Technical Field

The present invention relates to a hydraulic distributor.

Background Art

As is well known, hydraulic distributors are generally used to convey a work fluid under pressure, such as air, water or oil, to a plurality of user points, such as e.g. hydraulic cylinders.

For example, hydraulic distributors are used in agricultural machinery, in aerial vessels, in forklift trucks or in operating machinery, such as earthmoving machinery.

Hydraulic distributors generally comprise a supply channel for a work fluid under pressure, which can be connected to a source of the work fluid such as a pump or the like, a discharge channel, which can be connected to a discharge tank, a first and a second command line which can be connected to a user point, for example which can be connected to the opposed chambers of a hydraulic cylinder, valve means placed between the supply and discharge channels and the command lines and which can be operated to regulate the flow of work fluid towards the user points. There are also activation means for activating the valve means, e.g. of the electric type.

Today there are several types of hydraulic distributors, some of which, called “monoblock”, are designed and manufactured in a single body piece according to the specific needs of the case, or depending on the functions required and depending on the overall dimensions available.

These monoblock distributors, however, have the drawback of being very expensive, due in particular to the fact that the design and construction are linked to the specific needs of the case, so their use is not very flexible. For the same reason it is also complicated to manage the warehouse stocks.

An alternative to monoblock distributors are the so-called “modular” distributors, i.e. distributors made up of a plurality of separate modules that can be assembled according to the needs of the case.

The modular distributors are particularly adapted for small to medium fluid flow rates, such as in the case of agricultural machines or aerial vessels.

Each of these modules defines a length of the supply channel and of the discharge channel, has relative command lines that can be connected to a corresponding user point, relative valve means and activation means.

These modular distributors do have some drawbacks, although they are characterized by a wide flexibility of use, because they combine the various modules to each other so that various final configurations can be obtained.

In particular, their mutual fixing is complicated, since the number of modules used, and therefore the overall dimensions of the distributor, may vary from time to time depending on the specific needs of the case.

To date, one known solution for the mutual fixing of the various modules used is to make threaded parts that pass through all the modules used, tightening them together.

This, however, requires the realization of various types and sizes of threaded members, with a consequent increase in the manufacturing costs and in the complexity of the management of the warehouse stocks.

Another drawback of the modular distributors consists in the difficulty of avoiding leakage of the work fluid between one module and another.

Documents US 3215158A, US 3111139A, WO 2008/116481, US 2003/056840A1, EP 0959280A1, EP 2770217A2, US 2003/116208A1, describe some modular distributors of known type with which external valve means are associated which are necessary to divert the flow of the work fluid towards the relative user points.

Description of the Invention

The main aim of the present invention is to devise a hydraulic distributor of the modular type that is not only easy to design, but also easy to assemble, regardless of its sizes and functions.

Within this aim, one object of the present invention is to devise a hydraulic distributor that allows reducing, compared to the devices of known type, the components necessary for the production thereof.

Another object of the present invention is to optimize, from the hydraulic point of view, the path of the work fluid in the passage between the various modules. Still another object is to facilitate the management of the warehouse stocks.

A further object of the present invention is to minimize the risk of leakage between adjacent modules.

Another object of the present invention is to devise a hydraulic distributor that allows overcoming the aforementioned drawbacks of the prior art in a simple, rational, easy, effective to use and low-cost solution.

The aforementioned objects are achieved by the present hydraulic distributor according to claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will be more evident from the description of a preferred, but not exclusive, embodiment of a hydraulic distributor, illustrated by way of an indicative, but non-limiting example, in the attached tables of drawings in which:

Figure 1 is an axonometric view of a series of modules of hydraulic distributors according to the invention;

Figure 2 is a side elevation view of the modules in Figure 1 ;

Figure 3 is a cross-sectional view of the modules in Figure 2 along the trace plane III-III;

Figure 4 is a plan view from above of the modules in Figure 1 ;

Figures 4a to 4c are cross-sectional views of some of the modules in Figure 4 according to the IVa-IVa, IVb-IVb and IVc-IVc trace planes;

Figure 5 is a side elevation view of a distributor according to the invention; Figure 6 is a cross-sectional view of the distributor in Figure 5 along the trace plane VI-VI.

Embodiments of the Invention

With particular reference to these illustrations, reference numeral 1 globally indicates a hydraulic distributor.

The distributor 1 comprises a plurality of modules, identified in the figures with reference numeral 2, which are connected to each other in a removable manner. The modules 2 can therefore be assembled together depending on the available overall dimensions and the required functions.

Each module 2 comprises a relative body 3 provided with at least one supply channel 4 connectable to a source of a work fluid under pressure, such as a pump or the like, at least one discharge channel 5 connectable to a discharge tank and at least a first and a second command lines 6 and 7 connectable to a relative user point, such as e.g. a hydraulic cylinder.

According to the invention, inside the body 3 of each module 2, valve means 8 are housed which are positioned between the supply and discharge channels 4 and 5 and the command lines 6 and 7, where the valve means 8 are operable, by means of activation means 9, to regulate the flow of the work fluid towards the command lines themselves. The valve means 8 are suitably inserted in a removable manner inside the body 3 of the relative module 2.

The distributor 1 comprises an end module 2a, which is associated with only one module 2 and which has a connecting channel, not visible in detail in the illustrations, adapted to place the supply channels 4 of the various modules 2 in communication with the relative discharge channels 5.

The body 3 of each module 2 advantageously defines at least one coupling surface 10 adapted to rest against the coupling surface 10 of the adjacent module 2. In particular, each body 3 has two coupling surfaces 10 opposing each other, adapted to lean against the front module 2 and against the rear module 2, respectively. On the coupling surfaces 10 face the supply channel 4 and the discharge channel 5 of the relative module 2, thus defining relative inlet ports 4a, 5a of the work fluid inside the relative module 2 and relative outlet ports 4b, 5b of the work fluid from the relative module 2. More specifically, the supply channel 4 defined in each module 2 has a relative inlet port 4a and a relative outlet port 4b of the work fluid, which are arranged facing each other and facing the relative coupling surfaces 10. Similarly, the discharge channel 5 defined in each module 2 has a relative inlet port 5a and a relative outlet port 5b of the work fluid, which are arranged facing each other and facing the relative coupling surfaces 10.

The valve means 8 are then housed inside the body 3 of the relative module 2 and are positioned between the inlet port 4a, 5a and the outlet port 4b, 5b of at least one of the relative supply channel 4 and the relative discharge channel 5. The distributor 1 then comprises mutual connecting means 11 of the various modules 2.

More specifically, the connecting means 11 comprise, for each module 2, at least one threaded element 12 which engages in a removable manner with the threaded elements 12 of the adjacent modules 2 for the mutual fixing thereof.

By means of the mutual engagement of the threaded element 12 of a module 2 with the threaded element 12 of the adjacent module 2, it is therefore possible to fix the various modules 2 to each other.

Advantageously, as shown in Figure 3, each threaded element 12 has at least one externally threaded end l2a and at least one internally threaded hollow head l2b. The end l2a of the threaded element 12 of one of the modules 2 engages with the hollow head l2b of the threaded element 12 of the adjacent module 2. In the embodiment shown in the illustrations, the threaded elements 12 also comprise one stem l2c, positioned between the relative end l2a and the relative head l2b, where the stem l2c, the head l2b and the end l2a have diameters different to each other.

Each module 2 is then fixed to the adjacent modules 2 by means of the threaded elements 12.

Preferably, a plurality of threaded elements 12 is provided for each module 2. In particular, there are three threaded elements 12 for each module 2, which are arranged to define the vertices of a triangle, so as to evenly distribute the tightening torques.

More in detail, each threaded element 12 is inserted into a relative through hole 13 defined on the body 3 of the relative module 2. The hole 13 faces the coupling surfaces 10 of the relative module 2.

The holes 13 of each module 2 are separate from both the relative supply channel 4 and the relative discharge channel 5.

In the embodiment shown in the illustrations, the holes 13 extend substantially parallel to at least one of the supply channel 4 and the discharge channel 5 of the relative module 2.

Appropriately, the holes 13 have at least one recess l3a for at least partly housing the head l2b of the relative threaded element 12. More particularly, as can be seen from the sections of Figure 3, the head l2b of the threaded element 12 of a module 2 can be completely contained within the relative recess l3a, and therefore be substantially aligned with the relative coupling surface 10 of the module itself.

Alternatively, the head l2b of the threaded element 12 can be partly contained inside the relative recess l3a, therefore partly protruding from the relative coupling surface 10 of the module 2. In this case, the holes 13 comprise at least a first recess l3a for the housing of the head l2b of the relative threaded element 12 and at least a second recess l3b, which is opposed to the first recess 13 a, for the housing of the head l2b of the threaded element 12 of the adjacent module 2, so that the coupling surfaces 10 of the bodies 3 of the adjacent modules are arranged to rest against each other following the tightening of the threaded elements 12. The first and the second recesses l3a and l3b suitably have the same diameter, larger than the diameter of the intermediate portion l3c of the hole 13 placed between the recesses l3a and l3b.

Preferably, between the coupling surfaces 10 of two adjacent modules 2, at the supply and discharge channels 4 and 5, sealing means are interposed, e.g. of the O-ring type, not visible in detail in the illustrations, adapted to prevent leakage to the outside of the work fluid.

On the coupling surface 10 of at least one of two adjacent modules 2, a relative seat 14 is defined for the housing of the sealing means, located inside the inlet port 4a, 5a and/or the outlet port 4b, 5b of the relative supply and discharge channels 4 and 5.

Advantageously, each of the coupling surfaces 10 has a relative seat 14 for the housing of the sealing means; the seats 14 defined on the coupling surfaces 10 facing each other are substantially aligned with each other so that the sealing means are partly housed inside each of them. In this case, therefore, the body 3 of two adjacent modules 2 has a seat 14 defined at the outlet port 4b, 5b of one of the two modules 2 and a seat 14 defined at the inlet port 4a, 5a of the adjacent module 2 and with which the outlet port 4b, 5b is placed in communication.

This allows optimizing the sealing function between two adjacent modules 2 and at the same time facilitating the management of the warehouse stocks, since the bodies 3 of the various modules 2 have the same characteristics. Moreover, the presence of the seat 14 defined on each coupling surface 10 allows the relative module 2 to be rotated by 180° according to needs, maintaining the seal with the adjacent module 2 unchanged, thus allowing a wide flexibility of use. The operation of the present invention is as follows.

The distributor 1 is assembled by connecting the various modules 2 to each other.

In particular, the distributor 1 is assembled by choosing the modules 2 which are suitable for the performance of the desired functions, where the modules 2 are in turn assembled by inserting the appropriate valve means 8 into the relative bodies 3.

The assembly of the distributor 1 is carried out by inserting the threaded elements 12 into the holes 13 of each module 2 and by engaging the threaded elements 12 of each module 2 with the threaded elements 12 of the adjacent module 2.

In particular, the end l2a of each threaded element 12 is inserted into the head l2b of the threaded element 12 of the adjacent module 2. By tightening the threaded elements 12, the adjacent modules 2 are compacted together, bringing them to a“pack” configuration. The tightening force is discharged onto the coupling surfaces 10, so that the opposed coupling surfaces 10 of each module 2 are subjected to opposing and substantially equivalent forces.

Each module 2 is then associated with the adjacent module 2, starting with the end module 2a.

Appropriately, before tightening the threaded elements 12 together, the sealing means are positioned between the coupling surfaces 10 of two adjacent modules 2, at the relative seats 14. It has in practice been found that the described invention achieves the intended objects and, in particular, the fact has been pointed out that the distributor, which the present invention relates to, can be easily assembled by means of the threaded elements associated with each module, which in no way alter the fluid dynamics of the distributor himself and at the same time allow optimizing the warehouse stocks.

In particular, the fact that the threaded elements are inserted into the relative holes separate from the supply and discharge channels allows the fluid dynamics of the modules to be maintained unchanged and the threaded elements themselves to be sized at will.

The solution, which the present invention relates to, also allows standardizing both the modules and the threaded elements, allowing a high flexibility of design and an easy management of the warehouse stocks.