GB2187511A - Hydraulic control system of an actuating cylinder in an aircraft - Google Patents

Hydraulic control system of an actuating cylinder in an aircraft Download PDF

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Publication number
GB2187511A
GB2187511A GB08605373A GB8605373A GB2187511A GB 2187511 A GB2187511 A GB 2187511A GB 08605373 A GB08605373 A GB 08605373A GB 8605373 A GB8605373 A GB 8605373A GB 2187511 A GB2187511 A GB 2187511A
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GB
United Kingdom
Prior art keywords
hydraulic
actuating cylinder
hydraulic line
chamber
emergency
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.)
Withdrawn
Application number
GB08605373A
Other versions
GB8605373D0 (en
Inventor
Varvara Vasilievna Selivanova
Georgy Mikhailovich Kudrov
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to GB08605373A priority Critical patent/GB2187511A/en
Priority to DE19863608918 priority patent/DE3608918A1/en
Priority to FR8603894A priority patent/FR2600724A1/en
Publication of GB8605373D0 publication Critical patent/GB8605373D0/en
Publication of GB2187511A publication Critical patent/GB2187511A/en
Withdrawn legal-status Critical Current

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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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C25/00—Alighting gear
    • B64C25/02—Undercarriages
    • B64C25/08—Undercarriages non-fixed, e.g. jettisonable
    • B64C25/10—Undercarriages non-fixed, e.g. jettisonable retractable, foldable, or the like
    • B64C25/18—Operating mechanisms
    • B64C25/26—Control or locking systems therefor

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)

Abstract

A hydraulic control system of an actuating cylinder, especially for undercarriage in an aircraft, wherein a main hydraulic line (4, 8, 8a) having a valve distributor (7), communicates a hydraulic tank (2) with one of the chambers (12) of an actuating cylinder (13) via a check valve (11) which is piloted by the pressure admitted from a second chamber (15) of the actuating cylinder (13). An emergency hydraulic line (5) provided with a valve distributor (21), communicates a hydraulic tank (3) with one chamber (12) of the actuating cylinder (13) via a check valve (23) installed in said hydraulic line. This allows the main and emergency controls to be actuated independently. <IMAGE>

Description

SPECIFICATION Hydraulic control system of actuating cylinders The present invention relates generally to aircraft manufacture and more specifically, to hydraulic control systems of actuating cylinders in an aircraft.
The herein-proposed hydraulic system is most reasonable to be applied for control of undercarriage actuating cylinders of an aircraft.
The system is also applicable for control of any actuating cylinders or power jacks of an aircraft, such as flap or spoiler actuators, etc., which are connected to the main or emergency hydraulic line.
The hydraulic control system of the invention can also find application in some other branches of engineering and technology, wherein hydraulic cylinders or actuators are connected to the main and emergency (standby) hydraulic line.
There are commonly known and extensively applied hydraulic control systems of actuating cylinders used in the undercarriage of aircraft, which are provided with the main and emergency hydraulic lines. Each of the hydraulic lines incorporates a hydraulic tank communicating with the pump and valve distributor.
Then both of the hydraulic lines are connected to the undercarriage up-lock cylinder and, via the shutoff valving device, to one of the chambers of the actuating cylinder, whose other chamber is connected, via the main hydraulic line valve distributor, to the hydraulic tank of said line.
The shutoff valving device comprises intercommunicating an emergency valve and a piloted check valve.
Connected to the unions of the emergency valve are the main and emergency (standby) hydraulic lines, while the check valve is connected to one of the actuating cylinder chambers and is piloted by the pressure admitted from the other chamber of said cylinder.
Both the main and emergency hydraulic lines of such hydraulic systems are connected to the actuating cylinder through a common shutoff valving device, which affects adversely the operational reliability of the actuating cylinder and hence the reliability of the aircraft undercarriage extension and retraction.
It is a primary and essential object of the invention to provide a hydraulic control system of an actuating cylinder in an aircraft, wherein the shutoff valving device would feature such a construction arrangement that would make it possible to effect independent connection of the main and emergency hydraulic lines to the actuating cylinder.
Said object is accomplished due to the fact that in a hydraulic control system of an actuating cylinder in an aircraft, wherein the main and emergency hydraulic lines, each having a valve distributor, communicate the hydraulic tanks with one of the actuating cylinder chambers via a shutoff valving device, while the other chamber of said cylinder communicates with the hydraulic tank through the main hydraulic line valve distributor, according to the invention, the shutoff valving device comprises a check valve installed in the main hydraulic line and piloted by the pressure admitted from the other chamber of the actuating cylinder, and another check valve installed- in the emergency hydraulic line.
It is expedient that the other chamber of the actuating cylinder be additionally connected to the main line hydraulic tank through a valve piloted by the pressure in the emergency hydraulic line.
Such communication of the actuating cylinder second chamber makes it possible to provide for fully independent operation of the hydraulic system under emergency conditions.
The hydraulic control system of actuating cylinders made in accordance with the present invention, is constructionally simpler than the heretofore-known hydraulic system for the same application and is capable of providing a higher degree of safety and reliability in the course of operation of the actuating cylinder.
Given below is a detailed description of a specific embodiment of the present invention with reference to the accompanying drawing, wherein a hydraulic control system of the aircraft undercarriage actuating cylinders is schematically represented.
The specific embodiment of the invention describes the hydraulic system for control of the undercarriage of an aircraft. The system comprises a resourvoir 1 subdivided into two independent hydraulic tanks 2 and 3 which communicate with a main hydraulic line 4 and an emergency hydraulic line 5, respectively.
Installed in the main hydraulic line 4 are a pump 6 and a distributor made as a threeposition direction control valve 7 which feeds hydraulic fluid under pressure to an undercarriage extension main hydraulic line 8 or to an undercarriage retraction main hydraulic line 9.
Further on the hydraulic line 8 is connected to an undercarriage up-lock cylinder 10 and communicates, via a line 8a, with a piloted check valve 11, which in turn is connected to a chamber 12 of an actuating cylinder 13.
A movable member 14 of the actuating cylinder 13 is connected to the undercarriage controlled element (omitted in the drawing).
A second chamber 15 of the actuating cylinder 13 is connected to the hydraulic line 9.
The check valve 11 is piloted by the pressure of the hydraulic fluid fed from the hydraulic line 9 to the chamber of a cylinder 16, wherein an actuator 17 is accommodated, adapted to ineract with the check valve 11.
For the hydraulic fluid to discharge from the chamber 12 of the actuating cylinder 13 the hydraulic line 8a is connected, via a check valve 18 and a hydraulic line 8b, to the hydraulic line 8, by-passing the undercarriage uplock cylinder 10.
The specific exemplary embodiment of the present invention considers two actuating cylinders 13 and 19, both having similar modes of connection to the hydraulic lines; therefore, the aforementioned scheme of connection of the actuating cylinder 13 refers equally to the actuating cylinder 19. However, other connection patterns are also practicable, wherein a larger amount of actuating cylinders are connected in a way described hereinbefore.
Installed in the emergency hydraulic line 5 are a pump 20 and a two-position direction control valve 21 which feeds hydraulic fluid under pressure to the chamber 12 of the actuating cylinder 13 under emergency conditions whenever hydraulic fluid cannot be supplied to the actuating cylinder 13 through the main hydraulic line 4, 8, 8a, 8b.
Past the direction control valve 21 the emergency hydraulic line 5 communicates with the cylinder 10, which in turn communicates, via the hydraulic line 5a and through union 22, with the chamber 12 of the actuating cylinder 13. A check valve 23 is provided in the hydraulic line 5a.
The second chamber 15 of the actuating cylinder 13 is additionally connected to the hydraulic tank 2 through lines 24 and 25 via a valve 26 which piloted by the pressure in the emergency hydraulic line 5.
A hydraulic line 31 communicates the direction control valve 21 and the hydraulic line 5 with the hydraulic tank 3 for the leaks from the emergency hydraulic line device to return to said tank.
The hydraulic control system of actuating cylinders in an aircraft operates as follows.
Upon undercarriage extension (release), the hydraulic fluid is force-fed from the hydraulic tank 3 by the pump 6 to the hydraulic line 8 through the direction control valve 7 (in a position 7a). Further the hydraulic fluid is admitted to pass first to the undercarriage up-lock cylinder 10, thus causing its piston 27 to travel until the chamber of the cylinder 10 gets communicated with the hydraulic line 8a. Then the hydraulic fluid is fed to the hydraulic line 8a, and, upon opening the check valve 11, is supplied, via the union 28, to the chamber 12 of the actuating cylinder 13. The movable member 14 travels to the right (as in the drawing) and causes the controlled undercarriage element to actuate undercarriage extension.As a result, the hydraulic fluid from the chamber 15 of the actuating cylinder 13 is returned, via the hydraulic line 9 and the direction control valve, back to the hydraulic tank 2.
Upon turning the hydraulic system on for the undercarriage retraction (closing), the hydraulic fluid is force-fed from the hydraulic tank 2 by the pump 6 to the hydraulic line 9 via the direction control valve 7 (in a position 7b). Then the hydraulic fluid is admitted to pass from the hydraulic line 9 to the following hydraulic control system components at a time:: -to the undercarriage up-lock cylinder 10 to cause the piston to travel in the opposite direction (to the right as in the drawing), thus disconnecting the hydraulic line 8a; -to the chamber 15 of the actuating cylinder 13, thus causing the movable member 14 to travel to the left (as in the drawing) along with the controlled undercarriage element, thus actuating the undercarriage retract; -to the hydraulic line 9a to travel the piston 29 whose actuator 17 causes the check valve 11 to travel to the left (as in the drawing).Thus, the hydraulic fluid is discharged from the chamber 12 of the actuating cylinder 13, via the union 28, the check valve 11, to the hydraulic line 8a, whereupon it passes through the check valve 18, the hydralic line 8b and the direction control valve 7 (in the position 7b) to return to the hydraulic tank 2.
Whenever the hydraulic fluid cannot be fed to the actuating cylinder along the main hydraulic line 4, 8, 8a, undercarriage extension can be actuated by virtue of the hydraulic fluid force-fed along the emergency hydraulic line 5.
Such being the case, the hydraulic fluid is pressure-fed from the hydraulic tank 3 by the pump 20 via the two-position direction control valve 21 to the undercarriage up-lock cylinder 10 to travel the piston 30 for the undercarriage up-lock to release. Once the up-lock has been released the hydraulic fluid is fed to the hydraulic line 5a and further on, via the check valve 23 and the union 22 to the chamber 12 of the actuating cylinder 13, whose movable member 14 causes the undercarriage controlled emement to actuate undercarriage extension.
Return of the hydraulic fluid from the second chamber 15 of the actuating cylinder 13 is carried out in a way similar to that occurring in the case of undercarriage extension from the main hydraulic line. Whenever the hydraulic fluid cannot be returned to the hydraulic tank 2 through the direction control valve 7 due to any failue in the system, the hydraulic fluid is returned from the chamber 15 of the actuating cylinder 13 to the hydraulic tank 2 along the auxiliary hydraulic line 24, 25 and via the valve 26 upon pressure admission to the emergency hydraulic line 5 during undercarriage extension actuated from said hydraulic line.
The hydraulic control system of actuating cylinders in an aircraft made according to the present invention, has been tested under hydraulic rig conditions to confirm its service life to be equal to 9000 equivalent flying, hours, whereas its prototype model has passed inflight testing in aircraft under standard service conditions with positive test results obtained.

Claims (3)

1. A hydraulic control system of an actuating cylinder in an aircraft, wherein the main and emergency hydraulic lines, each having a valve distributor, communicate the hydraulic tanks with one of the actuating cylinder chambers via a shutoff valving device, while the other chamber of said cylinder communicates with the hydraulic tank through the main hydraulic line valve distributor; the shutoff valving device comprises a check valve installed in the main hydraulic line and piloted by the pressure admitted from the other chamber of the actuating cylinder, and a check valve installed in the emergency hydraulic line.
2. A hydraulic control system as claimed in Claim 1, wherein the other chamber of the actuating cylinder is additionally connected to either of the hydraulic tanks through a valve piloted by the pressure in the emergency hydraulic line.
3. A hydraulic control system of an actuating cylinder in an aircraft substantially as hereinbefore described with reference to, and as illustrated in the accompanying drawing.
GB08605373A 1986-03-05 1986-03-05 Hydraulic control system of an actuating cylinder in an aircraft Withdrawn GB2187511A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
GB08605373A GB2187511A (en) 1986-03-05 1986-03-05 Hydraulic control system of an actuating cylinder in an aircraft
DE19863608918 DE3608918A1 (en) 1986-03-05 1986-03-18 HYDRAULIC CONTROL OF THE AIR CYLINDER OF AN AIRCRAFT
FR8603894A FR2600724A1 (en) 1986-03-05 1986-03-19 HYDRAULIC CONTROL SYSTEM FOR A MOTOR CYLINDER OF A FLYING APPARATUS.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB08605373A GB2187511A (en) 1986-03-05 1986-03-05 Hydraulic control system of an actuating cylinder in an aircraft

Publications (2)

Publication Number Publication Date
GB8605373D0 GB8605373D0 (en) 1986-04-09
GB2187511A true GB2187511A (en) 1987-09-09

Family

ID=10594047

Family Applications (1)

Application Number Title Priority Date Filing Date
GB08605373A Withdrawn GB2187511A (en) 1986-03-05 1986-03-05 Hydraulic control system of an actuating cylinder in an aircraft

Country Status (3)

Country Link
DE (1) DE3608918A1 (en)
FR (1) FR2600724A1 (en)
GB (1) GB2187511A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1790567A3 (en) * 2005-11-28 2008-07-30 Northrop Grumman Corporation Electro-hydraulic actuator system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2811037B1 (en) 2000-06-28 2002-10-18 Aerospatiale Matra Airbus ELECTRICALLY CONTROLLED HYDRAULIC ACTUATION SYSTEM

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1126469A (en) * 1955-03-30 1956-11-23 Improvements to hydraulic or similar circuits
US3967532A (en) * 1974-01-07 1976-07-06 Caterpillar Tractor Co. Forward-reverse valve for elevating scraper drive
US3913324A (en) * 1974-05-01 1975-10-21 Deere & Co Flow-sensing switch for backup steering system
US4051676A (en) * 1976-03-25 1977-10-04 Ledeen Flow Control Systems, Inc. Hydraulic valve actuator
US4103699A (en) * 1976-07-16 1978-08-01 Avon Enterprises, Inc. Fluid cylinder mounted lock out valve device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1790567A3 (en) * 2005-11-28 2008-07-30 Northrop Grumman Corporation Electro-hydraulic actuator system

Also Published As

Publication number Publication date
FR2600724A1 (en) 1987-12-31
DE3608918A1 (en) 1987-09-24
GB8605373D0 (en) 1986-04-09

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Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)