EP1818631A2

EP1818631A2 - Improved plug for pressure-sealing a condenser of an air conditioning system for vehicles and related condenser

Info

Publication number: EP1818631A2
Application number: EP07101817A
Authority: EP
Inventors: Michele Bernini
Original assignee: SKG Italia SpA
Current assignee: SKG Italia SpA
Priority date: 2006-02-09
Filing date: 2007-02-06
Publication date: 2007-08-15
Also published as: EP1818631A3; ITMI20060222A1

Abstract

Plug for pressure-sealing a condenser of an air-conditioning system for vehicles comprises an aluminium disc (12), adapted to be attached and braze-welded in a cylindrical end of a collector tube (20), and a spacer rod (13), stably bound to the disc (12) at a first end and connectable at an opposite end to a drying and/or filtering device (14,27,28).

Description

The present invention refers to an improved plug for pressure-sealing a collector tube of an air-conditioning system for vehicles and to a related condenser.
An air conditioning system for vehicles comprises among other things a drying means for extracting water particles from the refrigerant liquid and a filtering element for holding the impurities possibly present in the refrigerant liquid, in which such means are in general integrated inside a collector tube of a condenser.
The drying means can be contained in a stiff, holed casing, or cartridge, or in a permeable sack. The filter is also commonly integrated in the cartridge.
The collector tube is therefore provided, at a cylindrical end thereof, with a plug which must sealingly close against the interior of the wall of the collector tube during the system operation.
Plugs in general are pressure-inserted in the collector tube and equipped with one or more rubber seal rings and/or with a safety ring. Alternatively, the plugs are of screw type.
The plugs described are removable and permit access to the inside the collector tube. Nevertheless, such plugs, in order to ensure a pressure seal, have a complicated and costly structure and must be made with a high dimensional precision.
The object of the present invention is to make an improved plug for pressure-sealing a collector tube of an air conditioning system for vehicles and a related condenser which overcomes the mentioned technical drawbacks.
Another object of the present invention is that of making an improved plug for pressure-sealing a collector tube of an air conditioning system for vehicles and a related condenser which ensures high functioning safety, even at high operating pressures, typical for carbon dioxide refrigerants (CO₂).
Another object of the present invention is that of making an improved plug for pressure-sealing a collector tube of an air conditioning system for vehicles and a related condenser which is particularly simple and functional, with reduced costs.
These objects according to the present invention are achieved by making an improved plug for pressure-sealing a collector tube of an air conditioning system for vehicles as set forth in claim 1.
Further characteristics of the improved plug for pressure-sealing a collector tube of an air conditioning system for vehicles and related condenser are foreseen in the dependent claims.
The characteristics and advantages of an improved plug for pressure-sealing a collector tube of an air conditioning system for vehicles and a related condenser according to the present invention will be more evident from the following exemplifying and nonlimiting description, referred to the attached schematic drawings in which:

Figure 1 is an elevation view of an improved plug for pressure-sealing a collector tube of an air conditioning system for vehicles according to a first embodiment;
Figure 2 shows the plug of figure 1 in a partially sectioned elevation view, associated with a drying and filtering cartridge installed in a condenser of an air conditioning system for vehicles;
Figure 3 is an elevation view of a second embodiment of an improved plug for pressure-sealing a collector tube of an air conditioning system for vehicles;
Figure 4 shows the plug of figure 3 in a partially sectioned elevation view, associated with a drying and filtering cartridge installed in a condenser of an air conditioning system for vehicles;
Figure 5 shows the plug of figure 3 in a partially sectioned elevation view, associated with a drying sack and with a filtering element installed in a condenser of an air conditioning system for vehicles.

With reference to the figures, an improved plug is shown for the pressure-sealing of a condenser of an air conditioning system for vehicles, indicated in its entirety with 10 or 10' according to a first and a second embodiment, respectively.
The plug 10 of figure 1 comprises an aluminium disc 12 and a spacer rod 13, stably bound at a first end to the disc 12 and connectable at an opposite end to a drying and/or filtering device, which in the example of figure 2 is composed of a cartridge 14.
The spacer rod 13 ends with a discoid connection means 15, which is pressure-inserted by interference, or snapped, into an upper, hollow cylindrical end 16 of the cartridge 14.
The cartridge 14 comprises a stiff plastic casing equipped with a holed portion 17, containing a drying means at its interior, and provided with a filtering element 18 for the refrigerant at an opposite end with respect to the spacer rod 13.
The cartridge 14 stably connected to the plug 10 or 10', i.e. to the spacer rod 13, is positioned such that the drying portion 17 and the filtering portion 18 are respectively in communication with an inlet portion 19 of the refrigerant in a collector tube 20 and an outlet portion 21, separated from each other by an intermediate ring 22.
In figure 3, the plug 10 is shown connected to the cartridge and axially inserted in a cylindrical end of the collector tube 20 of a condenser 23, shown schematically in section.
The disc 12, which has a diameter substantially equal to the internal diameter of the cylindrical end of the collector tube 20, is braze-welded on the internal wall of the collector tube, it too made of aluminium, to make a bond between the plug and collector tube which is non-removable and resistant even at high operating pressures.
The disc 12 is equipped with a central hole 24 for the fit-insertion of the first end of the spacer rod 13. The rod 13, made of aluminium, is braze-welded to the disc 12 at the same time as the braze-welding operation of the disc 12 to the collector tube 20.
In the second embodiment of the plug 10', shown in figure 3, the aluminium spacer rod 13 comprises a spherical joint 25 for the connection to an additional centring rod 26, made of plastic.
The insertion of the spherical joint 25 makes it possible to make an optimal positioning between the cartridge 14 and the collector tube 20, and in particular a correct seal of the intermediate ring 22, a necessary condition for the correct functioning of the air conditioning system.
In the example shown in figure 4, the additional plastic bar 26 bears connection means 15 for a cartridge 14, such as those described for figure 2, i.e. composed of a discoid connection means which is pressure-inserted by interference, or snapped, into an upper, hollow cylindrical end 16 of the cartridge 14.
In the example shown in figure 5, the additional spacer rod 26 bears, in an intermediate position, a permeable sack 27 containing a drying means, and at its end, a filtering means 28.
The condenser 23 of an air conditioning system for vehicles, shown schematically in section in the figures, comprises the collector tube 20 for the refrigerant, made of aluminium, which houses the drying and/or filtering device. The collector tube 20 is closed on its upper end by the plug 10 or 10', described above, braze-welded to the cylindrical end of the collector tube 20.
The plug 10 or 10', object of the present invention, comprising the aluminium disc 12 and the aluminium spacer rod 13 stably bound to each other, is associated with the drying and filtering device and then inserted in the aluminium collector tube 20 of the condenser 23, object of the present invention.
The braze-welding operation executed at the end of the collector tube 20 sealingly closes the plug 10 or 10' on the internal wall of the collector tube 20 and possibly also the additional bond between the disc 12 and the spacer rod 13.
The drying and filtering device is maintained by the spacer rod 13 in a suitable position with respect to the inlet 19 and outlet 21 of the refrigerant in the collector tube 20.
The improved plug for the pressure-sealing of a collector tube of an air conditioning system for vehicles, object of the present invention, has the advantage being composed of a low number of elements, which require a simple and fast assembly.
Moreover, the improved plug and related condenser have the advantage of minimising the risk of refrigerant leaks into the atmosphere, in particular in the case of use of carbon dioxide refrigerants (CO₂) which work at pressures on the order of 100 bars, i.e. three times the operating pressures of traditional refrigerants (R134A).
Another advantage consists of the possibility to verify, when the plug is mounted, the presence of the drying/filtering device inside the collector tube. In fact, the accidental absence of the spacer rod and drying/filtering device associated with it would be visible from the outside, by the presence of the through hole on the disc.
The improved plug for pressure-sealing a condenser of an air conditioning system for vehicles and the related condenser thus conceived are susceptible to numerous modifications and variants, all falling with the scope of the invention; moreover, all of the details can be substituted by technically equivalent elements.

Claims

Improved plug for pressure-sealing a condenser of an air-conditioning system for vehicles, characterised in that it comprises an aluminium disc (12) adapted to be attached and braze-welded to a cylindrical end of a collector tube (20), and a spacer rod (13), stably bound at a first end to said disc (12) and connectable at an opposite end to a drying and/or filtering device (14, 27, 28).
Plug according to claim 1, characterised in that said disc (12) is equipped with a central hole (24) for the fit-insertion of said first end of said spacer rod (13), said spacer rod (13) being made of aluminium.
Plug according to claim 2, characterised in that said disc (12) and said spacer rod (13) are joined by braze-welding.
Plug according to claim 1, characterised in that said disc (12) has a diameter which is substantially equal to the inner diameter of the collector tube (20), for the axial insertion in a cylindrical end of said collector tube (20).
Plug according to claims 2 or 3, characterised in that said spacer rod (13) comprises, at said opposite end, connection means (15) for a cartridge (14) containing a drying means and a filtering element for the refrigerant.
Plug according to claims 2 or 3, characterised in that said spacer rod (13) comprises, at said opposite end, a spherical joint (25) for the connection to an additional centring rod (26).
Plug according to claim 6, characterised in that said additional centring rod (26) bears connection means (15) for a cartridge (14) containing drying means and a filtering element for the refrigerant liquid.
Plug according to claim 6, characterised in that said additional centring rod (26) bears a permeable sack (27), containing a drying means as well as a filtering element (28).
Plug according to claim 6, characterised in that said additional centring rod (26) is made of plastic.
Condenser of an air conditioning system for vehicles comprising a collector tube (20) for the refrigerant and a drying and/or filtering device (14, 27, 28) contained at its interior, characterised in that said collector tube (20) is made of aluminium and is closed on its upper part by a plug (10, 10') according to any one of the preceding claims, braze-welded in one cylindrical end of said collector tube (20).