control operation of the actuator in response to the control signal, (b) freely controlling the actuator, and Allowing movement independent of the control signal, or (c) suppressing or preventing movement of the load independent of the control signal. These selected modes are functions of the input signal. The logic valving of each servo actuator is arranged to provide a hydraulic output signal. The hydraulic output signal of one servo actuator is provided to another servo actuator as a hydraulic input signal.

In a preferred embodiment, each control valve 1
02A and 102B are electrohydraulic servo valves, and these two servo valves are the same.

Each servo actuator 101A, 1
01B is further arranged to selectively communicate with the chambers on both sides of the associated actuator when the logic valve device moves the actuator freely and independently of the control signal. Are provided. Each servo actuator further comprises a second flow path having a constrained orifice 115A, 115B, wherein when the logic valve device causes the actuator to suppress the movement of the load independent of the control signal. A second flow path is arranged to selectively communicate with chambers on both sides of the actuator.

The logic valve device includes a bypass valve 104A, 104B and a fail-safe valve 10 hydraulically connected between the associated control valve and the associated actuator.
5A and 105B. The bypass valve is free between a first position where fluid can flow between the associated control valve and the actuator and a chamber where fluid cannot flow between them and both sides of the associated actuator. To a second position which can be bypassed (i.e., without intentional fluid constraint). The bypass valve may be pushed toward the second position. The bypass valve has a valve spool 110A, 1A, 1
10B, and further comprising springs 111A, 1 1B operably disposed to move the spool toward the second position.
11B. The spool may be moved toward the first position by fluid pressure.

The servo actuator further comprises a source of pressurized fluid (P _S1 ) and solenoid valves 103A and 103B operatively disposed between the source and the bypass valve, wherein the solenoid valves include When the solenoid valve is energized by communication with a source and the electrical input signal, pressurized fluid from the source causes spool 110A, 1
10B is moved toward the first position to provide the hydraulic output signal.

The fail-safe valves 105A and 105B
May move between an open position where fluid can flow between the associated bypass valve and the actuator and a closed position where fluid cannot flow between the associated bypass valve and the actuator. it can. The failsafe valve may be biased toward its closed position.
The fail-safe valve further includes a valve spool 112A, 112B mounted for sliding sliding within the body.
A spring 113A operatively arranged to move the spool of the fail-safe valve toward the closed position;
113B, wherein the servo actuator is provided with a fluid pressure as the hydraulic pressure input signal, and may bias the spool of the fail-safe valve toward the open position. .

Accordingly, it is an object of the present invention to provide an improved servo actuator for use in a redundant control operating system.

It is another object of the present invention to provide an improved redundant control operation system employing two such servo actuators.

It is yet another object of the present invention to provide an improved redundant control operating system employing hydraulic logic cross-linking between separate redundant servo actuators.

These and other objects and advantages are:
It will be evident from the description as-is, the description which is now underway, the drawings and the appended claims.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, like reference numerals are used to denote the same structural element, part, or surface throughout the several accompanying drawings, and such elements, parts, or surfaces are referred to by the same reference numerals. This will be described in detail in the specification including this detailed description. Unless otherwise noted, the drawings capture the description of the specification (eg, cross-section lines, component placement, ratios, degrees, etc.). That is, the drawings should be considered as part of the overall description of the invention. As used in the following description, "horizontal", "vertical", "left",
The terms “right,” “up,” and “down” as well as their adjective and adverb terms (eg, “horizontally”, “right”, “up”, etc.) Simply indicates the orientation of the described structure when facing the reader. Similarly, the terms "inward" and "outward" generally refer to the orientation of a surface with respect to its axis or longitudinal or rotational axis.

The present invention generally provides an improved servo actuator for use in a redundant control operation system, and a redundant control operation system employing such an improved servo actuator.
However, before discussing the improvements according to the present invention,
In order to better understand the significance of the present invention, it may be appropriate to review three embodiments of prior art servo actuators and redundant control operating systems incorporating the same.

[0020]

FIG. 1 shows a first prior art example (FIG. 1).
The conventional redundant control operation system according to
Indicated by This control system generally has two servo actuators. The servo actuator on the left is shown as servo actuator 21A,
The servo actuator on the right is servo actuator 2
1B. When used here,
The suffix “A” indicates a part, part, or surface of the left servo actuator 21A, and the suffix “B” indicates a corresponding part, part, or surface of the right servo actuator 21B. The two servo actuators are mirror images of each other and are connected by a common tandem piston actuator, generally indicated at 22.

The actuator 22 is shown having two axially spaced pistons 23A, 23B mounted on a common rod 24.
The left piston 23A is mounted for sliding sliding in the left cylinder 25A, and the right piston 23B is mounted for sliding sliding in the right cylinder 25B. The two servo actuators are mirror images of each other except as described herein. Therefore,
Although only the left servo actuator 21A will be specifically described, the corresponding reference numerals with the suffix "B" instead of "A" indicate corresponding parts, portions, or surfaces of the right servo actuator 21B. Is shown.

The servo actuator 21A includes a two-stage four-way electrohydraulic servo valve generally indicated by 26A,
It is shown to include a bypass valve 28A, a failsafe valve 29A, and a pilot solenoid valve 30A.

The servo valve 26A is supplied with a pressurized hydraulic fluid (P _s1 ) from a suitable liquid source (not shown) and is arranged so as to be connected to a _first liquid return pipe (R ₁ ). ing.
The servo valve 26A is, for example, disclosed in U.S. Pat. No. 3,023,
782, the entire disclosure of which is referenced. It is sufficient to explain that this servovalve is known and consists of an electrical part 31A and a hydraulic part 32A. This type of servo valve produces a differential pressure output at outlet holes (C ₁ ), (C ₂ ) proportional to the input electrical signal supplied via lead 33A to the electrical portion of the servo valve. Used for

The bypass valve 28A is shown having a three-valve valve spool 34A mounted for sealing sliding within the cylinder. The spool is biased leftward to the position shown by a spring 35A in the right spool end chamber.

The fail-safe valve 29A is shown as having a three-valve valve spool 36A mounted for sealing sliding within a valve body or chamber. The spool is biased to the left by a spring 38A in the right spool end chamber. An actuator piston 39A is operatively disposed within the cylinder and has a stub shaft disposed leaning against the left end of the spool 36A.

The solenoid valve 30A is also arranged so that pressurized fluid is supplied from a liquid source (P _S1 ) and connected to a return pipe (R ₁ ). The solenoid valve 30A is a conventional three-way two-position solenoid valve. When the solenoid is off (as shown), line 40
A communicates with the return pipe (R ₁ ). When the excitation current (i ₁ ) is supplied to the solenoid, the pressurized fluid from the liquid source (P _S1 ) is supplied to the pipe 40A, and the fail-safe valve (29B)
Supplied to the right spool end chamber. Conversely, another pipe 40B connects the solenoid valve 30B with the left spool end chamber of the actuator piston 39A.

The state shown in FIG. 1 is a state of no pressure and no excitation.

When this system is excited and pressurized, the supply pressures (P _S1 ) and (P _S2 ) are applied to the servo actuators 21A and 21B as shown. Similarly, the return holes communicate with independent fluid return pipes (R ₁ ) and (R ₂ ). Outlet holes (C ₁ ) for each servo valve,
At (C ₂ ), an electrical liquid differential pressure is generated according to the electrical signal applied to the associated servo valve.

The solenoid valves 30A and 30B are excited by currents (i ₁ ) and (i ₂ ), respectively. Therefore, the supply pressure (P _S1 ) is applied to the pipe 40A and is applied to the right end chamber of the piston 39B. This pressure causes the spool 36B of the fail-safe valve to move to the left, compressing the spring 38B. Conversely, the supply pressure ( _PS2 )
Is added to the pipe 40B and is added to the left end chamber of the piston 39A to move the spool 36A of the fail-safe valve to the right and compress the spring 38A. When the spools of the two fail-safe valves are moved by the supply pressures of the other servo actuators, respectively, 41A
A pipe having several constraining orifices indicated by is closed. Such excitation and force move the spool of each failsafe valve, where the bias force exceeds the opposing biasing force of the springs 38A, 38B, from the associated bypass valve, through the associated failsafe valve, and on both sides of the associated actuator. Unrestricted fluid can flow through the chamber.

The supply pressure is also supplied to the left spool end chamber of each bypass valve. As a result, the spool of each bypass valve is moved, and the springs 35A,
35B is compressed. When the spool of each bypass valve is moved, the outlet holes (C ₁ ) and (C ₂ ) of the servo valve are
Via the spool of the moved bypass valve and the fail-safe valve, it is selectively communicated with the actuator chambers on both sides.

The control system 20 shown in FIG.
It operates in one of two modes. An active-active mode in which both servo valves operate simultaneously to control fluid flow for each actuator chamber; one servo valve controls actuator movement and the other servo valve "feathers". An active-free bypass mode in which the actuators are in a state (i.e., the chambers on both sides of the associated actuator are in communication with each other without intentional fluid constraint), and both actuators do not control the actuator and the actuator rod There are three modes, a fail-safe mode that controls and resists the movement of the robot.

As described above, when both servo actuators are pressurized and excited, the spool of the bypass valve and the spool of the fail-safe valve are moved to their respective movement positions. Thus, each servo valve is directly connected to a chamber on either side of the associated actuator piston. Thus, when both servo actuators are normally pressurized and excited, the device operates in an active-active mode.

Next, in the servo actuator (B),
It is assumed that an excitation or pressurization failure has occurred. Either
The solenoid valve 30B is in another position.
And the pipe 40B is returned to the return pipe (R_TwoCommunicate with
You. Spool end chamber on right side of bypass valve 34B
And the spool end chain on the right side of the fail-safe valve 29B.
The bars are both return pipes (R_Two )
You. Therefore, the bypass valve 28B is in the moving state or the excitation state.
It will return from the state to the position shown in FIG.
U. However, in this example, the servo actuator
Eta (A) is still active (ie, still
In the excited and pressurized state) and the supply pressure (P _S1)
Is the right end of the fail-safe valve 29B via the pipe 40A.
Has been added to the member. Therefore, this
Spool 36B of the valve safe valve has been moved to the left
Will. Therefore, the chains on both sides of the right actuator
Bar passes through bypass valve 28B and fail-safe valve 29B
And the spools are still transferred
It has been moved. In other words, the actuator on the right
The chambers on both sides of the pump are communicated through a series of communication passages.
So the rightmost actuator is feathered
It is in a state. Therefore, the actuator is free to
You will be able to move, but the only resistance in that case is
Pressure for flowing a fluid in the communication passage. This
As shown in the above, there is a failure in pressurizing or exciting the servo valve (B).
If this occurs, the actuator is controlled by servo actuation.
Servo actuator (A)
(B) is "free bypass" or "featherine"
Mode ”. Of course, servo actuator
(A) becomes non-pressurized or non-excited,
When the robot actuator (B) continues to operate,
Is just the opposite.

Alternatively, if the pressurization and / or excitation of both servo actuators fails, the solenoid valves 30A, 30B are connected to the pipes 40A, 40B.
To the return pipes (R ₁ ) and (R ₂ ), respectively. Thus, the springs of the bypass valve and the fail-safe valve are both extended, causing the spools of each valve to move from FIG.
To return to the position shown in. In this state, the chambers on both sides of both actuators communicate with the respective fluid return pipes via the pipe passages provided with the respective restriction orifices 41A and 41B. Thus, in this third fail-safe mode, none of the servo valves will control the load, but the passage with the constrained orifices will allow the chambers on either side of the actuator to communicate with their respective return pipes. Although load variation is not controlled, this restraint of the load prevents the load from "fluttering" or becoming another form of dynamic instability.

Thus, this first embodiment provides three modes of operation. However, one drawback of this device was that it generally employed a tandem piston actuator in one common body. This was suitable for some purposes, but not for others.

[0036]

Second Prior Art Example (FIG. 2) FIG. 2 illustrates another prior art redundant control operation system, generally indicated at 50. FIG. Again, the system included a left servo actuator 51A and a right servo actuator 51B. These two servo actuators are arranged mirror-image with each other. Again,
Although only the left servo actuator will be described, it will be appreciated that the same reference numerals with the suffix "B" indicate corresponding parts, portions, or surfaces of the right servo actuator.

Each servo actuator has a respective separate actuator coupled to a common load 52. Another difference is that, as described below, a dump bypass valve operated by a solenoid is provided, and a fail-safe valve is omitted. The servo actuator 51A has a two-stage electro-hydraulic servo valve 53A, which also comprises an electric part and a hydraulic part. The servo valve may also be of the type shown and described in U.S. Pat. No. 3,023,782. Or,
Other types of servo valves may be employed. The servo valve 53A is supplied with a pressurized fluid (P _S1 ) from a liquid source, and communicates with a fluid return pipe (R ₁ ). The servo valve 51A also has a pilot solenoid valve 54A, a dump bypass valve 55A, and an actuator 56A. The solenoid valve 54
A is a solenoid operated valve in two positions in three directions, and the current (i
₁ ) to be excited. When the solenoid valve 54A is de-energized, the pipe 58A communicates with the fluid return pipe (R ₁ ). When the solenoid valve 54A is excited, the supply pressure (P _S1 ) is applied to the pipe 59A.
Similarly, when the solenoid valve 54B is de-energized, the pipe 5
8B communicates with the return pipe (R ₂ ). Solenoid valve 54
When B is excited, the supply pressure (P _S2 ) is applied to the pipe 58B.

The bypass valve 55A is shown as having a three-land valve spool 59A mounted for sliding sliding within the body. A spring 60A presses the spool 59A leftward to the position shown.

To prevent the exchange of logic information between two independent servo actuators, the system shown in FIG. 2 was operated in an active-standby mode. In other words, when one servo actuator is energized and pressurized, the other servo actuator is not. Therefore, for example, if the servo actuator 51A is pressurized and excited, the supply pressure (P _S1 ) is applied to the pipe 58A to move the spool 59A of the bypass valve to the right and compress the spring 60A. . This allows the control hole (C ₁ ) of the servo valve,
Fluid communication occurred between (C ₂ ) and the chambers on both sides of the actuator 56A. If servo actuator 5
When 1A is used to control load exercise,
The servo actuator 51B is normally depressurized and turned off, and its various components are in the state shown in FIG. In other words, the spring 60B extended and pressed the spool 59B of the bypass valve to the right. Therefore,
Fluid was able to flow with respect to the other opposing chamber of actuator 56B via constrained orifices, indicated in several places by 61B. Thus, with these constrained orifices, when one system is active, the other system will not operate and the inactive servo actuator will add additional dead weight, which is And moved the load 52. Thus, the servoactuator was manufactured oversized to handle this additional weight, and this unnecessary dimension was both a property and an expense.

If the servo actuator 51A fails due to pressure reduction or off, the servo actuator 51B is immediately pressurized and excited. When the servo actuator 51A failed, the spring 60A expanded and moved the spool 59A of the bypass valve to the position shown in FIG. 2, and at the same time, the servo actuator 51B was excited and pressurized.
Therefore, the state was reversed as described above, the servo actuator 51B controlled the movement of the load, and the servo actuator 51A switched to the dump bypass mode.

Alternatively, if both servo actuators fail due to pressure reduction or de-excitation, the spools of both bypass valves will move to the positions shown in FIG. Therefore, thereafter, neither servo actuator can actively control the load, and the orifices 61A,
61B will be a resistance to prevent dynamic instability of the load.

[0042]

Third Prior Art Example (FIG. 3) FIG. 3 shows a third prior art device, generally indicated at 70, which also includes hydraulic logic between servo actuators 71A, 71B. Was preventing the exchange of information. This system also has two independent servo actuators 71A, 7A
1B. Again, both servo actuators were mirror images of each other. Therefore, only the left servo actuator will be described, but corresponding parts, portions or surfaces of the right servo actuator are indicated by the same reference numerals with the suffix "B".

The servo actuator 71A is of an electrohydraulic type.
Servo valve 72A, bypass valve 73A, 2-position solenoid
The operation is controlled by the operation of the solenoid valve 74A and the solenoid 76A.
Controlled fail-safe valve 75A. Said
The solenoid valve 74A has a current (i ₁As excited by
Had become. Conversely, the solenoid valve 74B applies the current (i _Two)
Was to be excited. The solenoid
Valve 76A is the sum of two independent currents (i₁+ I_Two)
Therefore, it is excited, and the solenoid valve 76B also has two two
Sum of independent currents (i₁+ I_TwoExcited by
I was supposed to. Two actuators 78A, 7
8B is connected to a common load 79.

Again, the electrohydraulic servo valve 72
A is a two-stage, four-way servo valve shown in U.S. Pat. No. 3,023,782, which is supplied with a supply pressure (P _S1 ), which is connected to a fluid return pipe (R ₁ ). The liquid differential pressure is selectively generated in the communication or in the control holes (C ₁ ) and (C ₂ ).

When the solenoid valve 74A is excited, a supply pressure (P _S1 ) is generated in the pipe 79A.

Conversely, if the solenoid valve 74A is de-energized, the pipe 79A will communicate with the return pipe (R ₁ ).

The bypass valve 73A is shown as having a valve spool 80A with three protrusions mounted for sealing sliding within the body. The valve spool is pressed to the left with respect to the body by a spring 81A. The pipe 79A communicates with the left spool end chamber.

The failsafe valve 75A is also shown having a three land valve spool 82A mounted for sliding sliding within the body. The spring 83A urges the spool 82A to move leftward toward the position shown. When solenoid 76A is energized, spool 82A will compress spring 83A and move to the right.

This redundant control operation system mainly operates in an active-active mode. Normally, both servo actuators will be energized and pressurized. Accordingly, each ethical valve spool will be moved in the appropriate direction against the force of its associated spring. Thus, each servo valve will be in direct communication with its associated actuator.

If servo actuator 71A fails to pressurize, spring 81A will expand and move spool 80A of the bypass valve to the position shown in FIG. However, since both servo actuators are still energized, the two total energizing currents (i ₁ + i ₂ ) will still keep the valve spool 82A moved to the right. Therefore, in this device, the servo actuator 71A was depressurized, but if not turned off, the chambers on both sides of the actuator 78A could communicate with the return pipe. In effect, when servo actuator 71A is depressurized, actuator 78A will switch to free-by-pass mode, while servo actuator (B) will remain in active mode and control the load fluctuation.

Alternatively, if the servo valve (A) is turned off (not reduced pressure), the current (i ₁ ) disappears. As a result, the solenoid valve 74A is moved to its non-excited position. The spring 81A extends and the valve spool 80A
Will be moved to the left towards the position shown. However, even if the current (i ₁ ) disappears, the current (i ₂ ) from the servo actuator 71B which is still excited is not enough to hold the spool 82A of the fail-safe valve in the position where it has moved to the right. It is enough. Therefore, in this state, the servo actuator (A) is in the free bypass mode.

Alternatively, if both servo actuators fail electrically or hydraulically, the current (i ₁ )
And (i ₂ ) are eliminated from the solenoids 76A and 76B,
The fail-safe valve springs 83A, 83B are extended to move the fail-safe valves 82A, 82B to the positions shown in FIG. 3, respectively. In this state,
Both actuators will switch to dump bypass mode and the flow for the actuator chamber will be allowed to pass through the constraining orifices 84A, 84B.

[0053]

Improved Control System (FIG. 4) A redundant control operating system according to the present invention is shown generally at 100 in FIG. The device also has two independent servo actuators, with the servo actuator 101 on the left.
A is shown, and the right side is shown as servo actuator 101B. Again, these two servo actuators are substantially mirror images of each other, and the suffixes "A" and "B" are used to distinguish corresponding parts, portions, or surfaces of the two systems. The servo actuator 101A is shown as having an electro-hydraulic servo valve 102A to which a supply pressure (P _S1 ) can be applied, the supply pressure communicating with a return pipe (R ₁ ) or a respective outlet. The liquid differential pressure is provided in the holes (C ₁ ) and (C ₂ ). The servo actuator 101A also includes a solenoid valve 103A, a bypass valve 104A, a fail-safe valve 105A, and an actuator 106A. The two actuators are connected to a common load 108. Piping 109
A is an outlet of the solenoid valve 103A and a bypass valve 104.
A is connected to the left spool end chamber. When the solenoid valve 103A is energized by the current (i ₁ ), the supply pressure will be present in the pipe 109A and will overcome the biasing force of the spring 111A and move the spool 110A of the bypass valve to the right. . Conversely, when the solenoid valve 103A is de-energized, the pipe 109A communicates with the return pipe (R ₁ ). In this state, the spring 11
1A extends to move the spool 110A of the bypass valve leftward toward the position shown.

The failsafe valve 105A is shown as having a valve spool 112A with three lands mounted for sliding sliding within the body. The spring 113A urges the valve spool 112A to move rightward toward the position shown. The actuator 114A has a piston 115A arranged to act on the right end of the valve spool 112A of the fail-safe valve. The actuator 114A
To the right end chamber via piping 116B
Internal pressure is applied. Conversely, the pressure in pipe 109A is applied by pipe 118 to the left end chamber of actuator 114B. The left chamber of actuator 114A and the right chamber of actuator 114B are vented to atmosphere.

Therefore, the servo actuator 101A
When pressurized and excited, the supply pressure (P _S1) Is the pipe 109A
And 118, the spool 110A of the bypass valve is
Will move towards you. Conversely, in the pipe 109B
The pressure is applied to the right side of the actuator 114A by the pipe 116.
Spool of the fail-safe valve transmitted to the end chamber
To the left. Conversely, the pressure in the pipe 109A is
Left end chain of actuator 114B via tube 118
Transmitted to the bar, the spool 112B of the fail-safe valve
Is moved rightward from the illustrated position. Therefore, both
When the servo actuator is excited and pressurized, bypass
Fig. 4 shows the valve spool and the fail-safe valve spool.
Are moved from the position shown in
Therefore, the control of each actuator is related to the servo valve
Will be done by.

If solenoid 103A is turned off and solenoid 103B is energized, tubing 109A will communicate with the return tubing. Accordingly, the spool 110A of the bypass valve will move leftward to the position shown. This will separate servo valve 102A from actuator 106A. However,
The chambers on either side of the actuator 106A will be in communication with the return tube. In this regard, it should be noted that the pressurization signal from tubing 109B is transmitted via tubing 116 to attempt to move spool 112A of the failsafe valve to the left. As a result, the actuator 106A is operated in the free bypass mode.

Alternatively, if the servo actuator (A) fails in pressure reduction (not off), the piping 109
The pressure in A will again be exhausted to the return line (R ₁ ). The spring 111A is extended, and the spool 11 of the bypass valve is extended.
OA will be pushed to move it to the position shown in FIG. However, the pressure of the still functioning servo actuator 101B is transmitted to the rightmost chamber of the actuator 114A via piping 116,
The failsafe valve spool 112A will be held in the leftward movement position. Therefore, in this state,
The chambers on either side of the actuator 106A will be in communication with the return tube.

Alternatively, if both servo actuators are depressurized and / or off,
09A and 109B are return pipes (R ₁ ) and (R ₂ ), respectively.
Will communicate with Thus, the spool of the bypass valve will return to the position shown in FIG. Conversely, piping 109
A, loss of supply pressure in 109B is
Through the spool 113 of the fail-safe valve
A, 113B will extend to move each valve spool to the position shown. In this state,
The chambers on both sides of the actuator 106A communicate with the return pipe (R ₁ ) via restraining orifices 115A, 115A, while the chambers on both sides of the actuator 106B communicate with the return pipe (R ₂ ) via restraining orifices 115B, 115B. Will do.

Therefore, in summary, in the present invention shown in FIG. 4, the two servo actuators may operate simultaneously or independently. In other words, both servo actuators control the movement of the load,
It may be individually pressurized and excited. Or just one
Only one servo actuator will be pressurized and excited, and preferably the other servo actuator will be in standby mode. Therefore, if the improved device is initially operating in active-active mode and any servo actuator experiences a pressurization failure or an excitation failure, the failed servo actuator will immediately be in free bypass mode or stand-by mode. Moving to bi-mode, the non-failed servo actuator will continue to control the load. Alternatively, if both servo valves fail, both servo actuators will go into tamping bypass mode and free fluctuations in load will be suppressed as fluid passes through the constrained orifices.

[0060]

Modifications It is believed that the present invention is capable of many changes and modifications. For example, servo valves are disclosed in U.S. Pat.
The two-stage four-way electrohydraulic servo valve shown and described at 82 may be used. Alternatively, another type of servo valve may be used. In the aviation industry, it is desirable that the pressure sources (P _S1 ) and (P _S2 ) be independent of each other. However, while this is desirable, it is not critical to the operation of the present invention. Therefore, the fluid source (P
_S1 ) and ( _Ps2 ) may be independent of each other or may be made of a common source. Similarly, the return pipes (R ₁ ) and (R ₂ ) may be connected to a common return pipe or may be totally independent of each other. The bypass valve and the failsafe valve may be repositioned at a position between the control valve and the actuator,
It will still perform the same function. The bypass and failsafe valves may be spool-type valves as disclosed, but may be of other types or shapes. Similarly, the solenoid valve may be a pilot type poppet valve or a spool valve. They may be integral with the bypass valve or the bypass function may be integrated with the control valve.

Accordingly, while the preferred embodiment of the redundant control operation system of the present invention has been shown and described, and several modifications thereof have been discussed, those skilled in the art will appreciate that It will be readily appreciated that various additional changes and modifications may be made without departing from the spirit of the invention as distinguished.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a first prior art redundant control operation system with two integrated servo actuators coupled to a common load.

FIG. 2 is a schematic diagram of a second prior art redundant control operation system with two physically independent servo actuators coupled to a common load.

FIG. 3 is a schematic diagram of a third prior art redundant control operating system with two physically independent servo actuators coupled to a common load.

FIG. 4 is a schematic diagram of an improved redundant control operating system according to the present invention, which illustrates a hydraulic ethical cross-coupling between physically independent redundant servo actuators coupled to a common load. providing.

[Explanation of symbols]

100 Redundant control operation system 101A, 101B Servo actuator 102A, 102B Control valve 103A, 104A, 105A, 103B, 104B,
105B Logic valve device 103A, 103B Solenoid valve 105A, 105B Fail safe valve 106A, 106B Actuator 108 Load 110A, 110B Bypass valve spool 111A, 111B Spring 112A, 112B Fail safe valve spool 113A, 113B Spring 115A, 115B Restricted orifice

Claims (21)

[Claims] 1. A servo actuator for use in a redundant control operation system, comprising: a control valve arranged to provide a hydraulic output in response to a control signal; and a load in response to a hydraulic output from the control valve. A hydraulic actuator arranged to move; and a logic valve operatively associated with the control valve and actuator and adapted to receive hydraulic and electrical input signals. A valve device is operatively disposed between the control valve and the actuator, (a) enabling control of the actuator in response to the control signal, and (b) freely controlling the actuator with the control signal. Allows the movement of the load independent of the control signal as a function of the supplied input signal; and Servo actuator, characterized in that the valve device is arranged to provide a hydraulic output signal. 2. The servo actuator according to claim 1, wherein said control valve is an electrohydraulic servo valve. 3. An arrangement for selectively communicating with the chambers on both sides of the actuator when the logic valve device is allowed to move freely with the actuator and independently of the control signal. The servo actuator according to claim 1, further comprising a first flow path formed. And a second flow path having a constrained orifice, wherein the logic valve device causes the actuator to suppress the fluctuation of the load independently of the control signal. A flow path arranged to selectively communicate with the chambers on both sides of the actuator;
The servo actuator according to claim 3. 5. The logic device according to claim 1, wherein the logic valve device has a bypass valve and a fail-safe valve hydraulically connected between the control valve and the actuator. Servo actuator. 6. The bypass valve has a first position in which fluid can flow between the control valve and the actuator, and fluid cannot flow between the control valve and the actuator, but the fluid flows between the control valve and the actuator. The actuator of claim 1 wherein said bypass valve is movable toward and between said second position and said bypass valve is biased toward said second position. Range 5
The servo actuator according to the item. 7. The bypass valve includes a valve spool mounted for sliding sliding within the body, a spring operatively disposed to move the spool of the bypass valve to the second position. 7. The servo actuator of claim 6, wherein fluid pressure is selectively applied to move the spool of the bypass valve to the first position. And a source of pressurized fluid and a solenoid valve operatively disposed between the source and the bypass valve, the solenoid valve communicating with the source, and the electrical input signal. 7. The system of claim 7, wherein when the solenoid valve is energized, pressurized fluid from the source moves the spool of the bypass valve toward the first position to provide the hydraulic output signal. The servo actuator according to the item. 9. The valve according to claim 6, wherein the fail-safe valve has an open position where fluid can flow between the bypass valve and the actuator, and a closed position where fluid cannot flow between the bypass valve and the actuator. 6. The servo actuator of claim 5, wherein the servo valve is movable between the closed position and the fail safe valve is pressed to the closed position. 10. A valve spool mounted such that the fail-safe valve hermetically slides within the body, and a spring operably disposed to move the spool of the fail-safe valve toward the closed position. Fluid pressure is applied to the servo actuator as the hydraulic pressure input signal, and the servo actuator is operatively adjusted to move a spool of the fail-safe valve toward the open position. 10. The servo actuator according to claim 9, wherein 11. A redundant control operating system, comprising: a control valve including first and second servo actuators, each of said servo actuators being arranged to provide a hydraulic output in response to a control signal; A hydraulic actuator arranged to move a load in response to a hydraulic output from the control valve; and a hydraulic and electrical input signal operatively associated with the control valve and the actuator. And a logic valve device, wherein the logic valve device is operatively disposed between the control valve and the actuator, and (a) enables the control operation of the actuator in response to the control signal; b) allowing the actuator to move freely and independently of the control signal, or (c) allowing the supplied input signal to be independent of the control signal. As a number, the movement of the load is suppressed and the logic valve arrangement is arranged to provide a hydraulic output signal, the hydraulic output signal of each servo actuator being a separate hydraulic input signal. A redundant control operation system provided to a servo actuator. 12. The redundant control operation system according to claim 11, wherein each of said control valves is an electrohydraulic servo valve. 13. The redundant control operation system according to claim 12, wherein said control valves are identical to each other. 14. Each of the servo actuators further includes an associated logic valve device that allows the associated actuator to move the associated actuator freely and independently of the control signal. A first arranged to selectively communicate with the chamber;
12. The redundant control operation system according to claim 11, comprising: 15. Each servo actuator further comprises a second flow path having a constrained orifice, wherein the logic valve device causes the associated actuator to inhibit movement of the load independent of the control signal. When in operation, the second flow path is arranged to selectively communicate with chambers on both sides of the associated actuator;
The redundancy control operation system according to claim 14, wherein: 16. The system according to claim 1, wherein each of said logic valves comprises a bypass valve and a fail-safe valve hydraulically coupled between said associated control valve and said associated actuator. 12. The redundancy control operation system according to item 11. 17. Each of said bypass valves has a first position in which fluid can flow between said associated control valve and an associated actuator, and a first position in which fluid is associated with said associated control valve. Between the chambers on either side of the actuator, but can be freely bypassed between the chambers on either side of the actuator, and the bypass valve can be moved between the second position and the second position. 17. The redundant control operation system according to claim 16, wherein the redundant control operation system is pressed toward the second direction. 18. Each of the bypass valves has a valve spool mounted for sliding sliding within the body, and a spring operatively moves the spool of the bypass valve to the second position. 18. The system of claim 17, wherein the system is disposed and fluid pressure is selectively applied to move the spool of the bypass valve to the first position. 19. Each of said servo actuators further comprises a source of pressurized fluid and a solenoid valve operatively disposed between said source and said associated bypass valve, said respective solenoid valve. Is in communication with the source, and when the solenoid valve is energized by the supplied electrical input signal, pressurized fluid from the source moves the spool of the associated bypass valve toward the first position. 19. The redundant control operating system of claim 18, wherein said system provides said hydraulic output signal. 20. Each of the fail-safe valves has an open position in which fluid can flow between the associated bypass valve and the associated actuator, and fluid associated with the associated bypass valve and the associated actuator. 16. The redundant control operation system according to claim 15, wherein the fail-safe valve can be moved to and from the closed position where it cannot flow between, and the fail-safe valve is pressed to the closed position. 21. A valve spool wherein each said failsafe valve is hermetically slidably mounted within a body;
A spring operatively arranged to move the spool of the failsafe valve toward the closed position, wherein fluid pressure is applied to the servoactuator as the hydraulic pressure input signal; 21. The redundant control operating system of claim 20, wherein the safe valve spool is operatively adjusted to move the spool to the open position.