FR2837896A1 - Water flow overspeed control valve for irrigation supply has valve housing containing obturator and counter weight controlled by hydraulic cylinder - Google Patents

Abstract

The water flow overspeed control valve for an irrigation feed has a valve housing (1) with a fluid passage (2) having a movable obturator (3). It has a speed sensor plate (23) and a main counterweight (6) connected to the obturator. The obturator has two retainers to hold it in the open position, formed by a stop (8) and a hydraulic cylinder (13). The cylinder is purged if a flow overspeed is detected, to allow release of the counterweight.

Description

temperature.

OVERSPEED VALVE

  The present invention relates to valves for controlling a flow of liquid in a pipe such as a water supply pipe for irrigation, potable water, dam water. The invention relates more particularly to such valves provided with an automatic control device for closing in the event of

  liquid flow overspeed.

  The automatic closing control device is generally made up of various mechanical parts which are mounted movable with respect to each other, some being movable in rotation, others being movable in translation or sliding. The water supply pipes are fitted with valves with control devices, allowing on the one hand the voluntary opening and closing of the corresponding valve, and on the other hand ensuring a safety function by automatic closing of the valve on the assumption that the liquid would flow with a speed greater than a speed threshold

predetermined.

  One difficulty lies in the fact that the valves are open for very long periods, and generally they remain open almost permanently, but they must nevertheless ensure the automatic closing function after long periods of inactivity. In other words, the valve must close effectively in the event of overspeed while its parts have remained fixed relative to each other for a very long time. The relative immobility of the control parts significantly increases the risk of the parts seizing up or sticking after a long period of inactivity. In addition, the valve must be able to close in the absence of any external source of energy, since the valve is generally placed in a location far from any external energy supply, so that there is no energy important available to take off suddenly

  on seized control parts.

  To ensure automatic closing of the valve in the absence of any external source of energy, a valve has already been devised, comprising a valve body having a fluid passage in which is placed a movable selective closure means, with a fluid flow speed sensor in the form of a pallet positioned in transverse orientation in the fluid passage and movable in rotation around a transverse axis offset laterally. A main counterweight, mechanically coupled by means of movable selective shutter, is arranged to descend from an open position to a closed position under the effect of gravity by moving the selective shutter means towards a position obstruction of the fluid passage. The counterweight is retained by means for retaining the main counterweight, arranged to retain the main counterweight against gravity in its open position in which the selective closure means frees the passage of fluid. Control means inhibit the action of the main counterweight retaining means to ensure automatic closure of the valve when the fluid flow speed sensor detects that the fluid flow speed is

  higher than a predetermined speed threshold.

  The remote reset function, or opening of the valve after a closing sequence, is generally carried out by providing a cylinder which, supplied by a pressure source,

  pushes the main counterweight back to its open position.

  To ensure automatic closing of the valve, the fluid flow speed sensor causes the tilting of an eccentric flyweight which actuates a control fluid distributor to purge the main counterweight retaining cylinder. When the cylinder is vented, the main counterweight can tilt down by pushing the cylinder, and then ensures the displacement of the closure means

  selective moving towards the valve closing position.

  A drawback of these known devices is the risk of leaks in the hydraulic circuit of the jack, leaks which can occur at any location along the control fluid circuit between the jack and the pressure source which makes it possible to actuate it. These leaks, even slight, can cause a gradual drop in pressure in the hydraulic fluid circuit, which prevents the normal ascent of the main counterweight to the open position, and above all which risks releasing the counterweight which gradually switches to the d position. shutter. Conversely, if we imagine designing purely mechanical means to release the main counterweight and ensure the automatic closing of the valve, then there is a risk of seizure after a long period of immobility of the mechanical parts control valve. [The mechanical systems also present a risk of inadvertent unlocking, and therefore of closing the valve, in the event of vibrations due for example

  a turbulent flow of fluid or any other external cause.

  Reliability is therefore not satisfactorily ensured.

  The problem proposed by the present invention is to design a new overspeed valve structure, which provides good safety for holding open for a long period of time, even in the presence of parasitic vibrations, while retaining the closing safety function in good reliability conditions @, while retaining a simple means of resetting the main counterweight by actuating a cylinder supplied by a

pressure source.

  In addition, the invention aims to take advantage of the presence of a vArin which not only provides a simple reset function of the main counterweight, but also provides a Z5 function of damping the movement of the main counterweight during the

closing the valve.

  The invention further aims to realize all of these

  functions using a reduced number of parts.

  Another ob] and of the invention is to provide a particularly reliable operation, by experiencing the presence of all parts in translation, and by providing as much as possible rotational movements of the mechanical parts one by

compared to others.

  To achieve these and other objects, an overspeed valve according to the invention, for liquid flow, is provided with an automatic shutdown control device in the event of liquid flow overspeed. The valve comprises: - a valve body having a fluid passage in which is placed a movable selective closure means, - a fluid flow speed sensor, in the form of a pallet positioned in transverse orientation in the passage of fluid and mobile in rotation around a transverse arUre of pallet offset laterally, - a main counterweight, mechanically coupled by means of mobile selective closure, and arranged to descend under the effect of gravity from an elevated position of opening to a lowered closed position by moving the movable selective closure means towards a position for closing the fluid passage, - main counterweight retaining means, arranged to retain the main counterweight against the gravity in 1S its open position in which the movable selective closure means frees the passage of fluid, - control means, inhibiting the action of the mo main counterweight retaining yen to automatically close the valve when the fluid flow speed sensor detects that the fluid flow speed is greater than a predetermined speed threshold; according to the invention: - the retaining means comprise two separate retaining means, each ensuring the retaining of the main counterweight in the open position, - the first retaining means is a retractable mechanical stop, urged by the control means to be moved by the control means from a retaining position of the main counterweight to a releasing position of the main counterweight in the event of overspeed, - the second retaining means is a hydraulic cylinder, engaged on the main counterweight and arranged to recall the counterweight main in the open position and to retain it in this position, and supplied by a distributor itself actuated by the control means to put the hydraulic cylinder to the purge in case of overspeed and thus release the main counterweight for the

closing the valve.

  By this structure, a great flexibility of rearming control is achieved at the same time by displacement of the main counterweight towards the open position by means of the jack, a great operating reliability because the maintenance in full opening and the automatic closing of the valve. are ensured even in the event of leaks in the hydraulic circuit or in the event of vibrations. The valve effectively remains in the open position even in the case of such ends of the hydraulic circuit, since the counterweight is then retained by the retractable mechanical stop. Conversely, the valve remains effectively in the open position even in the case of vibrations liable to displace the retractable mechanical stop, since the counterweight is then retained by the jack. And these functions are carried out thanks to a system which

  contains a reduced number of additional parts.

  According to an advantageous embodiment, the retractable mechanical stop comprises a lever, movable around a tranaversal arUre between a retaining position and a release position, and in axial support against a portion of the main counterweight from which it escapes by rotation during of a transverse stress by the control means, the lever then coming simultaneously into lateral support against an actuating member of the dispenser to simultaneously put to the purge

the hydraulic cylinder.

  Preferably, the end of the lever carries a roller which

  rolls in axial support on a cam of the main counterweight.

  According to the invention, the control means can advantageously comprise an eccentric counterweight, rotatably mounted on an axis to pivot between an armed dressoe position above the axis and a triggered position, pivoted downward and in abutment against the lever to rotate it to the release position. The masseloUte is stressed by a cam coupled to the transverse pallet shaft which pushes it away from its armed position and beyond its upper unstable equilibrium position when the pallet is pushed by a current of fluid to be checked whose speed is greater than the predetermined speed threshold. Preferably, the cam is adjustable by rotation around

the transverse pallet order.

  The pallet can advantageously be rotated around its transversal pallet shaft towards its transverse orientation by a pallet counterweight mounted on a rod of adjustable length. We thus adjust the flow of the fluid stream

  command which causes the valve to close.

  The pallet cam can advantageously be in abutment against a roller of the masseloLte. This avoids any sliding contact, and promotes rolling contacts, which limit the risk of seizing after a long stop time. The massaging roller can be made of hard metal, violating the creep risks which would progressively increase the triggering threshold of the valve. All the active members of an automatic closing control device can advantageously be stored in a casing adjacent to the valve body, and are isolated from the fluid controlled by a seal on the pallet rear. This makes a particularly compact device, which can be integrated on the

valve itself.

  Other objects, features and advantages of

  The present invention will emerge from the following description of modes

  particular realization, made in relation to the attached figures, among which: - Figure 1 is a schematic side view of an overspeed valve according to the present invention, in the open position; - Figure 2 is a front view of the overspeed valve of Figure 1 in the open position; - Figure 3 is a cat view of the overspeed valve of the] 0 Figure 1, in the closed position; and - Figure 4 is a front view of the overspeed valve of the

Figure 1 in the closed position.

  In the embodiment illustrated in the figures, the overspeed valve comprises a valve body 1 having a fluid passage 2 in which is placed a mobile selective sealing means 3 such as a butterfly, or a ball, or any other known closure means movable between an open position and a

closed position.

  In the embodiment illustrated in the figures, the movable selective shutter means is a butterfly which moves by rotation around a diametral shaft 4. All the active members of the automatic valve closing control device are housed in a casing 5

  which is placed adjacent to the valve body 1.

  A main counterweight 6 is mounted on the diametral shaft 4 of the movable selective closing means 3, and is cantilevered to produce the rotation of the diametral shaft 4 under the effect of gravity. In FIGS. 1 and 2, the main counterweight 6 is shown in the open position, placed above the diametral shaft 4. Under these conditions, under the effect of gravity, the main counterweight 6 can tilt towards the bottom of 90 as indicated by the arrow 7, driving in rotation the diametral arUre 4 and the movable selective shutter means 3, thus moving the movable selective shutter means 3 to a position

  obstructing the fluid passage 2.

  Main counterweight retaining means 6 are arranged to retain the main counterweight 6 against gravity in an open position illustrated in FIGS. 1 and 2, position in which the movable selective shutter means

3 frees the passage of fluid 2.

  The retaining means comprise two separate retaining means, each ensuring the retaining of the main counterweight 6 in

open position.

  The first retaining means is a retractable mechanical stop, generally identified by the reference numeral 8, urged by control means to be moved by the control means from a retaining position of the main counterweight, illustrated in FIG. 1 up to a release position of the main counterweight illustrated in FIG. 3,

  overspeed of the fluid to be controlled.

  In the illustrce embodiment, the retractable mechanical stop 8 comprises a lever 9 movable around a transverse shaft 10 between a retaining position (Figure 1) and a release position (Figure 3), and in axial support against a portion 11 of the main counterweight 6 from which it escapes by rotation during a transverse stress by the control means. Advantageously, the main counterweight 6 is connected to the diametral shaft 4 by an arm 6a which offset the main counterweight 6 away from the diametral shaft 4. The main counterweight 6 is also placed laterally relative to the arm 6a, as illustrated in the figures, so that the main counterweight 6 is in unstable equilibrium when the arm 6a is vertical above the diametrical shaft 4, ensuring an effort of

  rotation by the effect of gravity.

  The counterweight portion 11 against which the lever 9 is axially supported may advantageously be a short longitudinal cam of the arm 6a, initially arranged in an orientation perpendicular to the longitudinal axis of the lever 9. Thus, the lever 9 is supported on the cam 11 without any effort opposing a lateral movement of the end of the lever 9 along the cam 11. Preferably, the end of the lever 9 carries a roller 12 which rolls on the cam 11, eliminating any effort of friction capable of opposing the free pivoting of the lever 9 around

its transverse arUre 10.

  As long as the lever 9 is in the retaining position, perpendicular to the arm 6a, it retains the main counterweight 6 against a pivoting around its diametral shaft 4, and maintains

  therefore the valve in the open position illustrated in FIGS. 1 and 2.

  On the other hand, when the lever 9 pivots a few degrees around its transverse shaft 10, it reaches the end of the cam 11 and it then escapes the cam 11 and is in the release position, allowing the main counterweight to pivot freely. 6 around its diametral shaft 4, which counterweight then causes the rotation of the movable selective obturation means 3 until

shutter position.

  The second means for retaining the main counterweight 6 is a hydraulic cylinder 13, engaged on the main counterweight 6 and arranged to return the main counterweight 6 to the open position and to retain it in this position. The hydraulic cylinder 13 is supplied by a distributor 14 which makes it possible either to put it in communication with a pressure source 15, or to put it to the purge by returning the control fluid to

  a reserve of control fluid 16.

  S The dispenser 14 includes an actuating member 17, in the form of a projecting rod, facing the lever 9. When the lever 9 is rotated towards its release position, the latter comes to bear laterally against the member d actuation 17 of the distributor

  14 to simultaneously purge the hydraulic cylinder 13.

  In other words, during its pivoting, the lever 9 causes the release of the main counterweight 6 both by venting the hydraulic cylinder 13 and by escaping the roller.

12 away from cam 11.

  The control means according to the invention comprise an eccentric weight 18, mounted at the end of an arm 19 and pivoting about an intermediate axis 20. The counterweight 18 can pivot around its axis 20 between an armed position (FIG. 1) erected above the axis 20 and a triggered position (FIG. 3) in which it is lowered. In the triggered position, illustrated in FIG. 3, the counterweight 18 bears against the lever 9 to

  rotate it to the release position.

  In its armed position illustrated in FIG. 1, the counterweight 18 is biased by a cam 21 coupled to a transverse pallet shaft 22. The transverse pallet arUre 22 passes through the valve body 1 in leaktight manner, and carries at its end inside the valve a centered Z3 pallet which

  found in transverse orientation in the fluid passage 2.

  Thus, the pallet 23 is movable in rotation around the shaft

  transverse pallet 22 which itself is offset laterally.

  The operation of the device is generally as follows: in the open position illustrated in FIGS. 1 and 2, the pallet 23 located in the flow of fluid to be checked in the fluid passage 2 is subjected to the thrust of the fluid. This push tends to rotate the pallet 23 around the transverse arUre of the pallet 22. As long as this thrust is less than a limit value defining a speed threshold prAd6Le = minA, the device remains in the state illustrated on the

Figures 1 and 2.

  When the fluid increases in speed, the push on the pallet 23 increases, and tends to pivot the pallet around 3 its tranaversal pallet arDre 22 from side to side. Beyond a speed threshold prAdAteminA, this pushing causes a rotation of the transverse pallet shaft 22 which, by the cam 21, causes the rotation of the counterweight 18 bringing it beyond its position of Unstable equilibrium around its axis 20. The weight 18, under the action of gravity, is then rotated and abuts against the left lever 9 of its transverse arEre, causing the rotation of the lever g around the transverse arUre 10 in the opposite direction to the alguilles of a watch. By this rotation, the roller 12 escapes from the cam 11 of the main counterweight 13 6, and, simultaneously, the lever 9 presses on the actuating member 17 of the distributor 14 which then purges the hydraulic cylinder 13, which hydraulic cylinder 13 also releases the main counterweight 6. The retaining means of the main counterweight, constituted by the lever 9 and the hydraulic valve 13, 2U are thus inhibited. Under the effect of gravity and its 11bAration, the main counterweight 6 then rotates counterclockwise as 111ustrA by arrow 7, causing the rotation of the diamAtral shaft 4 and the displacement from the movable selective sealing means 3 towards the closing position of the fluid passage 2. The valve then takes

  the closed state as illustrated in figure 3.

  The device can easily be fitted with various sensors making it possible to transmit information on the state of

valve.

  For example, it is possible to provide a sensor 30 which gives the information that the weight 18 is in the closed position, ready to ensure the closing of the valve. A sensor 31 can be provided to give the information that the weight 18 is in the triggered position, after pivoting of the lever 9. Another] 5 sensor can be provided to give information about the position of the

main counterweight 6.

  The pallet 23 and its transverse pallet shaft 22 can be rotated by a pallet counterweight 24 mounted eccentrically on a rod 25 of adjustable length, which recalls the pallet 23 towards its transverse orientation in the fluid passage 2. It is thus possible adjust the necessary force of the flow of fluid to control for sufficient rotation of the pallet 23 causing the tilting of the weight 18 and the

fe = valve measurement.

  The cam 21 of the pallet can advantageously be supported on a roller 26 of the hammer arm 18. This thus avoids friction which is liable to interfere with pivoting and tripping.

of the device.

  Preferably, the assembly 18 also includes mechanical coupling means with the main counterweight 6, said coupling means ensuring the return of the counterweight 18 to the armed position (FIG. 1) when the main counterweight 6 is itself moved to its position opening by the cylinder

hydraulic 11.

  Preferably, the hydraulic cylinder 13 is supplied with control fluid by a pressure source reserved for control fluid 16, the pressure source Atant pilot distance to selectively ensure the movement of the device by displacement

  from the main counterweight 6 to its open position.

  The active members of the automatic control device for fe = meture of the valve, logAs in the cowling 5, are isolated from the fluid controlled by a seal on the transverse pallet arEre 22. The present invention is not limited to the modes of which have been explicitly described, but it includes the various variants and generalizations contained in the field

of the claims below.

Claims (7)

  1 - Valve for liquid flow, provided with an automatic closing control device in the event of overspeed of liquid flow, comprising: - a valve body (1) having a fluid passage (2) in which is placed a selective mobile shutter means (3), - a fluid flow velocity sensor, in the form of a pallet (23) positioned in transverse orientation in the fluid passage (2) and movable in a roLaLion around '' a transverse pallet shaft J0 (22) of lateral transport, - a main counterweight (), mechanically coupled by means of mobile selective shutter (3), and arranged to descend under the effect of gravity from a position raised from opening until a lowered closing position by moving the movable selective shutter means 13 (3) to a fluid passage shutter position (2), - means for retaining the main counterweight (), arranged to retain the main counterweight weighs in its posiL opening position in which the movable selective sealing means (3) frees the passage of fluid (2), - control means, inhibiting the action of the main counterweight retaining means (6) to ensure the automatic closing of the valve when the fluid flow velocity sensor (23) detects that the fluid flow speed is greater than a preloaded velocity, characterized in that: - the retaining means comprise two separate retaining means, each ensuring the retention of the main counterweight (G) in the open position, - the first retaining means is a retractable mechanical stop (8 !, urged by the control means to move it by the control means from a retaining position from the main counterweight () to a position to release the main counterweight () in the event of overspeed, - the second retaining means and a hydraulic valve (13), engaged on the main counterweight (6) and arranged to recall the c main weight () in the opening position eL to hold it in this position, and supplied by a distributor (14) itself actuated by the control means to put the hydraulic cylinder (13) to the purge in case of overspeed and free as well   the main counterweight (6) for closing the valve.   S 2 - Valve according to claim 1, characterized in that the retractable mechanical stop (8) comprises a lever (9), movable around a transverse shaft (10) between a retaining position and a release position, and in axial support against a portion (11) of the main counterweight (6) from which it escapes by rotation during a transverse stress by the control means, the lever (9) then coming into lateral support against an actuating member (17 ) of the distributor (14) to put   simultaneously with the bleed the hydraulic cylinder (13).   3 - Valve according to claim 2, characterized in that 1S the end of the lever (9) carries a roller (26) which rolls in support   axial on a cam (11) of the main counterweight (6).   4 - Cylinder according to one of claims 2 or 3,   characterized in that the control means comprise an eccentric weight (18), rotatably mounted on an axis (20) to pivot between an armed dressoe position above the axis (20) and a triggered position, pivoted downwards and in abutment against the lever (9) to rotate it in the release position, and urged by a cam (21) coupled to the transverse pallet shaft (22) which pushes it away from its armed position and at beyond its upper unstable equilibrium position when the pallet (23) is pushed by a current of fluid to be controlled,   the speed is higher than the predetermined speed threshold.   - Valve according to claim 4, characterized in that the cam (21) is adjustable by rotation around the shaft pallet cross (22).   6 - valve according to any one of claims 1 to 5,   characterized in that the pallet (23) is rotated around its transverse pallet shaft (22) towards its transverse orientation by a pallet counterweight (24) mounted   on a rod (25) of adjustable length.   7 - Valve according to claim 6, characterized in that the cam (21) of the pallet bears against a roller (26) of the masseloLte (18).   8 - valve according to any one of claims 1 to 7,   S characterized in that the hydraulic cylinder (13) is supplied with control fluid by a pressure source (15) with reserve of control fluid (16), the pressure source (15) being remotely controlled to selectively ensure the resetting the device by moving the main counterweight (6) to its position opening.   9 - valve according to any one of claims 1 to 8,   characterized in that all the active members of the automatic closing control device are housed in a cover (5) adjacent to the valve body (1) and are isolated from the fluid to be controlled   by a joint of the pallet transverse shaft (22).   - Valve according to any one of claims 1 to   9, characterized in that the counterweight (18) comprises mechanical coupling means with the main counterweight (6), said coupling means ensuring the return of the masseloUte (18) in the armed position when the main counterweight (6) is it -even