EP0113708A1 - Dual control input flow control valve. - Google Patents
Dual control input flow control valve.Info
- Publication number
- EP0113708A1 EP0113708A1 EP82901677A EP82901677A EP0113708A1 EP 0113708 A1 EP0113708 A1 EP 0113708A1 EP 82901677 A EP82901677 A EP 82901677A EP 82901677 A EP82901677 A EP 82901677A EP 0113708 A1 EP0113708 A1 EP 0113708A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- control
- pressure
- chamber
- valve
- fluid
- 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.)
- Granted
Links
- 230000009977 dual effect Effects 0.000 title description 3
- 239000012530 fluid Substances 0.000 claims description 58
- 238000011144 upstream manufacturing Methods 0.000 claims description 2
- 230000004044 response Effects 0.000 abstract description 7
- 230000009471 action Effects 0.000 description 11
- 238000007789 sealing Methods 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 5
- 238000006073 displacement reaction Methods 0.000 description 3
- 230000036316 preload Effects 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 238000013022 venting Methods 0.000 description 2
- KKEBXNMGHUCPEZ-UHFFFAOYSA-N 4-phenyl-1-(2-sulfanylethyl)imidazolidin-2-one Chemical compound N1C(=O)N(CCS)CC1C1=CC=CC=C1 KKEBXNMGHUCPEZ-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000008707 rearrangement Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
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
- F15B13/0416—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor with means or adapted for load sensing
- F15B13/0417—Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves
Definitions
- This invention relates generally to flow control valves regulating, irrespective of variations in system pressure, the quantity of fluid flow to a- load. In more particular aspects this invention relates to flow control valves of a bypass type.
- this invention relates to flow control valves, in which the bypass member is controlled by a pilot valve.
- this invention relates to pilot operated flow control valves of a bypass type, which permit variation in the controlled pressure differential between valve inlet pressure and the load pressure, in response to an external control signal.
- the flow control valves of a throttling or bypass type regulate the flow of fluid to a load by automatically maintaining a constant pressure differential across an orifice leading to the load.
- the quantity of the flow is varied by the area of orifice, each area corresponding to a specific flow to the load, irrespective of the variations in the system pressure.
- the controlled constant pressure differential is usually selected quite high, providing a comparatively large throttling loss and therefore affecting the system efficiency.
- the forces necessary to vary the area of the orifice vary with the size of the valve and are usually quite high.
- Another object of this invention is to provide controls of flow control valve of a bypass type, through which control of flow to system load can be either accomplished by variation in area of the orifice, between the valve control and a fluid motor, while the pressure differential across this orifice is maintained constant at a specific level, or by control of pressure differential, acting across this orifice, while the area of the orifice remains constant.
- Fig. 1 is a diagrammatic representation of a pilot operated flow control valve provided with adjustment in the level of control differential from a certain preselected level to zero level, with fluid motor and system pump shown schematically;
- Fig. 2 is a diagrammatic representation of another embodiment of the pilot operated flow control valve of Fig. 1, with fluid motor and system pump shown schematically. Description of the Preferred Embodiments
- the hydraulic system shown therein comprises a fluid pump 10, which may be provided with an output flow control 11, connected to a reservoir 12.
- the fluid pump 10 is preferably of a fixed displacement type.
- the fluid pump 10 supplies pressure fluid into a fluid power circuit, composed of a differential bypass control, generally designated as
- the differential bypass control 13 bypasses a portion of flow delivered from the pump 10 to the reservoir 12, to regulate the pressure differential across variable orifice 14.
- the output flow control 11 of the pump 10 may be a conventional maximum pressure relief valve, well known in the art.
- the differential bypass control 13 is composed of bypass section, generally designated as 15a, a pilot section, generally designated as 16, a flow control section, generally designated as 17 and a signal throttling section, generally designated as 18.
- Discharge line 19 of pump 10 is connected to port 20 of differential bypass control 13 and through a check valve 21, line 22, variable orifice 14 and line 23 is also connected to the fluid motor 15.
- the fluid motor 15 is also connected by lines 23 and 69 with the differential bypass control, generally designated as 13.
- the bypass section 15a of the differential bypass control 13 comprises a housing 25 having an inlet chamber 26, a bypass chamber 27, a first control chamber 28 and an exhaust chamber 29, all of those cha bers being connected by bore 30, slidably guiding a bypass spool 31.
- the bypass spool 31, equipped with lands 32 and 33 and stop 34, is provided with throttling slots 35, terminated in cut-off edges 36, between the inlet chamber 26 and the bypass chamber 27.
- One end of the bypass spool 31 projects into the first control chamber 28, while the other end projects into the exhaust chamber 29 and is biased by a control spring 37.
- the exhaust chamber 29 is connected by passage 38 with the bypass chamber 27 and therefore with the system reservoir 12.
- the first control chamber 28 is connected by passage 39 with annular space 40 of the pilot valve section, generally designated as 16. Bore 41 connects annular space 40 with port 42 and a second control chamber 43 and axially guides a pilot valve spool 44.
- the pilot valve spool 44 equipped with metering land 45 and land 46> which define annular space 47, communicates with port 42 and projects into the second control chamber 43, where it engages a spring 48.
- Annular space 47 is connected by passage 49 with the exhaust chamber 29 and therefore the system reservoir 12.
- the second control chamber 43 is connected through passage 50 with the signal throttling section, generally designated as 18 and is also connected through passage 51 with the flow control section, generally designated as 17.
- Passage 51 connects the second control chamber 43 with a supply chamber 52, connected by bore 53 with a third control chamber 54 and an exhaust chamber 55.
- Bore 53 slidably guides a control spool 56, equipped with land 57, provided with throttling slots 58 and positioned between the supply chamber 52 and the third control chamber 54, a land 59 separating the supply chamber 52 and the exhaust chamber 55.
- the third control chamber 54 is connected by orifice 60 and passage 61 with the
- M exhaust chamber 55 which contains a spring 62, biasing the control spool 56 and is connected by passage 63 with the exhaust chamber 29.
- the second control chamber 43 is connected by passage 50 with chamber 64, which is selectively interconnected by metering orifice created by a stem 65 guided in bore 66 and provided with metering slots 67, with signal chamber 68.
- Signal chamber 68 is connected by line 69 with the fluid motor 15.
- the stem 65 is connected to an actuator 70, responsive to external control signal 71.
- Exhaust chambers 55 and 29, connected to the system reservoir 12 are also connected by passages 63 and 49 and orifice 72 with passage 39.
- the differential bypass control has bypass section 15a, pilot section 16 and flow control section 17 identical to those as shown in Fig. 1.
- a signal throttling section of Fig. 2, generally designated as 73, is different from the signal throttling section 18 of Fig. 1.
- the same components used in Figs. 1 and 2 are designated by the same numerals.
- the second exhaust chamber 43 is connected by passage 50 to chamber 74 of the signal throttling section, generally designated as 73.
- the signal throttling section 73 comprises a coil 75 retained in the housing, which guides an armature 76 of a solenoid, generally designated as 77.
- the armature 76 is provided with conical surface 78, selectively engageable with sealing edge 79 of inlet port 80 and venting passage 81, terminating in bore 82, guiding a reaction pin 83.
- the coil 75 is connected by sealed connector 84 to outside of housing 25, external control signal 85 being applied to the sealed connector 84.
- the differential bypass control 13 is introduced into a circuit between the pump 10 and fluid motor 15 and controls the fluid
- the fluid motor 15 can be substituted by any device to which fluid flow must be controlled.
- the differential bypass control 13 is composed of the bypass section 15a, the pilot section 16, the flow control section 17 and the signal throttling section 18.
- the bypass section 15a with its bypass spool 31 throttles with throttling slots 35 fluid flow between the inlet chamber 26, connected by discharge line 19 to the pump 10 and the bypass chamber 27, connected to the system reservoir 12 to automatically maintain a constant pressure differential across variable orifice 14, connected by line 23 with the fluid motor 15. This control action is accomplished in the following way.
- Fluid from upstream of variable orifice 14 of P pressure is supplied to port 42 where, reacting on the cross-sectional area of the pilot valve spool 44, generates a force tending to move the pilot valve spool 44 upward, to connect P, pressure through annular space 40 and passage 39 to the first control chamber 28 and therefore to increase the pressure level in the first control chamber 28.
- Fluid at load pressure Pw which is the pressure acting downstream of variable orifice 14, is supplied by line 69 to the signal throttling section 18.
- the pilot valve spool 44 subjected to P, and P 2 pressures and the biasing force of spring 48 will reach a modulating position, in which by throttling action of metering land 45 will regulate the pressure in the first control chamber 28 and therefore the bypass action of the bypass spool 31 to regulate the pump P, pressure which is higher, by a constant pressure differential ⁇ P, than P_ pressure and equal to the quotient of the biasing force of spring 48 and the cross-sectional area of the pilot valve spool 44.
- the pilot valve spool 44 subjected to low energy pressure signals, will act as an amplifying stage using the energy derived from the pump 10 to control the position and therefore the bypass action of the bypass spool 31.
- Leakage orifice 72 connecting the first control chamber 28 through passage 49 and the exhaust chamber 29 to the reservoir 12, is used, in a well known manner, to increase the stability of the pilot valve spool 44. If P 2 pressure is approximately equal to Pw pressure which is the case when the stem 65 is in the position fully displaced to the right from the as shown in Fig. 1, the bypass section 15a, by throttling fluid flow from the inlet chamber 26 to the bypass chamber 27, will automatically maintain a constant pressure differential ⁇ p between the pump pressure P, and P 2 pressure in the second control chamber 43 and with ⁇ Py becoming ⁇ P, will also maintain a constant pressure differential across variable orifice 14.
- Fluid under P 2 pressure is conducted through passage 51 to the supply chamber 52 of the flow control section 17, from where it is throttled by throttling slots 58 on its way to the third control chamber 54.
- the control spool 56 will automatically assume a modulating position, in which it will sufficiently throttle fluid at P 2 pressure to a constant pressure level in the third control chamber 54, equivalent to the preload of the spring 62. Since a constant pressure level is automatically maintained in the third control chamber 54 and since the exhaust chamber 55 is maintained at a constant atmospheric pressure level, constant flow will take place through orifice 60, independent of P 2 pressure level. Therefore the flow control section 17 will automatically maintain a constant preselected flow level from the second control chamber 43.
- the pressure differential, acting across orifice 14 and the flow through orifice 14 can be controlled from maximum to minimum by the signal modifying section composed of constant flow control section 17 and signal throttling section 18, each flow level automatically being controlled constant by the differential bypass control 13, irrespective of the variation in the load pressure Pw.
- Action of one control can be superimposed on the action of the other, providing a unique system, in which, for example, a command signal from the operator, through the use of variable orifice 14 can be corrected by signal 71 from a computing device, acting through the signal throttling section 18.
- the flow control valve is similar in construction and performs in a similar way as that of Fig. 1.
- the bypass section, the pilot section and the flow control section of Figs. 1 and 2 are identical.
- the signal throttling sections of Figs. 1 and 2 represent different embodiments of the control, which provides similar control characteristics.
- the signal throttling section of Fig. 2, generally designated as 73 contains the solenoid, generally designated as 77, which consists of coil 75, secured in the housing 25 and the armature 76, slidably guided in the coil 75.
- the armature 76 is provided with conical surface 78, which, in cooperation with sealing edge 79, regulates the pressure differential ⁇ Px between inlet port 80 and passage 50.
- the sealed connector 84 in the housing 25, well known in the art, connects the coil 75 with external terminals, to which the external signal 85 can be applied.
- a solenoid is an electro-mechanical device, using the principle of electro-magnetics, to produce output forces from electrical input signals.
- the force developed on the solenoid armature 76 is a function of the input current. As the current is applied to the coil 75, each specific current level will correspond to a specific force level, transmitted to the armature. Therefore, the contact force between the conical surface 78 of the armature 76 and sealing edge 79 to housing 25 will vary and be controlled by the input current.
- the cross-sectional area of the reaction pin 83 must always be smaller than the area enclosed by sealing edge 79, so that a positive force, due to the pressure differential ⁇ Px, opposes the force developed by the solenoid 77.
- the reaction pin 83 permits use of larger flow passages, while also permitting a very significant reduction in the size of solenoid 77, also permitting the solenoid 77 to work in the higher range of ⁇ Px.
- the second control chamber 43 is connected to the flow control section 17.
- the schematically shown actuator 70 of Fig. 1 may respond to many types of external control signals 71.
- the stem 65 can be manually operated through a mechanical linkage.
- the actuator 70 may be of a hydraulic or pneumatic type, responding to a hydraulic or pneumatic external control signal, it may be a solenoid or a torque motor, responding to an electrical input current signal, or it may be a stepper motor, responding to a digital electrical external control signal.
- Figs. 1 and 2 show a dual input flow control system supplying a fluid motor operating a load W.
- the check valve 21, preventing reverse flow from the fluid motor may be of some value. It should be noted that location of the check valve 21, in the position as shown, or in line 22 past port 42, will to some degree change the operating conditions of the flow control. With the check valve 21 in position as shown in Figs. 1 and 2, variable orifice 14 open and ⁇ PX larger than ⁇ P, the pilot section 16 will be operated by power derived from load W and P, will equal zero, with the pump 10 completely unloaded.
- the flow control valves of Figs. 1 and 2 may control the fluid flow to other devices than fluid motor, for example fuel flow to fuel nozzle or flow of fluid used in a chemical process or mixing operation. In such instances the flow to the device
- MP can be controlled, at all Pw pressure levels, at constant ⁇ Py by variation in flow area of orifice 14.
- the flow can also be controlled by variation in ⁇ Py, but that can be accomplished at Pw pressure levels higher than ⁇ P.
- a constant pressure differential throttling device in the form for example of a spring loaded check, located downstream of variable orifice 14 and throttling the fluid flow to the device, at a level higher than ⁇ p, can be inserted in line 23. In this way Pw can not drop below the minimum value of ⁇ P.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Flow Control (AREA)
- Control Of Fluid Pressure (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
Une soupape de commande de débit actionnée par pilote du type à bypass (13) effectue automatiquement la régulation du débit passant par l'orifice de commande (14) pour maintenir une pression différentielle relativement constante entre la pression d'alimentation (P1) et la pression de charge (Pw) et qui permet de varier le niveau de la pression différentielle (DELTAPy) en réponse à un signal de commande externe (71) pendant que cette pression différentielle (DELTAPy) est maintenue constante à chaque niveau commandé.A pilot operated flow control valve of the bypass type (13) automatically regulates the flow through the control port (14) to maintain a relatively constant differential pressure between the supply pressure (P1) and the charge pressure (Pw) and which makes it possible to vary the level of the differential pressure (DELTAPy) in response to an external control signal (71) while this differential pressure (DELTAPy) is kept constant at each controlled level.
Description
Claims
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PCT/US1982/000481 WO1983003644A1 (en) | 1982-04-19 | 1982-04-19 | Dual control input flow control valve |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0113708A1 true EP0113708A1 (en) | 1984-07-25 |
EP0113708A4 EP0113708A4 (en) | 1986-02-10 |
EP0113708B1 EP0113708B1 (en) | 1988-11-02 |
Family
ID=22167939
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19820901677 Expired EP0113708B1 (en) | 1982-04-19 | 1982-04-19 | Dual control input flow control valve |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0113708B1 (en) |
JP (1) | JPS59500574A (en) |
DE (1) | DE3279180D1 (en) |
WO (1) | WO1983003644A1 (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2143975A1 (en) * | 1971-06-29 | 1973-02-09 | Koppen Lethem Trading |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4828884A (en) * | 1971-08-19 | 1973-04-17 | ||
US4153075A (en) * | 1975-11-26 | 1979-05-08 | Tadeusz Budzich | Load responsive control valve |
US4282898A (en) * | 1979-11-29 | 1981-08-11 | Caterpillar Tractor Co. | Flow metering valve with operator selectable boosted flow |
US4330991A (en) * | 1980-01-02 | 1982-05-25 | Tadeusz Budzich | Load responsive system controls |
US4285195A (en) * | 1980-01-02 | 1981-08-25 | Tadeusz Budzich | Load responsive control system |
US4327627A (en) * | 1980-01-07 | 1982-05-04 | Tadeusz Budzich | Load responsive fluid control valve |
US4327763A (en) * | 1980-01-11 | 1982-05-04 | Tadeusz Budzich | Dual control input flow control valve |
US4325289A (en) * | 1980-01-11 | 1982-04-20 | Tadeusz Budzich | Load responsive fluid control valve |
US4333389A (en) * | 1980-01-18 | 1982-06-08 | Tadeusz Budzich | Load responsive fluid control valve |
-
1982
- 1982-04-19 WO PCT/US1982/000481 patent/WO1983003644A1/en active IP Right Grant
- 1982-04-19 EP EP19820901677 patent/EP0113708B1/en not_active Expired
- 1982-04-19 JP JP50165882A patent/JPS59500574A/en active Pending
- 1982-04-19 DE DE8282901677T patent/DE3279180D1/en not_active Expired
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2143975A1 (en) * | 1971-06-29 | 1973-02-09 | Koppen Lethem Trading |
Non-Patent Citations (1)
Title |
---|
See also references of WO8303644A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO1983003644A1 (en) | 1983-10-27 |
EP0113708A4 (en) | 1986-02-10 |
JPS59500574A (en) | 1984-04-05 |
DE3279180D1 (en) | 1988-12-08 |
EP0113708B1 (en) | 1988-11-02 |
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Legal Events
Date | Code | Title | Description |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
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