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
  • F15B13/01—Locking-valves or other detent i.e. load-holding devices
• • 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
  • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
  • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
  • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
  • F15B11/044—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed by means in the return line, i.e. "meter out"
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/405—Flow control characterised by the type of flow control means or valve
  • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/40—Flow control
  • F15B2211/46—Control of flow in the return line, i.e. meter-out control
• • 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
  • F15B2211/00—Circuits for servomotor systems
  • F15B2211/50—Pressure control
  • F15B2211/505—Pressure control characterised by the type of pressure control means
  • F15B2211/50509—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means
  • F15B2211/50545—Pressure control characterised by the type of pressure control means the pressure control means controlling a pressure upstream of the pressure control means using braking valves to maintain a back pressure

Definitions

• the invention relates to a valvular element for fluidodynamics, in particular of the adjustable, piloted throttle unidirectional type.
• Valves whatever their type or function, are indispensable components in any fluidodynamic circuit.
• the presence of valves is indeed designed to deviate, control, regulate and impede the flow of fluid in the circuit in order to permit the opportune functioning of actuators and motors controlled by fluid.
• valves There are various typologies of valves realised and present on the market and, among these, there are the so-called unidirectional piloted valves, so called because the controlling fluid flows through them following a preferential direction.
• unidirectional piloted valves so called because the controlling fluid flows through them following a preferential direction.
• embodiment possibilities for example, single or dual-action embodiments.
• valves In addition to the variety of embodiment possibilities for the aforesaid valves, there is a vast possibility of constructive forms for the said valves such as, for example, as a cartridge or on a line or as a manifold or flanged.
• pilot function of the valve itself a regulating function relating to the quantity of fluid passing through the said valve.
• the aforesaid pilot function is performed, generally, by sliding elements called small pilot pistons which, moving along their longitudinal axis by means of the fluid's thrusting action through the valve, determine the opening and closing of the opposing transit ways created for the fluid in the body of the said valve.
• small pilot pistons which, moving along their longitudinal axis by means of the fluid's thrusting action through the valve, determine the opening and closing of the opposing transit ways created for the fluid in the body of the said valve.
• the regulation function relating to the quantity of fluid transiting through the valves is performed by means of various typologies of regulation of the openings of the passageway holes for the said fluid such as, for example, needle elements which are adjusted by screwing or unscrewing the said elements or spring elements whose springs can be calibrated, or elements which can be screwed circumferentially.
• the said regulation is designed to reduce the opening of the passageway for the manoeuvring fluid in order to adapt the performance of the individual valves to the actual operative requirements.
• a throttle device is added to the unidirectional piloted valve, said throttle device either corresponding with a body which is external to the single piloted valve or being incorporated into an integrated unit where the said throttle is separate from the said unidirectional piloted valve, both the said current solutions having certain drawbacks, the main drawbacks being established as the possibility of fluid leaks, the overall dimensions and the cost.
• the fluid leaks these characterise, as it can be inferred, the embodiments in which the two elements, valve and throttle are materially separate. Even the coupling of the two said elements, performed directly, i.e.
• the valvular element for fluidodynamics in particular of a unidirectional piloted single-block type, is fitted with at least one valve and one pilot element for the said valve, characterised by the fact that the said valvular element comprises two stopping elements positioned along the longitudinal stroke of the said pilot element and reciprocally separated by a space, inside which the pilot element is positioned, whose axis of movement coincides with a longitudinal axis of symmetry of at least one valve, the said two stopping elements being designed to limit the movement of the pilot element, and by the fact that an adjusting element is centred axially in relation to the aforesaid longitudinal axis of symmetry, said adjustable axis being designed to vary the position of at least one holding seat in relation to the position of the pilot element and therefore to divide the flow of fluid through the said valvular element into parts.
• - figure 1 shows a total longitudinal section of the valvular element in question in this invention
• - figure 2 shows the functional diagram of the said valvular element.
• 1 is a valvular element composed of a single block 2 containing two valves 3 a and 3b of the unidirectional dual-action type, both the said valves extending along a single longitudinal axis of symmetry 4.
• the said longitudinal axis of symmetry coincides with the longitudinal running axis of a small pilot piston 5.
• Two elastic rings 6a end 6b, respectively the first and second, are fitted in suitable seats created in the single block 2 and are centred in relation to the longitudinal axis of symmetry 4.
• the said two elastic rings are reciprocally separated by a space 7 which corresponds with the possibility of movement of the small pilot piston 5 positioned between the said two elastic rings.
• the small pilot piston 5 has two pins 8a and 8b, opposite each other and centred according to the longitudinal axis of symmetry 4, each of which is facing one of the two small holding pistons 9a and 9b that are parts, respectively, of the valve 3a and 3b.
• Each of the small pistons 9a and 9b beats against a relative holding seat, respectively 10a and 10b, thanks to a spring 11.
• the said spring is contained within the said holding seat integrally restrained by a means of connection 12, for example a cylindrical pin as shown in figure 1, to a coaxially threaded adjusting screw 13 inside a valve body 14.
• the longitudinal axes of both the said valve body and the said adjusting screw correspond with the longitudinal axis of symmetry 4.
• the said holding seats are provided with a plurality of holes 23 bored radially into the depth of the said holding seats.
• a fastening nut 15 is positioned at the external end of the adjusting screw 13.
• first and a second inlet opening respectively 16 and 17, and there is a first and a second outlet opening, respectively 18 and 19.
• the said inlet openings are linked to a pump and a distributor not shown, while the outlet openings are linked to a driving element 20 in figure 2 which shows schematically a dual-action cylinder.
• 20a and 20b are a delivery chamber and a return chamber respectively of the said driving element 20.
• first and a second chamber respectively 21 and 22, reciprocally separated by the presence of the small pilot piston 5 and related, respectively, to the openings 16 and 18 and the openings 17 and 19.
• the withdrawal of the small holding piston 9a results in the said piston beating no longer against the holding seat 10 and the fluid can move through the plurality of holes 23 in the valve 3 a and flow, through the first outlet opening 18, towards the delivery chamber 20a of the dual-action cylinder 20.
• the pressure of the fluid present in the first chamber 21 pushes the small pilot piston 5 towards the elastic ring 6b and brings the pin 8b into contact with the small holding piston 9b. If the pressure of the fluid in the first chamber 21 is great enough to overcome the resistance of the spring 11 of the valve 3b, the pin 8b detaches the holding piston 9b from the relative holding seat 10b; in this way the passage of the fluid coming from the return chamber 20b is obtained.
• the elastic ring 6b limits the stroke towards small holding piston 9b of the small pilot piston 5, preventing the latter compressing the spring 11 of the valve 3b completely, thereby obtaining a throttling action in relation to the passage of the fluid from the return chamber 20b.
• the valve in question in this invention functions as a normal open unidirectional valve, while in the returning direction, it functions as an adjustable throttle.
• the position of the small holding pistons 9a and 9b can be varied inside the single block 2 in order to vary the moment of contact between the pins 8a and 8b and the small holding pistons 9b and 9a facing the said pins.
• the pin 8b during its movement towards the right-hand side of the said figure, will come into contact with the holding element 9b almost immediately and the latter, compressing the spring 11 to the maximum, will move by a distance corresponding to the movement made by the small pilot piston 5 until the latter beats against the elastic ring 6b.
• This situation corresponds with the maximum opening of the passageway for the fluid running from the opening 19 to the opening 17, i.e. for the fluid leaving the return chamber 20b of the dual-action cylinder 20.
• a first advantage of this invention is represented by the reduction in the overall dimensions and weight of the piloted valvular element performing, contemporaneously, the function of unidirectional dual-action valve and the throttle function.
• a further advantage consists in the reduced production cost thanks to the lesser quantity of material used, of elements used and the construction simplicity.
• piloted valve of the unidirectional type, but it is extremely evident that the art of this invention can also be applied, advantageously, to any typology of valve for fluidodynamics, in which there is at least one pilot element present, whether it is of the blow-down, balancing, sequence or any other kind.
• this element can also be constituted, advantageously, of a cartridge.

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

Applications Claiming Priority (2)

Publications (1)

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ID=30012729

Family Applications (1)

Country Status (3)

Families Citing this family (5)

Family Cites Families (3)

• 2003
  • 2003-05-07 IT IT000129A patent/ITMO20030129A1/it unknown
• 2004
  • 2004-05-04 EP EP04739127A patent/EP1627152A1/en not_active Withdrawn
  • 2004-05-04 WO PCT/EP2004/004709 patent/WO2004099626A1/en not_active Application Discontinuation

Non-Patent Citations (2)

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