Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
  • B05B12/08—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means
  • B05B12/085—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means responsive to flow or pressure of liquid or other fluent material to be discharged
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
  • B05B12/08—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means
  • B05B12/085—Arrangements for controlling delivery; Arrangements for controlling the spray area responsive to condition of liquid or other fluent material to be discharged, of ambient medium or of target ; responsive to condition of spray devices or of supply means, e.g. pipes, pumps or their drive means responsive to flow or pressure of liquid or other fluent material to be discharged
  • B05B12/087—Flow or presssure regulators, i.e. non-electric unitary devices comprising a sensing element, e.g. a piston or a membrane, and a controlling element, e.g. a valve
  • B05B12/088—Flow or presssure regulators, i.e. non-electric unitary devices comprising a sensing element, e.g. a piston or a membrane, and a controlling element, e.g. a valve the sensing element being a flexible member, e.g. membrane, diaphragm, bellows
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B12/00—Arrangements for controlling delivery; Arrangements for controlling the spray area
  • B05B12/14—Arrangements for controlling delivery; Arrangements for controlling the spray area for supplying a selected one of a plurality of liquids or other fluent materials or several in selected proportions to a spray apparatus, e.g. to a single spray outlet

Definitions

• the invention concerns a colour-change and washing method for use in a spreading device for a coating agent, advantageously a paint, and equipment for use in the method.
• the object of the invention is a colour-change and washing method of a new type as well as the equipment for use in the method, by means of which both the time used for the change of colour and the quantity of solvent used for washing can be minimized.
• a further object is a method and an equipment wherein it is possible to recover the solvent or equivalent used in the washing and by means of which it is possible to accomplish the change of colour with minimum cost of equipment and with minimum cost of maintenance.
• the method in accordance with the invention is mainly characterized in that in the method, when the change of colour takes place, the washing program is started, wherein the washing liquid is carried through a collector duct to the spreading device and from there further along an outlet duct into a collecting vessel.
• the equipment in accordance with the invention is mainly characterized in that the equipment comprises an outlet duct passing from the spreading device into the collecting vessel, whereat It is possible to recover the washing liquid completely.
• FIG 1 Is an illustration of principle of an equipment used in the method in accordance with the invention.
• Figure 2 is a block-diagram illustration of principle of the operation of the method in accordance with the invention.
• FIG. 3A shows the system diagram of an equipment in accordance with the invention.
• FIG. 3B illustrates a second advantageous embodiment of an equipment in accordance with the invention.
• Figure 4A shows the washing program no. 1 used In the method of the invention as a time chart illustration.
• Figure 4B shows the washing program no. 2 used in the method of the invention as a time chart illustration.
• Figure 5A is a side view of a paint pistol in accordance with the invention.
• Figure 5B is a sectional view of the paint pistol.
• Figure 5C shows a section along line I-I in Fig. 5A.
• Figure 6 illustrates a paint-quantity regulator and the principle of its operation.
• Figure 7 Is a schematical illustration of an embodiment of the in- vention in which an additional confirmation knob is used.
• Fig. 1 is a schematical illustration of the system in accordance with the invention.
• the spreading device 10 which is called the paint pistol in the present description, comprises an inlet duct or inlet ducts for paint.
• the system also comprises an outlet duct for the washing liquid, e.g. a solvent.
• the washing liquid is passed from the top end of the colour stock, i.e. of the collector duct 13, along the duct 23 to the paint pistol 10 and further, according to the invention, out °f th e paint pistol 10 through the outlet duct 24, being sucked by the pump 12a.
• the equipment further comprises a pre-controlled flow-regulation valve 11 in the duct 23.
• the flow speed is maximized by minimizing the throttle across the valve 11.
• the washing liquid is sucked into the collecting vessel 25, whereby the solvent can be recovered for further use.
• the new colour is introduced by opening the valve 14 of said colour.
• colours and paints are spoken of generally, which means herein substances used in coating and facing in general, such as paints, lacquers, etc. 1 Likewise, change of colour is to be understood as change of facing or coating agent in general.
• the system may also be applied to an embodiment wherein the spreading device used is a painting head suitable for electrostatic painting. It is also possible to use a
• the painting head e.g. a paint pistol
• the painting head is washed so that an inlet duct passes into the interior chamber in the painting head, into which the colour is introduced, and that an outlet duct for washing liquid - ⁇ Q passes from said chamber or from ducts connected to It to the collect ⁇ ing vessel.
• a paint pistol refers gen ⁇ erally to a device into which the paint or equivalent is passed from the collector duct 13 and out of which the paint or equivalent is lastly sprayed as small droplets onto the face to be painted.
• Fig. 2 shows the operating diagram of the method of the invention.
• the control logic studies what Is the next colour type in the colour register. Having ascer-
• the program examines when a different colour or the same colour is concerned. If a different colour is concerned, the control logic chooses the washing program for the colour type concerned, and thereupon the new colour is supplied. If the same colour is concerned, no washing program is chosen, but the system is
• Fig. 3A is a schematical illustration of an equipment in accordance with the invention.
• the equipment constitutes a system, which com ⁇ prises a paint pistol 10, a paint-pressure regulating valve 11, and 30 a pump 12a installed in the duct passing away from the paint pistol 10.
• the system comprises a collector duct 13, i.e. a colour stock, into which each colour is passed separately.
• the first set of valves 14 is fixed, which comprises pneumatically controlled on-off valves 14a,14b,14c...14j .
• the system further comprises a second set of valves 15, which consists of electrically controlled magnetic valves 15a,15b,15c...15j . 1
• a second set of valves 15 which consists of electrically controlled magnetic valves 15a,15b,15c...15j . 1
• a outlet-line closing valve 16 is fitted, which closes and opens the line.
• the valve 16 is advantageously a pneumatically controlled closing valve operating by the on-off principle.
• control valve 17 advantageously a magnetic valve.
• a pneumatically pre-controlled on-off valve 18 is installed in the line of the pump drive motor.
• the system comprises an or-valve 19 as the logic valve.
• Q circuit comprises air-pressure regulating valves 20a,20b and 20c.
• the confirmation knob 21 transmits a pressure pulse S ] _ to the pressure switch 22, which recognizes the pulse and converts it to an electric message S2.
• a paint-pressure regulation valve 11 Is fitted, which opens and closes the line 23.
• a duct 24 is passed further to the collecting tank 25 through the outlet-line closing valve 16 and the pump 12a.
• the ducts 23 and 0 2 are advantageously flexible teflon hoses, which have the advantage of low friction between the paint that is made to flow and the inner face of the hose.
• valve 15 pre-control pressure is passed to the 5 valves 14 so as to open the valves 14.
• the valve 15 is opened by passing the pre-control voltage of the magnetic valve 15 from the control logic 48 of the system, the valve 15 is opened and the com- 1 pressed air is transmitted to the valve 14 to the piston end of its spindle that opens and closes the paint line.
• the paint line Is opened while the valve 14 spindle is pressed against the spring force of the spring .
• the paint N has access further Into the colour stock, I.e. into the collector duct 13.
• the duct 30 includes an air-pressure regulation valve 20b.
• the duct 30 includes a branch duct 31 to the paint pistol 10.
• the air-pressure regulation valve 20a is fitted in the branch duct 31.
• a branch line or branch duct 35 is passed to the valve 16.
• the valve 16 opens and closes the line 24.
• the control pressure is passed to the valve 16 from the line 33 along the duct
• valve 16 spindle to the position in which the line 24 is closed.
• a branch line 39 is passed further to the confirmation knob 21, and said line passes further through the confirmation knob 21 to the pressure switch 22.
• the pressure switch 22 When the pressure switch 22 is pressed, the pressure is transmitted from the line portion 39a into the line portion 39b and further to the pressure switch 22, which converts said pneumatic signal S ] _ to an electric signal S2.
• the signal S2 is passed further to the control logic 48 of the system.
• the system in accordance with the invention comprises a colour stock, i.e. a collector duct 13 for several different colours N.
• the system comprises separate lines for different paints or liquids N_,N2,N3. . . .
• the figure shows an embodiment in which eight different paints are passed into the colour stock, i.e. the liquids N ] _...Ng (in the figure LIQUID 1, LIQUID 2 ... LIQUID 8).
• the solvent M is fed to the upper end of the colour stock 13.
• the solvent M is passed through the valve 14a in the way indicated by the arrow L ⁇ .
• the paint line 39b is passed to the colour stock 13.
• the paint line 39c of the paint N2 is passed to the collector duct 13, i.e. to the colour stock.
• the other paint qualities N ⁇ ...Ng have paint lines 39d...39i of their own.
• Each paint N j _...Ng is passed from a paint store E_...Eg of its own to the colour stock 13.
• the passing of the paints N ] _...Ng takes place by means of a pump (not shown) or some other, correspond ⁇ ing actuating member.
• a pump not shown
• Other possibilities of transfer for carriage of the paint to the valve system 14 and further to the collector duct 13, i.e. to the colour stock, are also possible.
• the direction of transfer of the paint is denoted with the arrow L2 in Fig. 3A.
• a one-way valve 42 advantageously a check valve, in the way indicated by the arrow L3.
• a one-way valve 42 advantageously a check valve, which permits the flow in one direction only, i.e. towards the colour stock 13.
• the electromagnetic control of the valves 15 takes place from the control logic 48.
• a certain sequence of colours has been fed in advance, which is the sequence in which the valves 15 are opened.
• the information on this is transmitted as a control command S to the control logic 48.
• the control logic 48 receives the information and starts the washing program when necessary.
• the washing program is started if the next colour with which painting is carried out is different.
• the control logic examines of what quality the preceding colour was and chooses the optimal washing program accordingly.
• the control logic 48 chooses the optimal washing program by means of which the washing time and the solvent quantity are minimized while, yet, permitting a good washing result.
• the invention it has been realized to use a return line 24 and a sucking pump 12a so as to remove the used solvent into a waste collecting vessel 25.
• No similar solution has been used in prior art in connection with paint pistols 10 or equivalent devices.
• the evacuation pump 12a is started and, in a corresponding way, the valve 11 is opened fully, i.e. its throttle is minimized, whereby the run of the solvent quantity in the pipe system to be washed is accelerated.
• the in- vention by using an adjustable valve 11 and by opening it fully for the time of washing, the washing can be accelerated considerably.
• the line 24 and the pump 12a all the solvent can be col- lected into the waste tank 25.
• the equipment in accordance with the invention can also be used in a variety of other even elec- trically operating paint heads operated by robots.
• the system in accordance with the invention can be used in paint robot lines.
• any one of the paint valves 14b...14i in the first set of valves 14 is open and allows pressurized paint to flow into the collector duct 13 , i.e. into the colour stock.
• the paint N ] _ or N2 or ...Ng enters into the valve 11, where the paint pressure and the flow-through of the paint can be throttled by means of the control pressure introduced along the duct 38.
• the paint flows along a duct, advantageously a flexible hose 23, into the paint pistol 10, from which it comes out when the trigger of the paint pistol 10 is pressed.
• the changing takes place as follows:
• the person who paints a component e.g. a car, presses the confirmation knob 21, whereby compressed air has access through the confirmation knob 21 to the pressure switch 22, which converts the compressed-air signal S ⁇ obtained from the confirmation knob 21 into an electric signal S2.
• Said electric signal S2 is processed by the control logic 48 related to the system.
• the program of the control logic 48 compares whether the next colour that follows in the sequence is of a different colour or of the same colour as the colour that is being painted at that time. If the colour is the same, no washing operation takes place, but the painting is continued normally. If the colour is different, the control logic 48 compares whether the subsequent colour is a metallic paint or a solid paint. In accordance with this, it determines the washing program.
• the control logic 48 removes the control current from the magnetic valve 15, whereby the compressed- air control Is removed from the colour valves 14 and causes closing of the valve 14 and discontinuation of the paint flow to the .paint pistol 10.
• the magnetic valve 17 receives the control current, whereby it is opened.
• the valve 16 Is pre- controlled and opened.
• the route for the exhaust solvent from the paint pistol 10 to the pump 12 is open.
• Compressed air also has access from the magnetic valve 17 to the logic valve 19 or to the or-valve.
• Compressed air has access to the control side of the or- valve 19 and passes through the valve 19, as there is a lower pressure i n the other branch of the or-valve 19, i.e. in the line 30.
• valve 19 After the pressure has passed through the valve 19, it has access to the paint-pressure regulation valve 11, to its control side, and opens the valve 11 to the fully open position. In such a case, the valve 11 does not throttle the washing flow at all, and In this way the washing is accelerated. Further, compressed air has access through the magnetic valve 17 to the control valve 18 and opens the air flow to the pump 12a to its drive motor 12b. In this way the pump 12a is started.
• the control logic 48 After the starting of the pump 12a, the control logic 48 passes the voltage to the magnetic valve 15j , from which compressed air has access to the control side of the valve 14j and opens the valve, whereby compressed air is allowed to flow through the check valve 43 to the colour stock 13.
• the compressed air pushes the paint in front of the air out of the colour stock 13 and also out of the paint hose 23 while the pump 12a contributes by sucking the paint.
• the control logic 48 removes the control from the valve 15j , whereby the air valve 14j is closed.
• a delay follows in the program of the control logic 48 , the duration of said delay being advantageously about 0.2 second.
• the control logic 48 gives the control to the magnetic valve 15a and opens the valve 14a, whereby the solvent M has access through the check valve 40 to the colour stock 13 as well as to the paint hose 23 and pistol 10 and cleanses the paint ducts.
• the cleansing capacity is very good, because the flow speed of the solvent is high because of the suction effect of the pump 12a and of the compressed air still present in the hose.
• control logic 48 removes the control from the magnetic valve 15a, whereby the valve 14a that controls the solvent L in the set of valves 14 is closed.
• the control logic 48 again controls the magnetic valve 15 , through which com ⁇ pressed air is admitted to the valve 14j to its control side and a connection is opened between the compressed-air source 40 and the colour stock 13. In this way, compressed air is fed again into the paint duct in order that the ducts could be dried of the solvent M and that the rest of the solvent L could be pushed into the outlet duct 24 or waste hose starting from the pistol 10.
• the control logic 48 controls the system and removes the control from the valve 15j , whereby the valve 14j is closed.
• the control logic 48 controls the system by controlling the magnetic valve 15 of the subsequent colour shade and opens the valve for said colour shade. Thereat compressed air has access to the corresponding valve 14 in the set of colour valves 14, to the control side of said valve, whereby said valve 14 is opened and allows the new colour shade to flow into the paint duct.
• the logic 48 removes the control from the magnetic valve 17, as a result of which: the suction pump 12a stops, the valve 16 is closed, and the valve 11 for regulation of the paint pressure returns to Its pre-set value.
• the equipment is again ready for a new colour shade until the confirmation knob 21 is pressed again.
• the washing process described above applies only to a metallic-type colour as well as to a paint-hose length of about 7 m and to a hose inner diameter of 6 mm. If the length of the paint hose, the inner diameter of the paint hose or the viscosity of the paint is altered substantially, the washing process remains the same in the other respects, but only the valve opening times and delay times are changed, becoming longer or shorter.
• the washing of a solid or acrylic paint out of the paint ducts follows primarily the same formula as the washing of a metallic colour, how ⁇ ever, differing from the latter in the respect that, at the beginning of the washing, solvent is fed into the paint duct for about 2 seconds, by means of which the acrylic paint is thinned in order that it could be removed from the walls of the system of ducts better.
• This thinning is not required for metallic colours, because they contain a proportion of about 50 to 70 % of thinner in the total material quantity.
• Fig. 3B illustrates a second advantageous embodiment of the equipment and method in accordance with the invention.
• the system is in the other respects similar to that in the embodiment shown in Fig. 3A except that the equipment comprises another pump 59 that accelerates the washing program.
• Said pump may be, e.g., a gear pump. It is fitted in the duct 23 between the collector duct 13 and the paint pistol 10.
• the pump 59 is fitted so that it can be driven by a compressed-air motor 60, to which a compressed-air line passes from the duct 34b between the valve 18 and the compressed-air motor 12b.
• said compressed-air line is denoted with the reference numeral 61.
• the system comprises a by-pass line 62 across the pump 59, which said line is provided with a check valve 63.
• the pump 59 acts as a pressure-increasing pump to increase the pressure in the duct 23.
• the running-in time of the new colour which means the period of time in the time chart that elapses from the starting moment of the feed of new colour to the stopping of the waste pump and the waste valve.
• FIGS 4A and 4B show washing programs for two different paints, a metallic paint and a solid paint, as time charts.
• Fig. 4A shows a washing program for a metallic paint.
• the program starts with the feed of compressed air into the colour ducts.
• the compressed air is on, i.e. in the stage 1, during the time period 0...2 seconds.
• T ⁇ there is a delay in the program, whereupon solvent is fed into the duct, followed by a delay, and again feed of compressed air.
• T2 After the feed of compressed air, there follows a longer delay T2, whereupon a new colour is fed in the way shown in the time chart.
• the waste pump is in operation from the moment 0 in the time chart to 10 seconds.
• Fig. 4B shows a washing program for a solid or acrylic paint.
• Said washing program substantially follows the washing program for a metallic colour, but differs from the latter in the respect that at the beginning of the washing, solvent is fed into the paint duct for about 2 seconds.
• the acrylic paint is thinned in order that it should be detached better from the walls of the system of ducts. This thinning is not needed for metallic colours, because in themselves they contain a proportion of about 50...70 % of thinner in the total paint quantity. From Figs. 4A and 4B it is seen that the total washing times are of an order of about 10 seconds. In the case of a solid paint, the washing time is slightly longer than in the case of a metallic paint.
• the total washing time was of an order of about 50 seconds.
• the economies of time obtained by means of the system In accordance with the invention are considerable.
• the quantities of solvent required in the new system are only a fraction of the quantities of solvent used in the prior-art systems.
• the whole quantity of waste solvent is recovered, and further, after purifica ⁇ tion, it can be reused or be utilized otherwise.
• the time graphs of the washing programs are to a considerable extent dependent on the length of the paint hose as well as on the volumetric flow of paint in the pipe system that feeds the paint.
• the washing times given in Figs. 4A and 4B are attained with a paint-hose length of 6 m and when the volumetric flow of paint is 1.5 litres per minute and when the pressure is 5 bars.
• Figs. 4A and 4B only two washing programs are illustrated. It is obvious that within the scope of the invention there may be an Infinite number of washing programs.
• Fig. 5A is a side view of a paint pistol 10 used in the method in accordance with the invention.
• the paint is passed along the duct 23 in the way shown by the arrow L5 into the paint pistol 10.
• the dispersing air Is passed along the duct 31 in the way shown by the arrow L to the lower end of the handle part of the paint pistol, whereby the air duct Is opened and closed by pressing the trigger 49 and by displacing the spindle 50.
• the trigger 49 is pressed and the spindle 50 displaced, air has access to the front end of the paint pistol and can be discharged through the nozzle 51.
• the paint is passed into the nozzle 51 centrally, and it is mixed with the dispersing air discharged out of the nozzle part.
• the equipment comprises an outlet line 24 or outlet duct, through which the washing liquid and residual paint are carried, being sucked by the pump 12a, into the collecting vessel 25.
• the trigger 49 When the trigger 49 is not being pressed, dispersing air does not have access along the duct 31 into the nozzle part 51.
• the closing spindle 59 which closes the paint opening 51a, because, by means of the pump 12a suction and negative pressure are produced in the ducts in the paint pistol 10, and consequently the washing liquid is carried by the effect of the suction directly into the duct 24.
• Fig. 5B is a sectional view of the solution of equipment shown in Fig. 5A.
• the figure shows one embodiment of a paint pistol.
• the solution in accordance with the invention may also be used for paint pistol constructions of other types as well as for painting heads operated by robots.
• Fig. 5C is a sectional view taken along the line I-I in Fig. 5A.
• the solution in accordance with the invention comprises a duct 52, advan- tageously a bore in one side of the paint pistol. The bore extends into the central colour chamber 53.
• the washing liquid is passed, in the way shown by the arrow L5 in Fig. 5C, first through the inlet connection 53a into the colour chamber 53 and from there directly through the duct 52 and the connection 53b into the outlet duct 24 and further into the collecting tank 25.
• Fig. 6 shows an advantageous embodiment of the valve 11 used in the system in accordance with the invention.
• the paint enters through the duct 23a in the valve 11 and runs from the inlet chamber ] _ through the flow opening 56 placed between the valve spindle 54 and the partition wall 55 into the outlet chamber A2 and further out along the duct 23b.
• the control pressure is passed along the duct
• Fig. 7 shows an advantageous additional embodiment of the invention.
• a separate confirmation knob 64 is fitted in the fan-air duct 31 at the proximity of the colour pistol 10.
• the confirmation knob 64 When the painting operator notices that a change of colour lies ahead, he may empty the set of colour pipes and utilize all the available colour by pressing the confirmation knob 64, in which case the compressed-air pulse is transmitted through the confirmation knob to the pressure switch 65, which transmits said change in pressure as an electric signal S3 to the control logic 48, which further opens the valve 14j in the air- pressure line 39j connected to the upper end of the collector duct
• the manual-painting equipment additionally includes a clock for the control logic 48, which is started by the impulse S3 of the Inter ⁇ mediate air and monitors that the paint is also indeed consumed to the exhaustion before the colour is changed.
• the control logic 48 gives permission for change of colour only after a certain period of time has elapsed from the pressing of the confirmation knob 64.
• a pressure detector is placed in the fan-air hose 31 of the pistol, which said detector monitors the fan-air time used.
• a data bus may further pass to the control logic 48, which monitors whether all the paint has been removed out of the paint pistol 10, and only hereupon is permission given for change of colour.
• the control logic 48 measures said time of lower pressure and, when a certain predetermined period of time has elapsed, the control logic 48 gives permission for change of colour and/or for starting of the washing program.
• the counting by the timing device is started by means of a time impulse, which is given by the other confirmation knob 64.

Landscapes

• Spray Control Apparatus (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Detergent Compositions (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8526450

Family Applications (1)

Country Status (3)

Cited By (5)

Citations (6)

• 1988
  • 1988-05-13 FI FI882260A patent/FI882260A/fi not_active Application Discontinuation
  • 1988-06-03 SE SE8802069A patent/SE8802069L/ not_active Application Discontinuation
• 1989
  • 1989-04-07 WO PCT/FI1989/000064 patent/WO1989010796A1/en unknown

Patent Citations (6)

Non-Patent Citations (2)

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