Connection member for a refrigerating machine and corresponding machine

Abstract

Connection member (10) for a refrigerating machine (100) for connecting a pipe (114) to a fitting (113) provided at the front with a conical coupling portion (113a), comprising a main body (11) provided with a central element (12) which is able to be inserted inside one end of said pipe (114) and be coupled to said fitting (113), a peripheral element (13) coaxial to said central element (12), and a ring nut (15).

Description

[0001] “CONNECTION MEMBER FOR A REFRIGERATING MACHINE AND CORRESPONDING MACHINE”

[0002] FIELD OF THE INVENTION The present invention concerns a connection member that can be used in the field of HVAC+R (Heating, Ventilation, Air Conditioning, Refrigeration) machines to connect, for example, but not only, a pipe made of multilayer metalplastic composite material, through which a refrigerant gas can pass at pressures of up to approximately 40-45 bar and temperatures comprised between approximately -40 °C and +130 °C, with a terminal fitting of such machines. Here and hereafter in the following description, by the term “refrigerating machine” we mean a machine that works with a refrigerant fluid, and which is effective in transferring heat.

[0003] BACKGROUND OF THE INVENTION In the refrigerating machines sector, it is known that pipes have to be used to connect two or more refrigerating modules that operate with a refrigerant fluid, for example the external unit and the internal unit of an air conditioning apparatus.

[0004] The refrigerating modules are normally equipped with male threaded fittings to which the pipe has to be connected during installation. The geometry of these fittings follows a specific standard, different from the one used for example in the plumbing and heating, or hydronic conditioning sectors.

[0005] At present, the most common type of connection is still achieved with copper pipes, which are connected to the male threaded fittings by means of a brass pipe union having a female thread that compresses a so-called “flare”, which is a flaring made in advance on the terminal part of the pipe by means of mechanical deformation.

[0006] However, this solution requires working the terminal part of the pipe using a flaring machine that requires a great deal of expertise on the part of the operator who carries out the installation, as well as considerable production time.

[0007] Recently, metal-plastic multilayer composite pipes, already used for some time in the heating and plumbing sector to distribute water, have been developed for this sector, suitably redesigned in terms of dimensions in order to respond to the different operating conditions (temperature, pressure, type of fluid, etc.).

[0008] Multilayer composite pipes, unlike classic copper ones, cannot be subjected to “flaring” work, therefore they are typically connected to the terminal fittings of the modules of refrigerating machines by means of so-called “push-fit” connection members, in which the permanent joint between the pipe and the connection member is achieved by pressing a part of the connection member called “bushing” that compresses the end of the pipe located inside it against a main body of the connection member, called “outlet connector”.

[0009] In the field of refrigerating machines, in order to create threaded connections that are reversible, that is, able to be disassembled and reassembled regularly even after the bushing has been pressed onto the pipe, connection members are used in which the main body comprises, in a single piece, a female threaded portion that is screwed “dry” directly onto the male threaded fitting, that is, without the interposition of any gaskets. A disadvantage of this solution, however, is that it does not allow to easily remove the connection member, because this involves the rotation of the fitting with respect to the pipe, with which it is substantially integral. This complicates disassembly operations and especially assembly operations when the pipe and fitting are already pressed together. The connection members used in the field of hydronic heating and plumbing have a particular geometry, called pipe union or rotating nut. This generally comprises two parts: the nut or pipe union, and the part that creates the seal, integral with the fitting’s main body, which is generally of the so-called “flat seal” or “O-ring seal” type, depending on the geometry of the fitting to which they are connected. In the first case, the hydraulic seal is achieved with the interposition of a flat geometry gasket, while in the second by using an O-ring. However, this solution is not feasible in the refrigerating machines sector due to the different geometry of the connection fittings and because the fluid’s operating conditions are more critical (pressures approximately 20-40 times higher). There is therefore the need to perfect a connection member that can overcome at least one of the disadvantages of the state of the art.

[0010] To do this, it is necessary to solve the technical problem of providing a connection member suitable for applications in which the fluid inside the multilayer composite material pipe flows with pressures of up to approximately 40-45 bar and temperatures comprised between approximately -40 °C and +130 °C, wherein the fluid is preferably a refrigerant fluid.

[0011] One purpose of the present invention is to provide a connection member that is easily installable and, if necessary, easily removable without stressing the pipe to which it is applied.

[0012] One purpose of the present invention is to provide a connection member that replicates the connection mode used in the case of copper pipes.

[0013] Another purpose of the present invention is to provide a refrigerating machine operating with a refrigerant fluid and provided with at least two modules connected to each other with pipes, preferably made of multilayer composite material, by means of the aforementioned connection member.

[0014] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0015] SUMMARY OF THE INVENTION

[0016] The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea. In accordance with the above purposes and to resolve the technical problem described above in a new and original way, also achieving considerable advantages compared to the state of the prior art, a connection member according to the present invention for connecting a pipe to a fitting provided at the front with a conical coupling portion, comprises a main body provided with a central element which is able to be inserted inside one end of the pipe and be coupled to the fitting, a peripheral element coaxial to the central element, and a ring nut.

[0017] In accordance with one aspect of the present invention, the central element has a mating conical connection portion, and the connection member comprises a connection body coaxially associated with the central element by mechanical interference and able to be screwed onto the fitting.

[0018] The conical shape of the connection portion, combined with the use of the connection body to ensure it is pushed against the threaded fitting, allows to achieve a coupling similar to that created with copper pipes, but in this case regardless of the type of pipe that can be coupled to the connection member. This is particularly advantageous, in particular for pipes made of multilayer composite material, for example a combination of plastic and aluminum, since it would not be possible to easily shape their ends. In accordance with another aspect of the present invention, the connection body is a component distinct from the central element. As a result, the hydraulic seal is guaranteed by the conical coupling between the connection and coupling portions, while the tightening by the connection body is independent.

[0019] In accordance with another aspect of the present invention, the connection portion has a front conical surface with a semi-opening angle equal to 45°. The conical surface advantageously has a concave conformation.

[0020] In accordance with another aspect of the present invention, the connection portion has no thread. According to the invention, in fact, the axial tightening is achieved with a distinct and independent component, which is the connection body.

[0021] In accordance with another aspect of the present invention, the connection body is provided with a first housing seating conformed to accommodate the connection portion with a same-shape coupling geometry.

[0022] In accordance with another aspect of the present invention, the connection portion and the first housing seating have an external peripheral surface and an internal peripheral surface, respectively, which configure an undercut. The undercut can be a shoulder or step.

[0023] In accordance with another aspect of the present invention, on the first housing seating and on the connection portion there can be created a circular groove in which a snap ring is housed.

[0024] In accordance with another aspect of the present invention, the connection body is provided with a second housing seating having a threaded internal surface mating with a corresponding threaded portion of the fitting.

[0025] The present invention also concerns a refrigerating machine comprising at least a first refrigerating module and at least a second refrigerating module which are provided with respective fittings, at least one pipe for the connection of the two refrigerating modules and at least one such connection member for the connection of one or both ends of the pipe with a respective one of the fittings. DESCRIPTION OF THE DRAWINGS

[0026] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein: - fig. 1 is an example schematic illustration of a refrigerating machine according to the present invention;

[0027] - fig. 2 is a three-dimensional view of a detail of fig. 1, showing a connection member attached on one side to the terminal fitting of a first refrigerating module and on the opposite side to a pipe for the fluidic connection to a second refrigerating module of fig. 1;

[0028] - fig. 3 is a longitudinal section view of an embodiment of the connection member of fig. 2; and

[0029] - fig. 4 is a longitudinal section view of a further embodiment of the connection member of fig. 2. We must clarify that the phraseology and terminology used in the present description, as well as the figures in the attached drawings also in relation as to how described, have the sole function of better illustrating and explaining the present invention, their purpose being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims. To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications.

[0030] DESCRIPTION OF SOME EMBODIMENTS OF THE PRESENT INVENTION With reference to fig. 1 , this shows a refrigerating machine 100 according to the present invention comprising at least a first refrigerating module 111 and at least a second refrigerating module 112, which are provided with respective externally threaded fittings 113 which at the front have a conical coupling portion 113a, figs. 3 and 4. The refrigerating machine 100 further comprises at least one pipe 114 for connecting the two refrigerating modules 11 1, 112 to each other, inside which pipe 114 a fluid can flow. In particular, two distinct pipes 114 can be provided, one of which is a delivery pipe and one of which is a return pipe. The fluid can be a refrigerant fluid at high pressure, up to approximately 40-45 bar, and temperature comprised between approximately -40 °C and +130 °C.

[0031] The pipe 114 is flexible and can preferably be made of a multilayer composite material, for example a combination of plastic and aluminum. It is not excluded that the pipe 114 can also be made of other metal or plastic materials, or a combination thereof.

[0032] The refrigerating machine 100 also comprises at least one connection member or connector 10 for connecting one or both ends of the pipe 114 with a respective fitting 1 13, fig. 2. Please note that in the example of fig. 1 , the refrigerating machine 100 is shown by way of example as a home air-conditioning apparatus, in which the first refrigerating module 111 is the external unit inside which the compressor is housed, while the second refrigerating module 112 is the internal unit, or split, in which the evaporator is housed. Additional examples of refrigerating machines in which it can be provided to use connection members 10 as described below can be refrigerating systems of the VRF type, or heat pumps of the monobloc or split type, or suchlike.

[0033] The connection member 10 comprises a main body 11 provided with a central element 12, also called outlet connector, configured to be inserted, by pressure- fit / snap-in, inside an end of a pipe 114.

[0034] The connection member 10 comprises an annular peripheral element 13, also called a bushing, having a through hollow cylindrical shape, able to be assembled coaxially to the central element 12 and to be fitted on the pipe 114.

[0035] The end of the pipe 114 is closed radially “sandwiched” between the central element 12 and the peripheral element 13 which, during installation, is deformed against the pipe 114 in order to clamp the main body 11 in position.

[0036] The main body 11 also comprises a ring nut 15 with which the central element 12 and the annular peripheral element 13 are associated. The purpose of the ring nut 15 is to keep the annular peripheral element 13 in position with respect to the central element 12, in such a way as to leave a space between them for the axial insertion of the pipe 114.

[0037] The central element 12 has a mating conical connection portion 16 able, during use, to be coupled at the front, that is, head end, against the coupling portion 113a of the fitting 113.

[0038] According to some embodiments, the connection portion 16 has a concave conical conformation. Correspondingly, the coupling portion 113a has a convex conical conformation. Preferably, the coupling between the connection portion 16 and the coupling portion 113a occurs without the interposition of any sealing element whatsoever.

[0039] The connection portion 16 protrudes from a central aperture 15a of the ring nut 15, on the opposite side with respect to the side with respect to which the central element 12 is inserted, during use, inside the pipe 114. The connection portion 16 is located, during use, outside the pipe 114.

[0040] The connection portion 16 has a front conical surface 17 having a semi-opening angle a which can be comprised between approximately 44° and approximately 46°, preferably it is equal to approximately 45°. In general, the semi-opening angle a depends on the conical shape of the geometry of the coupling portion 113a that is specific to the technical application which the connection member 10 will have to serve (type of fluid, pressures, temperatures).

[0041] According to further possible embodiments, the semi-opening angle a can be comprised between approximately 40° and approximately 50°.

[0042] The connection member 10 further comprises a hollow connection body 14 coaxially associated with the central element 12 by mechanical interference and able to be screwed onto the fitting 113 in order to keep the central element 12 in position against it.

[0043] In the example of fig. 2, the connection body 14 comprises an external portion, hexagonally shape so that it can be easily manipulated with a standardized tool. The connection body 14 is essentially a nut and is known in the field by the term pipe union.

[0044] The main body 11, formed by the central element 12, by the annular peripheral element 13 and by the ring nut 15, and the connection body 14 are, during use, substantially coaxial to each other along a common coupling axis X. According to possible embodiments, the main body 11 and the connection body 14 can be assembled in advance into a single block, and can be reciprocally mobile with a certain clearance, before the pipe 114 is connected to the fitting 113.

[0045] The connection body 14 is a distinct component from the central element 12. The tightening and the hydraulic seal are therefore achieved with two independent components.

[0046] The connection body 14 is provided with a first housing seating 18 conformed to accommodate the connection portion 16 with a same-shape coupling geometry. The first housing seating 18 has no thread, as is the case for the connection portion 16.

[0047] The connection portion 16 and the first housing seating 18 have an external peripheral surface 20 and an internal peripheral surface 21, respectively, which are essentially mating in shape. According to some embodiments, the external 20 and internal 21 peripheral surfaces are conformed into two annular segments having a different diameter DI, D2, fig. 3. The external 20 and internal 21 peripheral surfaces determine an undercut, for example a shoulder or step.

[0048] The peripheral surfaces 20, 21 are advantageously disposed in reciprocal contact, at least in correspondence with the shoulder defined between the two annular segments.

[0049] According to an alternative embodiment, on the external 20 and internal 21 peripheral surfaces there is created a circular groove 22, 23 in which a snap ring 24 is housed, fig. 4. In this case, the external 20 and internal 21 peripheral surfaces have a same diameter D, therefore the first housing seating 18 has an essentially cylindrical shape.

[0050] The two circular grooves 22, 23 face each other and together define a housing for the snap ring 24.

[0051] The snap ring 24 can preferably be made of a metal material. In both embodiments, when the connection body 14 is screwed, it axially pushes the central element 12 against the fitting 113, thanks to the mechanical interference caused by the undercut (fig. 3) or by the snap ring 24 (fig. 4), ensuring the “dry” hydraulic seal, that is, without sealing elements, between the connection portion 16 and the coupling portion 113a. The connection body 14 is also provided with a second housing seating 19, distinct from and communicating with the first housing seating 18.

[0052] The second housing seating 19 has a threaded internal surface 25. The threaded internal surface 25 is mating with a corresponding threaded portion 113b of the fitting 113. When the connection body 14 is screwed onto the fitting 113, the coupling portion 113a and part of the threaded portion 113b are accommodated inside the second housing seating 19 and the coupling portion 113a abuts against the connection portion 16. According to some embodiments, the central element 12 is a stem that extends longitudinally along the coupling axis X and is provided with a coaxial through channel 26 that has the function of guaranteeing continuity between the pipe 114 and the downstream components, and vice versa.

[0053] The through channel 26 communicates with the connection portion 16. The central element 12 comprises a first segment 12a which, during use, is located inside the pipe 114, and a second segment 12b which comprises the connection portion 16.

[0054] The first segment 12a cooperates with an internal surface of the pipe 114 and can be provided with a notch formed for example by annular indentations 27 which are able to cooperate with the internal surface of the pipe 114 by mechanical interference.

[0055] Sealing rings 29, for example O-ring type gaskets, can be disposed in the indentations 27, or in distinct special seatings 28.

[0056] It is clear that modifications and / or additions of parts may be made to the connection member 10 and to the refrigerating machine 100 as described heretofore, without thereby departing from the field and scope of the present invention, as defined by the claims.

[0057] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art will be able to achieve other equivalent forms of a connection member for a refrigerating machine and corresponding machine, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

[0058] In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.

Claims

CLAIMS1. Connection member (10) for a refrigerating machine (100) for connecting a pipe (114) to a fitting (113) provided at the front with a conical coupling portion (113a), comprising a main body (11) provided with a central element (12) which is able to be inserted inside one end of said pipe (114) and be coupled to said fitting (113), a peripheral element (13) coaxial to said central element (12), and a ring nut (15), characterized in that said central element (12) has a mating conical connection portion (16), and in that said connection member (10) comprises a connection body (14) coaxially associated with said central element (12) by mechanical interference and able to be screwed onto said fitting (113).

2. Connection member (10) as in claim 1, characterized in that said connection body (14) is a component distinct from said central element (12).

3. Connection member (10) as in claim 1 or 2, characterized in that said connection portion (16) has a front conical surface (17) with a semi-opening angle (a) equal to 45°.

4. Connection member (10) as in any claim hereinbefore, characterized in that said connection portion (16) has no thread.

5. Connection member (10) as in claim 1, characterized in that said connection body (14) is provided with a first housing seating (18) conformed to accommodate said connection portion (16) with a same-shape coupling geometry.

6. Connection member (10) as in claim 5, characterized in that said connection portion (16) and said first housing seating (18) have an external peripheral surface (20) and an internal peripheral surface (21), respectively, which configure an undercut.

7. Connection member (10) as in claim 5, characterized in that on said first housing seating (18) and on said connection portion (16) there is created a circular groove (22, 23) in which a snap ring (24) is housed.

8. Connection member (10) as in claim 1, characterized in that said connection body (14) is provided with a second housing seating (19) having a threaded internal surface (25) mating with a corresponding threaded portion (113b) of said fitting (113).

9. Refrigerating machine (100) comprising at least a first refrigerating module (111) and at least a second refrigerating module (112) which are provided withrespective fittings (113), at least one pipe (114) for the connection of the two refrigerating modules (111, 112) and at least one connection member (10) as in any claim hereinbefore for the connection of one or both ends of said pipe (114) with a respective one of said fittings (113).

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