HYDRAULIC FLOW RATE CONTROL VALVE WITH A DUAL ADJUSTING SCALE"

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D E S C R I P T I O N

TECHNICAL FIELD

The present invention refers to cartridge flow rate adjusting assembly and to hydraulic flow rate control valve with a dual adjusting scale.

More specifically, the present invention refers to a cartridge flow rate pre-adjusting control car tridge assembly with a stem-plug shutter and pre adjusting sleeve suitable for simple-type hydraulic control valves provided with a hand command or which can be motorized or made thermostatic and which can integrate a dynamically balanc ing/compensating a flow rate system.

STATE OF THE ART

Fluid control valves for adjusting a fluid flow rate configured also for a static pre-adjustment are known and widely used in the hydraulic systems and thermotechnical systems. Said hydraulic valves are generally also provided with means for balanc ing or compensating the inlet pressures and are typically known as Pressure Independent Control Valves or PICVs.

These fluid valves are hydraulic devices typi cally used in thermotechnical applications in which the availability at the inlet of a constant flow rate of a liquid fluid, usually water, independent ly from the fluid pressure variations occurring up stream and downstream, is sought.

Said known types of valves for dynamically ad justing and balancing a flow rate, enable a more flexible and simplified design and manufacturing of hydronic systems in which the flow rate of a fluid thermal carrier towards the ends of one or more us ers, such as heat exchanges, radiators, fan convec tors, is required to be constant. Moreover, the PICVs enable to adjust the flow rate independently from the fluid pressure conditions occurring up stream and downstream, maintaining constant a pre set flow rate or a user required flow rate.

Said adjusting/balancing valves or PICVs typi cally comprise three adjusting assemblies: a pre adjusting assembly for the flow rate configured to pre-select a maximum nominal flow rate at the inlet of a user, a feedback adjusting assembly, typically a shutter assembly, configured to adjust or choke the flow rate of a fluid thermal carrier required as a function, for example, of the environment tem perature, and a balancing/compensating assembly configured to maintain constant the flow rate inde pendently from the pressure conditions upstream and downstream the valve.

The PICVs generally comprise an actuator, such as a known electrothermal head provided with a pusher, capable of linearly actuating the stem, known also as valve cartridge, closing the plug shutter in the valve body for obstructing and clos ing the fluid passage. Typically, said actuator is implemented by a mechanical or electromechanical device, advantageously connected to an electronic central unit and configured to close the valve stem shutter, for example, as a function of the environ ment temperature. Further, these valves are typi cally provided with an adjusting knob system, actu- atable by an operator, connected to an adjusting sleeve provided with openings configured to rota- tively vary with the sleeve the cross-section in order to set the required maximum fluid flow rate value, for example, corresponding to the maximum thermal energy amount to be supplied.

Exemplary flow rate adjusting valves provided also with an assembly for dynamically balancing the flow rate are illustrated in documents WO-A-

2018051150 and EP-A-3067772.

Another example of valves for dynamically ad justing and balancing a fluid flow rate is de scribed in the European patent EP 3 201 500 (Bl) in the name of the same Applicant and regarding a valve comprising means for adjusting the fluid static flow rate configured to change the cross- section of a passage port between a valve inlet and outlet and means for dynamically balancing the flow rate, configured to adjust the flow rate of the fluid exiting the valve, as a function of an enter ing fluid flow rate change. The dynamic balancing means comprise a perforated element interposed be tween the inlet opening and an intermediate chamber in order to enable a fluid passage only through at least one opening of the perforated element. In ad dition, an elastic element is disposed at a face of the perforated element facing the fluid inlet open ing in the valve body so that, an increase of a pressure difference between the valve inlet and outlet is matched by an enlargement of the elastic element in order to reduce the passage area of the opening of the perforated element and to ensure a constant flow rate. A serious drawback of these cited valve types is that each standardized valve size is character ized by a corresponding flow rate range inside which the adjustment is performed. Consequently, the valve manufacturers must supply many versions of the same type and size of a valve, each with a different pre-adjusting assembly according to the flow rate range in which the valve must operate. This fact causes to manufacture and store a greater number of elements and also to sell many versions of a same valve, which differ from each other only for the pre-adjusting sleeve.

OBJECTS OF THE INVENTION

The object of the present invention consists of overcoming and obviating, at least partially, the operative disadvantages and limits of the above given prior art. More particularly, an object of the present invention consists of providing a car tridge flow rate adjusting assembly cartridge flow rate adjusting assembly and a corresponding hydrau lic valve (for example of a PICV type) capable to be configured and selected for operating in differ ent flow rate ranges: a range with greater flow rate levels and one with smaller flow rate levels.

A further object of the present invention con- sists of providing a cartridge flow rate adjusting assembly cartridge flow rate adjusting assembly and a corresponding hydraulic valve (for example of a PICV type) having a high level of reliability and durability and such in addition to be easily and economically manufactured.

It is also an object of the present invention to provide a cartridge flow rate adjusting assembly cartridge flow rate adjusting assembly and a corre sponding hydraulic valve (for example of the PICV type) which are capable to operate with small-sized economical actuators, in comparison with the known ones, for the same force required to cause the valve to close.

It is an object of the present invention a car tridge flow rate adjusting assembly cartridge flow rate adjusting assembly as defined in claim 1 and specific embodiments thereof described in dependent claims from 2 to 11. According to further aspect, it is an object of the invention a hydraulic valve described in claim 12 and a preferred embodiment thereof defined in claim 13.

BRIEF DESCRIPTION OF THE FIGURES

The structural operative characteristics of the cartridge flow rate adjusting assembly cartridge flow rate adjusting assembly and of the correspond ing hydraulic valve object of the present invention could be better understood from the following de tailed description, in which it is made reference to the attached drawings representing some pre ferred non-limiting embodiments, wherein:

Figure 1 is a schematic representation of an axonometric view of a hydraulic PICV comprising a cartridge flow rate adjusting assembly cartridge flow rate adjusting assembly object of the present invention;

Figure 2 is a schematic representation of an axonometric exploded view of a hydraulic PICV com prising a cartridge flow rate adjusting assembly cartridge flow rate adjusting assembly object of the present invention;

Figure 3 is a schematic representation of an axonometric exploded view of a cartridge flow rate adjusting assembly cartridge flow rate adjusting assembly of a hydraulic valve object of the present invention;

Figure 4 is an axonometric schematic represen tation from another point of view of the cartridge flow rate adjusting assembly cartridge flow rate adjusting assembly of the hydraulic valve object of the present invention;

Figure 5 is a schematic representation of a plan view of the hydraulic PICV comprising a car tridge flow rate adjusting assembly cartridge flow rate adjusting assembly object of the present in vention;

Figure 6 is a schematic representation of a cross-section view according to the plane VI of

Figure 5 of the hydraulic PICV comprising a car tridge flow rate adjusting assembly object of the present invention;

Figure 7 is a schematic representation of a cross-section view according to the plane VII of

Figure 5 of the hydraulic PICV comprising a car tridge flow rate adjusting assembly object of the present invention;

Figure 8 is a schematic representation of a plan view of the cartridge flow rate adjusting as sembly object of the present invention;

Figure 9 is a schematic representation of a cross-section view according to the plane IX of

Figure 8 of the cartridge flow rate adjusting as sembly object of the present invention;

Figure 10 is a schematic representation of an operation graph of a hydraulic PICV comprising a cartridge flow rate adjusting assembly object of the present invention, for adjusting a fluid flow rate with different ranges and different resolu tions as a function of the value of the pressure difference Dr .

DETAILED DESCRIPTION OF THE INVENTION

Referring to the figures and particularly to Figures 1, 2, 4, 5 and 6, a preferred embodiment of a hydraulic valve 100 of the PICV (Pressure Inde pendent Control Valve) type is shown according to the present invention. Valve 100 comprises a valve body 102 having an inlet opening 104, an outlet opening 105 and an actuating opening 106. An open ing 108 is made in the valve body 102, in particu lar in the PICV type, in which a per se known dy namic balancing/compensating pressure assembly 200 is received.

Such balancing assembly 200 generally comprises a tubular element 202 slidingly actuated by a flex ible diaphragm 204 (for example made of an elasto meric material) sensitive to the fluid pressure in the inlet opening 104 on a face thereof and to a fluid pressure in the outlet opening 105, on an op posite face thereof in order to cause the tubular element 202 to increase or limit the fluid flow in the valve as a function of the pressure difference

Dr between the inlet opening 104 and outlet opening 105. Moreover, the balancing assembly 200 typically comprises also an elastic element 206 configured to hold the tubular element 202 in a monostable posi tion (for example, in an opening position) .

Typically, the valve body 102 comprises also one or more service openings 110 configured to ser vice and control the valve 100 when is installed; said service openings 110 are usually closed by plugs 110' .

Valve 100 is provided with an inner wall 112 with a passage opening 114 suitable for a cartridge flow rate adjusting assembly cartridge flow rate adjusting assembly 10 and said balancing assembly 200.

Normally the valve 100 can be also provided with conventional connecting connectors 300 placed at the inlet and outlet openings 104 and 105.

The attached figures, and particularly Figures 3, 4, 8 and 9, illustrate a cartridge flow rate ad justing assembly cartridge flow rate adjusting as sembly 10 comprising a generally cylindrical shaped cartridge body 12 slidingly receiving a stem 14.

Said cartridge flow rate adjusting assembly car- tridge flow rate adjusting assembly 10 is inserted in the valve body 102 at the actuating opening 106.

A shutter 16 (a plug, for example) attached to a first end 14' of the stem 14, inside the valve 100, is configured to slide against the passage opening 114 of the valve 100 in order to adjust the fluid flow by the same, from a maximum amount to a complete closure thereof. A second end 14" of the stem 14 is exposed outside the valve body 100 and is configured to engage with a conventional mechan ical or electromechanical actuator (not shown) des tined to linearly move the stem 14 in order to close or open the passage opening 114 by the shut ter 16.

Said stem 14 is also provided with a further elastic element 18 (a coil spring, for example) co axially placed around the stem 14 and in the car tridge body 12 in order to hold the stem 14 with the shutter 16 in a monostable position normally open with respect to the opening 114 of the body 102. Said stem 14 and said elastic element are held in position in the cartridge body 12 by means of a first ferrule 19.

The cartridge flow rate adjusting assembly car tridge flow rate adjusting assembly 10 (in the fol- lowing briefly indicated by cartridge 10) further comprises a substantially tubular cylindrical shaped sleeve 20 attached to an inner end of the cartridge body 12.

Referring particularly also to Figures 6 and 7, said sleeve 20 is configured to adjust and limit the fluid flow exiting the passage opening 114 in the valve body 102 and moving towards the outlet opening 105 through at least one first shaped open ing 22 and at least one second shaped opening 22' made in the outer cylindrical wall 24 of the sleeve 20 itself. The shape of the first opening 22 is such to enable to adjust the maximum flow rate of the valve inside a first range of fluid flow rate values according to a first scale. The shape of the second opening 22' is such to enable to adjust the maximum flow rate of the valve inside a second range of the fluid flow rate ranges according to a second scale. Figures 6 and 7 show the shutter in a non-operative transition configuration.

A first resolution is associated to said first scale and a second distinct resolution is associat ed to said second scale. The term "resolution" means the flow rate range obtainable as a function of the sleeve 20 rotation of a preset angular val- ue .

Said first and second openings 22 and 22 of the sleeve 20 enable to preset the fluid maximum flow rate exiting the valve by rotating the sleeve 20 itself, varying the passage cross-section to wards the outlet opening 105.

The first and second openings 22 and 22' can have an open shape at the free end of the sleeve 20 (as shown in the figures) or can be integrally cir cumscribed in the cylindrical wall 24. The first and second openings 22 and 22' are formed on por tions of the cylindrical part 24 of the sleeve 20 which are separated by solid portions of said cy lindrical wall 24 in order to selectively operate (in other words not simultaneously) to adjust the fluid flow rate. Preferably, the first shaped open ing 22 and second shaped opening 22' are made on portions at diametrally opposite positions of the cylindrical wall 24.

Moreover, each said first and second shaped openings 22 and 22' have a cross-section facing a passage gap 116 of the valve body 102 varying as a function of the sleeve 20 rotation. When the first shaped opening 22 faces said passage gap 116, the second opening 22 is in a non-operative mode, dis- tally from the passage gap 116 (and viceversa) .

Each said first and second openings 22 and 22 can in turn comprise, more than one opening formed in the cylindrical wall 24, having cross-sections equal to or different from each other, configured to simultaneously or continuously face the passage gap 116.

According to the example in the figures, the first opening 22 has a greater size and the second opening 22' has a smaller size, for being capable of presetting two operative configurations of the valve 100, alternative to each other, in two dif ferent fluid flow or flow rate ranges.

Advantageously, said sleeve 20 can be made of a plastic material, polymeric or thermoplastic, metal or of other syntherized materials o can be made by additive manufacturing techniques. Advantageously, the sleeve 20 is attached to the cartridge body 12 by pressure snapping means 25 formed on the inner diametral surface of the sleeve and on the end di ametral surface of the cartridge 12.

The sleeve 20 can be put in rotation with the shutter body 12, but can also be put in rotation by the plug or washer 55 of the shutter 16 integral with the stem 14 by connecting means 56 to the stem 14 itself, such as for example flat portions made on the first end 14' of the stem 14 mated with a non-circular shaped opening of the plug or washer 55, as shown in Figure 3.

Still specifically referring to Figure 3, act ing on the stem 14 by a conventional wrench, at the second end 14", rotates the stem with the plug 55 which in turn puts in rotation the sleeve 20 by at least one protrusion 57 mated to a respective groove 57' formed on the inner surface of the sleeve 20.

Further, said cartridge 10 comprises graduated reference means 30 on the cartridge 10 itself (a disk, for example) or directly formed on it. The reference means 30 are configured to graphically show, outside said valve 100, said first and second scales and are placed on the cartridge body 12.

Said reference means 30 are divided in at least two parts and comprise a first graduated scale 32 corresponding to the open positions of the first shaped opening 22 and a second graduated scale 33 corresponding to the open positions of the second shaped opening 22'.

The cartridge 10 can be stationary or rotative in the valve body 12 by a second ferrule 118 (Fig- ure 2) attached at the actuating opening 106. Ac cording to a further embodiment, the cartridge 10 is integral with the valve body 12.

Referring particularly to Figure 1, in the pre ferred embodiment of the figures, the cartridge 10 is adjustable by a wrench acting on the second end 14" of the stem 14 and configured to rotate said stem 14 and consequently the sleeve 20 with respect to the cartridge body 12, for pre-adjusting the control valve 100. Once performed the pre adjustment, it is possible to install an actuator (not shown) provided with a linear operation or an electrothermal head, disposed at the actuating opening 106 of the valve 100 and configured to co operate with the stem 14 of the cartridge 10.

Referring particularly to Figures 6, 7 and 9, in a preferred embodiment, the stem 14 of the car tridge assembly 10 can also comprise a compensating duct 15 (Figure 9) partially extending along the axis of the stem 14 itself and having an opening 15' at the first end 14' and at least a further opening 15" at the outer diametral surface of stem 14 itself. The further opening 15", on the outer diametral surface of the stem 14, is in fluid com munication with a chamber 13 made in the cartridge body 12.

The shape of the compensating duct 15 can be curved .

The inside of said chamber 13 receives, through a central hole 52, a plunger 50 integral with the stem 14 so that it slides with the same stem inside said chamber 13. The plunger 50 is attached to the stem 14 by fixing means 54 comprising, for example, elastically deformable snapping means. Particular ly, the fixing means 54 comprise one or more diame tral collars formed on the inner surface of the central hole 52 and cooperating with further lat eral collars 17 formed on the lateral outer surface of the stem 14. Moreover, the plunger 50 is pre vented from axially translating towards the first end 14' of the shutter 16 attached to the same end of the stem 14. For example, said shutter 16 can be advantageously disposed on the stem 14 by a plug or washer 55 configured to move the shutter 16 in abutment with the cartridge body 12.

Advantageously, the plunger 50 is made of a plastic material, thermoplastic, polymeric or ther mopolymeric or metal material, or of other sintered materials or can be made by additive manufacturing techniques . The opening 15" of the compensating duct 15 can comprise a transversal hole or duct (for example, radial) which can be through, in other words it ex tends along all the cross-section of the stem 14 or partially extends in the stem 14 so that it is any way in fluid communication with the compensating duct 15 and chamber 13. The plunger 50 is also pro vided with fluid tight elements 90 (lip gaskets, 0- rings of elastomeric material, for example) dis posed between the inner diametral surface of the central hole 52 and outer diametral surface of the stem 14, and between the outer diametral surface of the plunger 50 and inner diametral surface of the chamber 13.

Particularly, the further opening 15" is in communication with a portion 13' of the chamber 13 interposed between the plunger 50 and second end 14" of the stem 14. More particularly, such portion 13' of the chamber 13 on which the further opening 15" is formed, is interposed between the plunger 50 and elastic element 18. It is observed the portion 13' is always fluid tight with respect to the pas sage opening 114.

Advantageously, said sealing elements 90 can be received in suitable annular housings or recesses formed on the outer surface of the plunger 50 and stem 14.

Advantageously, the cartridge 10 can be provid ed with a sealing element 95 such to ensure the fluid tightness between the cartridge 10 itself and valve body 12.

The operation, described in the following, can be understood from the beforehand given description of the valve 100.

The cartridge 10 inserted in the valve 100 of the present description has the advantageous char acteristic of a sleeve 16 capable of enabling the valve 100 to operate with different or very differ ent flow rate scales, different size from each oth er. For example, it is possible to operate accord ing to a configuration for high fluid flow applica tions and a low fluid flow with the same valve and the same inner components.

More particularly, during the installation step, an operator can configure the valve according to a preselected configuration by the wheel 400 by rotating the cartridge 10 and the sleeve 20 inte gral with the former. For example, the operator se lects an operative range corresponding to a config uration by rotating the wheel 400 and cartridge 10 according to the first graduated scale 32 by dif ferent opening degrees corresponding to different positions of the first shaped opening 22 facing the passage gap 116. With such configuration, the sec ond shaped opening 22' is inactive distally from the passage gap. Analogously, the operator can con figure the valve 100 by rotating the wheel 400 on the second graduated scale 33, in order to operate with the second shaped opening 22' facing the pas sage gap 116.

Different positions of the cartridge 10 refer ring to each of the first and second graduated scales 32 and 33 correspond to different selected flow rates from a minimum to a maximum one associ ated to two different operative configurations. When the sleeve 20 is switched from a configuration to another, it is placed in a non-operative inter mediate position clearly different from the two op erative configurations. The term non-operative po sition means a position wherein the outer cylindri cal part 24 faces the passage gap 116 without an adjusting configuration of the first and second openings 22, 22' in which no fluid passage or only a limited fluid passage is available. Generally, setting a minimum value of the configuration ranges on one of the graduated scales 32 and 33 causes the fluid flow rate to be never completely obstructed.

Referring particularly to Figures 1, 6 and 7, if the valve 100 is required to be closed by the shutter 16, the electromechanics actuator (not shown) acts on the second end 14' of the stem 14, downwardly thrusting it, overcoming the force of the further elastic element 18, for moving the shutter 16 in contact with the edge of the passage opening 114, obstructing the fluid passage between the inlet opening 104 and outlet opening 105.

Being the chamber 13 in fluid communication with the passage opening 114 by the compensating duct 15, cause a pressure PI of the fluid flowing through and at the passage opening 114 to be equal to a pressure P2 in the chamber 13, during the clo sure step of the shutter 16. Therefore, a force F2 is generated which acts on the plunger 50 surface facing the chamber 13, opposing a force FI exerted by the pressure PI of the flowing fluid, compensat ing the same. This enables the shutter 16 to be ac- tuatable by the corresponding stem 14 by a reduced force of the electromechanical actuator and mainly generated by the further elastic element 18, which generally remains constant as the pressure PI in- creases .

The opening 15' of the compensating hole 15 is move to a position adjacent to the closure of the shutter 16 at the passage opening 114, so that the same pressure contrasting the shutter 16 closure is transferred into the chamber 13. This feature al lows for an accurate compensation which neutralizes the forces acting on the shutter 16 by a force hav ing the same magnitude exerted on the plunger 50 surface facing the chamber 13.

Figure 10 particularly illustrates a graph with real values of the fluid flow rate expressed by 1/h (liters per hour) as a function of the range of values of the pressure difference Dr, expressed in kPa (kilopascal) between the inlet opening 104 and outlet opening 105 of the valve 100. It is observed from the shown values that rotating the sleeve (20) through the first opening 22 and second opening 22' obtains two different adjustment ranges shown in Figure 10 by the Roman numerals I and II respec tively at a low flow I (50-400 1 /h) and at a high flow II (200-800 1 /h) . Roman numerals from 1 to 4 of the values selectable by the first and second graduated scales 32, 33 differ from each other be sides from a different flow rate also for a differ- ent resolution between a level and another on the two ranges. While a range I is matched by a resolu tion of about 100 1/h, a range II is matched by a resolution of about 200 1/h.

From the preceding illustration, the obtained advantages of the valve for hydraulically adjusting and balancing a fluid flow rate object of the pre sent invention are clear.

The cartridge assembly and the corresponding hydraulic valve 100 are particularly advantageous since they enable to obtain a valve adjustable ac cording to two different flow rate ranges, overlap ping partially on each other or also completely distinct from each other and enable to balance the flow rate inside a range of values of Dr on both the ranges.

A further advantage of the valve is the imple mentation of one device or one valve in one version for each standardized size, without requiring to provide two versions of the same valve differing only for the pre-adjustment range of the flow rate the sleeve 20 can obtain, consequently manufactur ing, storing and marketing savings are obtained since only a single type of an off-the-shelf valve is needed due to the standard size of the connec- tions .

The present invention is also particularly ad vantageous since provides a user a hydraulic valve 100 with a conventional type thermostatic plug shutter or with a pressure balancing such to ensure a better resolution of the fluid flow rate pre adjustment, since it can operate between two ranges having two scales with different values. Indeed, valve 100 according to the present invention ena bles to make the hydraulic system in which the valve is installed, more versatile and adaptable to possible following expansions requiring to increase the available flow rates or, generally, to changed conditions due to, for example, design mistakes or not considered parameters, without requiring to substitute the valve 100.

The cartridge assembly and corresponding hy draulic valve 100 object of the present invention are further advantageous in the embodiment of the figures since they provide to compensate a force acting on the shutter during the closing step, ena ble to use smaller and economical actuators and with small power consumption with respect to the ones used according to the prior art. It is ob served the use of a small-sized actuator is advan- tageous also from a point of view of the size, since enables to install a valve in cramped spaces and cassettes. Moreover, using a duct extending in side the stem does not jeopardize the stroke of the stem itself. A further advantage of the described structure is that the compensating pressure inside the chamber 13 is exactly as the one acting on the shutter 16 at the passage opening 114 of the valve 100. The fluid flow pressure at said passage open ing 114 is indeed slightly less than the other parts of the valve due to the Venturi effect. The fluid connection between the passage opening 114 and chamber 13, through the compensating duct 15, ensures a perfect balancing of the forces generated by the pressures on the plunger 50 and an accurate closure, for example, also by a feedback by elec tromechanical actuators such as, for example, elec trothermal heads .

While the above described invention was de scribed by particularly referring to some preferred embodiments, given in an exemplifying non-limiting way, many modifications and variants will appear to a person skilled in the art in the light of the above discussed description. Consequently, the pre sent invention intends to encompass all the modifi- cations and variants falling in the scope of the following claims.