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
  • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
  • F15B11/06—Servomotor systems without provision for follow-up action; Circuits therefor involving features specific to the use of a compressible medium, e.g. air, steam
  • F15B11/068—Servomotor systems without provision for follow-up action; Circuits therefor involving features specific to the use of a compressible medium, e.g. air, steam with valves for gradually putting pneumatic systems under pressure

Definitions

• the invention relates to a control valve for a controlled supply of pressurized fluid, especially pressurized air, from a source of pressurized fluid to a pressurized fluid system, of the kind stated in the preamble of claim 1.
• Such a control or air supply valve is known from SE-C-7906261-8 and ensures that the pressure increase will be relatively slow during a first phase of air supply, so as to avoid that work cylinders or other apparatus operable by pressure perform sudden movements under the influence of a pressure shock.
• a pneumatic system has been left depressurized for some time, e.g. during a week-end, it could in fact occur that cylinder pistons or the like have arrived at such positions that, upon supply of air, the pistons have no counter-pressure and therefore perform an uncontrolled, jerky movement.
• the object of the present invention is to considerably simplify the known valve structure in such a way that the main valve is integrated with the choke and pressure control valve, so that these valve parts can be accomodated in a common valve chamber in a valve casing.
• the inlet port(which is connected to the source of pressurized fluid)of the control valve communicates with the valve chamber via, on the one hand a flow passage having a relatively large cross-sectional area and, on the other hand, a choke opening having a considerably smaller cross-sectional area, and that the slide of the valve is provided with a piston body, which is displaceable thereon and which, in the air supply position'! of the valve (wherein the inlet port communicates with the outlet port connected to the pressurized fluid system in question) ,is displaceable between an initial position, in which the inlet port communicates with the outlet port only
• control valve may comprise only one valve chamber, in which the valve slide with the adjoining piston body is displaceable. Moreover, a considerable structural .simplification is achieved by avoiding two separate valves each being arranged in a separate valve chamber and being conne ted to each other via a number of conduits or channels in the valve casing. Manufacture as well as operation and relia ⁇ bility will be enhanced thereby.
• a particularly good operabili s isachieved if the piston body, being displaceable on the valve slide, is provided with a piston surface facing the outlet port and being so dimensioned that, upon reaching a predetermined pressure in the connected pressurized fluid system, it is subjected to a reversing force, which exceeds a counter-force, e.g. exerted by a compression spring, so that the piston body is displaced to said final position.
• a counter-force e.g. exerted by a compression spring
• Fig. 1 shows a central longitudinal section through a control valve according to the invention, wherein a slide valve is located in a first position being uninfluenced by outer control forces;
• Fig.2 shows schematically the control valve according to Fig.1 with the slide valve located in a second position, during a fir air supply phase;
• Fig.3 shows the control valve according to Fig. 1 with the slide valve located in a third position, permitting full air supply.
• the control valve shown in Fig.1 comprises a two-part valve casing with an upper casing half 1 and a lower casing half 2 being screwed together into mutual contact in a parting plane and being sealed by means of a combination sealing element, which is formed in one piece and includes a planar portion (not shown) located in said parting plane as well as ring portions connected thereto and oriented perpendicularly to the planar portion. In Fig. 1 these ring portions are denoted 3a-3f.
• Each casing half 1,2 has half-cylindrical recesses located adjacent to the parting plane and forming together a cylindrical valve chamber 4. The latter is lined with a cylinder tube 5, which is provided with several hole openings
• valve slide 8 is displaceably mounted inside the cylinder tube 5, a valve slide 8 is displaceably mounted.
• the valve slide 8 is provided, at its end portion to the left in the figure, with a fixed piston portion 8a * with two sealing rings 9,10,which sealingly contact the inside of the cylinder tube 5.
• the opposite end of the valve slide con ⁇ sists of a central, rather narrow shank 8b, on which an en ⁇ closing, cylindrical piston body 11 is displaceable between a first abutment 12 formed by a shoulder surface at the foot of the shank 8b, and a second abutment 13 consisting of a steel ring, e.g. a so called Seeger-ring, inserted in an annular groove on the shank 8b.
• the movable piston body has piston portions 14 and 15, respectively, each provided with a piston sealing ring 16 and 17, respectively, at each end.
• a helical compression spring 18 is inserted between the end portion 7 and the movable piston body 11, so that the
• the valve casing 1,2 is provided with a number of connecting ports, which communicate with the valve chamber 4 via the hole openings of the cylinder tube and the recesses 6a, 7a of the end portions, respectively, namely an inlet port 19 to be connected to a source of pressurized fluid (not shown) , e.g. a central compressor unit, an outlet port 20 to be connected to a pressurized fluid system, e.g. a pneumatic system having working cylinders and components belonging thereto, an exhaust port 21, e.g. for venting the connected pressurized fluid system, and an actuatingport 22 to be pres ⁇ surized for displacement of the valve slide 8 to the right against the action of the spring 18, and an evacuation port 23.
• a source of pressurized fluid e.g. a central compressor unit
• an outlet port 20 to be connected to a pressurized fluid system, e.g. a pneumatic system having working cylinders and components belonging thereto
• valve casing 1 In the right part of the valve casing 1 , 2, there is also inser ⁇ ted an adjusting screw 24 in a central through-bore in the valve casing and a threaded hole in the end portion 7 oppo ⁇ site to the end of the shank 8b of the valve slide 8. Thereby, an adjustable stop means is obtained for the valve slide 8.
• the adjusting screw 24 can be fixed in an adjusted position by means of a lock nut 25 which is tightened into contact with the outside of the valve casing.
• the control valve In the shown position in Fig. 1 , the control valve is closed.
• the source of pressurized fluid communicates via the inlet port 19, an adjoining ring chamber 26, a set of hole openings 27 having a relatively large cross-sectional area and a choke hole 28 having a substantially smaller cross-sectional area, with the limited annular chamber formed between the sealing rings 26 and 27 of the movable piston body.
• the pressurized fluid system is vented in that the outlet port 20, connected thereto, communicates with the exhaust port 21 via an annular chambe a set of hol * e openings 2-9 in the cylinder tube 5, the annual space between the inside-, of the cylinder tube 5 and the out ⁇ side of the valve slide 8, still another set of hole openings 30 in the cylinder tube 5, and an annular chamber 32.
• valve slide 8 and the piston body 11 displaceable thereon can be reversed to a second, opening position according to Fig. 2 in that a control signal (e.g. pressurized air) is fed to the actuation port 22.
• a control signal e.g. pressurized air
• the connection between the outlet port 20 and the exhaust port 21 is broken, while the pressurized fluid from the source of pressurized fluid flows through the inlet port 19, the annular chamber 26, the choke hole 28, the hole openings 29, the annular chamber 31 and the outlet port 20 into the connected pressurized fluid system.
• a pressure build-up will occur relatively slowly, owing to the limited flow through the choke hole 28, so that possibly mal-positioned cylinder pistons or the like are dis ⁇ placed into distinct positions.
• a desired flow rate can be set by means of the adjusting screw 24, whereby the position of the sealing ring 16 can be varied relative to the choke hole 28.
• the choke hole 28 may be more or less covered by the sealing ring 16, so that the effective cross-sectional area is adjusted correspondingly.
• the pressurized fluid flow can increase quickly,, so that the furthe pressure build-up in the connected pressurized fluid system occurs relatively quickly during this second phase of the pressurized fluid supply.
• valve slide 8 When the control valve is to be closed again and the pressurize fluid system is to be vented, the valve slide 8 is relocated in that the pressure on the signal port 22 is brought to cease, whereby the compression spring 18 displaces the valve slide and the piston body 11 to the left in the figures, and the position according to Fig. 1 is reached.
• the choke opening 28 does not have to be an elongated hol as shown, but can be constituted by e- " g . a number of small holes distributed axially and/or circumferentially in such a way that the effective cross-sectional area is adjustable.
• One or several of these holes may furthermore consist of an elongated slot extending all the way to the hole openings 27. Even the latter may have a different configuration and a vari ⁇ able, effective cross-section,.
• the essential feature is that the choke opening 28 has a considerably smaller cross sectional area than the one of the flow passage formed by the hole ope ⁇ nings 27.
• the adjustin screw 24 may be eliminated or replaced by a stop displac ⁇ ably arranged on the shaft 8b of the valve slide, e.g. a nut which i screwed onto the shank and replaces the stop ring 13 as well.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fluid-Driven Valves (AREA)
• Valve Device For Special Equipments (AREA)
• Superconductors And Manufacturing Methods Therefor (AREA)
• Control Of Fluid Pressure (AREA)

Priority Applications (3)

Applications Claiming Priority (1)

Publications (1)

Family

ID=20350744

Family Applications (1)

Country Status (9)

Families Citing this family (7)

Citations (8)

Family Cites Families (3)

• 1983
  • 1983-04-11 SE SE8301993A patent/SE442434B/sv not_active IP Right Cessation
• 1984
  • 1984-04-09 JP JP59501759A patent/JPS60501020A/ja active Granted
  • 1984-04-09 AT AT84850112T patent/ATE28688T1/de active
  • 1984-04-09 WO PCT/SE1984/000129 patent/WO1984004147A1/en active IP Right Grant
  • 1984-04-09 HU HU842252A patent/HU197420B/hu not_active IP Right Cessation
  • 1984-04-09 EP EP84850112A patent/EP0122247B1/en not_active Expired
  • 1984-04-09 DE DE8484850112T patent/DE3465134D1/de not_active Expired
  • 1984-11-15 DK DK543384A patent/DK159796C/da not_active IP Right Cessation
  • 1984-11-23 FI FI844616A patent/FI73804C/fi not_active IP Right Cessation

Patent Citations (8)

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