EP0855519B1 - Monoblock controller for automatically regulating the pressure in a reservoir - Google Patents

Abstract

The unit has an intake regulator (002), an oil bath screw compressor (003) and an air/oil separator (004) and an accumulator tank (005). The distributor (001) itself comprises a one-piece metal housing with cavities for two fixed throttling valves, a rapid discharge valve, an air injection control valve, a proportional control valve and two selector valves. The valves are connected by a series of channels and branches inside the housing, and the distributor is fed through a single duct (007) which takes air from the air/oil separator, and has four outlets, two with discharge regulating screws and another with a minimum pressure control screw.

Description

The present invention relates to a dispenser monoblock for the automatic regulation of the pressure of air in an air tank, according to the preamble of the claim 1. Such a dispenser is, for example, of the type normally used for powering an installation of compressed air distribution.

In industrial applications, there is a known compressed air production facility, essentially consisting of a screw compressor with an oil bath, a air / oil separator tank, an accumulation tank of air under pressure, further comprising radiators separated for the cooling of air and oil, thermostatic valves, non-return valves, pressure (pressure switches or safety devices), minimum pressure and other control and control, arranged on the ducts of the installation.

In particular, it is normally planned upstream of the above-mentioned installation, a valve whose function is to intercept the passage of air from outside to inside the circuit.

This valve, normally called regulator of which a particular form of construction is described in the Italian patent IT-B-0 124 0865 filed in the name of the Applicant, is mounted on the suction mouth of the compressor and has the function of adjusting or to interrupt the flow of air from outside in according to the operating needs of the installation.

The suction regulator is essentially constituted by a cursor animated by an alternating rectilinear motion which is caused by the balancing effect between the action of thrust generated by the pressurized air taken from the circuit, and by the push action, in the opposite direction of the previous, generated by the outside air and by the action of resistance of one or more opposing springs.

The displacement of the metallic disk constituting the slider, relative to the fixed seat, can be of two types, namely with proportional movement or with complete movement (Switching).

In the first case, the cursor has an infinity of working positions and at each position corresponds a section of the well-defined passage of the suction duct of outside air, whereas in the second case only the extreme positions, which correspond to the two limit situations, total opening and closing complete the suction mouth.

It follows that in the first case it is necessary to have orders with an intensity that varies in while in the second case it is possible to use commands of the type called "all or nothing", or commands to variable intensity, provided that the value to which produces the switching is reasonably constant (value reference).

In the current state of the art, the functioning of the suction regulator in the two different modes is possible that by realizing enough hydraulic circuits complex and including valves that control the pressure of fluid, valves that regulate the flow of fluid and valves that control the flow of fluid, i.e. valves that define the directions of priority in the network of pipes.

The object of the present invention is to provide a system that achieves the same result as the known circuits, but with notable simplifications mechanical and construction. This goal is achieved by through the characteristics of the party characterized in claim 1.

According to another characteristic of the invention, it is provided that with the monoblock according to the invention, it is possible to generate a counter-pressure able to balance the action of negative thrust that engenders the mechanics of the pump during the proportional operation and during the vacuum operation.

According to another characteristic of the invention, provides, thanks to the particular internal conformation of the monobloc, and providing the two external solenoid valves of an electronic card order, the possibility of make a gradual and not instantaneous stop compressor, so as not to damage the mechanics of the screw pump.

According to another characteristic of the invention, provides that the suction regulator is equipped, on the suction mouth of the outside air and on the mouth of connection to the compressor, mobile fasteners, preferably flange.

Another characteristic of the invention lies in the possibility of creating a suction regulator of the type said "modular" where the same body of said regulator suction is likely to be equipped with another combination of flanged fasteners and dispensers monoblock. This allows you to achieve, quickly and with a outstanding economy, appliances meeting the requirements specific to each user.

• la fig. 1 représente un schéma général d'une installation de production d'air comprimé au moyen d'un compresseur à vis à bain d'huile comprenant le distributeur monobloc selon l'invention ;
• la fig. 2 représente le schéma du circuit fluodynamique réalisé à l'intérieur du distributeur monobloc selon l'invention ;
• la fig. 3 représente le schéma du circuit pendant la phase de démarrage du compresseur pour la mise à l'état de vide ;
• la fig. 4 représente le schéma du circuit pendant la phase de fonctionnement à commutation ouvert/fermé ;
• la fig. 5 représente le schéma du circuit pendant la phase de fonctionnement et de retour à l'état de vide du compresseur ;
• la fig. 6 représente le schéma du circuit pendant la phase de fonctionnement proportionnel ;
• la fig. 7 représente le schéma du circuit pendant la phase d'arrêt progressif du compresseur ;
• la fig. 8 représente une vue en perspective extérieure et le montage du distributeur monobloc selon l'invention ;
• la fig. 9 représente une vue en perspective partiellement en coupe du régulateur d'aspiration ;
• la fig. 10 représente la vue en plan du distributeur monobloc selon l'invention ;
• la fig. 11 représente une vue en élévation du distributeur, selon la direction "X" de la figure 10 ;
• la fig. 12 représente une vue en élévation du distributeur, selon la direction "Y" de la figure 10 ;
• la fig. 13 représente une vue en coupe du distributeur prise selon la ligne XIII-XIII de la figure 10 ;
• la fig. 14 représente une vue en coupe du distributeur prise selon la ligne XIV-XIV de la figure 12 ;
• la fig. 15 représente une vue en coupe du régulateur d'aspiration 002 dans la phase d'arrêt du compresseur ;
• la fig. 16 représente une vue en coupe du régulateur d'aspiration dans la phase de fonctionnement proportionnel ;
• la fig. 17 représente une vue en coupe du régulateur d'aspiration pendant la phase de fonctionnement à vide du compresseur ;
• la fig. 18 représente une vue en coupe du régulateur d'aspiration pendant la phase de fonctionnement commutatif ;
• la fig. 19 représente une vue en perspective éclatée, des combinaisons possibles des éléments sur un régulateur d'aspiration du type dit "modulaire" ;
• les fig. 20, 21 représentent deux vues d'ensemble en perspective de deux régulateurs d'aspiration équipés différemment.

These characteristics, of operation as well as construction of the invention, as well as others, will be described hereinafter, with the aid of the attached drawing plates, which represent an embodiment thereof given for a purely illustrative purpose. and not limiting, on which:

• fig. 1 represents a general diagram of an installation for producing compressed air by means of an oil-bath screw compressor comprising the monoblock dispenser according to the invention;
• fig. 2 shows the flow diagram of the flow circuit made inside the monobloc dispenser according to the invention;
• fig. 3 shows the circuit diagram during the compressor start-up phase for setting the vacuum state;
• fig. 4 shows the circuit diagram during the open / closed switching operation phase;
• fig. 5 shows the circuit diagram during the operation phase and return to the vacuum state of the compressor;
• fig. 6 shows the circuit diagram during the proportional operation phase;
• fig. 7 shows the diagram of the circuit during the phase of progressive stop of the compressor;
• fig. 8 represents an external perspective view and the mounting of the monoblock dispenser according to the invention;
• fig. 9 is a perspective view partially in section of the suction regulator;
• fig. 10 shows the plan view of the monoblock dispenser according to the invention;
• fig. 11 is an elevational view of the dispenser in the direction "X" of FIG. 10;
• fig. 12 is an elevational view of the dispenser in the "Y" direction of FIG. 10;
• fig. 13 is a sectional view of the distributor taken along line XIII-XIII of FIG. 10;
• fig. 14 is a sectional view of the distributor taken along line XIV-XIV of FIG. 12;
• fig. 15 is a sectional view of the suction regulator 002 in the stopping phase of the compressor;
• fig. 16 is a sectional view of the suction regulator in the proportional operating phase;
• fig. 17 is a sectional view of the suction regulator during the vacuum running phase of the compressor;
• fig. 18 is a sectional view of the suction regulator during the commutative operation phase;
• fig. 19 is an exploded perspective view of possible combinations of elements on a suction regulator of the so-called "modular"type;
• figs. 20, 21 represent two perspective overall views of two differently equipped suction regulators.

As can be seen in fig. 1, the installation of compressed air production, regulated by the distributor monoblock 001 according to the invention, consists essentially a suction regulator 002 that intercepts the air outside and route it to the screw compressor with oil bath 003, powered by an electric motor.

The mixture of fluid under oil / air pressure produced by the compressor enters a separation tank 004, where the separation of air and oil occurs.

The pressurized air will then fill the tank accumulator 005, waiting to be used, while the oil, after passing through the radiator 006, returns to compressor 003 in closed circuit.

The monobloc dispenser 001 according to the invention, powered by the pressurized air taken from the separator tank 004, via conduit 007, and controlled by the action of the two solenoid valves 008 and 009, is mounted on the body of the suction regulator 002 to adjust the operation, in a proportional or commutative manner, this to adjust and / or interrupt the flow of air from the outside according to the needs of installation, according to the modalities and schemes that are described in the following.

As shown in FIG. 2, the monobloc dispenser 001 according to the invention consists of a body 1, provided with a plurality of cavities in which the devices capable of performing the distribution action of compressed air control and a network of ducts that put said cavities in communication.

In detail, in the body 1 are housed two valves to fixed discharge guided choke 2A and 2B, a valve with fast discharge 3, a control valve of the air injection 4 in the compressor screw, a control valve 5, two selector valves 6A and 6B and one calibrated nozzle 7.

Outside the body 1, there are, besides said solenoid valves 008 and 009 anchored to the monobloc 001, a screw minimum pressure setting 8, a setting screw of discharge 9, and a check valve 10, which are anchored on the body of the suction regulator 002.

Still referring to fig. 2, we find below the ducts formed inside the monoblock 1 and which port the different devices of order listed above.

From the inlet port 100, connected to the separation circuit 004 by the outer conduit 007, comes air for the control of the dispenser.

The main conduit 111 supplies the discharge valve quick 3 and the valve 4 and, on this conduit, connect the conduits 112A and 112B which feed the respective valves 2A and 2B, and the conduits 113 and 114 which feed, at their turn, the corresponding solenoid valves 008 and 009, on which connect the ducts 115 and 116 which communicate with the corresponding valves 2A and 2B.

The conduit 116 is also connected by the branch 117 to the quick-release valve 3 from which leave the conduit 118 connected to the valve 6A and the conduit 119 provided with the setting 9, through the discharge port 101.

The valve 2B is placed in communication with the valve selector 6B through the conduit 120, which by the branch 121, is in communication with the pressure adjustment screw 8, through the discharge port 102 and the conduit discharge 119.

The conduit 122 puts the valve 2A in communication with the proportional control valve 5, from which the led 125 which, through the selector valve 6B, the conduit 126 and the discharge port 103, act on the cursor 022 which intercepts and regulates the suction mouth 021.

From the conduit 125, also leave the branch 124 which, via the selector valve 6A and the conduit 127, enters the valve 4, and the branch 123 going to the calibrated nozzle 7.

Finally, the valve 4 is in connection with the screw compressor 003 through line 128, the orifice of discharge 104 and the non-return valve 10.

1ère phase : de la mise en marche et jusqu'à la mise en état de vide initiale du compresseur ;

2ème phase : fonctionnement à pleine charge avec régulation du type commutatif (ouvert-fermé) ;

3ème phase : retour et fonctionnement à l'état de vide du compresseur ;

4ème phase : fonctionnement à pleine charge avec régulation de type proportionnel ;

5ème phase : arrêt progressif du compresseur.

The operating mode of the monoblock dispenser according to the invention is variable according to the different work phases and the operating mode of the compressed air production plant:

1st phase: from start up to initial compressor vacuum;

2nd phase: full load operation with commutative type control (open-closed);

3rd phase: return and operation in the vacuum state of the compressor;

4th phase: full load operation with proportional type control;

5th phase: progressive stop of the compressor.

In the start-up phase of the compressor (see Fig. 3), the function of the monobloc dispenser 001 is the closing the suction port 021 from the outside air by moving the cursor 022 of the suction regulator 002, to allow to put under pressure the air contained in the circuit.

During this phase, the two solenoid valves 008 and 009 remain de-energized and therefore normally closed while compressed air, via line 007, which comes of the separator tank 004, will feed the valves 2A, 2B, 3, 4 and 5 contained in the body of the monoblock 1.

In addition, from the 2B valve, it is possible to feed the conduit 120 and, through the selector valve 6B, leads 126 and thus cause the displacement of the slider 022 and the total closure of the suction mouth 021.

In the bypass duct 121, is mounted a screw of minimum pressure setting 8 which, set by the operator, ensures a minimum air pressure value in the circuit and allows possible evacuation pressure by through conduit 119, intercepted by the screw of discharge setting 9, which communicates with the outside.

Switched type full load regulation (see Fig. 4), which includes the total displacement of the cursor 022 for the opening of the suction mouth 021, takes place in exciting the two solenoid valves 008 and 009 which, by via the discharge ducts 115 and 116 respectively, change the state of both valves with fixed throttling 2A and 2B.

Branch 117 Attacks Quick Discharge Valve 3, generating a counterpressure with respect to the duct principal 111.

With this arrangement, outside the duct 122, one also isolates the conduit 120 and the air which is contained, in escaping through ducts 119 and 121, allows opening cursor 022 for suction of a new quantity of air that it is to put under pressure.

In the vacuum running phase of the compressor (see Fig. 5) when the operating pressure has been reached in the storage tank, the two solenoid valves 008 and 009 are de-energized, so that in the first phase, the air passing through ducts 120 and 126, with the intervention of the directional valve 6B acts on the slider 022 by closing the suction port 021.

A small 023 suction valve ensures the maintenance minimum air intake from the outside.

In addition, the quick-release valve 3 opens, so that the air, going through ducts 118 and 127, which communicate via the directional valve 6A, will feed the valve 4 which, therefore, allows the air from the main inlet duct 111, passing through the led 128 and the check valve 10, to return to the compressor 003 by realizing, in this way, a back pressure positive in the mechanics of the screw pump, in reducing wear, vibrations and resulting noises.

This actuation of the valve 3 further allows, by through conduits 007, 111 and 119, to unload the air contained in the air / oil separator 004 to the external environment, with the interposition of a filter, not shown, and which, in addition to the filtration action of way that said air can return to the circuit, limit the noises.

Full proportional proportional regulation (see Fig. 6), with the cursor 022 which opens according to the amount of air demanded by consumption, is realized in exciting the solenoid valve 009, while the solenoid valve 008 remains closed so that the air, passing through the duct 122, enters the proportional control valve 5 from where, through conduits 125 and 126 and under the effect of the action of the selector valve 6B, it will actuate said slider which regulates proportionally the opening of the suction mouth 021.

The bypass 124 will feed through the valve selector 6A and the conduit 127, the valve 4 which maintains the positive action of back pressure in the mechanics of the screw pump, even during this phase.

Branch 123 is provided with the calibrated nozzle 7 which serves to balance the interaction between the valve proportional 5 and the displacement of the cursor 022.

The progressive stopping action of the compressor (see fig. 7) is done with the use of an electronic card which, simultaneously and in a progressive way, de-excites (closes) the solenoid valve 009 and excites (opens) the solenoid valve 008.

With this arrangement, evacuation is carried out, progressive way, from the air of the monoblock dispenser to through the discharge ports 101, 102, 103, 104 and through the corresponding ducts 119, 121, 126, 128 until the compressor 003 stops.

Figs. 8-14 illustrate a possible form of practical realization of the monobloc dispenser according to the invention.

In fig. 8, we can see the monobloc dispenser according to the invention 001 constituted by a metallic element 1, of substantially parallelepipedal shape, mounted by means of screw 011 on the body of the suction regulator 002, provided with suction port 021 and connection flange 024 to the compressor.

On the body 1, we can see the solenoid valves 008 and 009, the valves 2B, 3, 4, 5 and the inlet conduit 007 the control air through the opening 100.

On the body 002, we can also see the screws of setting 8 and 9.

As can be seen in FIG. 9, the distributor monoblock 001 according to the invention, is fixed to the regulator 002, by pressing on a flat surface 025, where the inlet ports 119, 121, 126 and 128 are present, corresponding conduits 101, 102, 103 and 104, and the holes threaded 012 fixing said monobloc.

Partial section of the body of the suction regulator 002 allows to see the cursor 022 which plays the role of piston, the piston guide 026 which slides in the cylinder 027 and the return springs 028 and 029.

In figs. 10-12, the details of complete monoblock construction that bring out the compactness and minimal size.

In figs. 13 and 14, there is shown in construction, in addition to the connecting ducts, also the cutting of the organs distribution and control systems, which have sliders and actuations of a different form, which corresponds to a different mode of operation of the said organs.

In detail, the fixed throttling valves 2A and 2B are equipped with two shuttle sliders 2A1 and 2B1 and actuated by the air.

Valves 3, 4 and 5 are operated by air and by the return springs 32, 42, and 52 and provided with a slider shuttle 33 and 43, or membrane 53, as well as stroke adjustment, 41 and 51 respectively.

Finally, in figs. 15-18, we can see four different positions of the cursor 022, inside the suction regulator 002, which correspond to the four different phases of the operation of the installation.

In particular, it is necessary to highlight the action reciprocal antagonism exercised by both coaxial 028 and 029, which compete with the air of command from duct 126 and the outside air of the suction port 021, cause reciprocating movement of the cursor 022 in the piston guide 026 and of the latter in the fixed cylinder 027.

In figs. 19-21, there is shown a conformation possible so-called "modular" of the entire device.

In said figures, the body of the regulator 002.1 is connected to the external pipe air inlet and compressor 003 with interposition removable fasteners 031 and 034, which go respectively replace the soldering attachment of the suction port 021 and the fixed flange 024 for connection to the aforementioned compressor.

In detail, the body of the pressure regulator 002.1 has at the entrance a plane surface 041, on which come to rely, by means of screws 042, the fasteners to flange 031.1A / 1B and 031.2A / 2B which respectively have their axis confused or perpendicular to the axis of the body.

In a similar way, always in the same body of pressure regulator 002.1, fixed flange 024 is replaced by the removable flanges 034.A / B, which assemble this audit body by a mechanical assembly, preferably a bayonet fitting made between the tail 35 and the cavity 36 formed in the body.

Of course, both 031 flange 034 flanges have nominal diameters different, thus allowing to equip the same body of regulator 002.1 of different combinations of the same elements (see Fig. 20, 21), which makes it possible to use it on 003 compressors that have different operating characteristics.

Finally, since the monoblock dispenser 001 is also removable from the regulator body 002.1, the benefits we get as well during assembly of the entire device only during operations normal maintenance or replacement of different components are obvious.

Claims (10)

1. Monobloc distributor for automatic regulation of the air pressure in a tank, designed for mounting in a compressed air production circuit, said circuit comprising a suction regulator (002), a screw-type oil-bath compressor (003), an air/oil separating tank (004) and a collecting tank (005), the distributor being characterised in that it is made from a single monobloc (001) constituted by a metal body (1) equipped with cavities suitable for accommodating two fixed-throttle valves (2A, 2B), a rapid-discharge valve (3), an air injection control valve (4) in the compressor screw, a proportional-control valve (5), two selector valves (6A and 6B), said elements being actuated by the air controlled by two solenoid valves (008, 009), with calibrated adjustment (7) also being provided, said valves for controlling, verifying and regulating the air flow and air pressure being interconnected by a plurality of conduits and branches (111-128) arranged inside said body, the operation of said monobloc distributor (001) relying on the action of the two solenoid valves (008 and 009), which, perform proportional-type or commutative-type regulation.
2. Monobloc distributor according to claim 1, characterised in that it is fed, via the intake port (100), by a single conduit (007) which samples the compressed air in the air/oil separating tank (004).
3. Monobloc distributor according to claims 1 and 2, characterised in that it has four outlets (101, 102, 103, 104).
4. Monobloc distributor according to claim 3, characterised in that through the first and second outlets (101, 102), corresponding first and second conduits (119, 121), respectively provided with a discharge regulating screw (9) and with a minimum pressure regulating screw (8), communicate with the external environment via an interposed filter.
5. Monobloc distributor according to claim 3, characterised in that through a third outlet (103) a third conduit (126) controls the displacement of the cursor (022) which intercepts the suction port (021) of the suction regulator.
6. Monobloc distributor according to claim 3, characterised in that through a fourth outlet (104) a fourth conduit (128), provided with a non-return valve (10), creates a counterpressure adapted to compensate for the negative thrust action that is produced on the mechanism of the screw pump (003) during proportional-type operation and during vacuum operation.
7. Monobloc distributor according to one or more of the preceding claims, characterised in that it has an electronic board used to enable the operation of the solenoid valves (008, 009).
8. Monobloc distributor according to one or more of the preceding claims, characterised in that it is combined with a suction regulator (002.1) the body of which is connected to the external ducting, with interposed removable fasteners (031, 034).
9. Monobloc distributor according to claim 8, characterised in that the suction regulator (002.1) is of the modular type, thereby making it possible to combine removable fasteners of different nominal dimensions, shapes and diameters (031.1A/B, 031.2A/B, 034.A, 034.B).
10. Monobloc distributor according to claim 8, characterised in that the removable fasteners (031, 034) feature a bayonet-type coupling.

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