EP2929944A1 - Dye spraying device - Google Patents

Abstract

The invention relates to a paint spraying device (1) comprising a spray head (3) discharging an amount of paint via a needle valve and a paint delivery line (20) leading to the spray head (3), the ink discharge line (20) being a pressure reducer / pressure regulator (40) controlling the ink discharge pressure. upstream, which keeps the pressure in the ink discharge line (20) to the spray head (3) is substantially constant.

Description

The invention relates to a paint spraying device according to the preamble of claim 1.

There are a variety of air-driven paint sprayers in the prior art which typically include a paint reservoir, an air flow generator, such as a compressor or blower, and a spray gun.

In the so-called HVLP system (high-volume, low pressure), the paint is atomized by means of an air blower through a high air volume flow at low pressure on a spray head. The color is provided to the spray head either by a conveying air pressure or otherwise. The amount of ink delivered is usually controlled by a needle valve and a trigger mechanism. The air blower and paint supply are housed either in the gun unit or, alternatively, individually or collectively in a base station. Such HVLP sputtering is, for example, in the US 2011/0073677 A1 called. A portable sprayer with control unit, paint spray lance as well as spray head and separate paint reservoir is in the WO 2011/038712 A1 described.

In order to promote the color of a remote from a paint spray gun paint reservoir for spray gun, considerable pressures are necessary especially for higher-viscous colors. The required delivery pressure is particularly associated with the line length used and their cross-section. The spraying on the spray head itself, however, should be done with a reasonably lower pressure to avoid an uncontrolled color leakage, called "spitting" when opening a needle valve on the spray head. If this is not realized results in a non-uniform application of ink due to fluctuating discharge amounts of atomizable paint on the paint spray head. In the prior art, this effect is avoided by switching on and off the color promotion according to the amount of ink to be dispensed. However, this requires complex and short-term switching operations, which make the corresponding equipment complicated, prone to failure and expensive.

The invention has for its object to provide a paint spraying device that produces the most uniform application of paint with economically improved construction.

This object is achieved on the basis of a paint spraying device according to the preamble of claim 1 by the characterizing features of claim 1. Advantageous and expedient developments of the paint spraying device are specified in the subclaims.

According to the invention, this object is achieved in that a pressure reducer or a pressure regulator is connected upstream of the paint delivery line, which supplies a spray head with paint, to a spray gun or the like in such a way that the color print in the color delivery line is kept substantially constant.

To the high-viscosity paint by, for example, about 7 m To pump long delivery hose, pump pressures of up to 8 bar are often required. This high pump pressure must be reduced to a very low level on the spray head, for which a special pressure reducer is provided. This is particularly critical when the spraying process is interrupted, and thereby the high delivery pressure builds up throughout the system, as there is no continuous color removal and concomitant pressure reduction. If the color pressure applied to the spray head is kept as constant as possible at a lower value, a "spitting" of the gun is reliably prevented.

For this purpose, the pressure reducer is subordinated according to the invention a Farbzuflussleitung and upstream of a color delivery line.

For the purposes of the invention, a paint feed line is to be understood as meaning a line which is provided for supplying ink to the input of a paint dispensing device, for example to a spray gun or a paint input line of such a device. In this case, such a paint supply line lengths up to 8 m have. For the purposes of the invention, a paint feed line can be understood, for example, as a paint hose.

For the purposes of the invention, a paint delivery line is to be understood as meaning a line which is provided for supplying ink to the outlet of an ink dispenser, for example a spray gun. For the purposes of the invention, the ink discharge line is disposed within a paint dispenser, such as a spray gun.

In a preferred embodiment, it is provided that the pressure reducer / pressure regulator comprises a color input line for guiding high-pressure ink and a color output line for guiding color at substantially constant lower pressure. The two lines are connected to each other via a pressure reducer housing, wherein the housing has a preferably annular or circular interior having a diaphragm plate arranged therein. The diaphragm plate has means which, depending on the pressure, change the cross section of the color input line or the cross section of the access to the preferably annular interior in the sense of throttling in the color input line.

Cross-sectional changes on a pressurized color input line cause pressure reduction according to known physical principles (force per area, hydrostatic paradox). The provision of appropriate means for changing the cross section of a color input line to a pressure reducer housing by means arranged in the same housing diaphragm plate has the advantage that by simple mechanical means a feedback of the applied pressure in the housing on the input cross section of the color input line, and thus no additional control loops necessary are.

In a further preferred embodiment, it is provided that the diaphragm plate is pressurized with an annular pressure diaphragm on its rear side facing away from the ink supply line by a, preferably adjustable in bias voltage spring or the like.

The pressurization of the diaphragm plate on the side facing away from the ink causes a precise specification of the aspired interior pressure and allows, if the bias voltage is additionally designed to change the interior pressure according to the required parameters.

In a moreover expedient embodiment, it is provided that a front side of the diaphragm plate to be conveyed is connected via a piston rod to a closure element, in particular a cross slide for the cross section of the color input line, the closure element corresponding to the cross section of the color input line corresponding to a deformation of the membrane and a associated movement of the diaphragm plate changed, or for Reduces pressure reduction.

The direct coupling of the diaphragm plate via a piston rod with a closure element controls, depending on the internal pressure of the interior of the cross section of the color input lines and thereby causes, according to the known physical principles that only one of the open cross-sectional area corresponding proportion of the pressure in the color input line is transmitted to the interior ,

A related expedient development provides that the position of the closure element is adjustable relative to the piston rod, in particular via a thread adjustable. Depending on the viscosity characteristics of the ink, it may be necessary to change the ratio of the internal pressure to the opened cross-section of the paint input line, which is caused by a relative change in position of the closure element to the piston rod. Thus, for example, an increased internal pressure and thus an increased pressure on the paint outlet line at the pressure reducer / pressure regulator can be effected.

It is also expedient that the diaphragm plate is formed as a screen-shaped element with integrally formed piston rod and consists of a rigid material and a flexible material relative to the rigid membrane at least partially rests or a membrane is attached to the diaphragm plate, wherein the membrane in the outer region of the diaphragm plate a bendable portion for sealing the annular interior with respect to a housing cover is formed.

The membrane plate, which acts together with the membrane as a pressure-receiver for the pressure in the interior of the housing, is held in its edge region by the corresponding membrane movable without causing a significant influence or even change the pressure-force relationships in the interior the membrane unit of diaphragm plate and membrane is required.

In an expedient refinement, it is provided to design the closure element with at least one, preferably two, sealing elements. The sealing elements can be arranged in particular as O-rings in a recess.

A further expedient development provides that in the region of the interior of a raised surface of a raised structure is arranged, the structure as flow deflector or flow collar or the like at least partially surrounds a Farbeinlassöffnung, and a flow for continuous circulation of the color in the interior during operation or cleaning the paint spraying device generated. In this way, it is avoided that in the area of the pressure reducer / pressure regulator color dwells and, if necessary, dries or forms dormant areas which are not exposed to the color flow.

It is further provided that a flexible membrane between a lower housing part of the pressure reducer and a housing cover of the pressure reducer circumferentially fixed, in particular clamped or welded.

The flexible membrane, which is clamped or held in a similar manner between two housing components of the pressure reducer housing, serves as a suspension for the diaphragm plate, which in turn serves the means for varying the cross section of the color input line. In this way, a simple separation of the color area from a rear area, which comprises for example a spring for providing a back pressure, is possible.

It is also expedient provided that the closure element is designed as a slide or valve element with internal channel.

The closure element allows in this embodiment, either a cross-sectional change by direct action on the channel cross-section of the color input line, or a cross-sectional change by relative displacement of two channels to each other, as is realized for example in conventional ball valves or the like.

It is further provided, in an expedient embodiment of the paint spraying device according to the invention to form the pressure reducer as an exchangeable module, in particular as a module with screw and / or quick connector on the color input line and / or color output line. The pressure reducer, which is the subject of contamination or drying of paint by its movable components and possibly narrow cross-sections, can be designed as a replaceable assembly, in particular as a disposable part, so as not to reduce the life of the entire paint spraying device.

Moreover, it is preferably provided that the diaphragm plate and / or the membrane is formed as a one-piece component, in particular as an injection-molded component, wherein in particular rigid components thick-walled and flexible components are formed thin-walled and / or the membrane in its outer edge region a bulge or a clamping edge having.

The diaphragm plate and the diaphragm may be made in one piece (mainly plastic) e.g. by means of plastic injection molding process. Elastic parts are made thin-walled, rigid parts are made thick-walled, and thereby obtained in each case the desired property and elasticity. Threads can also be molded. Preferably, the outermost membrane periphery is made thicker to stabilize the attachment / clamping in the housing. In addition, the membrane can be impressed in cross-section a ripple, which defines the defined deformation range defined.

Besides the spraying of paint are too Paint application device for applying paint to a substrate, such as paint rollers, paint brush, color pad or the like known, the paint application device is supplied via a paint reservoir by means of a paint pump with paint. According to the invention can also be provided here that a pressure reducer / pressure regulator is arranged according to the embodiments of the present invention description.

For a more detailed explanation of the embodiment according to the invention and the expedient developments exemplary embodiments are shown below.

For the desired color application, a substantially constant color print, in particular usually a reduced pressure to about 0.3 to 0.4 bar, is desirable in order to produce a uniform spray pattern.

figure description

Figur 1

eine Farbsprüheinrichtung mit Sprühkopf und Farbdüse im Schnitt sowie zugehörigem Druckminderer/Druckregler,

Figuren 2a bis 2c

einen erfindungsgemäßen Druckminderer in verschiedenen Schließstellungen der Farbzuflussleitung,

Figuren 3

eine Teilansicht auf das Druckminderer-Gehäuse in verschiedenen Ansichten,

Figur 4

eine Farbsprüheinrichtung mit modular aufgebautem Druckminderer/Druckregler als Baugruppe.

Show it:

FIG. 1

a paint spraying device with spray head and paint nozzle in section and associated pressure reducer / pressure regulator,

FIGS. 2a to 2c

a pressure reducer according to the invention in different closed positions of the paint supply line,

Figures 3

a partial view of the pressure reducer housing in different views,

FIG. 4

a paint spraying device with a modular structure Pressure reducer / pressure regulator as an assembly.

Description of the embodiments

The FIG. 1 shows a paint spraying device 1 as a so-called front end 2 of a paint spray gun. Such structures are known from a variety of devices of the applicant. The so-called front end is detachably connected as an assembly which contains the ink-carrying constituents, with another assembly which, for example, carries the fan or the air supply line, whereby flexibilities are generated by exchangeable front ends. The paint spraying device comprises a spray head 3 with a front paint nozzle 4, which is actuated by a needle valve 5 through a trigger 6. The spray head 3 forms by an air cap 7 and an air curtain 8 an atomizer nozzle, which can be opened or closed by the needle head 9 of the needle 10 of the needle valve 5. The system of the spray head 3 is fixed by the union nut 11 and held on the body 12. The needle 10 is withdrawn via the trigger 6 by means of a bolt 13 against a spring 14 and can thus deliver in the form of a paint spray gun paint through the spray head 3.

If the needle valve 5 remains closed, a certain internal pressure builds up in the interior of the ink-carrying components of the paint spraying device 1, that is, in the volume around the needle 10, in the ink discharge line 20 and in the ink dispensing space 21, which in addition to the atomizer effect of the needle valve 5 during reopening Air atomization can leak the paint from the needle valve 5. If this internal pressure is too high, the paint sprayer spits out the first drops of paint, resulting in undesirable results.

Below the spray head 3 is a connection housing 30 for the ink supply and for receiving a pressure reducer / pressure regulator 40 (hereinafter only Pressure reducer) provided.

The pressure reducer 40 comprises a color input line 41, to which the paint supply line 42 is connected via a connection hose. The color input line 41 is tapered at the pressure reducer in its cross section 43, wherein a closure element 44 is arranged at this point.

Adjoining the tapered cross-sectional location 43 is an interior space 50 of the pressure reducer 40, in which in turn a diaphragm plate 51 is arranged, which acts on the closure element 44 via a piston rod 59. The diaphragm plate 51 is laterally circumferentially suspended on a membrane 52 and supported on its rear side 53 against a spring 54.

A fitting in the interior 50 pressure by color is thus on the diaphragm plate 51 and the diaphragm front 55, the diaphragm plate 51 and thus the closure member 44 via the piston rod 59 in the direction of the spring 54 to move until the pressure force of the ink from the interior 50 of the spring force the spring 54 is compensated. At the same time, the closure element 44 closes the cross-section 43 and thus reduces the pressure transfer from the ink feed line 42 via the color input line 41 into the interior space 50. Through this interaction, the pressure in the interior space 50 remains substantially constant.

At the interior 50, the color output line 56 connects, which opens into the color discharge line 20, via which the color is then transferred at a constant, compared to the input side reduced pressure to the ink discharge space 21.

The FIGS. 2a to 2c show the pressure reducer 40 in an isolated sectional view. FIG. 2a shows the opened state, FIG. 2b the state in the middle control operation and Figure 2c the closed state. The components are denoted by the same reference numerals as used in the description FIG. 1 were introduced.

That in the FIGS. 2a to 2c illustrated pressure reducer housing 60 comprises a housing lower part 61 and a housing cover 62. The paint supply line 42 (not shown) is connected via a threaded screw connection 63 as shown in FIG FIG. 1 attached. The pressure reducer 40 is the upper side, connected to the color discharge line 20 in the paint spraying device 1 at its color output line 56 via a quick release 64, in the present case in the form of a positive locking connection.

That in the FIGS. 2a to 2c shown pressure reducer housing 60 includes a pressure regulating device by means of a diaphragm 52 control. For this purpose, a diaphragm plate 51 is arranged in a lateral housing projection 65 with a cup-shaped housing cover 62, which comprises an annular pressure membrane 52. The annular pressure membrane 52 is secured between the housing extension 65 and the cup-shaped housing cover 62 with a clamp 66. The diaphragm plate 51 with annular pressure diaphragm 52 thus defines an annular interior space 50 through which the paint to be conveyed flows.

The diaphragm plate 51 comprises, on its front side 55 facing the inner space 50, a piston rod 59 which extends transversely to the direction of flow 70 of the ink. The piston rod 59 is connected on its side facing away from the diaphragm plate 51 with a closure element 44 in a receiving bore 71. The closure element 44 is designed as a kind of cross slide and movably mounted within the pressure reducer housing 60 in the transverse direction to the flow direction 70. The storage and sealing in the transverse direction via two O-rings 72, 73 which surround the cylindrical part of the closure member 44. Through the receiving bore 71 with internal threaded rod 75 of the piston rod 59, the initial position of the closure member 44 relative to the piston rod 59 can be changed. As a result, the distance between diaphragm plate 51 and closure element 44 is changed in the sense of a change in a throttling for the color flow.

The cylindrical body of the closure element 44 serves to change the inlet cross section 43 of the color input line 41 to the annular inner space 50 of the housing extension 65 of the pressure reducer housing 60.

The in the FIGS. 2a to 2c shown movement of the piston rod 59 causes opening and closing of the cross section 43. The FIG. 2a shows a kind of open position that FIG. 2b a position of the closure element 44 at the beginning of the closed position and Figure 2c the closed position of the cross section 43. In this position, the O-rings 72, 73 via the closure member 44 seal the interior 50 relative to the color input line 41 completely.

Due to the transverse movement of the piston rod 59, the diaphragm plate 51 is moved from the open position into FIG. 2a to the closed position of the cross section 43 in the Figure 2c emotional. To generate a back pressure and thus to carry out the opposite movement, the cup-shaped housing cover 62 has a helical spring 54, which presses the diaphragm plate 51 and thus the annular diaphragm 52 in the opposite direction, that is in the direction of the closure member 44. In this case, the coil spring can be made variable in their bias.

The FIG. 2a shows within the housing projection 65, a first stop 80, on which the diaphragm plate 51 is laterally supported in its one end position and a second end stop 81 in Figure 2c on the pot-shaped housing cover 62nd

In FIG. 3 the lower housing part 61 is again shown separately with the housing projection 65. The FIG. 3 shows the housing projection 65 without the diaphragm plate. In particular, a U-shaped web in the form of a flow collar 90 can be seen, which partially surrounds the inlet opening 91, in which the closure element 44 is movably arranged, the color input line 41. Upon entry of the color from the color input line 41 into the annular one Interior 50 through the inlet opening 91, the color is deflected by the U-shaped flow collar 90 and passes from the annular interior 50 into the opening 93 to the color output line 56. The U-shape of the flow collar 90 within the pressure reducer 40 also serves to clean (for Example with water) to generate turbulence, so that the entire pressure reducer is flushed through, at the same time thus avoided in operation with color fluidic dead spaces in which, for example, color crumbs could settle.

FIG. 4 shows an example of the construction of the pressure reducer 40 as an assembly 96, which can be attached to a front end 2. In this way, the pressure reducer is interchangeable and can be adapted to the physical properties of the color to be processed, or easily replaced in the event of contamination.

• Die Farbsprüheinrichtung wird mit einem reduzierten Druck von ca. 0,3 bis 0,4 bar betrieben. Die Farbe wird über einen zum Beispiel ca. 7 m langen Förderschlauch oder Anschlussschlauch der Farbsprüheinrichtung zugeführt. Es ist ein hoher Pumpendruck am Farbreservoir (nicht dargestellt) von zum Beispiel 8 bar notwendig, um die hochviskose Farbe durch diesen langen Förderschlauch 98 zu pumpen.

For the operation of the pressure reducer:

• The paint spraying device is operated at a reduced pressure of about 0.3 to 0.4 bar. The paint is supplied to the paint spraying device via a delivery hose or connection hose, for example, about 7 m long. It is a high pump pressure at the ink reservoir (not shown) of, for example, 8 bar necessary to pump the high viscosity paint through this long delivery hose 98.

The pressure reducer according to the invention now serves to reduce the pressure prevailing in the ink supply line 42 high pressure of up to 8 bar to a required in the color discharge line 20 lower pressure of about 0.3 to 0.4 bar. This is necessary in particular in the event of an interruption of the ink delivery, for example during a work break, in order to ensure the inking quality.

In contrast to arrangements which, in addition to the pressure reduction or pressure control, comprise a color return line in a color supply, to a dynamic pressure over circulating color To regulate, the present invention, in particular with only one color flow line and only one color output line.

Under a needle valve according to the invention are all types of needle valves, including those with a, deviating from a rotationally symmetrical head shape needle head, as they are known from inventions of the Applicant to understand.

Under an annular or circular interior in the context of the invention, the interior is to be understood, which forms annularly substantially around a color entry around. It is irrelevant whether a ring is actually formed with centric lying interruption of the room, or whether there is a circular cavity with befindlichem in the center inlet channel without interruption.

The invention is not limited to the illustrated and described embodiment. On the contrary, it also encompasses all variants within the scope of the protective rights claims.

LIST OF REFERENCE NUMBERS

1

paint spraying

2

frontend

3

spray nozzle

4

paint nozzle

5

needle valve

6

deduction

7

air cap

8th

air backdrop

9

pinhead

10

needle

11

Nut

12

corpus

13

bolt

20

Color discharge line

21

Color output space

30

connection housing

40

Reducer / pressure regulator

41

Color input line

42

Color inflow line

43

cross-section

44

closure element

50

inner space

51

diaphragm plate

52

membrane

53

back

54

feather

55

front

56

Color output line

59

piston rod

60

casing

61

Housing bottom

62

housing cover

63

Threaded screw connection

64

quick release

65

housing extension

66

clamping

70

Flow direction

71

Receiving bore with internal thread

72

O-ring

73

O-ring

75

threaded rod

80

attack

90

flow collar

91

inlet opening

93

opening

96

module

Claims (15)

Paint spraying device (1), With a spray head (3) dispensing a quantity of paint via a needle valve (5) to a spray gun As well as a color delivery line (20) leading to the spray head (3), characterized in that The ink discharge line (20) is preceded by a pressure reducer / pressure regulator (40) regulating the ink discharge pressure, • wherein the pressure in the ink discharge line (20) by means of the pressure reducer / pressure regulator (40) is kept substantially constant. Paint spraying device according to claim 1, characterized in that • the pressure reducer (40) a color input line (41) for guiding high-pressure ink • and a color output line (56) for guiding color at substantially constant lower pressure, • which are connected to each other via a pressure reducer housing (60). Paint spraying device according to claim 2, characterized in that • in the pressure reducer housing (60) In a preferably annular interior (50) A diaphragm plate (51) or membrane carrier is provided, • the pressure-dependent the cross-section (43) of the color input line (41) or the cross-section (43) of access to the preferably annular or circular space (50) with diaphragm plate (51) in the sense of throttling in the color input line (41) changed. Paint spraying device according to claim 1, 2 or 3, characterized in that • The diaphragm plate (51) with an annular pressure diaphragm (52) on the back, on its side facing away from the ink supply line (53) by a, preferably in the bias variable spring / coil spring (54) or the like is pressurized. Paint spraying device according to claim 1, 2 or 3, characterized in that A front side (55) of the diaphragm plate (51) which is pressurized by the ink to be conveyed is connected via a piston rod (59) to a closure element (44), in particular a transverse slide (44) for the cross section (43) of the color input line (41), Wherein the closure element (44) reduces the cross-section (43) of the color input line (41) in accordance with a deformation of the membrane (52) and a concomitant movement of the diaphragm plate (51), in particular reduced to the closure. Paint spraying device according to one of the preceding claims, characterized • that a position of the closure element (44) relative to the piston rod (59) is variable, in particular via a thread (75) is adjustable, Wherein preferably the cross slide (44) has a receiving bore (71) with internal threads for the piston rod (59), • wherein preferably the piston rod (59) is formed at least in sections longitudinally as a threaded rod. Paint spraying device according to one of the preceding claims, characterized • that the diaphragm plate is designed as a screen-shaped element with integrally formed piston rod • and made of a rigid material • and at least partially accommodates a flexible membrane opposite the rigid material • or a membrane is attached to it, • in such a way that the membrane is outside of the Membrane disc forms a flexible portion for sealing the particular annular space relative to a housing cover. Paint spraying device according to one of the preceding claims, characterized • that the closure element comprises at least one, preferably two sealing elements, wherein the sealing elements are arranged in particular as O-rings in a recess. Paint spraying device according to one of the preceding claims, characterized That in the region of the interior a structure which rises in a raised manner from a surface, in particular a flow deflector or flow collar, is arranged, Wherein the structure at least partially surrounds a paint inlet opening and generates a flow for continuously circulating the paint in the interior during operation of the paint spraying device. Paint spraying device according to one of the preceding claims, characterized • That a flexible membrane between a lower housing part of the pressure reducer and a housing cover of the pressure reducer fixed circumferentially, in particular clamped or welded. Paint spraying device according to one of the preceding claims, characterized • that the closure element is designed as a slide or valve element with internal channel. Paint spraying device according to one of the preceding claims, characterized • that the pressure reducer is designed as a replaceable module, in particular as a screw-type module and / or quick connector on the color input line and / or color output line. Paint spraying device according to one of the preceding claims, characterized • that the diaphragm plate and / or the membrane is formed as a one-piece component, in particular as an injection molded component, in particular rigid components thick-walled and flexible components are formed thin-walled and / or the membrane has in its outer edge region a bulge or a clamping edge. Paint spraying device according to one of the preceding claims, characterized
that only one color supply line and / or only one color delivery line is formed. Paint application device for applying paint to a substrate, for example a paint roller, paint brush, color pad or the like, the paint application device being supplied with ink via a paint reservoir by means of a paint pump, characterized • that a pressure reducer / pressure regulator is arranged according to the embodiments of any one of the preceding claims.

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