Conveyor device having a rinsing device and method for operating the conveyor device

Abstract

A conveying device with a flushing device comprises a material conveyor (1) for conveying coating material (31). The material conveyor (1), in turn, has an inlet valve (7) comprising a valve inlet (7.1) and a valve outlet (7.9). The material conveyor (1) also has a conveyor inlet (1.1) for coating material (31), which is connected or connectable to the valve inlet (7.1). The conveying device further comprises a flushing agent conveyor (3) for conveying flushing agent (30), which is also connected to the valve inlet (7.1).

Description

Technical area

[0001] The invention relates to a conveying device with a flushing device and a method for operating the conveying device.

[0002] To coat workpieces with coating material, the coating material is transported from a storage container to a spray applicator by means of a conveyor device, and then sprayed onto the workpiece using the spray applicator. The coating material can be, for example, paint, adhesive, or an emulsion containing zinc dust. Once the coating process is complete or the coating material needs to be changed, the conveyor device, the material-carrying lines, and the spray applicator should be cleaned or flushed. For this purpose, the coating material is replaced with a flushing medium. The flushing medium can be, for example, flushing gas (e.g., compressed air or nitrogen), flushing agent (e.g., solvent or water), or a mixture of flushing gas and flushing agent. State of the art

[0003] From the prior art EP 2 956 242 B1, a coating agent pump and a cleaning method for the coating agent pump are known. The coating agent pump comprises a supply line and a pump inlet connected to it, through which coating agent is supplied to the pump. The pump inlet is connected to the pump chamber via a check valve. During conveying operation, coating material is sucked into the pump chamber via the pump inlet and the check valve and then pushed out of the pump outlet. The pump also comprises an exhaust opening through which compressed air is supplied to the pump. The exhaust opening is also connected to the check valve. During cleaning operation, compressed air is blown through the check valve, blowing the coating material out of the pump chamber towards the pump outlet.This solution has the disadvantage that the material-carrying components upstream of the coating material pump, such as the supply line, are not cleaned. Therefore, the supply line must be cleaned separately. Description of the invention

[0004] An object of the invention is to provide a conveying device with a flushing device in which, in addition to the conveying device, its upstream, material-carrying components, such as the supply line, can also be cleaned with the flushing device.

[0005] A further object of the invention is to provide a method for operating the conveying device which is particularly time-efficient.

[0006] Advantageously, the operating personnel can switch the conveying device according to the invention from conveying mode to cleaning mode particularly easily.

[0007] Another advantage is that the amount of detergent required per color change can be significantly reduced. This also reduces disposal costs for waste material (a mixture of coating material and detergent).

[0008] The object is achieved by a conveying device with a flushing device having the features specified in claim 1.

[0009] The conveying device according to the invention with a flushing device comprises a material conveyor for conveying coating material. The material conveyor, in turn, has an inlet valve comprising a valve inlet and a valve outlet. The material conveyor also has a conveyor inlet for coating material, which is connected or connectable to the valve inlet. The conveying device further comprises a flushing agent conveyor for conveying flushing agent, which is also connected to the valve inlet.

[0010] Advantageous further developments of the invention result from the features specified in the dependent patent claims.

[0011] In one embodiment of the conveying device according to the invention, the inlet valve is designed as a check valve. This ensures that the fluid can flow unhindered in one direction, while backflow (i.e., flow in the opposite direction) is automatically prevented. This can be achieved by a return spring in the check valve, which ensures that the check valve closes automatically. This increases the efficiency of the conveying device and the application system, and the risk of backflow damage is minimized.

[0012] In a further embodiment of the conveying device according to the invention, the inlet valve is designed as a poppet valve, ball valve, or needle valve. The use of a poppet valve is particularly advantageous because it can be designed for optimal flushing. Furthermore, the poppet valve can handle large flow rates. Furthermore, the poppet valve has a simple design that is reliable and low-maintenance.

[0013] In an additional embodiment of the conveying device according to the invention, the material conveyor is designed as a bellows pump, diaphragm pump, centrifugal pump, gear pump, peristaltic pump, piston pump, piston metering device, or positive displacement pump. Which material conveyor design is most suitable depends on the application. The most suitable material conveyor can be selected depending on the application.

[0014] In another embodiment of the conveying device according to the invention, the rinsing agent conveyor is connected to the valve inlet via a check valve. This ensures that no coating material enters the rinsing agent line.

[0015] Advantageously, the check valve is located close to the valve inlet. This minimizes dead space.

[0016] In a further development of the conveying device according to the invention, a shut-off device is provided, which is connected to the conveyor inlet on the inlet side and to the inlet valve on the outlet side. The shut-off device is thus arranged between the conveyor inlet and the inlet valve. When the shut-off device is closed, the pressure in the flushing medium can be increased even further. The increased flushing medium pressure allows the conveying chambers as well as the downstream material lines and components connected to the conveying chamber to be cleaned even more effectively. Without the shut-off device, most of the flushing medium would be discharged through the supply line.

[0017] In another embodiment of the conveying device according to the invention, a control system is provided that is designed and operable to control the shut-off device. This enables user-friendly use of the conveying device.

[0018] In an additional development, the conveying device according to the invention has a compressed gas source that can be connected to the valve inlet. The use of compressed gas as a flushing medium or as an additive in the flushing medium enables significant savings in flushing agent.

[0019] In a further development, the conveying device according to the invention comprises a compressed gas valve through which compressed gas from the compressed gas source can be mixed with the rinsing agent. This creates a mixture of rinsing agent and gas, referred to as the rinsing medium, which achieves a very high cleaning effect through high flow velocities and turbulence.

[0020] Flushing with the flushing medium can be continuous, discontinuous, or pulsed. If compressed air is mixed with the flushing agent in pulses via a timed valve and has a higher pressure than the flushing agent, the flushing agent flow is interrupted intermittently.

[0021] Advantageously, in the conveying device according to the invention, the flushing agent conveyor is connected to the inlet valve via a flushing line. Furthermore, the compressed gas source is connected to the flushing line via a check valve. Without this check valve, there would be a risk of flushing agent from the flushing line entering the compressed gas line.

[0022] Furthermore, it is proposed that the conveying device according to the invention have a further shut-off device, which is connected on the output side to a conveying chamber inlet of the conveying chamber and on the input side to the flushing agent conveyor. This embodiment does not require a shut-off device in front of the valve inlet. Thus, flushing of the conveying device can also take place without the shut-off device.

[0023] Furthermore, the conveying device according to the invention can be provided with a flushing agent control valve, which is designed and operable to control whether the flushing agent flows to the valve inlet or to the conveying chamber inlet. With this embodiment, both the conveying device and the supply line can advantageously be flushed.

[0024] When the flushing agent control valve is designed to flush the conveying device and the supply line sequentially. The flushing agent control valve can also be designed and operated in such a way that the conveying device and the supply line are flushed simultaneously.

[0025] Another embodiment of the conveying device according to the invention comprises a first compressed gas valve which is connected on the output side to the flushing agent line and which, in the open state, delivers a first compressed gas volume flow V1 into the detergent line. In addition, there is a second compressed gas valve, which is connected to the detergent line on the outlet side and which, when open, releases a second compressed gas volume flow V 2 into the flushing agent line. This allows the appropriate pressure or volume flow of the compressed gas to be specified for each process step. For example, it is advantageous to empty the supply line with reduced air pressure or throttled volume flow to prevent contamination at the end of the supply line when draining the coating material.

[0026] In one embodiment of the conveying device according to the invention, a cam control is provided, via which the compressed gas valves can be controlled. This enables reliable and optimized processes with good operability.

[0027] To determine the first compressed gas flow V1, a throttle can be provided in the compressed gas line leading to the purge line. To adjust the second compressed gas flow V 2, the compressed gas line can be connected directly to the purge line, bypassing the throttle. At the beginning of the purge, the flow rate in the sections to be purged is still low because there is still viscous or even highly viscous material in these sections, which is only gradually forced out. Later, when there is hardly any viscous material left in the sections to be purged, the flow rate is higher. The throttle can be used to limit the flow rate so that the flow rate in the supply line (intake hose) does not become too high. This can prevent the material from splashing out of the supply line.

[0028] Another embodiment of the conveying device according to the invention comprises a pinch valve, which is designed and operable to open or close the conveyor inlet. A pinch valve offers the possibility of effective sealing by squeezing a hose or pipe to stop the flow. This is particularly advantageous when conveying abrasive or viscous media. Due to its simple design and the absence of moving parts, a pinch valve is low-maintenance and offers reliable performance over extended periods of operation.

[0029] Furthermore, an application system is proposed that comprises the aforementioned conveying device and an applicator connected to the conveying device. This allows the advantages of the flushing process to be extended to the supply line to the applicator and the applicator itself.

[0030] In the method according to the invention for operating the aforementioned conveying device, the downstream side of the conveying device is closed to flush the supply line. This can be done, for example, with a valve. The flushing agent conveyor then pumps flushing agent into the supply line.

[0031] To flush the first conveying chamber, the downstream side of the conveying device is opened, and flushing agent is pumped into the first conveying chamber using the flushing agent conveyor. The upstream side of the conveying device should be closed, for example, via a valve or a shut-off device.

[0032] The optimal sequence of rinsing operations allows a rinsing process to be carried out with a high degree of material recovery and high rinsing agent effectiveness, saving both time and rinsing agent.

[0033] In a further development of the method according to the invention, rinsing is carried out in pulsed mode. Whether rinsing is best in pulsed mode or continuously, and whether rinsing is carried out with a mixture of pressurized gas and rinsing agent or with rinsing agent alone, depends on the material to be rinsed. Accordingly, the pulsed method may be more efficient in one case, while rinsing with a mixture of pressurized gas and rinsing agent may be more efficient in another. Because the proposed embodiment provides various rinsing methods, the most efficient method can always be selected.

[0034] In an additional development of the method according to the invention, compressed gas with a first compressed gas volume flow is supplied by means of the first compressed gas valve V 1 to the conveyor inlet when the pressure gas valve is open. If the pressure gas is to be fed into the conveyor chamber, a second pressure gas volume flow is V2. This prevents unnecessary contamination when the compressed gas escapes from the supply line.

[0035] The previously described valve operation can be carried out both manually, i.e. by hand, or automatically by a control system. This means that the valves can also be controlled automatically using a control system. Other components can also be controlled or regulated by the control system. This could be, for example, the pump pressure of the material conveyor. The drain valve for the drain line on the filter and the drain valve for the drain line on the spray applicator can also be controlled with the control system. If required, the application system can be further automated. For example, changing the containers or lifting the suction hose out of the container can be automated. This also eliminates manual intervention in cleaning mode. Short description of the drawings

[0036] In the following, the invention is further explained with several embodiments using six figures. Figure 1 shows a possible embodiment of the lower section of the material conveyor in a three-dimensional view. Figure 2 shows the lower section of the material conveyor in longitudinal section. Figure 3 shows a block diagram of the basic structure of a first embodiment of an application system with the material conveyor. Figure 4 shows a block diagram of the basic structure of a second embodiment of the application system with the material conveyor. Figure 5 shows the basic structure of an embodiment of a cam control for setting the operating mode of the material conveyor. Figure 6 shows an operating panel via which the operating modes of the material conveyor can be set. Ways to implement the invention

[0037] In the Figures 1 and 2A first possible embodiment of the lower (suction-side) section of a material conveyor 1 is shown. This suction-side section of the material conveyor 1 is also referred to below as the intake tract 1.7. In addition, Figures 1 and 2 the lower part of the compressor stage 1.8 is shown. The coating material conveyor 1 is also referred to below as the material conveyor or conveyor. The material conveyor 1 is preferably part of an application system. Figure 3The basic structure of a first embodiment of the application system is shown. The application system is designed to convey coating material 31 from a storage container 22 via a supply line 9. The storage container 22 is also referred to as a material storage container or container for coating material. The material conveyor 1 conveys the coating material 31, or material for short, out of the storage container 22 and to an applicator 45. From there, it can be applied to a workpiece (not shown in the figures). The applicator 45 can, for example, be a manually operated spray gun. An automatically operated spray gun is also not excluded. There can also be several spray guns connected to the material conveyor 1.

[0038] The material conveyor 1 can be designed, for example, as a bellows pump, diaphragm pump, centrifugal pump, gear pump, peristaltic pump, piston pump, piston dosing pump or positive displacement pump. Figures 1 to 4 The material conveyors shown are piston pumps driven by an air motor. Instead of the air motor, an electric motor or a hydraulic motor can also be used to drive the piston 1.4. The electric motor is preferably a servo motor.

[0039] The material conveyor 1 comprises an inlet for coating material 1.1, or in short material inlet or conveyor inlet, to which a supply line 9 is connected. The supply line 9 can be designed, for example, as a pipe or hose and is provided to conduct coating material 31 from a storage container 22 to the material conveyor 1. The material inlet 1.1 can be closed by means of a shut-off device 1.5. The shut-off device 1.5 is preferably designed as a pinch valve. The pinch valve 1.5 is controlled via a control connection 1.6. When pressurized air is applied to this connection, the pinch in the pinch valve 1.5 expands and closes the channel 1.9 behind the inlet 1.1. In the pressure-free state, the pinch in the pinch valve 1.5 is relaxed and the channel 1.9 is open.

[0040] Depending on requirements, the shut-off device 1.5 can be operated automatically or manually. For example, the shut-off device 1.5 can be operated electrically (not shown in the figures) or pneumatically (see Figures 3 and 4 ) is controllable. The pinch valve 1.5 is preferably made of solvent-resistant rubber.

[0041] The material conveyor 1 also comprises an inlet valve 7, which has a valve inlet 7.1 and a valve outlet 7.9 and a valve plate 7.7 in between. In the closed state, the valve plate 7.7 sits on the valve seat 7.2. The inlet valve 7 is preferably designed as a self-closing valve. The inlet valve 7 can have a return spring 7.8 (see Figure 2) which ensures that the inlet valve 7.7 is closed in the pressure-free state. It is also advantageous if the inlet valve 7 is designed as a check valve. The inlet valve 7 is preferably installed in the material conveyor 1 in such a way that it closes the conveyor inlet 1.1 when the first conveyor chamber 1.11 is under pressure. The inlet valve 7 ensures that the coating material 31 can only flow in one direction, namely in the direction of the spray applicator 45. The inlet valve 7 is preferably designed such that it has the smallest possible dead space. This has the advantage that only a small amount of coating material can deposit there, so that the risk of color carryover during a color change is minimized. The inlet valve 7 is preferably designed as a poppet valve because a poppet valve has a particularly small dead space.

[0042] Preferably, the flushing agent inlet 1.2 is connected to the valve inlet 7.1 even when the inlet valve 7 is closed.

[0043] When the shut-off device (pinch valve) 1.5 is open, the conveyor inlet 1.1 is connected to the valve inlet 7.1. When the pinch valve 1.5 is closed, the conveyor inlet 1.1 is not connected to the valve inlet 7.1. Therefore, the pinch valve 1.5 can connect the conveyor inlet 1.1 to the valve inlet 7.1.

[0044] The material conveyor 1 also has a flushing agent inlet 1.2 for a flushing medium / flushing agent 30. With the aid of a flushing agent conveyor 3, flushing agent 30 can be sucked from a storage container 20 via a flushing line 32 and conveyed to the valve inlet 7.1 via a flushing line 33, a check valve 24, a flushing line 34, a check valve 8, and a flushing line 35. The flushing medium can be, for example, solvent, water, air, or a mixture thereof.

[0045] The check valve 8 is preferably arranged in the immediate vicinity of the valve inlet 7.1 (see Figure 2 ). It comprises an inlet 8.1 and an outlet 8.9, with a valve plate 8.7 between them. The inlet 8.1 of the check valve 8 simultaneously forms the flushing agent inlet 1.2 of the material conveyor 1. The check valve 8 is preferably designed to be self-closing. It can also have a return spring 8.8, which ensures that the check valve 8 is closed in the depressurized state.

[0046] The material conveyor 1 also includes a second conveyor chamber 1.12, which is connected or connectable to the first conveyor chamber 1.1 via a check valve 1.14. When the piston 1.4 is moved upward, the volume of the second conveyor chamber 1.12 is reduced, and the coating material contained therein is forced out of the conveyor outlet 1.3 and into the material line 42. A filter 44 can be located between the material line 42 and the material line 43. The coating material can be drained into the residue container 21 or back into the storage container 22 via a drain valve 41.

[0047] As in the Figures 3 and 4As shown, a controller 2 can be provided to control the material conveyor 1 and the flushing agent conveyor 3. The controller 2 has a control valve 13, which is connected on the inlet side via a line 39 and a shut-off valve 11 to a compressed gas source 10. The compressed gas source 10 provides a compressed gas with a defined pressure. The compressed gas can be, for example, compressed air or nitrogen. When the control valve 13 is open, the compressed gas reaches the control inlet 1.6 of the pinch valve 1.5 via a control line 36.

[0048] The controller 2 further comprises a compressed gas valve 14, which is connected to the compressed gas source 10 on the inlet side via a flow reducer 18, a compressed gas valve 12, and the shut-off valve 11. When the compressed gas valve 14 is actuated, compressed gas is fed into the purge line 34 via a flow reducer 17, a compressed gas line 37, and a check valve 23. The flow reducer 17 can be, for example, a throttle or an orifice. The flow reducer 18 is provided to regulate the mass flow of the compressed gas.

[0049] The compressed gas valve 12 serves as a safety valve to prevent the system operator from accidentally activating one of the valves 14, 15, or 16, which could cause flushing medium to enter the material conveyor 1 during conveying operation. Only after the compressed gas valve 12 has been activated can the system switch to cleaning mode. The compressed gas valve 12 is optional.

[0050] The control unit 2 also has a compressed gas valve 15, which is connected to the compressed gas source 10 on the inlet side via the flow reducer 18, the compressed gas valve 12, and the shut-off valve 11. When the compressed gas valve 15 is actuated, compressed gas is fed into the purge line 34 via the compressed gas line 37 and the check valve 23.

[0051] When the compressed gas valve 14 is actuated, compressed gas with a first pressure or compressed gas volume flow V 1 into the purge line 34. If, however, the pressure gas valve 15 is actuated, pressure gas with a second pressure or pressure gas volume flow V 2 into the flushing line 34.

[0052] The control system 2 also has a flow valve 16, which is connected to the compressed gas source 10 on the inlet side via the compressed gas valve 12 and the shut-off valve 11. When the flow valve 16 is actuated, compressed gas is supplied to the rinsing agent conveyor 3 via a compressed gas line 38 and a flow reducer 25 to drive it.

[0053] In a preferred embodiment, the control 2 also comprises a cam control 60, with which the valves 13, 14, 15 and 16 can be actuated. The principle of a possible embodiment of the cam control 60 is shown in Figure 5. The cam control 60 has a camshaft 61 rotatable about its longitudinal axis with a plurality of cams, wherein Figure 5 only the cams 61.1, 61.2,... 61.8 are visible. In the embodiment according to Figure 5the camshaft 61 can be turned to seven different positions 0 - 6 (see arrow). When the camshaft 61 is in position 0, the conveying device goes into conveying mode. In position 0, neither the control valve 13 nor any of the pressure gas valves 14 and 15 or the flow valve 16 are actuated by the cams. The valves 13 - 16 are closed. If the camshaft 61 is moved to position 4, for example, the pressure gas valve 15 and the flow valve 16 are actuated via the cam 61.7. This opens the valves 15 and 16. In addition, the control valve 13 is actuated (opened) via the cam 61.6. In position 2, the control valve 13 and the pressure gas valve 15 are actuated, i.e. opened, by the cams 61.2 and 61.4. In position 1, the compressed gas valve 14 is actuated by the cam 61.3.

[0054] In the application system according to Figure 4The coating material conveyor 1 has a conveyor chamber inlet 1.13, which is connected to a flushing agent control valve 51 via a flushing agent line 48 and a check valve 47. The flushing agent inlet 1.2 is also connected to the flushing agent control valve 51. The control valve 13 now controls (unlike in Figure 3 ), whether the delivery chamber inlet 1.13 or the flushing inlet 1.2 is supplied with flushing agent 30 via the flushing agent control valve 51. Funding mode

[0055] To put the application system into conveying mode, the system operator turns the rotary knob 71 (see Figure 6) on the control panel 70 until the rotary knob 71 points to the spray gun pictogram 72. The camshaft 61 connected to the rotary knob 71 is then in position 0. The application system is now in feed mode. As soon as the system operator pulls the trigger on the spray applicator 45, the coating material 31 is sprayed.

[0056] When the rotary knob 71 points to the pictogram 72, the camshaft 61 of the cam control 60 causes the valves 13, 14, 15, and 16 to be locked. Thus, no compressed gas enters the control line 36 and the compressed gas lines 37 and 38. Because the control line 36 is depressurized, the shut-off device (pinch valve) 1.5 is open, allowing coating material 31 to reach the valve inlet 7.1 via the coating material supply line 9. When the piston 1.4 now moves upward, the coating material 31 is sucked from the reservoir 22 and drawn via the supply line 9, the inlet 1.1, the valve inlet 7.1, and through the inlet valve 7 into the first delivery chamber 1.11. The check valve 1.14 is closed, i.e., blocked. The coating material already in the second feed chamber 1.12 is pushed out of the second feed chamber 1 by the piston 1.4.12 and transported via the material line 42, the filter 44, and the material line 43 to the spray applicator 45. As soon as the piston 1.4 reaches its top dead center, the inlet valve 7 closes, so that the first delivery chamber 1.11 is closed on the inlet side. When the piston 1.4 subsequently moves downward, the coating material 31 is pressed from the first delivery chamber 1.11 through the check valve 1.14 into the second delivery chamber 1.12. The piston 1.4 then moves upward again, and the process described above repeats.

[0057] Various pressures, such as pump pressure, spray pressure, circulation pressure, filling pressure and / or cleaning pressure, can be set or regulated on the conveying device.

[0058] The pump pressure is the pressure at which the coating material 32 is present at the conveyor outlet 1.3. It can be adjusted in conveyor mode. The spray pressure is the pressure at which the coating material 31 is sprayed onto the workpiece. The circulation pressure is the pressure at which the material 31 is circulated via a drain valve in the conveyor device. The circulation pressure is generally lower than the spray pressure. The filling pressure is the pressure at which the material conveyor 1 is filled with coating material 31. The filling pressure is generally lower than the spray pressure. The cleaning pressure is the pressure of the rinsing medium with which the material conveyor 1 is to be cleaned (before switching to cleaning mode). The cleaning pressure is normally lower than the spray pressure. Cleaning mode Position 1: Empty supply line 9 (suction hose)

[0059] To switch the application system from conveying mode to cleaning mode, the system operator turns the rotary knob 71 on the control panel 70 to the cleaning position (position 1). In this position, the compressed gas valve 14 is actuated by the cam 61.3 of the camshaft 61 and opened. This causes compressed gas to flow via the compressed gas valve 14, the flow reducer 17, the purge line 37, and the check valve 23 into the purge line 34. Due to the flow reducer 17, the compressed gas flow into the purge line 34 has a throttled volume flow. V1. From there, it flows via the check valve 8 into the flushing line 35 and to the valve inlet 7.7. The closing force of the return spring 7.8 on the inlet valve 7 is preferably so great that the inlet valve 7 remains closed even when gas pressure is applied. Because the pinch valve 1.5 is open, the compressed gas transports the coating material back into the supply line 9 and ultimately reaches a residual agent container 21. In this way, the valve inlet 7.1, the pinch valve 1.5, the conveyor inlet 1.1, and the supply line 9 are emptied. Position 2: Empty material conveyor 1 towards the spray gun

[0060] When the system operator moves the rotary knob 71 to position 2, the control valve 13 is opened by the cam 61.2, so that compressed air reaches the control port 1.6 and the shut-off device 1.5 closes the channel 1.9. Furthermore, the compressed gas valve 15 is actuated by the cam 61.4 and brought into the open state. Thus, compressed gas reaches the control port 1.6 with the second compressed gas flow rate. V2 from the compressed gas source 10 via the compressed gas valve 15 and the compressed gas line 37 into the purge line 34. When the system operator now pulls the trigger on the spray applicator, the inlet valve 7 opens because the pressure in the compressed gas is greater than the return force of the return spring 7.8 in the inlet valve 7.7. The purge gas thus reaches the first conveying chamber 1.11. From there, the purge gas flows via the check valve 1.14 into the second conveying chamber 1.12 and then into the material hoses 42 and 43 up to the spray applicator 45. The remaining coating material is thus sprayed out via the spray applicator 45.

[0061] Alternatively, the drain valve 46 on the spray applicator 45 can be opened so that the remaining coating material can be drained via a line 49 into the residue container 21 or back into the storage container 22. Once the rinsing process is complete, the drain valve 46 is closed again.

[0062] Alternatively, the drain valve 41 on the filter 44 can be opened so that the remaining coating material can be drained via a line into the residue container 21 or back into the storage container 22. Once the rinsing process is complete, the drain valve 41 is closed again. Position 3: Flush supply line 9 (suction hose)

[0063] If the system operator turns the rotary knob 71 to position 3, the valves 14 and 16 are actuated by the cams 61.1 and 61.8 of the camshaft 61 and opened. Thus, compressed gas with the first compressed gas volume flow V1 from the compressed gas source 10 via the compressed gas valve 14, the flow reducer 17 and the compressed gas line 37 into the flushing line 34. In addition, the flushing agent pump 3 is driven with the help of the compressed gas, which reaches the flushing agent pump 3 via the flow valve 16 and the line 38. This then pumps flushing agent 30 from the flushing agent container 20 via the flushing agent line 32 into the flushing agent lines 33 and 34 and from there via the check valve 8 into the flushing agent line 35. The flushing agent then reaches the valve inlet 7.1 via the flushing inlet 1.2.

[0064] The closing force of the return spring 7.8 on the inlet valve 7 is preferably so great that the inlet valve 7 remains closed even when the flushing agent pressure is applied. Because the pinch valve 1.5 is open, the supply line 9 is flushed with the help of the compressed gas and the flushing agent, ultimately reaching a residual agent container 21. In this way, the valve inlet 7.1, the pinch valve 1.5, the conveyor inlet 1.1, and the supply line 9 are flushed. Position 4: Flush material conveyor 1 towards spray gun 45

[0065] If the system operator turns the rotary knob 71 to position 4, the valves 13, 15, and 16 are actuated by the cams 61.6 and 61.7 of the camshaft 61 and opened. This causes compressed gas to flow via the control valve 13 and line 36 to the control inlet 1.6 of the pinch valve 1.5, closing the pinch valve 1.5. In addition, compressed gas flows with the volume flow V2 from the compressed gas source 10 via the compressed gas valve 15 and the compressed gas line 37 into the flushing line 34. In addition, the flushing agent pump 3 is driven with the help of the compressed gas, which reaches the flushing agent pump 3 via the flow valve 16 and the line 38. This then pumps flushing agent 30 from the flushing agent container 20 via the flushing agent line 32 into the flushing agent lines 33 and 34 and from there via the check valve 8 into the flushing agent line 35. The flushing agent then reaches the valve inlet 7.1 via the flushing inlet 1.2. When the system operator now pulls the trigger on the spray applicator 45, the inlet valve 7 opens because the pressure in the compressed gas (flushing gas) and flushing agent is greater than the restoring force of the return spring 7.8 in the inlet valve 7.7. The mixture of purge gas and purge agent (purge medium) thus enters the first delivery chamber 1.11. From there, the mixture flows via the check valve 1.14 into the second delivery chamber 1.12 and then into the material hoses 42 and 43 up to the spray applicator 43. The rinsing medium is sprayed out via the spray applicator 45.

[0066] Alternatively, the drain valve 46 on the spray applicator 45 can be opened so that the rinsing medium can be drained via line 49 into the residue container 21 or back into the storage container 22. Once the rinsing process is complete, the drain valve 46 is closed again. Alternatively, the drain valve 41 on the filter 44 can be opened so that the rinsing gas and rinsing agent can be drained via a line into the residue container 21 or back into the storage container 22. Once the rinsing process is complete, the drain valve 41 is closed again. Position 5: Dry supply line 9

[0067] In position 5, a cam of the camshaft 61 (the cam is in Figure 5not visible) the compressed gas valve 14 is actuated and opened. This causes compressed gas to flow at the first volume flow V 1 flows into the flushing line 34. From there, it flows via the check valve 8 into the flushing line 35 and to the valve inlet 7.7. Because the pinch valve 1.5 is open, the remaining flushing agent is now blown out via the supply line 9 with the help of the compressed gas. In this way, the valve inlet 7.1, the pinch valve 1.5, the inlet 1.1, and the line 9 can be dried. Position 6: Dry material conveyor 1 towards spray gun 45

[0068] When the operator moves the rotary knob 71 to position 6, two cams of the camshaft 61 (cam 61.5 and a second cam located in Figure 5not visible) the control valve 13 and the compressed gas valve 15 are actuated and opened. This causes compressed gas to flow via the control valve 13 and the line 36 to the control inlet 1.6 of the pinch valve 1.5 and closes the pinch valve 1.5. This causes compressed gas to flow with the second volume flow V 2 from the compressed gas source 10 via the compressed gas valve 15 and the compressed gas line 37 into the purge line 34. When the system operator now pulls the trigger on the spray applicator 45, the inlet valve 7 opens because the pressure in the compressed gas is greater than the return force of the return spring 7.8 in the inlet valve 7.7. The purge gas thus reaches the first conveying chamber 1.11. From there, the purge gas flows via the check valve 1.14 into the second conveying chamber 1.12 and then into the material hoses 42 and 43 up to the spray applicator 45. The remaining purge agent still present there is thus sprayed out via the spray applicator 45.

[0069] Alternatively, the drain valve 46 on the spray applicator 45 can be opened so that the remaining rinsing agent can be blown out via line 49. This allows the pressure stage 1.8 and the lines 42, 43 and components located downstream of the pressure stage to be dried. Once the drying process is complete, the drain valve 46 is closed again.

[0070] Rinsing or drying can be performed in pulsed or continuous mode. Using compressed air as the rinsing medium, the solvent residues in material conveyor 1 are blown out.

[0071] In position 4 (flushing material conveyor 1 in the direction of spray gun 45), it may also be advisable to flush without compressed air, i.e., only with flushing agent 30. After the flushing process is complete, the material conveyor 1 can be switched off and left to stand, fully or partially filled with flushing agent 30. If coating material 31 is still in the material conveyor 1, the flushing agent 30 can now slowly dissolve the material residue. This ensures that any remaining material residue in the material conveyor 1 does not dry out. An additional switching valve (not shown) can be installed for this purpose, which deactivates the compressed gas valve 15.

[0072] In a further embodiment, a throttle 26 (see Figure 4) is installed between the flushing agent pump 3 and the check valve 24. The throttle 26 is optional. It also allows the flushing agent flow to be throttled so that not too much flushing agent 30 flows into the flushing line 34. This allows the supply of flushing gas into the flushing line 34 to be better adjusted via the flow reducer 19, which is designed, for example, as a pressure control valve. The throttle 26 allows the flushing agent in the flushing line to be atomized into fine droplets, thereby achieving better mixing of the flushing gas and flushing agent.

[0073] In one embodiment of the cleaning method, the first conveying chamber 1.11 and preferably also the second conveying chamber 1.12 are emptied before rinsing. This can be done, for example, by opening the drain valve 41 and moving the piston 1.4 up and down several times. This drains most of the coating material still present in the two conveying chambers 1.11 and 1.12 through the drain valve 41.

[0074] In a further embodiment of the cleaning method, the first conveying chamber 1.11 and preferably also the second conveying chamber 1.12 are dried after flushing. For this purpose, the drain valve 41 is opened and compressed gas is blown through the conveying chambers 1.11 and 1.12.

[0075] It may happen that only the two conveyor chambers 1.11 and 1.12 (compressor stage 1.8) of the coating material conveyor 1 are to be flushed. In this case, the shut-off device 1.5 is activated, closing the conveyor inlet 1.1. The flushing agent introduced via the flushing inlet 1.2 opens the inlet valve 7 due to the pressure, so that the flushing agent is now directed into the paint stage.

[0076] To flush the intake tract 1.7, the shut-off device 1.5 is opened. The flushing agent introduced via the flushing inlet 1.2 now flows through the intake tract 1.7 toward the supply line 9.

[0077] When closed, the shut-off device 1.5 allows the flushing agent pressure required for cleaning the compressor stage 1.8 to be built up by preventing the flushing agent from escaping through the supply line 9.

[0078] When opened, the shut-off device 1.5 allows the detergent to be directed towards the supply line 9 in order to clean it.

[0079] The coating material still in the application system can be recovered by displacing the coating material from the system using compressed gas.

[0080] The cleaning process may also include the following process steps.

[0081] The supply line 9 is removed from the material storage container 22 and directed into the residue container 21. This ensures that no rinsing agent enters the material storage container 22 when flushing the intake tract 1.7 and the supply line 9.

[0082] The material conveyor 1 can also be emptied by activating the spray applicator 45 and moving the piston 1.4 up and down. This causes the remaining coating material to be discharged via the conveyor outlet 1.3 and sprayed via the spray applicator 45.

[0083] Advantageously, the supply line 9 and / or the piston pump and / or the material hose 42, 43 can be purged with compressed gas. This allows unused material to be recovered.

[0084] The coating material conveyor 1 and the upstream components (feed line 9, etc.) can be flushed with a gas-solvent mixture. The addition of gas can reduce solvent consumption.

[0085] Using the application line cleaning procedure described above, cleaning times can be significantly reduced.

[0086] Disassembly of system components (filter 44, housings 1.15, 1.16, 1.17 on the inlet tract) is not necessary with the process described above. This also massively reduces the amount of manual cleaning required.

[0087] In some applications, it may be advantageous if the material conveyor 1 remains filled with flushing agent 30 until the next use (conveying coating material).

[0088] After the material conveyor 1 and the respective lines no longer contain flushing agent 30 and have been dried if necessary, the material conveyor 1 can be refilled with coating material 31. For this purpose, several piston strokes are performed to convey the coating material 31 into the conveying chambers 1.11 and 1.12. The material conveyor 1 is then ready to convey coating material 31 to the applicator 45.

[0089] The foregoing description of the embodiments according to the present invention is for illustrative purposes only. Changes and modifications are of course possible. For example, the various embodiments shown in the Figures 1 to 6 The components of the application system shown can also be combined with one another in a manner other than that shown in the figures. List of reference symbols

[0090] 1Material conveyor 1.1Inlet for coating material 1.2Inlet for flushing agent / flushing medium 1.3Conveyor outlet 1.4Piston 1.5Shut-off device, e.g. pinch valve 1.6Control connection for pinch valve 1.7Intake tract 1.8Compressor stage / paint stage 1.9Channel 1.11First conveyor chamber 1.12Second conveyor chamber 1.13Conveyor chamber inlet 1.14Check valve 1.15Housing on the inlet tract 1.16Housing on the inlet tract 1.17Housing on the inlet tract 1.18Housing of the conveyor chamber 2Control system 3Flushing agent conveyor 7Inlet valve 7.1Valve inlet 7.2Valve seat 7.7Valve plate 7.8Spring 7.9Valve outlet 8Valve 8.1Inlet 8.7Valve plate 8.8Spring 8.9Valve outlet 9Supply line 10Compressed air source 11Shut-off valve 12Compressed gas valve 13Control valve 14Compressed gas valve 15Compressed gas valve 16Flow valve 17Flow reducer 18Flow reducer 19Flow reducer 20Container for flushing agent 21Waste container 22Container for coating material 23Check valve 24Check valve 25Flow reducer 26Throttle 30Flushing agent 31Coating material 32Flushing line 33Flushing line 34Flushing line 35Flushing line 36Control line 37Compressed gas line 38Compressed gas line 39Compressed gas line 39.1Control line 39.2Control line 40Compressed gas line 41Drain valve 42Material line 43Material line 44Filter 45Spray applicator 46Drain valve 47additional shut-off device / check valve 48flushing line 49flushing line 51flushing agent control valve 60cam control 61camshaft 61.1cam 61.2cam 61.3cam 61.4cam 61.5cam 61.6cam 61.7cam 61.8cam 70control panel 71rotary knob 72pictogram.

Claims

1. Conveying device with rinsing device, - with a material conveyor (1) for conveying coating material (31), -- which has an inlet valve (7) comprising a valve inlet (7.1) and a valve outlet (7.9), and -- which has a conveyor inlet (1.1) for coating material (31) which is connected or connectable to the valve inlet (7.1), and - with a rinsing agent conveyor (3) for conveying rinsing agent (30), which is also connected to the valve inlet (7.1).

2. Conveying device according to claim 1, wherein the inlet valve (7) is designed as a check valve.

3. Conveying device according to claim 1 or 2, wherein the inlet valve (7) is designed as a poppet valve, ball valve or needle valve.

4. Conveying device according to one of claims 1 to 3, wherein the material conveyor (1) is designed as a bellows pump, diaphragm pump, centrifugal pump, gear pump, peristaltic pump, piston pump, piston dosing device or positive displacement pump.

5. Conveying device according to one of claims 1 to 4, wherein the rinsing agent conveyor (3) is connected to the valve inlet (7.1) via a check valve (8).

6. Conveying device according to one of claims 1 to 5, with a shut-off device (1.5) arranged between the conveyor inlet (1.1) and the inlet valve (7).

7. Conveying device according to claim 6, with a control (2) which is designed and operable to control the shut-off device (1.5).

8. Conveying device according to one of claims 1 to 7, with a compressed gas source (10) which can be connected to the valve inlet (7.1).

9. Conveying device according to claim 8, with a compressed gas valve (14) via which compressed gas originating from the compressed gas source (10) can be mixed into the flushing agent (30).

10. Conveying device according to claim 8 or 9, - in which the flushing agent conveyor (3) is connected to the inlet valve (7) via a flushing line (34), and - in which the compressed gas source (10) is connected to the flushing line (34) via a check valve (23).

11. Conveying device according to one of claims 1 to 10, with a further shut-off device (47) which is connected on the output side to a conveying chamber inlet (1.13) of the conveying chamber (1.11) and on the input side to the rinsing agent conveyor (3).

12. Conveying device according to claim 11, comprising a flushing agent control valve (51) which is designed and operable to control whether the flushing agent (30) flows to the valve inlet (7.1) or to the conveying chamber inlet (1.13).

13. Conveying device according to one of claims 1 to 12, - with a first compressed gas valve (14) which is connected on the output side to the flushing agent line (34) and which, in the open state, directs a first compressed gas volume flow into the flushing agent line (34), and - with a second compressed gas valve (15) which is connected on the output side to the flushing agent line (34) and which, in the open state, directs a second compressed gas volume flow into the flushing agent line (34).

14. Conveying device according to claim 13, with a cam control (60) via which the compressed gas valves (14, 15) can be controlled.

15. Conveying device according to one of claims 1 to 14, with a pinch valve (1.5) which is designed and operable to open or close the conveyor inlet (1.1).

16. Application system comprising a conveyor device according to one of claims 1 to 15 and an applicator (45) connected to the conveyor device.

17. A method for operating a conveyor device according to one of claims 1 to 15, - in which the downstream side of the conveyor device is closed for flushing the conveyor inlet (1.1), and - in which flushing agent (30) is conveyed into the supply line (9) with the aid of the flushing agent conveyor (3).

18. Method according to claim 17, wherein, for rinsing the first conveying chamber (1.11), rinsing agent (30) is conveyed into the first conveying chamber (1.11) with the aid of the rinsing agent conveyor (3).

19. Method according to claim 17 or 18, wherein, in order to flush the first conveying chamber (1.11), the shut-off device (1.5) is closed and the inlet valve (7) is opened.

20. Method according to one of claims 17 to 19, wherein the rinsing is carried out in a pulsed manner.

21. Method according to one of claims 17 to 20, - in which compressed gas with a first compressed gas volume flow is passed to the conveyor inlet (1.1) with the aid of the first compressed gas valve (14) when the first compressed gas valve (14) is open, and - in which compressed gas with a second compressed gas volume flow is passed into the conveyor chamber (1.11) with the aid of the second compressed gas valve (15) when the second compressed gas valve (15) is open.

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