The present invention relates to a fluid supply for a sprayer, particularly for a paint or varnish sprayer, and a method of its use.
For a paint change in a sprayer, the system must be cleaned of the paint used, and subsequently, the new paint has to be put into use. To this end, when the pumps are on the outside, the feed lines to the atomizer and all the parts contained in them, such as paint changer, pressure regulator, or metering units, are cleaned with a cleaning fluid. In these methods, the paint contained in the line is discarded, which entails a high consumption of paint and cleaning fluid and a long flushing time.
Another method of cleaning feed lines is feeding the paint back into a ring line and then cleaning the feed lines with cleaning fluid. In these methods, it is true that the loss of paint when changing paints can be kept low, but the technical effort for control is very great, making such systems very liable to break down, and cost-intensive.
Proceeding from this state of the art and the disadvantages described in this connection, the object to be attained was therefore providing a sprayer that allows a rapid and efficient paint change, and, in this connection, makes do without a pigging system for the cleaning required for this. Furthermore, such a system should be characterized by low installation effort and cost.
According to the invention, this object is attained in that a fluid supply for a sprayer, particularly a paint or varnish sprayer, is composed of two modules.
The first module of the device according to the invention consists of:
at least two ring or supply lines for paint or varnish that are independent of one another and connected with the first paint changer provided with paint valves and circulation valves,
at least two lines for circulating respective paints or varnishes, that are independent of one another, and that extend from the first paint changer to a second paint changer provided with release valves,
where on the one hand the paint valves of the first paint changer are connected with a cleaning-agent valve and an air valve, by a common line, and on the other hand are connected with the release valves, a drain valve, as well as a drain line of the second paint changer, through a common pressure regulation line, through a pressure regulator and a metering pump.
The second module comprises at least two lines that are independent of one another for feeding the paints or varnishes from a second paint changer to a third paint changer and/or a two-component mixer, where the third paint changer and/or the two-component mixer has release valves and/or return lines for paints and varnishes, and is preferably provided in the immediate vicinity of the spraying device.
Such a system allows rapid and efficient automatic paint change, with the valve arrangement according to the invention allowing a low installation effort and cost for operation, and, in particular, for the cleaning that is required. Furthermore, no complicated pigging systems are used.
In the second module, the fluid supply according to the invention can optionally be equipped with any desired number of paint changers and/or two-component mixers. Fluids in the sense of the present invention are all fluids that can be used for surface treatment, particularly paints or varnishes. The device according to the invention thus makes it possible to transport a plurality of paints or varnishes, for example 20 or 30 paints or varnishes, separately from one another in the fluid supply. Cleaning fluid in the sense of the invention is understood to mean suitable solvents that can completely remove the paints and varnishes, in each instance. If a two-component mixer is present in the second module, it is advantageous to provide this module with a feed line for a hardener, the metering of the hardener being done by a valve referred to below as a hardener valve. Thus, it is possible to mix a hardener with the paint and/or varnish mixture. It is furthermore advantageous if the paint changer has circulation valves. It is advantageous if needle valves are used for the circulation valves, paint valves, and hardener valves, where the needle valves can be turn on and off pneumatically, through control lines. It is advantageous if the control takes place in computer-based manner, for example through a PLC system. In an advantageous embodiment of the fluid supply, the metering pump in the first module is connected with a cleaning agent line through a separate flushing valve; thus, this metering pump can be flushed with a cleaning agent, independently of the remaining system, where it is particularly advantageous if the metering pump is a flushable metering gear pump. In another advantageous embodiment, the first module is mounted outside of a cabin or on a cabin wall, and the second module is mounted on a robot or automatic varnishing machine.
A method according to the invention, for supplying fluid to a sprayer, particularly to a paint or varnish sprayer, is presented below:
In this connection, paints or varnishes are passed into the first paint changer provided with the paint valves and circulation valves, through at least two supply lines that are independent of one another. These paints or varnishes can be passed to a second paint changer provided with release valves through at least two separate lines for circulating the paints or varnishes. Furthermore, the paints or varnishes are passed from the second paint changer to a third paint changer and/or to a two-component mixer provided in a second module, through at least two lines, which are independent of one another. If it is practical, fundamentally two or more paint changers and/or two-component mixers as well as any desired combinations of these can also be provided in the second module. The paints can therefore constantly circulate through the system, in separate circuits, or can be optionally passed from the third paint changer and/or from the two-component mixer to a spraying device, when the valves are switched accordingly. In the cleaning mode, air and/or a fluid cleaning agent is/are passed through the first paint changer, through a common line with the pressure regulator, and a metering pump, through the second paint changer, through a drain valve, into a drain line. Furthermore, at the same time, air and/or a fluid cleaning agent is/are passed through the third paint changer and/or the two-component mixer and the spraying device. It is particularly practical for cleaning purposes to alternately pulse fluid cleaning agent and air through these components, with the shape of the pulse adapted to the fluid to be removed. If necessary, cleaning can also take place exclusively with a fluid cleaning agent, without air.
The fluid supply according to the invention furthermore has the advantages that in spite of the fact that the metering pump is outside, the paints circulate through the complete device, and circulation can be started or stopped. Furthermore, it is advantageous that a very slight loss of paint and cleaning agent occurs, that a rapid paint change is possible in spite of the pumps being outside, that there is simple and rapid access to all the components, and that the effort for the technology and the control structure is very low, as compared with a pigging system.
The fluid supply for a sprayer, according to the invention, can be used to coat a surface with a varnish, for example, preferably in a varnish coating system.
An illustrated embodiment of the invention is shown in the drawings and will be described in greater detail in the following. The drawing shows:
a, b a paint changer having circulation valves,
a, b a two-component mixer having circulation valves, and
In the two-component mixer 510 of the second module 2, as can also be seen in
All the valves in this embodiment shown in
As is furthermore evident from
According to
a and 2b show the paint changer 100 for two paints, with its flow-through paint valves 103 and 104, the circulation valves 105 and 106, as well as the cleaning-agent valve 101 and the air valve 102. The common paint line 82 runs inside the paint changer 100. In this connection, the valves are needle valves and are screwed into the paint changer 100, thereby allowing easy replacement, if necessary.
a and 3b show a two-component mixer 510 for two paints and a hardener, having the release valves 501 and 503 for the paints, and a release valve 505 for the hardener. The circulation valves 502 and 504, the cleaning-agent valves 506 and 507, and the air valves 508 and 509 are also screwed in. The paint line 81 and the hardener line 80 run inside the two-component mixer 510. In this connection, the valves are also needle valves.
In the paint changer 500 of the second module 2, the release valves 501 and 503 are connected with an atomizer 77, through a short line 83, as can also be seen in
According to
In the following, it is described how fluid is supplied to a sprayer 40 according to the invention, having a two-component mixer 510 that is mounted on a robot or automatic varnishing machine. To this end, circulation of the two paints takes place, using a system according to
A fluid supply according to the sprayer shown in
Number | Date | Country | Kind |
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10 2006 048 037.6 | Oct 2006 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2007/058906 | 8/28/2007 | WO | 00 | 12/9/2010 |