GB2368813A

GB2368813A - Aluminium brazing apparatus

Info

Publication number: GB2368813A
Application number: GB0022399A
Authority: GB
Inventors: Stephen Robert Williams; Peter Neil Roy Bendall
Original assignee: GEA Spiro Gills Ltd
Current assignee: GEA Spiro Gills Ltd
Priority date: 2000-09-13
Filing date: 2000-09-13
Publication date: 2002-05-15
Also published as: GB0022399D0

Abstract

Apparatus for (semi) automatically assembling aluminium heat exchangers includes means 16,18 for delivering first tubular components, means 36 for delivering for delivering second fin strip components for brazing to the tubes, means 28 for arranging several of the tubes and fins in engagement with one another and means 46 for brazing them together. The tubular components may be provided as a coil. De-coiler 10 straightens this coil, suitable sized pieces are sheared from the coil, dimpled in dimpler 22, fed to flux sprayer 26 and then to assembly station 28. The fin components may similarly be provided from a supply coil, through de-coiler 32 to strip cutter/corrugator 34 and from there to assembly station 28. The two components may be assembled into heat exchangers on jigs. Brazed assemblies may be passed to welding areas 58,60,62,64 where additional components (inlet connectors, mounting lugs etc.) are installed.

Description

Aluminium Brazing Apparatus The present invention concerns improvements in or relating to aluminium brazing apparatus and especially, but not exclusively, apparatus for assembling aluminium heat exchange radiators.

According to one aspect of this invention, there is provided aluminium brazing apparatus comprising means for delivering a first component, means for delivering a second component for brazing to the first component, means for arranging a plurality of layers of the first and second components in engagement with each other, and means for brazing the layers to each other.

The apparatus may include deformation means for deforming the first component to form a plurality of heat exchange enhancing spaced indentations in the tubes, the deformation means being operable to cease formation of said indentations at the ends of each tube.

The means for delivering the first component may include storage means for storing a plurality of lengths of said first component. The storage means may include feed means to feed said lengths of the first component to cutting means. The feed means may comprise push cylinders.

The cutting means may include a saw and a conveyor whereby the lengths of the first component are fed to the saw which produces a length of said first component for brazing.

The cutting means may be arranged upstream of the deforming means.

Flux coating means may be provided downstream of the deformation means to coat the first component with a brazing flux. A conveyor may be provided to convey the first component from the deformation means to the flux coating means.

The means for arranging the layers in engagement with each other may comprise an assembly means which may include jigs to hold the first and second components during brazing.

Preferably, the jigs are adapted to hold each side of the component and also to hold different sizes of components and assemblies of components.

Where the first component is provided in the form of a coil, the means for delivering the first component may comprise straightening means and may also include shearing means for separating predetermined lengths of the first component from the straightened coil.

Where the second component is in the form of a coil, the means for delivering the second component may include further straightening means, and may further include cutting means for cutting the second component into desired lengths.

The means for delivering the second component may also include corrugation means for forming corrugations in the second component.

According to another aspect of this invention there is provided a method for brazing aluminium components comprising delivering a first component to an assembly station, delivering a second component to an assembly station, arranging a plurality of layers of the first and second components in engagement with each other at said assembly station and thereafter brazing the layers to each other.

An embodiment of the present invention will now be described by way of example only with reference to the accompanying diagram which shows a plan of an automated radiator assembly apparatus.

The apparatus of the embodiment is intended particularly for use in the automated or semi-automated assembly of radiators for use in automotive applications manufactured from aluminium which takes advantage of the inventive aluminium brazing method which forms the subject of our co-pending U. K. Patent Application No. 0006773 of 22nd March 2000.

The radiators to be assembled comprise a plurality of extruded rectangular cross sectional tubes which are formed integrally with longitudinally extending transverse partitions thereby providing a plurality of longitudinally extending passages through the tubes.

To increase the external surface area, that is the cooling surfaces of the tubes, strips of aluminium are deformed by corrugation and are fixed to the external surfaces of the tube by brazing. The tubes with fins attached thereto are assembled together into a radiator by attaching each end thereof to a header which is also an aluminium member. This assembly is then fitted, during subsequent operations, with further components for example connections and fixings which are attached thereto either at automatic welding stations or at manual welding stations. After testing for leaks the assembled aluminium radiator cells are subjected to a Bohmitting process as detailed in our copending U. K. Patent Application No. 0006773 referred to above.

The aluminium used for the tubes, fins and headers is chosen to have a purity of at least 99.5% and the corrugated fins are pre-coated with a flux, for example AlSi8-12.

As illustrated in the drawing, aluminium tube is first straightened from a coil in which it is delivered from the extruding plant in a de-coiler 10 and thereafter is automatically fed to a sub-assembly 12 including a final tube straightening arrangement and shears for separating predetermined lengths of tube from the straightened coil. The sheared off lengths of tube are then stored in a tube stillage 14 which has an automatically controlled feeding assembly including push cylinders 16 to feed lengths of tube on to a saw conveyer 18 having a drive motor 19, which feeds a length of tube to a saw 20 driven by a motor 21, which produces final tube lengths. On exiting from the saw 20 the tubes are passed through a dimpler 22 which deforms the outer surface of the tubes by passing them through a pair of rotating press rollers to form spaced indentations which project into the fluid passages within the tubes and also cause deformation of the partitions with a view to increasing the turbulence in the heat exchange fluid passing therethrough. The feed of tube through the rollers is so controlled that indentations are not formed at the end regions of the tube. A further conveyor 24 then conveys the cut and dimpled tubes to a flux sprayer 26 which coats the tube with a flux carried in an aqueous solution.

Coated tubes exiting from the flux sprayer 26 are fed to a first assembly station 28 where they meet up with aluminium strip fins. The fins are supplied from supply coils of strip that pass through a de-coiler 32 into a strip cutter and corrugator 34 which feeds them, by way of an output track 36 to a loading assembly 38 at which point the fins and tubes are assembled together either automatically or manually on the first assembly and jig loading station 28, empty jigs having been supplied to the station 28 from a feed table 40.

The strips, which are pre-coated with flux at manufacture, are placed against the external surfaces of the tubes in sandwich fashion and when a cell has been assembled on a jig it is clamped together and passed to a second manual or automatic assembly station 42 where headers are fitted and clamped thereto.

Multiple layers of cells can be assembled together in the jig, each layer of cells being spaced apart by a spacer/positioning member, which is brazed to the cells in the subsequent operation, the spacer member having a sinuous or zigzag configuration. Side walls are also positioned on the assembly and held by the jig. The side walls are formed from the same grade of aluminium as the tubes and fins and are flux coated. The headers (tubesheets) and side walls are of modular design such that multiple row blocks can be manufactured simply by stacking the individual rows/cells one on top of each other. The tubesheets and the side walls are brazed together in the same way. An assembly of typically 3m x 1.5m x 0.5m can be held in a jig.

When a sufficient batch has been assembled the jigs carrying the assemblies to be brazed are then moved from the second assembly station 42 over a roller conveyor 44 into a furnace 46 in which they remain for a period of 18 minutes having been elevated to a temperature of 620 C. During this time the brazing process takes place and it is significant to note that according to the present invention the heating is carried out in an ambient air atmosphere.

After the required period within the furnace 46 the jigs carrying the assemblies thereon are then removed over the roller conveyor 44 to a cooling zone 48 at the end of the roller conveyor 44 remote from the furnace 46.

Brazed components are then removed for further processing over a discharge conveyor 50 and jigs are returned to the feed table 40 over a return conveyor 52. Facilities are provided at the cooling area 48 of the roller conveyor 44 to remove components, for example one-off assemblies, on to a collection station 54.

The brazed radiator tube, fin and header assemblies are then passed along a conveyor 56 to aluminium welding areas 58,60, 62,64 at each of which, either manually or automatically, additional components, for example inlet connectors, mounting lugs, are welded to the brazed assembly, transfer conveyors 66 being provided to transport components from the conveyor 56 to the welding areas and from the welding areas onto a discharge conveyor 68.

Approaching the end of the conveyor 68 there is provided a test station 70 where a hydraulic test for leaks is carried out. Thereafter the assemblies are passed to a steaming station 72 where the assemblies are submitted to a Bohmitting process as described in the co-pending U. K. Patent Application No. 0006773. After treatment, final assembly is carried out, for example by incorporating frameworks, mountings, fan mounting lugs, etc. , at an assembly station 74 following which the assemblies may be painted in a paint shop 76.

Various modifications can be made without departing from the scope of the invention. For example the arrangement of conveyors can be altered and relative positioning or the component parts of the plant can be altered.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

Claims :

1. Aluminium brazing apparatus comprising means for delivering a first component, means for delivering a second component for brazing to the first component, means for arranging a plurality of layers of the first and second components in engagement with each other, and means for brazing the layers to each other.

2. Aluminium brazing apparatus according to claim 1, wherein the apparatus includes deformation means for deforming the first component to form a plurality of heat exchange enhancing spaced indentations in the tubes, the deformation means being operable to cease formation of said indentations at the ends of each tube.

3. Aluminium brazing apparatus according to claim 1 or claim 2, wherein the means for delivering the first component includes storage means for storing a plurality of lengths of said first component.

4. Aluminium brazing apparatus according to claim 3, wherein the storage means includes feed means to feed said lengths of the first component to cutting means.

5. Aluminium brazing apparatus according to claim 4, wherein the feed means comprises push cylinders.

6. Aluminium brazing apparatus according to claim 4 or claim 5, wherein the cutting means includes a saw and a conveyor whereby the lengths of the first component are fed to the saw which produces a length of said first component for brazing.

7. Aluminium brazing apparatus according to any of claims 4 to 6, wherein the cutting means is arranged upstream of the deformation means.

8. Aluminium brazing apparatus according to any of claims 2 to 7, wherein flux coating means is provided downstream of the deformation means to coat the first component with a brazing flux.

9. Aluminium brazing apparatus according to claim 8, wherein conveyor is provided to convey the first component from the deformation means to the flux coating means.

10. Aluminium brazing apparatus according to any of the preceding claims, wherein the means for arranging the layers in engagement with each other comprises an assembly means which may include jigs to hold the first and second components during brazing.

11. Aluminium brazing apparatus according to claim 10, wherein the jigs are adapted to hold each side of the component and also to hold different sizes of components and assemblies of components.

12. Aluminium brazing apparatus according to any of the preceding claims, wherein the first component is provided in the form of a coil.

13. Aluminium brazing apparatus according to claim 12, wherein the means for delivering the first component comprises straightening means.

14. Aluminium brazing apparatus according to claim 13, wherein the means for delivering the first component also includes shearing means for separating predetermined lengths of the first component from the straightened coil.

15. Aluminium brazing apparatus according to any of the preceding claims, wherein the second component is in the form of a coil.

16. Aluminium brazing apparatus according to claim 15, wherein the means for delivering the second component includes further straightening means.

17. Aluminium brazing apparatus according to claim 16, wherein the means for delivering the second component further includes cutting means for cutting the second component into desired lengths.

18. Aluminium brazing apparatus according to any of the preceding claims, wherein the means for delivering the second component includes corrugation means for forming corrugations in the second component.

19. A method for brazing aluminium components comprising delivering a first component to an assembly station, delivering a second component to an assembly station, arranging a plurality of layers of the first and second components in engagement with each other at said assembly station and thereafter brazing the layers to each other.

20. Aluminium brazing apparatus substantially as hereinbefore described with reference to the accompanying drawing.

21. A method for brazing aluminium components substantially as hereinbefore described with reference to the accompanying drawing.

22. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.