The present invention refers to a modular valve for fluidic circuits and to a process for making the same particularly but not exclusively used in the field of industrial plants.

Currently, it is known to produce modular oil-hydraulic valves, for example to reduce pressure in fluidic circuits, suitable for coupling on one another in order to carry out the desired adjustment in one or more stages.

In general, an oil-hydraulic valve currently known comprises a valve body inside which a series of ducts for the passage of oil or another fluid are made. Inside such a valve body an actuator is placed which is functional for the different work configurations in the circuit, each corresponding to a predetermined adjustment of the flow of oil, at intersecting fixed ducts as well.

Making the complex configurations of the aforementioned ducts inside the valve body forces the adoption of rather complex manufacturing processes like the lost wax casting and/or microcasting method. According to such a method, in particular, a wax model of the required shape is manufactured, it is coated with a ceramic material by immersion or spraying and then it is brought to a high temperature in a furnace. At this point the wax evaporates, leaving a hard ceramic shell; into such a ceramic shell molten material is poured, which is then solidified. Thus a valve body of the desired shape is obtained, complete with ducts for the fluid, holes for the bolts, references for drainage and identification marks. The valve body obtained is finally subjected to further mechanical processing that allows fine adjustments of the geometric characteristics of the valve body itself to be carried out .

It is clear that the aforementioned lost wax casting method is very long and expensive, as well as not very flexible and adaptable to the different configurations that can be required for the valve body. In fact, it is necessary to reproduce a wax model at each of the configurations of the valve body that it is wished to make, even in the case in which there is a need to make some slight modifications to a valve body the wax model of which has already been made .

The low flexibility of the lost wax casting method is reflected in high production costs and makes such a method not very suitable for application to serial production contexts.

The purpose of the present invention is to avoid the aforementioned drawbacks and in particular to conceive a modular valve for fluidic circuits that is simple to manufacture .

Another purpose of the present invention is to provide a process for making a modular valve for fluidic circuits that is not very expensive and highly flexible.

These and other purposes according to the present invention are accomplished by making a modular valve for fluidic circuits and a process for making the same as outlined in independent claims 1 and 8.

Further characteristics of the modular valve for fluidic circuits and of the process for making the same are the object of the dependent claims.

The characteristics and advantages of a modular valve for fluidic circuits and of a process for making the same according to the present invention will become clearer from the following description, given as an example and not for limiting purposes, referring to the attached schematic drawings, in which:

- figures la, lb and lc are three schematic perspective views of an embodiment of the modular valve for fluidic circuits according to the present invention;

- figures 2a and 2b are two schematic perspective views of a collecting bush comprised in the modular valve for fluidic circuits of figure 1, whereas figure 2c is a transparent schematic perspective view of such a bush;

- figure 3 is a schematic perspective section view of the collecting bush of figures 2a, 2b and 2c ;

- figures 4a and 4b are two schematic perspective views of the body of the modular valve for fluidic circuits of figure 1, whereas figure 4c is a transparent schematic perspective view of such a valve body;

- figure 5 is a view from above of the body of the modular valve for fluidic circuits of figure 1; - figure 6 is a section view along the line VI-VI of the body of the modular valve for fluidic circuits of figure 1;

- figure 7a is a first partially cut-away schematic perspective view of the modular valve for fluidic circuits of figure 1;

- figure 7b is a schematic perspective view, partially cut-away and partially in section, of the modular valve for fluidic circuits of figure 7a;

- figure 7c is a schematic perspective view, partially cut-away, partially in section and transparent of the modular valve for fluidic circuits of figure 7a;

- figure 8a is a second partially cut-away schematic perspective view of the modular valve for fluidic circuits of figure 1;

- figure 8b is a schematic perspective view, partially cut-away and partially in section of the modular valve for fluidic circuits of figure 8a;

- figure 8c is a schematic perspective view, partially cut-away, partially in section and transparent of the modular valve for fluidic circuits of figure 8a;

figures 9a and 9b are further partially cut-away schematic perspective views of the modular valve for fluidic circuits of figure 1.

With reference to the figures, a modular valve for fluidic circuits is shown, wholly indicated with 10. In such a modular valve 10 for fluidic circuits at least two inlets and/or outlets 11 are obtained, through which it is possible to make the feeding fluid flow. The modular valve 10 for fluidic circuits comprises a valve body 12 that defines on its inside a bush seat 13.

In particular, the aforementioned bush seat 13 is a through one and has a preferably circular cross section.

Preferably, the valve body 12 comprises a plurality of through seats 17 for engagement with fixing means (not illustrated) like for example screws. In this way, the valve body 12 can be stably applied onto a bracket comprised in a fluidic circuit or onto a further valve body comprised in a further modular valve in order to make complex valve configurations for multi-stage adjustments .

The modular valve 10 for fluidic circuits also comprises a collecting bush 14 suitable for being stably inserted in the aforementioned bush seat 13.

In particular, the collecting bush 14 is preferably a circular cross-section and also comprises at least one blocking recess 21 made on its outer surface at the through seats 17. Such a blocking recess 21 is suitable for collaborating with the fixing means engaged in the through seats 17 in order to allow bracketing also on a further valve body.

Preferably, on the outer surface of the bush 14 at least one passage recess 15, optionally a plurality of recesses 15, is obtained, such as to form together with the valve body 12, at least one duct length 16, optionally a plurality of duct lengths 16. It should be emphasised that the at least one passage recess 15 is groove-shaped and that the at least one duct length 16 is defined by the at least one passage recess 15 and the inner surface of the bush seat 13 obtained in the valve body 12.

In particular, the at least one duct length 16 puts in fluidic communication the at least two inlets and/or outlets 11.

According to the present invention, the collecting bush 14 is suitable for rigidly engaging with the valve body 12 so as to become integral with it, and comprises sealing means 22 to make a hermetic seal of each of the duct lengths 16.

In this way a modular valve 10 is thus made that is configured to carry out a predetermined function in a fluidic circuit.

Preferably, the collecting bush 14 comprises at least one inner duct 18 in fluidic communication with at least two openings 19 made on the outer surface of the bush 14. Preferably, the openings 19 can be made at the at least two inlets and/or outlets 11, and/or at the passage recesses 15, allowing the fluidic communication between the inner duct 18 and the duct lengths 16.

It should be emphasised that the at least one duct length 16, therefore, can put in fluidic communication the at least two inlets and/or outlets 11 not just facing directly onto them, but also through the at least one inner duct 18 and the at least two openings 19. In this way it is possible to make a plurality of modular valves for fluidic circuits which differ from each other by the number of inlets and/or outlets.

Preferably, the at least one passage recess 15 does not define a complete revolution surface around the rotation axis of the collecting bush 14. In this way, the at least one duct length 16 extends partially on the outer surface of the collecting bush 14.

Preferably, the sealing means 22 are made on the outer surface of the collecting bush 14 so as to prevent liquid leaks from each duct length 16. In detail, as can be observed in figure 2a, preferably the sealing means 22 comprise at least one sealing seat 22 that extends around the at least one passage recess 15 and/or the at least one blocking recess 21 and a sealing paste or a gluing material at least partially inserted in the sealing seat 22.

The seal of the single duct length 16 can, in fact, be made through a sealing paste, like for example a per se known copper paste, or else through a gluing material that is spread at the sealing seats 22.

In a first alternative embodiment the sealing means 22 comprise a gluing material spread directly on the outer surface of the collecting bush 14 in particular around the passage recesses 15 and/or the blocking recesses, in case the sealing seats 22 are not made.

In a second alternative embodiment, the seal of the single duct length 16 can be obtained through just the shape coupling between the valve body 12 and the collecting bush 14.

In case a plurality of passage recesses 15 is made on the outer surface of the collecting bush 14, it is therefore possible to obtain a plurality of lengths of ducts 16 that are substantially isolated from one another from the fluidic point of view.

Moreover, in this case, it is possible to obtain a plurality of lengths of ducts that can be configured so as to obtain a plurality of different distribution circuits depending on the role that the modular valve 10 for fluidic circuits is intended to perform in the circuit that it is part of.

The process for making a modular valve 10 for fluidic circuits according to the present invention is as follows.

Such a process comprises an initial operation in which a first processing is carried out, making the bush seat 13 and the at least two inlets and/or outlets 11 in the valve body 12.

Thereafter there is a second processing in which the at least one passage recess 15, optionally a plurality of passage recesses 15, is made on the outer surface of the collecting bush 14. After such a second processing sealing means 22 are applied around each passage recess 15.

Preferably, the process for making a modular valve for fluidic circuits also comprises a third processing in which the through seats 17 are made in the valve body 12 and the at least one blocking recess 21 is made on the outer surface of the collecting bush 14 at the aforementioned through seats 17.

Preferably, the process for making a modular valve for fluidic circuits comprises a fourth processing in which the at least two openings 19 are made on the outer surface of the bush 14 and the at least one inner duct 18 is made in fluidic communication with them.

Preferably, the process for making a modular valve for fluidic circuits comprises a fifth processing in which the at least one sealing seat 22 is made on the outer surface of the collecting bush 14.

Preferably, the aforementioned processing operations are carried out through chip removal processing, like for example perforation, cutting, turning, milling, grinding and so on.

Preferably, the processing operations are carried out through electrical discharge machining processing.

Preferably, the processing operations are carried out through hot or cold forming processing.

After the processing operations, the processed collecting bush 14 is inserted into the bush seat 13 made inside the valve body 12, obtaining the modular valve 10 for fluidic circuits.

In case the at least one sealing seat 22 is made on the outer surface of the collecting bush 14, before the insertion operation, the operation of spreading a sealing paste or a gluing material on the at least one sealing seat 22 is provided. Alternatively, before the insertion operation, the operation of spreading a gluing material on the outer surface of the collecting bush 14 without the sealing seats 22 and in particular around the passage and/or blocking recesses 15, 21 is provided. In any case, after the insertion of the collecting bush 14 in the bush seat 13, such an assembly is heated in a controlled-atmosphere furnace set at the melting temperature of the sealing paste or of the glue .

In the case in which the sealing paste is copper paste, such a temperature is comprised within the range indicated by the manufacturer of the paste.

In an alternative embodiment, considering a collecting bush with a larger cross section than the cross section of the bush seat 13, to insert such a collecting bush 14 in the bush seat 13, the valve body 12 is heated under controlled atmosphere, which, expanding due to the temperature, allows the insertion of the bush 14. When such an assembly is cooled a substantial adhesion of the collecting bush 14 with the valve body 12 is achieved.

In any way, it is possible to make duct lengths 16 that are substantially isolated from one another from the fluidic point of view. After the heating, step, finally, a cooling step is provided which brings the modular valve 10 for fluidic circuits obtained to room temperature .

From the description that has been made the characteristics of the modular valve for fluidic circuits and of the process for making the same, object of the present invention, are clear, just as the relative advantages are also clear.

In fact, the modular valve according to the present invention is simple to make since the ducts suitable for placing in fluidic communication the inlets and/or outlets are defined by the passage recesses made on the collecting bush and the inner surface of the bush seat of the valve body.

In this way, it is possible to provide a modular valve for fluidic circuits equipped with fluid distribution ducts having the most varied paths, thus allowing valves suitable for different application contexts to be made. The passage recesses, in fact, can be made through low-cost mechanical processing, like for example chip removal, avoiding the lost wax casting method .

The process for making a modular valve for fluidic circuits, according to the present invention, does not foresee making any model, being flexible and suitable for the production of different types of modular valves .

Finally, it is clear that the modular valve for fluidic circuits and the process for making the same thus conceived can undergo numerous modifications and variants, all of which are covered by the invention; moreover, all of the details can be replaced by technically equivalent elements. In practice, the materials used, as well as the sizes, can be whatever according to the technical requirements.