Integrated condenser/receiver and insert for use therein

Abstract

An integrated condenser/receiver unit including a filter insert. The filter insert extends just beyond a refrigerant inlet of the receiver and is formed from a unitary plastic body having a flow-deflection portion and a filter portion. The flow-deflection portion is located opposite the refrigerant inlet of the receiver housing to prevent the refrigerant flow from the inlet from directly impinging a desiccant charge contained within the receiver housing. A method is provided for forming the condenser/receiver wherein a desiccant and filter are inserted into the receiver housing after the remainder of the condenser/receiver has been brazed together as a unit, and after insertion of the desiccant and filter, an end cap is metallurgically bonded to the receiver housing to close the same.

Description

FIELD OF THE INVENTION

This invention relates to heat exchangers and, more particularly, to condensers and receivers used in air conditioning systems.

BACKGROUND OF THE INVENTION

Integrated condenser/receiver units are known for use in vehicular air conditioning applications. It is common for such units to have a receiver housing or tank mounted on a manifold or header of the heat exchanger with ports that direct refrigerant between the receiver tank and the header. It is also known for such units to include a desiccant material and/or a filter as inserts, or as a combined insert, that is contained within the receiver housing.

In some cases, the desiccant and/or filter insert(s) are nonreplaceable components that are permanently contained in the receiver housing because they are locked within the receiver housing during the brazing process for the integrated condenser/receiver. In such cases, the desiccant and/or filter insert(s) must consist of special materials, such as ceramics, which can withstand the brazing temperatures for the integrated condenser/receiver unit. Examples of such units can be found in U.S. Pat. No. 5,088,294 issued Feb. 18, 1992 to Ando and U.S. Pat. No. 5,159,821 issued Nov. 3, 1992 to Nakamura.

In other applications, the desiccant and/or filter insert(s) are replaceable by virtue of a removable cap or plug of the receiver housing.

One example of this can be found in unpublished European Patent Application No. 03004717.9 which discloses a desiccant bag that is supported over its entire length by a holding device which is secured to the removable plug or cap of the receiver housing. The wall of the holding device is impervious to the refrigerant flow directed into the receiver housing so as to prevent the refrigerant flow from impinging directly on the desiccant. Another example can be found in published U.S. application No. US-2004-0031285-A1, published on Feb. 19, 2004.

While many of the known integrated condenser/receiver structures may perform suitably for their intended function, there is always room for improvement.

SUMMARY OF THE INVENTION

In accordance with one form of the invention, an integrated condenser/receiver is provided for use in a vehicular air conditioning system. The condenser/receiver includes a heat exchanger core, at least one header connected to the heat exchanger core, and a receiver housing connected to the header. The receiver housing has an inlet opening for directing refrigerant flow from the header into the receiver housing, and a refrigerant outlet for directing refrigerant from the receiver housing. A desiccant charge is contained within the receiver housing. An improvement is provided including a unitary filter insert contained within the receiver housing. The filter insert includes a unitary body having an end terminating adjacent the refrigerant inlet. The unitary body includes a flow-deflection portion and a filter portion. The flow-deflection portion extends from the end to past the refrigerant inlet to prevent the refrigerant flow from directly impinging the desiccant charge.

In one form, a filter insert is provided for use in a refrigerant receiver of a vehicular air conditioning system. The receiver has a housing containing a desiccant charge. The housing is connected to a header of a condenser via a refrigerant inlet and further includes a refrigerant outlet. The filter insert includes a unitary body having an end terminating adjacent the refrigerant inlet with the insert received in the housing. The unitary body includes a flow-deflection portion and a filter portion. The flow-deflection portion extends from the end to past the refrigerant inlet to prevent the refrigerant flow from directly impinging the desiccant charge with the insert received in the housing.

In one form, the flow-deflection portion includes a cylindrical wall. In a further form, the inlet and outlet of the housing are spaced by a linear distance, and the unitary body has a total length that corresponds approximately to the distance.

In one form, the filter portion comprises a cylindrical-shaped filter basket.

According to one form, the unitary body includes a seal that engages an inner wall of the receiver. According to a further form, the unitary body includes another seal that engages the inner wall of the receiver.

In accordance with one embodiment of the invention, a method is provided for manufacturing an integrated condenser/receiver for use in a vehicular air conditioning system. The condenser/receiver includes a heat exchanger core, a header connected to the core to receive refrigerant therefrom, and a receiver housing connected to the header. The method includes the steps of brazing the heat exchanger core, the header and the receiver housing together in an oven; after the brazing step, inserting a desiccant charge and a filter into the receiver housing through an opening in the receiver housing; and after the inserting step, closing the opening by metallurgically bonding a cap to the receiver housing.

In one form, the inserting step comprises inserting the filter in the form of a unitary plastic body.

According to one form, the inserting step includes inserting the desiccant charge in the form of a plastic container through which refrigerant can flow and within which the desiccant is contained, with the plastic container having a shape that conforms to an interior shape of the housing.

In one form, the metallurgical bonding includes a welding method that involves a small input of heat, and the step further includes cooling a region of the housing containing the filter as needed to prevent heat damage to the filter.

Other objects, features, and advantages of the invention will become apparent from a review of the entire specification, including the appended claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a somewhat diagrammatic section view of one end of an integrated condenser/receiver and filter insert for use therein embodying the present invention;

FIG. 2 is a perspective view of the receiver housing and insert of FIG. 1, with internal components being visible;

FIG. 3 is a perspective view of the filter/insert of FIGS. 1 and 2;

FIG. 4 is a perspective view of a desiccant container shown in FIGS. 1 and 2; and

FIG. 5 is a perspective view of the receiver housing shown in FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As seen in FIG. 1, an integrated condenser/receiver 10 is provided for use in a vehicular air conditioning system. The condenser/receiver 10 includes a heat exchanger core 12, a pair of manifolds or headers 14 (only one shown) located at either end of the heat exchanger core 12, and a receiver housing 16 connected to the header. The core 12 is composed of a plurality of flattened tubes 18 that extend between the headers 14, and a plurality of serpentine fins 20 (only two shown for purposes of illustration) which extend between each adjacent pair of tubes 18. The ends of the tubes 18 are received in the headers to transfer refrigerant to and from the headers. In the illustrated embodiment, a baffle 22 is provided in each of the headers 14 so as to provide a multipass configuration for the refrigerant flow through the core 12, with the portion of the condenser above the baffle 22 preferably being a condensing section and the portion of the condenser below the baffle 22 being a super or subcooling section. It should be appreciated that while a specific type of core 12 has been illustrated, the inventive concept will find use with any suitable type of heat exchanger core 12, including, for example, heat exchanger cores 12 that utilize round tubes, tubes that include one or more bends to form so-called “hairpin” tubes, cores that include plate fins, etc. Similarly, while the headers 14 are shown as being formed from a cylindrical tube, any suitable type of header construction can be utilized, including constructions that utilize a header plate in combination with a tank.

As seen by the arrow in FIG. 1, the receiver housing has an inlet opening 24 for directing refrigerant flow from the header 14 into the receiver housing 16, and a refrigerant outlet 26 for directing refrigerant from the receiver housing 16 back into the header 14. As best seen in FIGS. 1 and 2, the receiver housing 16 includes a generally cylindrical wall 27, with three saddle-shaped mounts 28, 30 and 32 that are shaped to generally conform to the cylindrical outer wall of the header 14 so that they may be bonded thereto, such as by brazing. The inlet opening 24 extends through the saddle mount 30 into the interior of the housing 16, and the outlet opening 26 extends through the saddle mount 32 into the interior of the housing 16. The upper opening of the cylindrical wall 21 is closed by a suitable cap, cover or plug 34, and the bottom opening of the cylindrical wall 27 is closed by a suitable cap, cover or plug 36. In the illustrated embodiment, both of the caps 34 and 36 are permanently bonded to the cylindrical wall 27 using a suitable bonding technique, and preferably a suitable metallurgical bonding technique such as by welding or brazing. It should be appreciated that while a preferred form of the receiver housing 16 has been shown in FIGS. 1, 2 and 5, any suitable construction can be used for the housing 16, many of which are known.

As best seen in FIGS. 1 and 2, a desiccant charge 40 and a filter insert 42 are contained within the receiver housing 16. Preferably, the desiccant charge 40 is in the form of a net-like plastic container or bag 44 through which refrigerant can flow in order to contact a desiccant 46 that fills the container 44. Preferably, the desiccant charge 40 fills almost the entire space available above the filter insert within the receiver housing 16. Again, while a preferred form of the desiccant charge 40 is shown, any suitable form of desiccant charge may be incorporated, many of which are known.

The filter insert 42 has an end 51 that terminates adjacent the inlet 24, as best seen in FIGS. 1 and 2, and is formed from a unitary, i.e., one piece, body 50 which is preferably formed from plastic. The body 50 includes a flow deflection portion 52 located above a filter portion 54, with an outwardly extending annular seal 56 located approximately at the intersection between the portions 52 and 54.

The flow deflection portion 52 extends from the end 51 to past the inlet 24 so as to be positioned opposite the inlet 24 and thereby prevent the refrigerant flow from directly impinging the desiccant charge 40 by either holding the desiccant charge 40 away from the refrigerant inlet 24, as shown in FIGS. 1 and 2, or by blocking the refrigerant flow should the desiccant charge extend down into the interior of the flow deflection portion 52. Preferably, the flow deflection portion 52 is formed from a cylindrical wall 60 that extends from the end 51 down to the filter portion 54, with the seal 56 extending outwardly from the cylindrical wall 60. While the flow deflection portion 52 is shown in the preferred form as having a cylindrical wall 60, in some applications it may be advantageous for it to have other shapes, such as for example, as simply a baffle wall that extends above the inlet opening 24, preferably with some contour.

The filter portion 54 extends downward from the seal 56 to an end 61 that terminates adjacent the refrigerant outlet 26. Preferably, the filter portion 54 is in the form of a cylindrical-shaped filter basket with window-shaped, fine-mesh filter elements 62 provided in the side walls and bottom thereof.

The seal 56 engages the interior side of the cylindrical wall 27 of the receiver housing 16 so as to locate and hold the filter insert 42 within the housing 16 and to ensure that the refrigerant flows through the filter portion 54 rather than around the outside of the filter insert 42. Preferably, the engagement of the seal 56 with the interior side of the cylindrical wall 27 acts to essentially clamp the filter insert 42 at its desired location within the receiver housing 16. In this regard, while the filter insert 42 is shown with a single seal 56, in some applications it may be advantageous for a second seal 56 to be provided below the illustrated seal 56 so as to provide a second support for the filter insert 42 and thereby improve the hold of the filter insert 42 within the receiver housing 16. In addition, or as a replacement, other attachment means can be provided, for example, in the area of the inlet and outlet openings 24 and 26, and preferably in the form of stud-like projections that are supported on the edge of the inlet and outlet openings 24 and 26. Furthermore, it may be advantageous in some applications to provide the cylindrical wall 27 with a pair of inwardly directed impressions, one at the upper end 51 and the other at the lower end 61 so as to restrict axial shifting of the filter insert 42 within the receiver housing 16.

In operation, refrigerant flows through the tubes 18 of the core 12 to the interior of the header 14 located above the baffle 22. The refrigerant then flows from the header 14 through the inlet 24 into the interior of the receiver housing 16 where it is deflected both circumferentially and upward by the flow deflection portion 52 so as to not directly impinge against the desiccant charge 40. After having been deflected by the flow deflection portion 52, the flow passes through the desiccant charge 40 and is preferably separated into gas and liquid components. After flowing through the desiccant charge 40 the refrigerant enters the interior of the flow deflection portion 52 via the open upper end 51 and flows downwardly into the filter portion 54 before passing through the fine-mesh filter elements 62 and flowing out from the receiver housing 16 via the outlet 26 to the interior of the header 14 located below the baffle 22.

It should be appreciated that because the filter insert 42 is a comparatively small construction, it can bring advantages with respect to costs in comparison to other known filter inserts. For example, it can be made utilizing the one piece plastic body 50.

In a preferred manufacturing method of the integrated condenser/receiver 10, the tubes 18 and fins 20 of the core 12, the headers 14, and the generally cylindrical wall portion 27 of the receiver housing 16 are preferably made of aluminum and are assembled together and then brazed as a unit in a suitable braze oven using any suitable brazing or soldering technique, with at least one end of the housing 16 being left open by not assembling the cap 34 or 36 therewith. In this regard, one of the caps 34 or 36 can also be assembled and brazed with the remainder of the components during this step. After the brazed assembly is formed, the desiccant charge 40 and the filter insert 42 are inserted into the receiver housing 16 and one or both of the caps 34 and 36 are metallurgically bonded to the cylindrical wall 27 using a suitable welding technique that requires only a local and relatively small heat input in the region of the weld seam so as to not damage the desiccant charge 40 or the filter insert 42. Suitable welding techniques have been found to include plasma welding, laser welding, or welding methods under a protective gas, such as the MIG or WIG welding methods. Experiments have shown that cooling of the cylindrical wall 27 of the receiver housing 16 in the area of the filter insert 42 has not been necessary when welding the cap 36. However, the inventive method anticipates providing cooling through the region of the receiver housing 16 containing the filter insert 42 if needed to prevent heat damage to the filter insert 42.

It should be appreciated that by utilizing the inventive method, a “permanent” filter and dryer configuration can be provided within the receiver housing 16 without requiring materials that must withstand the brazing temperatures associated with brazing the remaining components of the integrated condenser/receiver 10 together as a unit, which can present a cost savings. While the method has been described in connection with the illustrated desiccant charge 40 and filter insert 42, it should be understood that the manufacturing method can be used independently of the how the filter and desiccant charge are designed in detail.

Additionally, it should be appreciated that while the desiccant charge 40 and filter insert 42 have been shown in connection with a non-replaceable, permanent construction, in some applications it may be desirable to allow the desiccant charge 40 and filter insert 42 to be replaceable by replacing one of the caps 34 or 36 with a removable cap or plug.

Claims

1. In an integrated condenser/receiver for use in a vehicular air conditioning system, the condenser/receiver comprising: a heat exchanger core, at least one header connected to said core to receive refrigerant therefrom, and a receiver housing connected to said header, said receiver housing having an inlet opening for directing a refrigerant flow from said header into said receiver housing, and a refrigerant outlet for directing refrigerant from said receiver housing, and a desiccant charge contained within said receiver housing, the improvement comprising:

a filter insert contained with said receiver housing, said filter insert comprising a unitary body having an end terminating adjacent said refrigerant inlet, said unitary body including a flow-deflection portion and a filter portion, said flow-deflection portion extending from said end to past said refrigerant inlet to prevent said refrigerant flow from directly impinging said desiccant charge.

2. The improvement of claim 1 wherein the flow-deflection portion comprises a cylindrical wall.

3. The improvement of claim 2 wherein said inlet and said outlet are spaced by a linear distance, and the unitary body has a total length that corresponds approximately to said distance.

4. The improvement of claim 1 wherein said filter portion comprises a cylindrical shaped filter basket.

5. The improvement of claim 1 wherein said unitary body comprises a seal that engages an inner wall of said receiver housing.

6. The improvement of claim 1 wherein said unitary body comprises another seal that engages the inner wall of said receiver housing.

7. The improvement of claim 1 wherein said receiver housing comprises a cylindrical wall and a pair of end caps, one of the caps closing a first open end of said cylindrical wall and the other of the caps closing a second open end of said cylindrical wall, with at least one of said caps inseparably connected to the cylindrical wall.

8. A filter insert for use in a refrigerant receiver of a vehicular air conditioning system, the receiver having a housing containing a desiccant charge, the housing connected to a header of a condenser via a refrigerant inlet and further including a refrigerant outlet, said filter insert comprising:

a unitary body having an end terminating adjacent said refrigerant inlet with the insert received in said housing, said unitary body including a flow-deflection portion and a filter portion, said flow-deflection portion extending from said end to past said refrigerant inlet to prevent said refrigerant flow from directly impinging said desiccant charge with the insert received in the housing.

9. The filter insert of claim 1 wherein the flow-deflection portion comprises a cylindrical wall.

10. The filter insert of claim 9 wherein said inlet and said outlet are spaced by a linear distance, and the unitary body has a total length that corresponds approximately to said distance.

11. The filter insert of claim 8 wherein said filter portion comprises a cylindrical shaped filter basket.

12. The filter insert of claim 8 wherein said unitary body comprises a seal that engages an inner wall of said receiver housing.

13. The filter insert of claim 8 wherein said unitary body comprises another seal that engages the inner wall of said receiver housing.

14. A method of manufacturing an integrated condenser/receiver for use in a vehicular air conditioning system, the condenser/receiver comprising a core, a header connected to said core to receive refrigerant therefrom, and a receiver housing connected to said header, the method comprising the steps of:

brazing the heat exchanger core, the header, and the receiver housing together in an oven;

after the brazing step, inserting a desiccant charge and a filter into the receiver housing through an opening in the receiver housing; and

after the inserting step, closing said opening by metallurgically bonding a cap to the receiver housing.

15. The method of claim 1 wherein said inserting step comprises inserting the filter in the form of a unitary plastic body.

16. The method of claim 1 wherein said inserting step comprises inserting the desiccant charge in the form of a plastic container through which refrigerant can flow and within which the desiccant is contained, the plastic container having a shape that conforms to an interior shape of said housing.

17. The method of claim 1 wherein said metallurgical bonding comprising a welding method that involves a small input of heat, and further comprises cooling a region of the housing containing said filter as needed to prevent heat damage to said filter.