FR3024204A1 - VALVE CLOSING DEVICE BY OPERATING THE RELIEF VALVE - Google Patents

Abstract

Expansion device (1) comprising a movable element (20) displaceable in an expansion chamber (6) having a movable wall connected to the movable element (20), characterized in that: - the movable wall comprises an external portion ( 21) and an inner portion (22) coaxially mounted for sliding from a supply position of a counter-expansion chamber to a fluid isolation position of a counter-expansion chamber; - Displacement means (15) of the inner portion (22) act on the inner portion (22) independently of the outer portion (21); a first elastic element (26) pushes the outer portion (21) against a pressure in the counter-expansion chamber (40); - Stop means (35, 37) are arranged between the inner portion (22) and outer (21).

Description

FIELD OF THE INVENTION The present invention relates to the expansion of fluids and more particularly the expansion devices incorporating a closure valve.

BACKGROUND OF THE INVENTION A single-stage fluid expansion device generally comprises a chamber provided with a fluid inlet port and a fluid outlet port. A piston movable in the chamber comprises a substantially disk-shaped portion which separates the chamber into two volumes forming, for one, an expansion chamber and, for the other, a counter-expansion chamber. The piston also comprises a portion having a free end which projects into the expansion chamber and which is provided with a sealing member, such as an elastomer buffer, capable of closing off the fluid inlet port. . A channel drilled in the projecting portion connects the relaxation chamber and the counter chamber. A helical return spring extends from a wall of the expansion chamber to the disk-shaped portion of the piston and urges the piston to oppose the effect of pressure in the counter. relaxation chamber and thus to maintain the port of arrival of open fluid. The force exerted by this return spring is calibrated and defines the pressure at the outlet of the expansion device. Upstream of the arrival port of the expansion device is often connected a shutoff valve of the fluid supply. It has been envisaged to implant the valve in the body of the expansion device but this considerably increases the weight and volume of the expansion device. Normative requirements, in particular relating to the capacity of the tap to be able to cut off the supply of fluid when the device is subjected to a torch flame, for example (so-called "flame exposure test"), require the use of These materials are expensive and fire-resistant and contribute to increasing and increasing the size of a device that integrates these two functions. One could have imagined to act directly on the piston so as to block it in a position in which the sealing member of the protruding portion is held against the fluid inlet port. This would have cut off the fluid supply without the need to add a dedicated faucet. Several difficulties 10 oppose such a design and in particular the fact that a direct action on the piston requires to exert a force opposing the action of the expansion spring on the piston. In the case of such a design, the effort required to close the supply is dependent on the variation of the expansion pressure and therefore causes premature wear of the expansion stage. The consequence is a random seal quality. The user is obliged to exert a large force on the piston, which may damage the arrival port and / or the sealing member and thus degrade the sealing of the sealing member. -port of arrival. OBJECT OF THE INVENTION An object of the invention is to reduce the bulk and the weight of a fluid expansion device incorporating a function of cutting off the fluid supply. SUMMARY OF THE INVENTION To this end, there is provided a device 30 for expanding a fluid, the device comprising a holding chamber provided with an arrival port and an exit port, a mobile movable element. in the expansion chamber between a supply position and a fluid isolation position of a counter-expansion chamber 35 having a movable wall connected to the movable element, the moving element comprising a channel connecting the chamber relaxing and against the room of relaxation. According to the invention, the movable wall of the expansion chamber 5 comprises an outer portion and an inner portion mounted coaxially with the outer portion to slide from the feed position in which the inner portion feeds the counter chamber. fluid expansion to the fluid isolation position in which the inner portion fluidly isolates the flash chamber from the arrival port; - Means for moving the inner portion to the closed position are arranged to act on the inner portion independently of the outer portion; A first elastic element is arranged to push the outer portion against a pressure in the counter-expansion chamber; - Stop means are arranged between the inner and outer portions so as to interact when the outer portion is moved under the effect of pressure in the counter-expansion chamber. There is thus obtained an expansion device for cutting off its fluid supply by moving the inner portion of the movable member. The force required to cut off the supply is independent of the force exerted by the elastic element acting on the outer portion of the movable element and corresponding to the desired expansion. The maneuvering force, especially for medical personnel in the case of medical applications (medical oxygen) is reduced. Advantageously, the movable element comprises a piston defining the movable wall of the counter-expansion chamber. There is thus obtained a piston expansion device comprising an inner portion and an outer coaxial portion.

According to another embodiment, the movable element comprises a cylinder resting on a membrane. This provides a membrane expansion device that can be used for applications in which the use of a membrane is required. According to a particular embodiment, the displacement means of the inner portion of the movable element comprise an elastic element. Thus, the force bringing the internal portion of the piston to the closed position is calibrated by the elastic element which limits the possibility that the user applies an excessive force on the internal portion likely to damage the arrival port. . The sensitivity of closure to aging is reduced. Indeed, the closing forces at the level of the sealing member are almost constant and insensitive to variations in upstream and downstream pressures, which makes it possible to implement the invention at a wide range of pressures (downstream pressure). higher) or relaxation (piston of larger diameter).

The invention also relates to an integrated pressure reducing valve assembly comprising a previously defined device and further comprising a secondary expansion stage installed downstream of the expansion device.

BRIEF DESCRIPTION OF THE DRAWINGS Reference is made to the appended figures in which: FIG. 1 is a diagrammatic sectional view of an expansion valve assembly incorporating a first embodiment of an expansion device according to the invention in a fluid intake phase, the expansion pressure not yet reached; FIG. 2 is a view identical to that of FIG. 1 in which the expansion device is at the end of the expansion phase; FIG. 3 is a view identical to that of FIG. 1 in which the fluid supply is cut off; FIG. 4 is a schematic representation of an integrated pressure reducing valve assembly comprising an expansion device according to the invention; - Figure 5 is a schematic representation of an integrated pressure regulator valve assembly incorporating a second embodiment of an expansion device 10 according to the invention, wherein the fluid supply is cut off; FIG. 6 is a view identical to that of FIG. 5, in which the fluid supply is open, the expansion pressure not yet being reached; - Figure 7 is a view identical to that of Figure 6, wherein the expansion device is at the end of the expansion phase.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, the integrated pressure regulator valve assembly according to the invention, generally designated 1, comprises a body 2 provided with a threaded end 3 adapted to be screwed onto a reservoir. a fluid such as a gas, which may be from a medical oxygen cylinder. The end 3 comprises a bore 4 supplying a fluid inlet port 5 which opens into an expansion chamber 6. The expansion chamber 6 comprises a first cylindrical section 6.1 into which the bore 4 opens and which opens into a second section 6.2. The second section 6.2, comprises an annular portion surrounding a portion of the first section 6.1 delimiting therewith a tubular step 7 projecting from an annular surface 27 in the second section 6.2. The second section 6.2 35 of the expansion chamber 6 opens into a bore 8 of diameter 3024204 greater than that of the second section 6.2. An outlet channel 9 connects an outlet 10 of expanded fluid with an outlet port 11 opening into the bore 8. A last bore 14 is formed from the face of the body 25 opposite the supply port 5 to open into the 8. The sections 6.1 and 6.2 of the expansion chamber 6, the bore 8 and the bore 14 are, here, coaxial. The bore 8 receives a disk 12 whose opposite face to the bore 14 defines a volume 13 in communication with the section 6.2 of the expansion chamber 6. A piston 20, forming a movable element, extends into the expansion chamber 6 and comprises an outer portion 21 substantially in the form of a ring and an inner tubular portion 22 slidably mounted in the outer portion 21, coaxially with the outer portion 21. The outer portion 21 of the piston 20 comprises a peripheral groove 23 which accommodates an O-ring 24 sealing between the outer portion 21 of the piston 20 and the wall of the second section 6.2 of the expansion chamber 6. A helical spring 26 is mounted in the second section 6.2 of the chamber The spring 26 has a first end 25 bearing against the annular surface 27 projecting from which the tubular step 7 extends and a second end 28 bearing against the outer portion. 21 of the piston 20 so that the spring 26 pushes the piston 20. The inner portion 22 of the piston 20 comprises a first end 22.1 engaged in the first section 6.1 of the expansion chamber 6 and a second end 22.2 engaged in a bore 21.1 of the outer portion 21. The two ends 22.1 and 22.2 of the inner portion 22 of the piston 20 respectively comprise grooves 29 and 30 respectively receiving an O-ring 31 and 32. The connection between the internal portion 22 and the wall of the first section 6.1 of the 3024204 7 expansion chamber 6 and the connection between the inner portion 22 and the outer portion 21 of the piston 20 are sealed. Thus the outer portions 21 and inner 22 define with the disk 12 a counter chamber 5 of relaxation 40 which includes the volume 13. The end 22.1 of the inner portion 22 also comprises a sealing member, here a buffer 33 of material elastomer or plastic facing the fluid inlet port 5. A first end of an axial channel 34 extending longitudinally in the inner portion 22 feeds a radial duct which is formed transversely in the inner portion 22, between the buffer 33 and the seal 31, so that the radial duct opens in the first section 6.1 of the expansion chamber 6.

The other end of the axial channel 34 opens at the end 22.2 of the inner portion 22 in the counter-expansion chamber 40 and thus connects the expansion chamber 6 and the counter-expansion chamber 40. The inner portion 22 comprises also an annular protrusion 20 35 on which rests the first end of a helical spring 36 having a second end bearing on a front face of the tubular step 7. The spring 36 is of a section - and therefore d a stiffness-lower than the section of the spring 26 and pushes the inner portion 22 against a shoulder 37 of the outer portion 21. The piston 20 can therefore move in the expansion chamber 6 between a position of fluid supply shown in Figure 1 in which the inner portion 22 discovers the arrival port 5 and feeds the counterplate chamber 40 fluid to a fluid isolation position shown in Figure 2 in which the internal portion 22 closes the arrival port by contacting the buffer 33 with the arrival port 5 and 35 thus fluidly isolates the counter-chamber 40 3024204 8 of the arrival port 5. The counter-chamber of relaxation 40 possesses therefore a movable wall defined by the surface of the piston 20 facing the disc 12. A lever-cam assembly 15 is housed in the bore 14. The disc 12 comprises a central bore 50 opening into the volume 13 and whose diameter is substantially equal to that of the inner portion 22. The bore 50 accommodates a cylindrical pin 51 projecting from the plate 52 of a pusher 53 extending into the bore 14. The pin 51 comprises a groove 54 receiving an O-ring 55 abuts against the walls of the bore 50. A coil spring 56 extends between the plate 52 and an inner surface 57 of a cap 58. This cap 58 is immobilized in the bore 14 by means of a staple. 60 cooperating with a 59th countersink t which extends in two holes made perpendicularly to the cutting plane. The end 61 of the pusher 53 opposite the stud 51 projects from the body 2 and comprises a circumferential groove 62. A lever 63 is hinged around an axis 64 radially crossing the end 61 of the pusher 53. The lever 63 is provided with a holding system in position comprising a ball 65 constrained by a spring 66 to cooperate with the groove 62 and which selectively locks the lever 63 in a first position (shown in FIG. 1) or a second position (shown in FIG. 3) corresponding to a rotation of the lever 63 by 180 ° about the axis 64. point of articulation of the lever 63 on the axis 64 and its geometry are defined so that the lever 63 30 has a cam profile which, under the effect of the spring 56, causes a displacement of the piston 53 towards the port of arrival 5 when it passes from the first to the second position. Thus, the passage of the lever 63 from the first to the second position causes a displacement of the pin 51 35 which then bears on the only inner portion 22 of the piston 20 and acts on it independently of the outer portion 21. This movement brings the buffer 33 into contact with the arrival port 5 and closes it. This situation is represented in FIG.

This results in a valve opening / closing in half a turn, allowing to have fixed and identifiable positions of the valve operating means. The operation of the device 1 will be described with reference to FIGS. 1 to 3. The lever 15 being in its first position (FIG. 1), the pressurized fluid enters through the arrival port 5 in the first section 6.1 of the chamber. 6 and flows through the channel 34 to invade the counter-chamber 40. Once the resultant on the piston 20 of the pressure in the counter-chamber of relaxation 40 is greater than the force exerted by the spring 26 on the outer portion 21 against this pressure, the inner 22 and outer 21 portions of the piston 20 move from the fully open position of the arrival port 5 (shown in FIG. 1) to a position closing the arrival port 5 (shown in Figure 2). At this time, the pressures respectively in the first section 6.1 of the expansion chamber 6 and in the counter-expansion chamber 40 are equal to the expansion pressure.

The equipment to be supplied connected to the outlet 10 then receives the relaxed pressure. The pressure prevailing in the first section 6.1 of the expansion chamber 6 and in the counter-expansion chamber 40 decreases as fluid consumption expanded by the equipment 30 connected to the outlet 10 reaches a value insufficient to counter the return force of the spring 26 which then returns the piston 20 to the fully open position of the arrival port 5 (Figure 1). A new relaxation cycle can then begin.

When he wishes to cut off the fluid supply of the expansion device 1, the user moves the lever 15 from the first position shown in FIG. 1 to the second position shown in FIG. 3. During this movement, the pin 51 bears on the inner portion 22 of the piston 20 and, under the effect of the spring 56, brings the inner portion 22 in the closed position of the arrival port 5. In addition to improved compactness, the expansion device 1 according to the invention has several advantages over existing solutions. The force exerted by the inner portion 22 on the arrival port 5 is calibrated and defined by the spring 56, the device according to the invention thus preserves the arrival port and ensures a good durability of the seal of this- ci in the closed position. The effort required to open the fluid supply is more important than the effort required to cut off the power supply. Thus, in the event of a shock on the lever, the latter is more inclined to adopt a power-off position or to remain in the power-off position, except in the zone of full opening where the lever is maintained by a truncation in the cam. It is possible to realize the lever in a fuse material, such as a synthetic material, whose cast iron will release the spring 56 and bring the internal portion 22 to the closed position of the arrival port 5. Thus, the requirements standards of the flame test are performed automatically. The particular arrangement of the expansion stages and the closing device of the arrival port reduces the path of the high pressure and prohibits any adiabatic compression phenomenon associated with an excessively rapid opening of the valve especially in use with oxygen. . This further increases the security of the device.

According to a preferred embodiment shown in FIG. 4, the expansion device 1 according to the invention is integrated with an integrated pressure regulator valve assembly 70 comprising a secondary expansion stage 71 installed downstream of the expansion device 1. The integrated pressure regulator valve assembly 70 may also include one or more of the following equipment: a pressure gauge 72 indicating the pressure in the cylinder to which the integrated pressure regulator valve assembly 70 is connected; A residual pressure valve 73 and a filter 74 located upstream of the device 1; a second filter 75 situated between the device 1 and the secondary expansion stage 71; a debiliter 76 located upstream of an outlet connection 77; a safety valve 78 situated between the outlet of the secondary expansion stage 71 and the debiliter 76; a safety valve 84 situated between the outlet of the expansion valve assembly 1 and the inlet of the secondary expansion valve 71; a port 79 for filling the bottle to which is connected the integral pressure reducing valve assembly 70. This port 79 can be mounted in series with a filling valve 80 and a filling filter 81. A medical version may also be provided with a flow restrictor 82 located upstream of the filter 74 as well as a pressure outlet 83. Other devices such as heat exchanger, pressure relief valve and / or non-return can also be provided. Identical or similar elements to those previously described will bear a numerical reference identical to them in the following description of a second embodiment of the invention. With reference to FIG. 5, the integrated pressure regulator valve assembly according to the invention, generally designated 1, comprises a body 2 provided with a bore 4 supplying a fluid inlet port 5 which opens into an expansion chamber 6. The expansion chamber 6 comprises a first cylindrical section 106.1 in which the bore 4 opens and which is in fluid communication via a bore 107 with a second section 106.2 of the expansion chamber 10. A release 10 of relaxed fluid opens in the second section 106.2 of the relaxation chamber. The end of the bore 107 opening into the first section 106.1 of the expansion chamber 6 comprises a flared portion 108. The portion 109 of the second section 106.2 of the expansion chamber 6 facing the bore 107 is closed by sealingly by a membrane 110, here made of rubber, comprising a rigid central pellet 111. A cylinder 112 is resting on the central pellet 111 and protrudes into the second portion 106.2 of the expansion chamber 6. This cylinder 112 comprises a transverse wall 112.1 facing the diaphragm 110. A piston 120 cylindrical, forming a movable member, extends slidably in the expansion chamber 25 6 through the bore 107 and comprises a first end 120.1 extending into the first portion 106.1 of the expansion chamber 106. The first end 120.1 of the piston 120 comprises a conical section 121 provided with a circular groove 122 for receiving an O-ring 123. The second end 120.2 of the piston 120 slidably traverses the transverse wall 112.1. The piston 120 comprises an axial channel 34 opening radially along a first channel 125 at the base of the conical section 121 and along a second radial channel 126 at the level of the second portion 106.2 of the chamber 3024. Finally, the channel 34 also opens, at the second end 120.2 of the piston 120 into a cavity 127 defined by the cylinder 112, the transverse wall 112.1 and the central pellet 111. The second end 120.2 of the piston 120 also comprises a ridge 128 extending radially in the cavity 127. The washer 128 makes the piston 120 abut against the transverse wall 112.1. The first and second portions 106.1 and 106.2 of the expansion chamber 6, the bore 107, the piston 120, the cylinder 112, the pellet 111 and the membrane 109 are coaxial. The wall 112.1 then defines a movable wall-because of the flexibility of the membrane 109 of a counter-expansion chamber 40 comprising an outer portion, namely the wall 112.1 and an inner portion, namely the piston 120, mounted coaxially. The piston 120 can take two positions: a first position shown in Figure 5 in which the conical section 121 of the piston 120 cooperates with the flared portion 108 of the bore 120. This flared portion 108 serves as seat for the conical section 121 against which the O-ring 123 is compressed, then fluidly isolating from the arrival port 5, the second portion 106.2 of the expansion chamber 6 as well as the counter-expansion chamber 40. Indeed, the first channel 125 is no longer fed by the fluid dispensed by the bore 4 in the first portion of the expansion chamber 106.1. The second position of the piston 120 is shown in FIG. 6 and corresponds to a position in which the conical section 121 of the piston 120 is no longer in contact with the flared portion 108 of the bore 107. In this position, the fluid distributed in the first portion 106.1 of the expansion chamber 6 through the bore 4 is conveyed to the counter 35 expansion chamber by the succession of channels 124- 3024204 14 125 and 126. A pressure balance of the space 127 is also realized. The integral pressure regulator valve assembly 1 also includes a cylindrical hood 129 facing the surface of the membrane 109 opposite to that defining the cavity 127 and defining a volume 130. A coil spring 26 is mounted in the volume 130 and has a first end 25 bears against a transverse surface 131 of the cover 129 and a second end 28 bears against the central pellet 111 of the membrane 110 in such a way that the spring 26 pushes the pellet 111 and the cylinder 112. A second spring The spring 36 extends in the cavity 127 between the pellet 111 and the washer 128. The spring 36 is of a section - and therefore 15 of a stiffness - less than the section of the spring 26 and pushes the washer 128 against the wall 112.1. A lever-cam assembly 15 controls the movement of a pusher 132 between a supply position of the fluid counter-chamber 40 shown in FIG. 6 (first position of the lever 15) and an isolation position in FIG. fluid of the counter-expansion chamber 40 shown in FIG. 5 (second position of the lever 15). The lever-cam assembly releases the action of a helical spring 56 which bears on the first end 120.1 of the piston 120 and thus moves it independently of the wall 112.1. The operation of the device 1 will be described with reference to FIGS. 5 to 7. With the lever 15 in its first position (FIG. 6), the pressurized fluid 30 enters the inlet port 5 in the first section 106.1 of the chamber. 6, penetrates the channel 125 and circulates through the channel 34 to invade the counter-chamber 40 via the channel 126. Once the resultant on the wall 120.1 of the pressure in the counter-chamber 40 ( added to the pressure 3024204 15 exerted on the end 120.1 of the piston 120) is greater than the force exerted by the spring 26 on the cylinder 120 against this pressure, the inner and outer portions of the movable wall 112.1 move from the fluid supply position of the counter chamber 40 (shown in FIG. 6) to a position of fluid isolation of the counter chamber 40 from the inlet port 5 (shown in FIG. in Figure 7). At this time, the pressure in the counter chamber 10 is equal to the expansion pressure. The equipment to be supplied connected to the outlet 10 then receives the fluid at the relaxed pressure. The pressure prevailing in the counter-expansion chamber 40 decreases as fluid consumption expanded by the equipment connected to the output 10 decreases until it reaches a value that is insufficient to counter the return force of the spring 26 which then returns the piston 20 to the fully open position of the arrival port 5 (Figure 6). A new relaxation cycle can then begin.

Of course, the invention is not limited to the embodiments described, but encompasses any variant within the scope of the invention as defined by the claims.

In particular: - although here, the fluid to be released is medicalized oxygen, the invention applies to any type of fluid such as welding gases, gaseous fuels, inerting gases; 30 - although here the displacement of the internal portion of the piston is provided by a lever-cam assembly, the invention also applies to other types of means for moving the inner portion such as a button push-button, screw-in pusher, single lever or mechanical actuator; Although here the lever and the cam are made in one piece, the invention also applies to a lever actuating a cam separate from the lever; although here the inner portion of the piston is brought into abutment against the outer portion of the piston by a helical spring, the invention also applies to other types of elastic elements such as elastomeric buffers or Belleville washers; although here the outer portion of the piston is pushed back by a helical spring against a pressure in the counter-expansion chamber, the invention also applies to other types of elastic elements such as, for example elastomeric pads or Belleville washers; 15 - although here the internal portion of the piston comprises an annular protrusion which abuts on a bore of the outer portion of the piston, the invention also applies to other abutment means such as a tooth single radially projecting element 20 internal or a shoulder in the inner portion abutting on the outer portion; although here the sealing member comprises a buffer 33 of elastomeric or plastic material, the invention is applicable to other types of sealing members such as for example a metal / metal seal or a portion covered with teflon; although here the closing and opening operations are carried out in half a turn, the invention also applies to closing and opening operations carried out with the aid of a quarter turn of the lever or indexing according to several positions of the lever which may correspond to partial partial opening states, these intermediate positions being held by clip or friction; - Although here the membrane is rubber, the invention is also applicable to other types of membranes such as an elastomeric membrane, metal or other waterproof and flexible material. 5

Claims (7)

REVENDICATIONS1. Device for the expansion (1) of a fluid, the device comprising an expansion chamber (6) provided with an inlet port (5) and an outlet port (11), a displaceable movable element (20) in the expansion chamber (6) between a supply position and a fluid isolation position of a counter-expansion chamber (40) having a movable wall connected to the movable element (20), the movable element (20) comprising a channel (34) connecting the expansion chamber (6) and the counter-expansion chamber (40), characterized in that: - the movable wall of the counter-expansion chamber (40) comprises a portion external member (21) and an inner portion (22) mounted coaxially with the outer portion (21) for sliding from the feeding position in which the inner portion (22) feeds the counter-expansion chamber with fluid to the position d fluid isolation in which the inner portion (22) fluidly isolates the flash chamber from the port of arrival; moving means (15) for moving the inner portion (22) towards the closed position are arranged to act on the inner portion (22) independently of the outer portion (21); a first elastic element (26) is arranged to push the outer portion (21) against a pressure in the counter-expansion chamber (40); stop means (35, 37) are arranged between the inner (22) and outer (21) portions so as to interact when the outer portion (21) is moved under the effect of a pressure in the counter chamber (40). 2. A device (1) for expanding a fluid according to claim 1 wherein the movable member (20) comprises a piston (20) defining the movable wall of the chamber against expansion chamber (40). 3. Device for expanding (1) a fluid according to claim 1 wherein the movable member (20) comprises a cylinder 112.1 resting on a membrane (110). 5 4. A device (1) for expanding fluid according to claim 1, wherein the displacement means (15) of the inner portion (22) of the piston (20) comprise an elastic member (56). The fluid expansion device (1) according to claim 1 or 2, wherein the displacement means (15) comprises a cam actuating lever (63). 6. A device (1) for expansion of fluid according to claim 1 wherein the inner portion (22) of the piston (20) is brought into abutment against the outer portion (21) of the piston (20) by a second element elastic (36). An integrated pressure regulator valve assembly (70) comprising a device (1) as claimed in any one of the preceding claims, the assembly (70) comprising a secondary expansion stage (71) installed downstream of the expansion device (1).