EP3283231B1 - Colour change system - Google Patents

Description

The invention relates to a color change system according to the preamble of claim 1.

From a previously filed invention, the DE 10 2015 102 332 A1 has been published, a color change system is known in which fluid pressure-controlled media valves are arranged in a stator, a media inlet arranged in a selection head, which was rotated in front of the media valve outlet of an open media valve, being supplied with a colored medium (lacquer). Furthermore, a flushing line is provided which opens laterally into the media line adjoining the media inlet. Such an arrangement only allows the media line to be flushed when the selection head rests on the stator. Thus, during a flush, the selection head cannot be rotated with respect to the stator and thus there can be no color change.

According to the DE 201 22 759 U1 The media valve consists of a valve closing body and a valve seat in the stator and a fluid-operated tappet in the selection head. For flushing, this is withdrawn so that the media valve closes. A flush valve is then opened to flush the media line. The selection head rests on the stator to keep the media inlet closed.

According to the EP 2 075 073 A1 the media valve is actuated by a plunger fixed to the selection head. Here too, the selection head rests on the stator to keep the media inlet closed when the media line is flushed.

From the WO 01/51216 A2 discloses a color change system with a stator having a plurality of color connections, a media valve being located in each color connection. A selection head can optionally be coupled to one of the paint connections, a plunger connected to an actuating piston in the selection head pushing open the respective media valve, so that a medium can flow from the selected paint connection into a media line in the selection head. A flushing line, which is controlled by an externally operated valve, opens into the media line.

The invention is based on the task of simplifying the control of the media valves and making them safer and of creating a possibility that the media line can be flushed during a color change.

To solve the problem, the invention provides that a check valve is arranged in the media inlet in the immediate connection to the rear of the selection head, which blocks to the back of the selection head and that the flushing line, in which the flushing check valve is located, downstream of the check valve in the media line flows into.

This makes it possible to separate the stator and the selection head from one another during a color change. The media line can still be flushed because the check valve blocks the media inlet.

In order to ensure that the media valve required in each case can only be opened when its media valve outlet is in overlap with the media inlet, the invention further provides that the stator has a fluid connection which in each case has a control channel with the control pressure chambers of the media valves is connected to switch them, that in each of these control channels there is a switching valve mechanically actuated by a cam, and that a cam is attached to the rear of the selection head, which, when the rear of the selection head is placed on the front of the stator opens the switching valve belonging to the media valve, the media valve outlet in the stator of which is connected to the media inlet in the selection head.

In this way it is first achieved that the respective media valve can only be operated when the Stator and the selection head are coupled to each other. Only then does the cam release the switching valve, so that the media valve can be actuated by the fluid pressure at the fluid connection or in the control channel (the control pressure).

Such an actuation can be implemented most simply by the fact that the selection head can be moved perpendicularly to the front of the stator, that the cam is formed on the rear of the selection head and projects vertically from it, that the switching valves are accommodated in the bores opening into the front of the stator, the cam being adapted to immerse in the bores and the bores being oriented to the media valve outlets in the same manner as the cam to the media inlet.

The same goal is achieved in a further embodiment. The invention provides that the media valves are fluid-controlled, that the stator for each media valve has a fluid connection on the front of the stator, which is connected via a control channel to the control pressure chamber of the associated media valve in order to switch it, with a check valve being present in each control channel that blocks towards the fluid connection, and that a collection control channel runs in the selection head, which opens into the rear of the selection head, the opening of the collection control channel being aligned with the fluid connection, the control channel leading to the media valve, the media valve outlet of which is in register with the media inlet.

According to the invention explained so far, a color change can therefore take place relatively quickly. While the selection head is moving to a next position, the media line is flushed in the selection head so that the the next media valve that is fed in does not mix with the remnants in the media line. According to the invention, the conversion time is used for flushing the media line, so that the change between two colors can take place more quickly.

Generally, there is a single color on each of the media valve inlets, so it is actually only necessary to flush the media line in the selection head. Some rarely used colors are only introduced via a single media valve. Its media supply is connected to several paint containers via individually switchable lines. When changing colors, the media valve must also be cleaned.

However, the use of a single media valve for several colors has the advantage that little used colors do not occupy a number of media valves, which are then no longer available for the frequently used colors. A larger number of media valves would have to be made available, which increases the change system and also leads to longer change times, since the selection head has to cover longer distances between the media valves.

The invention is therefore based on the task of setting up a color change system with at least one multi-color media valve to which several colors are connected so that it is possible to clean it after a color change and thereby a color change by adjusting the selection head to other media valves not to hinder time.

To achieve the object, the invention provides that at least one of the media valves has a circulation valve in the Stator is assigned, the outlet of which has a connection to the inlet of the media valve, and that the media valve is designed such that when its control pressure chamber is pressurized, the valve closing body of the circulation valve is connected to an actuating piston which can be acted upon by a fluid pressure and which is arranged within the stator is adjacent to a control pressure chamber, the circulation valve being designed such that it is closed when pressure is applied to its control pressure chamber.

For painting, a control pressure is applied to both control pressure chambers, whereby the media valve opens and the circulation valve closes. Paint that is in contact with the media feed of the media valve is fed through the open media valve into the media line.

To flush the media valve, the control pressure is taken from the control pressure chambers so that the media valve closes and the circulation valve opens. The result of this is that the current paint can first be fed from the media valve back into a container via the switching valve by means of a sliding medium and then the media valve is cleaned by means of a purge air.

Since the media outlet of the media valve is closed, the selection head need not be docked. Rather, it can be brought in one position to another media valve so that the paint supplied there can be used.

This arrangement allows the media valve to be flushed so that it can be used as a multi-color media valve.

To make sure that the circulation valve is closed when the selection head is removed is the Control pressure chamber of the circulation valve connected to the fluid connection via a switchable additional control channel. The additional control channel is switched with the switching valve of the associated media valve. Control channel and additional control channel are thus opened or closed at the same time.

Alternatively, an additional switching valve that can be mechanically actuated by a cam can be provided in the additional control channel. There is an additional cam on the back of the selection head, which opens the additional switching valve when the back of the selection head is placed on the front of the stator.

Furthermore, the system already described above can also be used, in which the control channel runs over the separating surface between the stator and the selection head.

Fig. 1

ein Farbwechselsystem in einer ersten Ausführung und zwar in einer Situation, in der der Stator und der Auswahlkopf miteinander gekoppelt sind, so dass das Schaltventil geöffnet ist,

Fig. 2

die Situation wie in Fig. 1, wobei über einen Fluidanschluss ein Steuerfluid dem Medienventil zugeleitet wird, so dass dieses öffnet,

Fig. 3

die Situation wie in Fig. 1, wobei bei einem geschlossenen Medienventil über eine Spülleitung ein Spülmittel der Medienleitung im Auswahlkopf zugeleitet wird,

Fig. 4

eine Situation, bei der der Stator und der Auswahlkopf voneinander entkoppelt sind und weiterhin über eine Spülleitung der Medienleitung ein Spülmittel zugeleitet wird,

Fig. 5

einen vergrößerten Ausschnitt aus einem Farbwechselsystem in einer zweiten Ausführung und zwar in einer Situation, in der der Stator und der Auswahlkopf miteinander gekoppelt sind,

Fig. 6

eine Situation der zweiten Ausführung, bei der der Stator und der Auswahlkopf voneinander entkoppelt sind und weiterhin über eine Spülleitung der Medienleitung ein Spülmittel zugeleitet wird,

Fig. 7

einen Stator mit einem Medienventil und einem Umlaufventil, wobei der Auswahlkopf am Stator angedockt ist, aber am Fluidanschluss kein Steuerdruck anliegt, so dass sich das Medienventil und das Umlaufventil in ihren Grundstellungen befinden,

Fig. 8

dieselbe Situation wie in Fig. 7, allerdings liegt ein Steuerdruck an, so dass das Medienventil und das Umlaufventil umgeschaltet sind,

Fig. 9

einen Stator mit einem Medienventil und einem Umlaufventil, wobei der Auswahlkopf vom Stator entfernt ist, so dass die Schaltventile geschlossen sind,

Fig. 10

eine vergrößerte Ansicht des Ventilschließkörpers und des Ventilsitzes von einem Medienventil und einem Umlaufventil.

The invention is to be explained in more detail below on the basis of exemplary embodiments. Each shows in a cross section:

Fig. 1

a color change system in a first embodiment, specifically in a situation in which the stator and the selection head are coupled to one another so that the switching valve is open,

Fig. 2

the situation as in Fig. 1 , wherein a control fluid is fed to the media valve via a fluid connection so that it opens,

Fig. 3

the situation as in Fig. 1 , With a closed media valve, a flushing agent is fed to the media line in the selection head via a flushing line,

Fig. 4

a situation in which the stator and the selection head are decoupled from one another and a flushing agent is also supplied to the media line via a flushing line,

Fig. 5

3 shows an enlarged section of a color change system in a second embodiment, specifically in a situation in which the stator and the selection head are coupled to one another,

Fig. 6

a situation of the second embodiment, in which the stator and the selection head are decoupled from one another and furthermore a detergent is supplied to the media line via a flushing line,

Fig. 7

a stator with a media valve and a circulation valve, the selection head being docked on the stator, but there being no control pressure at the fluid connection, so that the media valve and the circulation valve are in their basic positions,

Fig. 8

the same situation as in Fig. 7 , however, there is a control pressure so that the media valve and the circulation valve are switched,

Fig. 9

a stator with a media valve and a circulation valve, the selection head being removed from the stator, so that the switching valves are closed,

Fig. 10

an enlarged view of the valve closing body and the valve seat of a media valve and a circulation valve.

The individual positions of the system are based on the Fig. 1 explained. The same positions appear in the following figures, although different switching situations are shown here.

The color change system consists of a stator 1 and a selection head 2, the z. B. is designed as a rotor.

In the stator 1 there are a large number of media valves 3, each of which is connected to a media feed 4 and whose media valve outlets 5 are located in the front 6 of the stator 1. The media valves 3 are z. B. on a circle, so that by rotating the selection head 2, the media line 7, which opens into a media inlet 8 in the rear 9 of the selection head 2, can be brought to cover with one of the media valve outlets 5.

In the Fig. 1 only one of these media valves 3 is shown. Immediately behind the media inlet 8 is a check valve 10 that opens into the media line 7. Downstream of the media line 7, a flush line 11 opens, in which there is a further flush check valve 12 which opens in the direction of the media line 7.

The media valve 3 is controlled by compressed air (hydraulic control is also possible in principle). For this purpose, the valve closing body is connected to an actuating piston which can be acted upon by a fluid pressure and which is arranged within the stator and which adjoins a control pressure chamber. The actuating piston is not shown here. A suitable version of the media valve with an actuator is in the DE 10 2015 102 332 A1 described: The valve closing body are located within a Stator-formed valve chamber and are displaceable against a valve sealing seat directed into the valve chamber.

Each media valve 3 is embedded in a cartridge which is fastened in a recess on the back of the stator 1. Inside the cartridge is a hollow valve stem, on the head of which the conical valve closing body is attached. This interacts with the likewise conical valve seat, which is formed in the head of the cartridge. The hollow design of the valve stem ensures that the medium is guided in a streamlined manner.

The back of the stator 1 has a fluid or compressed air connection 16 on a ring line 17, which is connected via a control channel 18 to the actuation of the media valves 3. In each of these control channels 18 there is a switching valve 19 which has a dumbbell-shaped closing body 20, one head of the closing body 20 being able to be placed against a sealing ring 21, so that the control channel 18 is closed.

The closing body 20 is actuated by means of a cam 22 which is located on the rear 9 of the selection head 2 and which plunges into a bore 23 in which the switching valve 19 is located.

The Fig. 1 shows that the stator 1 and the selection head 2 are placed against one another, that is to say are coupled, so that the cam 22 dips into the bore 23 and the switching valve 19 opens, so that the control channel 18 is released. However, since there is still no pressure at the compressed air connection 16, the media valve 3 is still closed, ie its valve closing body 24 is still resting on the valve sealing seat 25. The check valve 10 is slightly open, since its valve ball is applied to the valve closing body 24 of the media valve 3.

The Fig. 2 shows the situation in which compressed air is applied to the compressed air connection 16. As a result, the media valve 3 opens, as a result of which the valve closing body 24 moves away from the valve sealing seat 25. The inflowing paint pushes the valve ball of the check valve 10 in front of it and opens the media inlet 8 further. The flush line 11 is blocked by the flush check valve 12.

To change a color, first, as in Fig. 3 shown, the compressed air is switched off again, so that the media valve 3 closes and the check valve 10 also changes into a largely closed position. If a flushing agent is now introduced via the flushing line 11, the flushing check valve 12 opens and the flushing agent flows into the media line 7. An escape via the media inlet 8 is prevented since the latter is sealed off from the outside by means of a sealing ring 26.

If selection head 2 is now withdrawn (see Fig. 4 ), so that the media inlet 8 is opposed to another media valve 3 by its rotation or parallel displacement, the switching valve 19 is first closed because the cam 22 has withdrawn from the bore 23. In addition, the check valve 10 closes, so that the media inlet 8 is closed and the flushing can continue during the movement of the selection head 2 to the next media valve 3. This is associated with a considerable saving of time.

In the 5 and 6 Another embodiment of the invention is shown. In contrast to the embodiment described above, no cam-operated switching valve is provided, rather each media valve 3 is connected to its own control channel 31 with its own fluid connection 32 in the front side 6 of the stator 1. In each fluid connection 32 there is a check valve 33, which closes towards the front 6. In the selection head 2 there is a single collective control channel 34 which is connected to a fluid source (compressed air connection), not shown here. The mouth of the collective control channel 34 is aligned with the fluid connection 32 (compressed air connection), whose control channel 31 leads to the media valve 3, the media valve outlet 5 of which overlaps the media inlet 8 in the selection head 2. An actuation with compressed air opens the media valve 3, so that varnish is conducted into the media line 7 to a spray head, not shown here.

In the Fig. 7 the combination of a media valve 3, which is to be used as a multi-color media valve, with a circulation valve 40 is shown. The connection of the media valve 3 corresponds to that in the 1 to 4 is shown. Next to it is the circulation valve 40, which in principle has the same structure as the media valve. However, the adjusting piston, not shown here, is arranged such that pressurization via an additional control channel 42 leads to the valve closing - and not - as with the media valve, to the valve opening.

The arrangement of media valve 3 and circulation valve 40 shown here serves to clarify the mode of operation. As a rule, so many media valves 3 are required that they are arranged in two circles on the stator 1. In this case, the media valves 3 and 3 are preferably used Circulation valves 40 in different circles - offset from one another - arranged. As a rule, this also makes it necessary to provide two parallel switching valves (19, 41), namely one for the media valve 3 and an additional switching valve 41 for the circulation valve 40, as shown here. In terms of function, however, only one switching valve is required which opens or closes both control channels 18, 42.

As from the Fig. 9 shows, the media valve outlet of the circulation valve 40 has no opening in the front 6 of the stator 1, but rather is connected to the valve chamber of the media valve 3 via a connecting channel 44 within the stator 1.

In the in Fig. 7 shown position of stator 1 and selection head 2, the additional switching valve 41 is actuated by an additional cam 45 on the selection head 2, so that it is open. However, there is no pressure at the fluid connection 16. As a result, the media valve 3 is closed and the circulation valve 40 is open. There is thus a continuous connection between the media valve 3 and the circulation valve 40 through the connecting channel 44, which - as will be explained further below - can be used for flushing.

In principle, the additional control channel 42 to the circulation valve 40 can also be controlled by the switching valve 19 of the media valve 3, so that the additional switching valve 41 shown for the circulation valve 40 can be dispensed with.

The Fig. 8 shows the same situation as in Fig. 7 . However, here a control pressure is applied to the fluid connection 16, which causes the media valve 3 to open and the circulation valve 40 to close.

A medium that rests on the media feed 4 of the media valve can, as in connection with the 1 to 4 described, via the open media valve 3 into the media line 7 and further to a consumption (spray gun). There is no return of the medium via the circulation valve 40, since this is closed.

Fig. 9 shows the situation with a color change. The selection head 2 is removed from the stator 1 and can thus be rotated into a new position so that its media inlet 8 can be moved to the media valve outlet of another media valve.

Since the cams 22, 45 are also removed from the switching valves 19, 41, they are closed, so that regardless of a pressurization at the fluid connection 16, which may be necessary to open the other media valves, the media valve 3 shown is closed and the circulation valve 40 is open.

This allows the two valves to be flushed. For this purpose, a so-called sliding medium is first inserted into the media feed 4 of the media valve, which pushes the current color out of the media valve 3 and the circulation valve 40, and then, alternately, flushing medium and air are fed in around the media valve, the connecting channel 44 and the circulation valve from To remove paint residues. Then it is possible to apply a new paint color via the media feed 4 of the media valve 3.

This flushing process takes place while the system as a whole continues to work and, if necessary, paint is discharged from another media valve.

In order to carefully clean the area of the media valve 3 around the valve closing body 24 and the valve sealing seat 25, in particular - like that Fig. 10 shows - provided that the valve stem has a hollow channel 50 which ends in front of the valve closing body 24 and which has lateral exits 51.

The head dips into a sleeve 52, in which the valve sealing seat 25 of the media valve 3 is formed and in the outer lateral surface of which a circumferential groove runs. Since the lateral surface rests on the wall of a media valve receiving bore in the stator 1, an annular channel 53 is created which is connected to the hollow channel 50 via a transverse bore 54 in the sleeve 52.

The transverse bore 54 is located at the level of the lateral outputs 51 of the valve closing body 24 when the latter is in a closed position.

The connecting channel 44 opens into the annular channel 53 opposite the transverse bore 54.

The air or the flushing medium which emerges from the side outlets 51 is therefore forced to flow around the outside of the valve closing body 24 in order to reach the annular channel 53 via the transverse bore 54 and to flow from there in the direction of the connecting channel 44 can. This opposite arrangement of the connecting channel 44 and the transverse bore 54 ensures that the valve closing body 24 is cleaned on all sides. <b> List of reference symbols </b> 1 stator 31 Control channel 2nd Selection header 32 Fluid connection 3rd Media valves 33 check valve 4th Media feed 34 Collective control channel 5 Media valve outlets 40 Circulation valve 6 Front 41 Auxiliary switching valve 7 Media management 42 Additional control channel 8th Media admission 9 back 44 Connecting channel 10th Check valve 45 cam 11 Flushing line 50 Hollow channel 12th Flush check valve 51 Exits 52 Sleeve 16 Fluid connection 53 Ring channel 17th Loop 54 Cross hole 18th Control channel 19th Switching valve 20 Closing body 21 Sealing ring 22 cam 23 drilling 24th Valve closing body 25th Valve sealing seat 26 Sealing ring

Claims (9)

1. A colour change system with a stator (1) comprising a front side, the stator having a plurality of media valves (3) the inlets of which are connected each to a media supply (4) and the outlets (5) of which feed into the front side of the stator (1), wherein each media valve (3) within a valve chamber formed in the stator comprises a valve closing body (24), which is movable against a valve sealing seat (25) pointing into the valve chamber, wherein the valve closing body is connected to a control piston arranged within the stator and subjectable to fluid pressure, the control piston being adjacent to a control pressure chamber, and with a selection head (2) arranged upstream of the front side of the stator (1), which is rotatable about an axis extending vertically to the stator front side and/or is movable in parallel to the stator front side, wherein the selection head (2) comprises a media inlet (8) on its back facing the stator front side, which by a rotation and/or a move of the selection head (2) can be brought to overlap with one of the media valve outlets (5), and wherein the selection head (2) comprises a media line (7), which connects the media inlet (8) to a media discharge of the system, wherein a rinsing line (11) feeds into the media line (7), the rinsing line containing a rinsing non-return valve (12) opening in direction of the media line (7), characterised in that a blocking non-return valve (10) is arranged in the media inlet (8) in direct connection to the back of the selection head (2), which blocks in direction of the back of the selection head (2), and in that the rinsing line (11) containing the rinsing non-return valve (12) feeds into the media line (7) downstream of the blocking non-return valve (10).
2. The colour-change system according to claim 1, characterised in that the stator (1) comprises a fluid port (16), which is connected via respective control channels (18) to the control pressure chambers of the media valves (3), in order to switch the same, in that a switching valve (19) mechanically operable by a cam is present in each of these control channels (18), and in that the back of the selection head (2) has a cam (22) attached to it, which when the back of the selection head is brought into contact with the front side of the stator, the switching valve (19) opens, which belongs to the media valve (3), the media valve outlet (5) of which in the stator is connected to the media inlet (8) in the selection head (2).
3. The colour-change system according to claim 2, characterised in that the selection head (2) is movable vertically to the stator front side, in that the cam (22) is formed on the back of the selection head (2) and vertically protrudes from the same, in that the switching valves (19) are accommodated in bores (23) feeding into the front side of the stator, wherein the cam (22) is adapted to plunge into the bores, and in that the bores are each oriented in the same way to the media valve outlets (5) as the cam (22) is to the media inlet (8).
4. The colour-change system according to claim 1, characterised in that the stator (1) has, for each media valve (3), a fluid port (32) on its front side (6), which is connected via a control channel (31) to the control pressure chamber of the respective media valve (3) in order to switch the same, wherein each control channel (31) contains a non-return valve (33), which blocks in direction of the fluid port (32), and in that a collecting control channel (34) extends in the selection head (2), which feeds into the back of the selection head (2), wherein the mouth of the collecting control channel (34) is aligned with the fluid port (32), the control channel (31) of which leads to the media valve (3), the media valve outlet (5) of which overlaps with the media inlet (8).
5. The colour-change system according to one of the preceding claims, characterised in that at least one of the media valves (3) has a circulation valve (40) in the stator (1) associated with it, the outlet of which has a connection to the inlet of the media valve (3), and in that the media valve (3) is configured such that it is open when its control pressure chamber is pressurised, in that the valve closing body of the circulation valve (40) is connected to a control piston arranged within the stator (1) and subjectable to fluid pressure, the control piston being adjacent to a control pressure chamber, wherein the circulation valve (40) is configured such that it is closed when its control pressure chamber is pressurised.
6. The colour-change system according to claim 5, characterised in that the control pressure chamber of the circulation valve (40) is connected to the fluid port (16) via a switchable additional control channel (42) .
7. The colour-change system according to claim 6, characterised in that an additional switching valve (41) is present in the additional control channel (42) .
8. The colour-change system according to claim 7, characterised in that an additional switching valve (41) mechanically operable by a cam (45) is present in the additional control channel (42), and in that an additional cam (45) is attached on the back of the selection head (2), which when the back of the selection head (2) is brought into contact with the front side of the stator (1), the addition switching valve (41) opens which belongs to the circulation valve (40).
9. The colour-change system according to claim 5, characterised in that the stator (1), for each media valve (3), has a fluid port (32) on its front side (6), which is connected via a control channel (31) to the control pressure chamber of the respective media valve (3) in order to switch the same, wherein a non-return valve (33) is present in each control channel (31), which blocks in direction of the fluid port (32), and in that a collecting control channel (34) extends in the selection head (2), which feeds into the back of the selection head (2), wherein the mouth of the collecting control channel (34) is aligned with the fluid port (32), the control channel (31) of which leads to the media valve (3), the media valve outlet (5) of which overlaps with the media inlet (8), and in that an additional control channel (42) branches off from the control channel (31) of at least one of the media valves (3) in direction of the circulation valve (40) .

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