GB2416720A

GB2416720A - Multiple fluid delivery system

Info

Publication number: GB2416720A
Application number: GB0417256A
Authority: GB
Inventors: Benjamen Barber; Andrew Tobijanski; Philip Gouldbourn; Keith Bestwick
Original assignee: Decoma International Inc
Current assignee: Decoma International Inc
Priority date: 2004-08-03
Filing date: 2004-08-03
Publication date: 2006-02-08
Also published as: GB0417256D0

Abstract

A spray paint system has a plurality of sources of pressurized paints 14a, 14b ... 14n which are connected to a colour change valve 16. The colour change valve 16 is operable to selectively connect two of the pressurized paint sources to first and second supply hoses 18, 20 respectively, the other end of the supply hoses being connected to a selector valve 22. The selector valve is operable to selectively connect one of the hoses 18 to a discharge port and thence to a spray head 12 and simultaneously connect the other of the hoses 18, 20 to a dump port (66a, 66b). By connecting two supply hoses between the colour change valve 16 and the selector valve 22 it is possible simultaneously to discharge one paint through the spray head 12 and purge the other supply hose through the dump port (66a, 66b) and refill that hose with the next paint to be used. In order to change the paint being sprayed it is then merely necessary to purge the spray head 12 and actuated the selector valve 22 to discharge the new paint colour.

Description

DT,SCRIP'I'ION MULTTPLT'1 FLUID) DEI,IVF,RY SYSTEM The present invention

relates to multiple fluid delivery systems and in particular, but not exclusively, to paint spray systems capable ol'sprayng a plurality of dil'ferent paints in turn, as desired.

Paint spray systems are used in vehicle component manul-'acturing facilities in order to spray-paint a series of vehicle components which are transported sequentially on a conveyor through a paint booth. Typically, the spraying is carried out automatically by a robot spraying device which is fed via a supply hose with one of a plurality of 1 () di thereat paint colour supplied to a selection valve under pressure. The desired paint is selected by appropriate operation of the valve, and the pressurized paint is thereby fed along the supply hose to the robot arm, which carries out the spraying of the vehicle components in the selected colour-.

A problem arises when it is required to change from one paint colour to another.

In order to do so, it is necessary to purge the existing colour from the supply hose connecting the selection valve to the robot arm. This is achieved by applying, in secluence, a "chop" comprishlg pressurized air, a paint solvent and pressurized air again to the hose connecting the paint selection valve and the robot arm 'I'he paint selection valve may then be operated in order to 1;11 the hose with the new selected colour, to allow the robot arm to paint the next component in the desired colour.

The operation of purging the paint hose and refilling with the new colour takes of' the order ozone minute to carry out, during which thne it is not possible to spray any vehicle components. Ideally, the operation of changing from one paint colour to another should be ol' the order of a flew seconds, specifical Iy the time taken I'or a painted vehicle component to move out ol' the spray booth and for the next component to move into the booth.

In accordance with a first aspect of the present invention, a multiple fluid delivery system comprises a plurality of sources ol'pressuri:zed fluid. A first valve means, to which said sources ol' pressurized fluid are fed, is operable to selectively 1() connect first and second sources ol' pressurized fluid to first and second supply lines respectively. A second valve means is connected to the first and second supply lines downstream ol'the first valve means. 'I'he second valve means has a first fluid delivery port and a second fluid discharge port and is operable to selectively connect one of the first and second supply lines to the fluid delivery ports and simultaneously connect the other of the first and second supply lines to the fluid discharge port.

By connecting two supply lines between the first valve means and the second valve means, when changing Dons one fluid (e.g. paint concur) to another, only the second valve means (and, for example, attached spray head) need be purged of' the first liquid bel'ore the second fluid can be connected, greatly reducing the time taken to change the fluid to be discharged.

Moreover, it is possible to discharge the fluid (c.g. paint) in one of the supply lines through the delivery port (e.g. to a spray gun) and simultaneously purge the second supply line through the discharge port (e. g. a dump port) and to refill the second supply line with a desired different pressurized fluid (e.g. paint), so that the system Is ready lor the next changeover of' fluid.

I'rel'erably, the sources of pressuri;<cd fluid comprise a source of' purging Fluked lref'erably, the purging fluid comprises a solvent for one or more of the other pressurized fluids. AIternatively, or in addition, the purging fluid may comprise a gas, Air example air.

In one embodiment, the second valve means comprises a fluid delivery passage leading to one of the fluid delivery discharge port and first and second inlet passages leading from the f irst and second inlet ports respectively to the fluid delivery I () passage. The second valve means is operable to selectively connect one of' the inlet passages to the fluid delivery passage.

The system may further comprise a first fluid discharge passage extending between the first inlet passage and a first fluid discharge port and a second fluid discharge passage extending between the second inlet passage and a second fluid discharge port. Tile second valve means is operable to selectively connect the first fillet passage tr-, the first florid discharge port and the second inlet passage and the second fluid discharge port.

I'reierably, the second valve means further comprises a purmg passage lor the ingress oi'a pressurized purging fluid and the second valve means is operable to 2() selectively connect the purging port to the fluid delivery passage.

I'rel'erably, the second valve means is operable to selectively connect the purging passage to the first and second fluid discharge port.

In one embodiment, the second valve means comprises first and second purging passages for the ingress of a pressurized purging fluid. The second valve means is operable to selectively connect the first and second purging ports to the first and second outlet passages and the second purging port to the fluid delivery port.

Preferahly, the second valve means is operable to selectively connect the first and second purgmg passages to the first and second fluid discharge ports respectively.

In one embodiment, one of the discharge ports of'tlle second valve means is connected to a spray nozzle.

In one particular embodiment, the multiple fluid delivery system comprises a spray paint system, wherein the sources of pressurized fluid comprise a plurality ol' 1 () different paints and/or coatings to be sprayed.

In accordance with a second aspect of the present invention a method of operating a multiple fluid delivery system having a plurality of sources of pressurised fluid and a fluid delivery outlet comprises connecting first and second of said pressurised fluids to first and second supply lines respectively, delivering the fluid t'rom a first of' the supply lines through the fluid delivery outlet and at the same time purging the fluid from the second of the supply lines and connecting a further pressurised fluid to the second supply line.

Pret'erably the method further comprises purging the fluid delivery outlet of fluid from the first supply line and subsequently delivering the second fluid from the 2() second supply line through the fluid delivery outlet.

I'he method also preferably comprises delivering the second fluid through the fluid delivery outlet at the same time as purging the fluid from the first of the supply lines and connecting a different pressurised fluid to the first supply line.

In accordance with a third aspect of the present invention, valve assembly comprising a housing, first and second lewd inlet ports leading to first and second fluid inlet passages respectively. l'irst valve means are provided for controlling fluid flow through said first and second inlet passages. A fluid delivery passage, is also provided and second valve means selectively connecting the fluid delivery passage to the first and second fluid inlet passages. A discharge passage means is provided and third valve means selectively connecting the first and second inlet passages to the discharge passage means.

Preferably the discharge passage means comprises first and second discharge passages leading Tom the first and second fluid inlet passages respectively, the third valve means being operable Lo control fluid flow between the first inlet passage and the first discharge passage and between the second inlet passage and the second discharge passage.

The valve assembly preferably further comprises a purging fluid inlet means ] 5 leading to a purging fluid passage and fourth valve means for controlling the flow of purging fluid into the valve.

I'rel'erably, the purgmg fluid passage is connectable tot he fluid delivery passage.

The ptlrgillg fluid passage is also preferably connectable to the first and second fluid inlet passages.

I'he purging fluid inlet may comprise first and second inlets lor the ingress ol'li:luid gas r espeetively The fourth valve means is operable to selectively eoruleet the t'irst and second inlets to the purging fluid passage. (]

Preferably, first and second purging fluid inlets means are provided, leading to first and second purging fund passages respectively By way of example only, a specific embodiment of the present invention will now be clescribed, with reference tic the accompanying drawings in which: Fig. 1 is a schematic view of a paint spraying apparatus in accordance with the present invention; Figs. 2a, 2b rued 2c are a plan, longitudinal crosssection and transverse cross secticn respectively ol'a colour change valve forming part of the apparatus of Fig. 1; and 1 () Fig. 3 is a schematic view ol'a selector valve forming part ol'the apparatus of Fig,. 1 Referring to the l'igures, an automatic paint spray apparatus comprises a conventional programmable logic controlled (PLC) robot arm 10 fitted with a conventional paint spray head 12 at its free end. A plurality of sources ol'paint are 1 5 supplied under pressure through respective supply lines 1 4a, 1 4b, 1 4c 1 4n to a first, colour change valve 16. As will be explained, the colour change valve 16 is operable to supply a selected two ol'tlle sources of prcssuri:.ed paint to first and second hoses I X, 20 respectively. The other end ol' each of the hoses 18, 2() is connected to a second, selection valve 22, which, as will be explained, is operable to connect a 2() selected one of the hoses 18, 2() to the spray head 12, thereby to deliver a selected paint to tile spray head 12 and simultaneously purge the other ol'the hoses and rel-'ill it with a new pamt cclour. An example ol colder change valve I 6 is illustrated in legs. 2a to 2c and comprises a valve block 30 having a plurality of inlet ports 32a, 32h, 32c... 32n each being connected to a respective one of the lines 14a, 14b, 14c 14n conveying a selected paint l'ron1 the paint kitchen culd aligned retune ports 34a, 34h,34c. 34n for conveying non-selected paint back to the source via further hoses (not shown). 'I'wo of the lines 14 connected to two -1'the inlet ports 34 supply pressurized air and solvent respectively to the valve blocks as will be explained.

Each pair of the aligned inlet and return ports 32,34 for pressurized paint, air and paint solvent is connected by means of a transverselyextending passage 40. 'I'he transverse passages 40 each intersect with two parallel longitudinal passages, 42, 44, which terminate In valve outlet ports 46, 4X respectively, to which the hoses 18, 20 respectively are connected.

A solenoid-actuated poppet valve SO is located at the juneti-'n of each transverse passage 40 and longitudh1al passage 42, 44 and by appropriate operation ol'tl1e poppet valves, a source ot'pressuriz.ed paint of the desired eolour or the air supply or the solvent supply can be connected as required to the first and second longitudinal passages 42, 44, and thence to the hoses 18, 20.

With reference to Fig 3, an example of a selector valve 22 is illustrated. 'I''he selector valve 22 comprises a valve block 51 having inlet ports 52, 54 to which the hoses 18, 20 respectively are connected. ISael1 of the Inlet ports 52, 54 can be selectively isolated l'rom the interior of the valve by means ol'solenoid-actuated inlet poppet valves 60a, 60b located in valve inlet passages 62a, 62b respectively. When the valves boa, 60b are open, the valve Inlet passages 62a, 62b, and therel'ore the hoses 1 X, 20, are selectively connectable either to a respective transversely extending dump passage 64a' 64b terminating in a dump Effort 66a, 66b or to a common outlet passage 68 whose outlet port 70 is connected to the spray head 12, by means of further solenoid-actuated popper valves 72a, 72b located at the inner end calf the dump passages 64a, 64h and poppet valves 74a' 74b located between the mlet passages 62a, 62b and the outlet passage 6X, respectively.

The valve block 51 further comprises inlet ports 78a, 78b for pressurized air and inlet ports 80a, 80b for pressurized paint solvent which are selectively connectable to the outlet passage 6X and the dump passage 64a, 64b by means oi further solenoid-actuated poppet valves 82a, 82b; 84a, 84b.

In use, the Pl,C is programmed with information as to the colours to be sprayed onto the components as they travel through the paint shop. Thus, the colour change valve 16 is actuated to supply one of the hoses 18, 20 with a first paint colour and the other of the hoses I X, 2(), with a second paint colour. The selector valve 22 is then actuated to supply the desired colour from one of the two hoses 18, 20 to the outlet port 70 and thence to the spray head 12. For example, if the desired colour for the component to he sprayed is supplied to hose 18, poppet valves 60a and 74a will be opened to allow the paint in hose 18 to be supplied to the outlet passage 68 and the outlet port 70 and thence to the spray gun 12. All of the other poppet valves within the selector valve 52 will remain closed When it is desired to change the colour to be sprayed, the PL,C will have 2() cletermined that the next colour to be sprayed is already loaded in the other hose 20.

All that needs to be done is for the selector valve 22 to be purged of paint ol the first cclour and for the paint in hose 20 to be supplied to the selector valve 52. T his is aclleved by closing valve 60a, opening poppet valve 74a and applying the''cllop'' comprising pressurised air, solvent and air in that order from inlet ports 78a, 80a to purge the paint t'rom the outlet passage 6X through the outlet port 70 and through the spray head 12. The poppet valve 74a is then closed and poppet valves 60b, 74b on the other side ol'the valve 22 arc then be opened to supply the paint in line 2() to the outlet passage 68 of the valve and thence to the spray head 12.

Optionally, a further purging ol'the side of the valve connected to the hose 18 can tic place. 'I'his is carried out by closing the poppet valve 74a, opening the dump valve 72a and applying a further "chop" ol'pressurised air, solvent and air in that -'rder by actuation oi'thc valves 82a and 84b. The optional further purging can be 1 () carried -' at before or after the previously-described purging.

As spraying oi'the new colour is taking place, the paint in hose 18 is purged.

I'o do so, the poppet valves 50 of the colour change valve 16 are operated to supply a "chop" comprising pressurised air, solvent and air, in that sequence, furor the relevant inlet ports to the hose 18, with the poppet valves 60a and 72a of the selection valve opened, thereby purging the hose 18 of the now unwanted paint colour. Once the hose 18 has been purged of the unwanted colour, the relevant poppets 5() of' tile colour change valve 16 are then actuated to fill the hose 18 with the paint which will he recluired at the next colour change as determined by the lily.

At that next colour change, the supply of paint from hose 20 will be cut off by closing poppet valve 60b of the selector valve 22 and all that is required bel-,re the paint hi the other hose 18 can be supplied is for a "chop" of prcssurised air, solvent and air in that sequence to he apphed to the inlet ports 78b, Sob of the selector valve, with dump valve 72b open, and then repeated with the dump valve 72b closed and poppet valve 74b open to purge the selector valve 52 and the spray head 12 of any remaining paint. ()nce that has occurred, the new colour, in line 18, can be supplied rnmediately to the outlet passage of the distribution valve and thence to the spray head by opening poppet valves 6()a and 74a with all the other poppet valves in the selector valve closed. As the new colour is being sprayed, the hose 20 is then purged opts contents as described previously Nor hose 18 and is filled with the colour which will be required at the next colour change, and so on.

As for the other side of the valve, a further purging of the valve 22 may optionally be carried out by applying a l'urther "chop" of pressurised air, solvent and 1 () air in that sequence to the inlet ports 78b, 80b with the inlet valve 60b and the selector valve 74b closed and with the dump valve 72a open, either before or after the previously-descrbed purging.

By having two supply hoses 18, 20 to the selector valves, while one colour is being supplied through one hose to the spray head 12 From the colour change valve 16, the other hose can be purged of its contents and filled with the paint which will he recluired at the next colour change Thus, only a very small amount of paint needs to be purged From the selector valve 22 before the paint in the other supply hose with Lllc new colour paint can be connected, which greatly reduces the time taken to change over the paint to be sprayed.

The invention is not restricted to the details of the foregoing embodiment.

For example, although the invention has been described with rel'erence to two supply hoses, more than two supply hoses could he usecl, il' desired, with appropriate connections to purge the non-utilsed hoses as one fluid is being supplied.

Claims

C LATMS

1. A multiple fluid delivery system comprises a plurality of sources of pressurized fluid, first valve means to which said sources of pressurized fluid are fed, the first valve means being operable to selectively connect first and second of said sources of pressurized fluid to first and second supply lines respectively and second valve means connected to said first and second supply lines downstream of said first valve means, the second valve means comprising a fluid delivery port and a fluid discharge port and being operable to selectively connect one of said first and second supply lines to the fluid delivery port and simultaneously connect the other of said 1 () first and second supply lines to the fluid discharge port.

2. A system as claimed in claim I, wherein the sources of pressurized fluid comprise a source of purging fluid.

3. A system as claimed in claim 2, wherein the purging fluid comprises a solvent for one or more of the other pressurized fluids.

4. A system as claimed in claim 2 or claim 3, wherein the purging fluid comprises a gas.

5. A system as claimed in claim 4, wherein the purging fluid comprises air.

6 A system as claimed in any of the preceding, claims, wherein the second valve means comprises a fluid delivery passage leading to said fluid delivery port and 2() first and second mlet passages leading from said first and second inlet ports respectively to the fund delivery passage, the second valve means being operable to selectively connect one of'said inlet passages to said fluid delivery passage.

7. A system as claimed in claim 6, further comprising a first fluid discharge passage extending between said first inlet passage and a first fluid discharge port and a second fluid discharge passage extending between said second inlet passage and a second Muid discharge port, the second valve means being operable lo selectively connect said first inlet passage to said first fluid discharge port and to connect said second inlet passage to said second fluid discharge port.

8. A system as claimed h1 claim 7, wherein the second valve means comprises a purging passage for the supply of a pressurized purging fluid and wherein the second valve means is operable to selectively connect said purging passage to said fluid delivery passage.

1()

9. A system as claimed in claim 8, wherein the second valve means is operable to selectively connect said purging passage to said first and second Duid discharge ports.

10. A system as claimed in claim 7, wherein the second valve means comprises first and second purging passages for the ingress of a pressurized purging fluid and wherein second valve means is operable to selectively connect said first and second purging passages to said fluid delivery port.

11. A system as claimed in claim 10, wherein the second valve means Is operable to selectively connect said first purging passage to said first fluid discharge port and said second purging passage to said second fluid discharge port.

12. A system as claimed in any of claims 8 to 1 1, wherein the purging fluid comprises a solvent for one or more oi the pressurized fluids supplied tall the second valve means.

1. A system as claimed in any ol claims 8 to 12, wherein the purging fluid comprises a gas.

14. A system as claimed in claim 13' wherein the purging fluid comprises air.

15. A system as claimed in any of the preceding claims, said fluid delivery port ol' said second valve means is connected to a spray nozzle.

16. A system as claimed in claim 15, wherein the sources of pressurized fluid comprise a plurality of sources cl',naint or other coatings.

17. A system as claimed m any ot' the preceding claims, wherein the said discharge port of'said second valve means comprises a dump port.

1 X. A method of operating a multiple fluid delivery system having a plurality ot' sources ol'pressurised fluid and a fluid delivery outlet, the method comprising connecting first and second oi'said pressurised fluids to first and second supply lines respectively, delivering the fluid from a first ol'the supply lines through the fluid delivery outlet and at the same time purging the fluid from the second of the supply lines and connecting a further pressurized fluid to the second supply line.

I S

19 A method as claimed in claim I X, further comprising purging the fluid delivery outlet of fluid t'rom the t'irst supply Ime and subsequently delivering the second 11Ujd t'rom the second supply line through the fluid delivery outlet.

20. A method as claimed in claim 19, comprising delivering the second fluid through the fluid delivery outlet at the same time as purging the fluid from the first ol'the supply lines and connecting a dit't'erent pressurized fluid to the first supply line.

21. A valve assembly comprising a housing, first and second fluid inlet ports leading to first and second fluid inlet passages respectively, first valve means for controlling fluid flow through said first and second inlet passages, a fluid delivery ]4 passage, second valve means for selectively connecting the fluid delivery passage to the first and second fluid inlet passages, a discharge passage means and third valve means lor selectively connecting the first and second inlet passages to the discharge passage means.

S

22. A valve assembly as claimed in claim 2], wherein the discharge passage means comprises first and second discharge passages leading from the first and second fluid inlet passages respectively, the third valve means being operable to control fluid flow between the first inlet passage and the first discharge passage and between the second inlet passage and the second discharge passage.

23. A valve assembly as claimed in claim 22, further comprising a purging fluid inlet means leading to a purging fluid passage and fourth valve means for controlling the flow of purging fluid into the valve.

24. A valve assembly as claimed in claim 23, wherein the purging fluid passage is connectable to the fluid delivery passage.

25. A valve assembly as claimed in claim 23 or 24, wherein the purging fluid passage is connectable to the first and second fluid inlet passages.

26. A valve assembly as claimed in any of claims 23 to 25, wherein the purging fluid inlet comprises first and second mlets for the ingress ol liquid and gas respectively and wherein the fourth valve means is operable to selectively connect the 2() first and second inlets to the purging fluid passage.

27. A valve assembly as claimed in any of claims 23 to 25, comprising first and second purging fluid inlet means leading to first and second purging fluid passages.

28 A multiple fluid delivery system substantially as herein described, with reference to and as illustrated in the accompanying drawings.

29 A method of operating a multiple fluid delivery system substantially as herein described with reference Lo, and as illustrated in, the accompanying drawings.

30. A valve assembly substantially as herein described with reference to and as illustrated in 1 ig. 3 ol the accompanying drawings