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
  • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
  • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
  • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
  • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
  • F15B13/043—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves
• • 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
  • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
  • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
  • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
  • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
  • F15B13/043—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves
  • F15B13/0436—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves the pilot valves being of the steerable jet type
• • 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
  • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
  • F15B13/16—Special measures for feedback, e.g. by a follow-up device
• • 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
  • F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
  • F15B9/02—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type
  • F15B9/06—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by means using a fluid jet
• • 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
  • F15B9/00—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member
  • F15B9/02—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type
  • F15B9/06—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by means using a fluid jet
  • F15B9/07—Servomotors with follow-up action, e.g. obtained by feed-back control, i.e. in which the position of the actuated member conforms with that of the controlling member with servomotors of the reciprocatable or oscillatable type controlled by means using a fluid jet with electrical control means
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/2278—Pressure modulating relays or followers
  • Y10T137/2409—With counter-balancing pressure feedback to the modulating device

Definitions

• the invention relates to a servovalve control stage, which can serve as a first stage in a two - stage servovalve.
• a conventional servovalve consists of a control stage controlling a mobile power distribution device ⁇ tion of a power stage.
• the function of the power stage is to deliver a pressure or a flow proportional to an instruction transmitted to the control stage.
• the control stage comprises two hy ⁇ hydraulic elements, namely a hydraulic transmitter (nozzle or ejector) and a hydraulic receiver (pallet, defl ⁇ tor or fixed receiver) whose modification of their relative position generates pressure differentials which are operated to finely move a movable power distribution member of the power stage of the servovalve.
• This movable member of distribution then ⁇ slide defect in a cylindrical sleeve implanted in the body of the servovalve.
• the position of the transmitter or of the hydraulic receiver is controlled by a torque motor that moves one of the elements of the hydrauli c ⁇ pilot stage next to the other.
• the displacement of the mobile power distribution member in its liner then communicates a set of bored channels and lights whose arrangement makes it possible to deliver a pressure or a flow, proportional to the displacement of said movable member. distribution and ⁇ failure.
• These servovalves comprise a mechanical connection between the rotor of the torque motor and the mobile power distribution member, made using a device of feedback.
• the feedback member is generally connected to the movable power distribution member in the middle thereof and is also connected to the hydraulic element associated with the rotor via the latter.
• the feedback member slaves the position of the movable power distribution member to the rotor of the servovalve and generates on the torque motor a torque which is withdrawn from the control action.
• the feedback member comprises a rod or a flexible blade operably connected to the rotor at one end and carrying a ball at its other end.
• the ball member of the re ⁇ troaction interacts with a groove or a bore located in the center of the movable power distribution.
• An operating clearance permits swiveling and glis ⁇ ment of the ball in the groove allowing ⁇ moves the movable member of power distribution in a direction transverse to the axis of the shaft / blade re ⁇ troaction.
• This connection allows relative sliding of the two elements by generating little parasitic friction of the mobile power distribution member on the liner which carries it, resulting in hysteresis performance and resolution of the servovalve acceptable against the requirements of the users of these equipments.
• the ball presses and rolls on one or other of the faces of the throat that contains it.
• Repeated displacements of the mobile power unit by soliciting the interface between the ball and the groove which contains it, cause the wear of this link which aug ⁇ mente then the clearance between the mobile power distribution member and the ball of the feedback organ.
• This wear increases the clearance between the ti ⁇ roir and the feedback element which disturbs the servo of the servovalve. This disturbance is at the origin of many returns for defective servovalves. Reducing this frictional wear therefore makes equipment more reliable and improves their service life.
• An object of the invention is to decrease the wear generated by the relative movements of the re member ⁇ FEEDBACK AND of the movable dispensing then ⁇ ciency of a servo while maintaining a resolution of the characteristics and acceptable hysteresis.
• a two-stage hydraulic servovalve comprising:
• a power stage comprising a mobile power distribution device
• the movable power distribution comprises means clamp ⁇ of the feedback element which are shaped to allow movement of a pinched portion of the feedback member relatively to the moving member of distribution bution of power at least in a direction trans vers ⁇ a pinch force generated by the clamping means.
• connection made by clamping between the movable power member and the feedback member is then without play and reduces the wear of the junction between the parts.
• the clamping means are shaped to allow at least one displacement of a pinched portion of the feedback member relative to the mobile power distribution member at least in a direction transverse to the pinch force generated by the clamping means.
• This type of clamping allows a connection between the movable power distribution member and the feedback member which limits the creation of forces detrimental to the displacement of the movable dis ⁇ tribution power in his shirt. These displacements are preferably obtained by the use of slender metal rods.
• FIG. 1 is a sectional view along a plane normal to the axis of movement of the movable power distribution member of a servo valve according to the invention.
• FIG. 1 is a sectional view along a broken plane A-A shown in Figure 1.
• FIG. 3 is a view similar to that of FIG. 1 illustrating the power stage during a movement of the mobile power distribution device of the servovalve
• the servovalve generally designated 1 comprises a control stage 100 and a power stage 200.
• the control stage 100 comprises a torque motor comprising a stator 2 and a rotor 3.
• the stator 2 comprises a cage surrounding the rotor 3 which rotates along the axis Z.
• the rotor 3 comprises two main elements:
• the column 20 carries a fluid ejector 4 facing a fixed receiver 5.
• the column 20 is ALIMEN ⁇ ted fluid and the fluid ejector 4 supplies hydraulic fluid jet towards the fixed receiver 5 according to an angular orientation function
• the column 20 is coupled to an elastic return member (not shown here) to an equilibrium position in which the ejector 4 is substantially opposite the center of the receiver 5.
• the power stage 200 includes a shirt cy ⁇ lindrique 10 sealingly secured to the frame of the ser ⁇ vovalve 1.
• This jacket comprises an axial bore 12 machined in its center in which slides a slide 7.
• the sleeve 10 is provided with drilled channels and lights communicating with the hydraulic power supply (P), output (U1 and U2) and return (R) ports of the servovalve.
• the liner 10 is pierced with a second radial bore 13 made in the middle.
• the receiver 5 is fluidly connected to the pilot chambers 9 located on either side of the ti ⁇ roir 7; so that an angular displacement of the ejector 4 facing the receiver 5 produces a differential pressure in the control chambers 9 which ⁇ ⁇ on the drawer 7 a displacement force.
• the slide 7 is of cylindrical shape and pierced with two bores including a first axial bore 14 and a radial bore is ⁇ cond 15 made substantially at its mid ⁇ place.
• a feedback blade 6 mechanically linked to the 7 and integral tray of the column 20 passes through the radial bore 13 of the sleeve 10 and the radial bore 15 of ti ⁇ roir 7 so that one end of the rhyroidac ⁇ blade 6 extends into the axial bore 12 of the slide 7.
• the feedback blade 6 has a substantially triangular shape and comprises a base 23 which is re ⁇ connected to a sleeve 11 hooped on the column 20.
• the tip of the blade 6 forms an end 22 which extends through radial bores 13 and 15 of the liner 10 and the drawer 7.
• the end 22 of the feedback blade 6 is gripped by pinch means 8 integral with the slide 7.
• the clamping means 8 comprise pressure screws 16 screwed into the slide 7 in internal threads. it is coaxial with the bore 12.
• the pressure screws 16 push on pinches 17 slidably mounted in the axial bore 12 and carrying metal rods 18 extending cantilevered to clamp the end 22 of the feedback blade 6.
• the pinch of the feedback blade 6 is achieved by the screwing of the pressure screws 16 which exert a force on the pincers 17, which transmit this ef ⁇ strong to the rods 18.
• the ends of the rods 18 come to pinch the feedback blade 6 ensuring the connection between the latter and the drawer 7.
• the assembly operations preferably comprise the following succession of steps:
• an instruction in the form of an electric current is sent to the stator 2 of the torque motor.
• This instruction causes an angular movement of the rotor 3 around the Z axis.
• the torsion exerted by the torque motor on the column 20 via the rotor 3 modifies the relative position of the ejector 4 and the fixed receiver 5, and causes a difference.
• - tial pressure between the chambers 9 located on either side of the drawer 7. the latter then moves a value substantially proportional to the elec tric ⁇ instruction received by the torque motor.
• Moving the ti ⁇ roir 7 in the jacket 10 then communicates a set of drilled channels and lights whose arrangement allows to deliver a pressure or a flow rate proportional to the displacement of said ⁇ power distribution member 7.
• the base 23 of the feedback blade 6 embedded in the column 20 is then subjected to an angular displacement in one direction and its pinched end is subjected to a displacement of the slide 7 in an opposite direction, as ⁇ glossy in Figure 4.
• feedback blade 6 then exerts an elastic return by servo function between the drawer 7 and the rotor 3 (via the column 20 ) by generating on the rotor 3 a torque which comes to evade the control action.
• the clamping means 8 of the re ⁇ troaction member 6 may comprise a single screw 16 pinching, for example, the feedback member against a fixed part;
• the flexibility of the clamping means of the feedback member described here can be provided by deformable members such as springs, polymer or latex-based elements, a damping hydraulic ⁇ , or Belleville washers;
• the feedback member 6 can be connected to ro ⁇ tor via the column 20 or by mechanical connection with the ejector or the nozzle of the control stage.
• the invention also applies to a ser- vovalve equipped with other types of mobile bodies then ⁇ ciency such as, for example, rotary valves;
• the invention also applies to a servo valve equipped with other types of re ⁇ troaction organs such as, for example, rods of rodiac ⁇ .
• hydraulic transmitter is connected to the motor rotor by a column
• the invention is of course not limited to this configuration, and applies to other types of servovalves in which the position of the hydraulic transmitter relative to the receiver re ⁇ is fixed for example by an eccentric or a connecting rod connected to the movable part of the motor.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Servomotors (AREA)
• Manipulator (AREA)
• Hydraulic Motors (AREA)

Applications Claiming Priority (2)

Publications (3)

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Family Cites Families (9)

• 2011
  • 2011-10-12 FR FR1159209A patent/FR2981414B1/fr active Active
• 2012
  • 2012-10-08 ES ES12769114.5T patent/ES2624141T3/es active Active
  • 2012-10-08 WO PCT/EP2012/069860 patent/WO2013053668A1/fr active Application Filing
  • 2012-10-08 US US14/351,390 patent/US9644645B2/en active Active
  • 2012-10-08 EP EP12769114.5A patent/EP2766612B8/de active Active

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