EP2189225A1 - Colour spray gun with beam distortion - Google Patents

Abstract

The gun (1) has an airflow gate arranged in front of an air cap (3) in airflow direction in a region of a paint dispensing device. An airflow director (61) comprises an air passage cross section that is larger than another air passage cross section of another airflow director (62). The airflow gate has a centrically arranged paint passage orifice that cooperates with a valve needle as a paint metering device. The air cap is pierced centrically by the paint metering device. The air directors are designed as separate individual elements which are fastened to the air cap.

Description

The invention relates to a paint spray gun with color beam deflection according to the preamble of claim 1.

Spray guns find a variety of applications in the craft sector. Both in professional painters and Lackierbereich as well as home improvement and semi-professional application spray guns are known in a large number of configurations.

An advanced type of spray gun are the devices of the so-called HVLP class. The HVLP technology makes use of a large volume of air available at a relatively low working pressure (H igh V olume L ow P reassure).

Basically, the prevailing principle of spray guns always refers back to the mechanism that a small defined amount of color from a color dispenser, usually a needle valve and radially symmetrical flows around an air jet, which entrains the color and produces a fine paint mist, a so-called spray. A spray or color jet is usually also formed radially symmetrical, which is often perceived as a disadvantage in the coating of flat surfaces.

From the prior art, for example from the EP 1 880 771 A1 Spray guns are known which allow over a defined arrangement of an air cap in front of a Luftstromkulisse an adjustment of the ink jet geometry in that additional air horns in the form of air horns are traversed on the air cap with air, wherein the air flowing through the air horn is directed to the color jet. The thus laterally on the Directional air impinging on the jet of color produces a flat jet from the hitherto radially symmetric color jet, which enables a much more homogeneous application of paint and thus more efficient working for the treatment of surfaces.

A disadvantage of such paint spray guns that extreme hold positions such as vertically up or down must be taken in particular in hard to reach places or on ceilings and floors in order to achieve a decent result.

In the DE 32 48 578 A1 a development of a flat jet-generating paint spray gun is presented. An advantage of this development is that the flat jet can be additionally deflected by provided in the air funnels Reduzierventile perpendicular to the spray direction and perpendicular to the flat beam extension by the air flow through the air horn is throttled on one side by cross-sectional constriction.

However, such paint spray guns have an increased susceptibility to interference, since the rather filigree openings and fine mechanical trainees Reduzierventile by color particles, which inevitably accumulate over time in the air funnels, can stick together, and thus are impaired in their function. In addition, in HVLP devices, the air flow generating fan units are usually set to a continuously constant air flow, not least because this air flow must be dissipated for operational cooling of the fan. A cross-sectional constriction in the specified air flow therefore has a change in the deliverable air flow result, which in turn causes an air backlog in the gun body.

Based on the prior art, the present invention has now the object to provide a spray gun with color beam deflection available, which avoids the disadvantages of the prior art.

According to the invention, this object is achieved on the basis of a paint spray gun according to the preamble of independent claim 1 by the characterizing features of patent claim 1.

Advantageous developments and expedient refinements are specified in the subclaims.

The paint spray gun with color jet deflection according to the invention comprises a spray gun body with ink reservoir, a paint dispenser, a Luftstromkulisse with flow openings, an air cap with flow openings and a first flowed through air horn or air horn with a first air passage cross-section and at least a second flow-through air horn or air horn with a second air passage cross-section, said the Luftstromkulisse is arranged in the air flow direction in front of the air cap in the region of the ink dispenser. In the present case, the invention is characterized in that the first air passage cross-section is formed larger than at least the second air passage cross-section.

Based on the prior art, the ink dispenser may be formed as a complete valve assembly, but it may also include only one color delivery channel with a movable needle, which then forms a needle valve assembly in combination with the air flow gate. The air flow direction corresponds to the longitudinal axis of the upper gun body and gives essentially the exit direction of the sprayed color jet. The ratio of the air passage cross sections of the air horns to each other offers the possibility to promote different amounts of air, since at a defined air flow inside the gun body and the resulting defined internal pressure of the free cross section of a passage area decides on the passing air quantity.

In an advantageous development of the paint spray gun, it is provided that in a first air funnel the first air passage cross section is formed from a double channel system and in a second air funnel the second air passage cross section is formed from a single channel.

Air ducts offer little resistance when possible edge-free design of the guided air flow, so that turbulence and vortex formations are avoided in the air flow. Air ducts can be easily realized by manipulators or through holes especially in the manufacturing process of the air horn as an injection molded part.

In a further embodiment of the paint spray gun is provided that an elongated longitudinal axis of the first air passage cross section with an elongated longitudinal axis of the second air passage cross section with a sprayed ink jet substantially forms an intersection.

If one looks at the exit direction of the air flows from the air funnels, the extended direction axes and the sprayed color jet meet essentially at an intersection point. To form a flat jet, the effect of air currents on the color jet is to be designed such that at least one subcomponent the direction of flow of a shaping air jet is not in the spray direction. The color jet thus experiences a transverse force, which influences the color jet geometry, in particular generates a flat jet.

In a further expedient embodiment of the paint spray gun, a preferably centrally arranged ink passage opening, in particular in cooperation with a valve needle as Farbdosiervorrichtung is provided in the air flow scenery.

The arranged at the front end of the gun body Luftstromkulisse can act as part of a Farbdosiervorrichtung via a centrally disposed paint passage by a arranged in the gun body needle element, which is on a control element, preferably a trigger guard on the handle of the spray gun, movable, formed with the paint passage opening a needle valve.

In a further developed embodiment of the paint spray gun, the air cap is preferably pierced centrally by a Farbdosiervorrichtung.

The Farbdosietvorrichtung, which is preferably designed as a needle valve assembly can be formed either by the air flow backdrop or otherwise formed components of the paint spray gun according to the invention. To avoid contamination in the airways during operation, it is advantageous to pass the color beam as possible after its generation by the nebulization of the metered paint by passing air, not by components of the paint spray gun, but the Farbdosiervorrichtung for generating the color beam through, on lead the air cap resting on the front end of the paint spray gun.

In an expedient development of the paint spray gun according to the invention, it is provided that the air funnels are designed as separate individual elements which can be fastened to the air cap and are preferably attachable.

About a separate training as attachable items, the air horns are much easier, for example, produced by injection molding. They can be produced as air funnel forming, mutually foldable half-shells, which are connected by means of a film hinge, and which are fixed by fastening to the air cap in the attachment point to each other.

In an advantageous embodiment of the paint spray gun is provided that the air cap is rotatable relative to the Luftstromkulisse formed around the air flow direction or about a longitudinal axis of the gun body and / or the Luftstromkulisse inserted in the gun body, preferably formed using defined insertion positions.

A rotatable position of the air cap relative to the Luftstromkulisse allows the realization of different coverage positions of the two parts one above the other. In this case, different air guiding tasks can be achieved by different cover positions of the respective air flow openings, which corresponds for example to a switchover between a radially symmetrical omnidirectional jet and a flat jet.

However, one possible embodiment of this possibility of variation of the air-guiding tasks to be implemented would also be that position-fixed exchangeable air caps are provided for different air-guiding tasks.

In addition or as an alternative to the rotatable position of the air cap relative to the airflow backdrop, the airflow scenery may also be designed to be removable from the gun body. A removable Luftstromkulisse can be used in a rotated relative to the pistol body position back into the body, so that the Luftdurchströmöffnungen the Luftstromkulisse can be variably arranged with respect to the gun body to solve various air ducting tasks.

It is expedient to equip the gate and the body with mutually acting latching elements, so that the possible positions of the Luftstromkulisse are defined. Such locking elements can also be provided between the air cap and Luftstromkulisse.

Also, a removable Luftstromkulisse, which is interchangeable for different air management tasks against other scenes, can be provided.

In an advantageous development of the air flow scenery, the air flow scenery comprises a color passage opening, at least one air passage opening on a first radius around the color passage opening and at least one second air passage opening on a second radius around the color passage opening.

The defined arrangement of the air passage openings radially symmetrical about a color passage opening offers for the solution of defined air management tasks from a radially symmetric symmetry system comprising different defined coverage conditions of the flow openings in the air flow scenery and in the air cap.

In a further advantageous embodiment of Luftstromkulisse is provided that at least one air passage opening comprises both the first radius around the color passage opening and the second radius around the color passage opening.

Such a trained air passage opening in the air flow scenery offers the opportunity to provide an air flow with an enlarged cross-section available, which can be limited only by the downstream in the flow direction air cap in its cross section. In principle, embodiments are also conceivable in which the enlarged air passage opening between the first radius and the second radius is interrupted by a web, for example, but both resulting openings are formed radially circumferentially at the same position.

In a further embodiment of the air flow backdrop, at least one forced ventilation opening between two working air openings is provided on the first radius around the color passage opening, and at least one working air opening is provided on the second radius between two forced ventilation openings.

As a working air opening those passage openings are referred to, which act actively on the generated color beam, on the one hand for generating a flat jet, on the other hand, for oblique deflection from the color exit direction for the operation of the oblique spraying.

Forced air vents allow even with fully or partially closed working air openings a constant air flow rate of the blower, so that damage to the blower, for example by backwater and thus reduced cooling, are avoided. The forced ventilation openings do not affect the color jet or insignificant, but ensure that vented areas of contamination and paint deposits are kept free during operation of the spray gun.

In a further variant of the paint spray gun according to the invention, the air flow scenery has an inner air throughflow area around a preferably central color passage opening.

A throughflow area surrounding the color passage opening is necessary for the formation of a defined symmetrical color jet, since the most uniform laminar airflow at the front color outlet opening must entrain and atomize the exiting paint. In this case, unevenness or depressions in the surface of the air stream backdrop have proven to be advantageous, which improve the flow behavior of the air flowing past.

In an expedient development of the paint spray gun, the air cap has a centric flow opening.

In addition to the color jet, the air cap must also guide the amount of air carrying the jet of color. In the case of piercing the air cap through the Farbdosiervorrichtung the air flow, which forms the jet of color must be performed to Farbdosiervorrichtung. The air passage gap forming between the centric flow opening of the air cap and the air flow gate is also referred to as an annular gap.

In a further expedient development of the paint spray gun is provided that the air cap on a first radius at least one air passage opening, preferably four pairs Having mirror-symmetrically arranged air passage openings.

Such air passage openings are provided as air outlet openings to ensure a constant air flow volume for the round jet operation. On the back of the air cap, the air outlet openings can be developed so that you can communicate with a working air opening of the first or second radius.

In a further expedient development of the paint spray gun is provided that the first air horn and the second air horn are arranged opposite one another, preferably radially symmetrically between further air passage openings.

Opposing air funnels can transform the emerging color theft either by acting on both sides of the air streams to a flat jet, or provide in asymmetric operation, preferably in one-sided operation, a color beam deflection of the original color beam direction in an angled direction. The other air passage openings represent air outlet openings for the omnidirectional operation or to avoid dirt deposits in the airways.

In a further advantageous embodiment of the paint spray gun, at least one air passage opening, preferably at least one air funnel, is to be brought onto the air cap with at least one air passage opening on a radius around the paint passage opening on the air flow curtain in such a way that a continuous air passageway is formed.

Such arranged in cover to each other air passage openings offer a variety of combinations of air ducts, which are suitable for solving a variety of air handling tasks, such as the generation of an omnidirectional, a horizontal flat jet, a vertical flat jet and an oblique deflection to the side, up or down.

In the following exemplary embodiments, the basic idea according to the invention will be further explained and clarified on the basis of embodiments.

However, the invention is not limited to the embodiments shown, but rather includes all those embodiments that make use of the inventive idea.

Fig. 1:

Eine Spritzpistole komplett zusammengesetzt.

Fig. 2:

Eine Spritzpistole mit offenem Korpus.

Fig. 3:

Beispiele für eine Spritzpistole im Schrägspritzbetrieb.

Fig. 4:

Eine Luftstromkulisse in Frontalansicht.

Fig. 5:

Eine Luftstromkulisse in perspektivischer Ansicht.

Fig. 6:

Eine Luftkappe in Frontalansicht.

Fig. 7:

Eine Luftkappe in perspektivischer Ansicht.

The figures show:

Fig. 1:

A spray gun completely assembled.

Fig. 2:

A spray gun with an open body.

3:

Examples of a spray gun in the helical spray operation.

4:

An airstream backdrop in frontal view.

Fig. 5:

An airflow backdrop in perspective view.

Fig. 6:

An air cap in frontal view.

Fig. 7:

An air cap in perspective view.

In detail shows FIG. 1 a paint spray gun 1, constructed of a pistol body 2, an air cap 4 behind an air cap 3 and a cap securing the air cap 5 on a thread 6. The paint spray gun 1 further comprises a paint reservoir 7 and an air supply port 8 and a Farbdosierabzug 9. Radialsymmetrisch to the air flow direction 10, which corresponds in principle to the longitudinal axis of the gun body 2 are arranged on the air cap 3, a first air horn 61 and a second air horn 62 in the form of air horns. The paint outlet opening 11, in the present case in the form of a needle valve, is guided through a central air passage opening 60 in the air cap 3, which forms an annular gap together with the air gap for the air flow through the jet producing the jet. Other components covered by the paint spray gun are not or only slightly developed in the present case, so that a detailed description does not take place. The knowledge of the prior art is expressly incorporated.

FIG. 2 shows a paint spray gun 1 with removed cap nut 5, removed air cap 3 and remote air curtain 4. The color dispenser 20 is filled in use with paint from the reservoir 7 and seals with the air gate 4 via a sealing element 21 against the air flow volume 22 in the gun body 2 from. At the lower region of the front opening of the body 2, a latching element 23 is provided, which allows defined locking positions of the air slide to be used. The needle 24 is designed to be movable via the paint metering hood 9 and, in cooperation with the ink passage opening 40 of the air gate 4, provides a paint metering device in the form of a needle valve.

FIG. 3 shows different applications of a Paint spray gun 1 according to the invention with color beam deflection. Without activated color beam deflection, the operation can be carried out, for example, with a round color jet or a horizontal or vertical flat jet as shown in FIG.

For the treatment of ceiling surfaces, it is advantageous if the gun does not have to be tilted by 90 degrees, as this prevents the color from flowing out of the paint reservoir into the mounting area of the ink reservoir. In addition, the handling of a paint spray gun, especially for longer work is significantly improved when a natural hand attitude approximate attitude can be taken. Since a landing angle 34 of the color jet on the surface of 90 degrees is always desired for a successful and high-quality color coating of a surface, improved handling of the spray gun can be ensured in the oblique spray operation upwards 32 by the color beam deflection.

By adjusting the arrangement of the air passage cross sections of the first air former in the reverse direction and an oblique injection operation down 33 can be realized.

The various options for setting the operating modes of a paint spray gun according to the invention are described below by the functional description of the individual flow openings in the air gate 4 and the air cap 3.

The air flow gate 4 has around its center of the paint passage opening 40 on an outer first radius 41 and an inner second radius 42. On the first link radius 41 are radially symmetric in the distance each arranged a quarter turn air outlet openings, which differ in the available cross-sections. The small forced ventilation opening 43 is surrounded on both sides by two working air openings 44, 45, and has, on the opposite side, an enlarged working air opening 46, moreover.
On an inner second link radius 42 is also the enlarged working air opening 46, surrounded by two forced ventilation 47,48 and opposite an internal working air opening 49th

In the FIG. 5 illustrated perspective view of the air flow gate 4 shows the intended for cooperation with the locking element 23 grooves 51,52,53,54, which provide defined positions of the air gate 4 in the gun body 2. The radial symmetrical inner air flow area 55 serves to generate the color jet from the paint emerging from the color passage opening 40. The region located within the inner radius 42 is at least partially provided with troughs 56 which provide improved airflow behavior.

FIG. 6 shows an air cap 3 in front view with a first air horn 61 and a second air horn 62. The central passage opening 60 forms together with this piercing cone 57 of the air gate 4 an intermediate annular gap, which favors the formation of an optimal color theft.
On a cap radius 63 surrounding the central opening 60, air outlet openings 64, 65, 66, 67 are arranged, which allow a controlled release of air in the omnidirectional mode.

The first air horn 61 has a first air passage cross-section 68, which through a inner air passage 68a and an outer air passage 68b is formed.

The second air horn 62, as the second cross-section 69, has only one air duct 69a.

In FIG. 7 is a perspective view of the air cap 3 according to the invention is shown, which also has on parts of the surface wells 71 for improved air flow.

The air funnels can either be produced in one piece with the air cap 3, for example by injection molding, or they can be produced in a simplified manner as separate parts, for example folded parts formed in half. The halves produced in this way could be fixed in a folded fashion by means of a film hinge connection in the region 72 and be introduced into a fastening region 73, for example into a dovetail structure or a different rear engagement structure, whereby a firm connection with the air cap 3 is produced.

To solve various air management tasks, the air cap 3 and the air gate 4 are now positioned relative to one another in such a way that a specific combination of working air openings 44, 45, 46, 49 can be applied to a specific combination of air outlet openings 64, 65, 66, 67 or air ducts 68 a, 68 b, 69 a to meet. As an example, the operation with color beam deflection is described above.

In the Fig. 4 Port 46 shown meets in the indicated position on both channels 68a and 68b. The inside of the radius 63 ending channel 69 a, which corresponds to the position on the radius 41 of the air cap and thus the forced ventilation 43, is supplied only with a very small amount of air, the settling of Color particles in the channel 69a prevented. The openings 64,65,66,67 of the air cap 3 are in this position without function. In this way, the exiting jet of color is deflected by the exiting from the first air horn 61 through its first cross-section 68 air amount upwards, which is the mode 32 from FIG. 3 equivalent. If the air cap 3 is now rotated by 180 degrees relative to the guide 4, the opening 49 meets the channel 68a, wherein the channel 68b only receives forced ventilation through the opening 43. The channel 69a lies in this case over the enlarged opening 46, and thus receives the air volume corresponding to its cross-section 69. As a result of this setting is a non-deflected but formed as a horizontal flat jet color beam.

By appropriate variations of the position of the air gate 4 and the air cap 3 with respect to the gun body 2, the other mentioned modes can be realized. If the openings 64, 65, 66, 67 are brought into coincidence with the working air openings 44, 45, 46, 49, an omnidirectional jet is formed.

COVERS LIST:

1

Spray Gun

2

gun cabinet

3

air cap

4

air backdrop

5

Nut

6

thread

7

ink reservoir

8th

Air supply port

9

Farbdosierabzug

10

Air flow direction

11

Color outlet opening

20

Color dispenser

21

sealing element

22

Air flow volume

23

locking element

24

needle

31

normal operation

32

Inclined spraying operation upwards

33

Inclined spraying operation downwards

34

angle of impact

40

Color through opening

41

First backdrop radius

42

Second link radius

43

Forced ventilation opening

44.45

Working air openings

46

enlarged working air opening

47.48

Ventilation ducts

49

inside working air opening

51,52,53,54

groove

55

inner air flow area

56

Hopper

57

cone

60

central air passage opening

61

First Luftrichter

62

Second air funnel

63

cap radius

64,65,66,67

Air outlet openings

68

first air passage cross section

68a

inner air duct

68b

outer air duct

69

second air passage cross section

69a

air duct

71

Hopper

72

Hinge area

73

fastening area

Claims (15)

A color spray gun (1) with color jet deflection, comprising a spray gun body (2) with ink reservoir (7), an ink dispenser (20), an airflow gate (4) with flow openings, an air cap (3) with flow openings and a first through-flow air horn or air horn (61 ) with a first air passage cross section (68) and at least one second air horn or air horn (62) with a second air passage cross section (69), wherein the air flow gate (4) in the air flow direction (10) in front of the air cap (3) in the region of the ink dispenser ( 20) is arranged,
characterized in that
the first air passage cross section (68) is formed enlarged relative to at least the second air passage cross section (69). Paint spray gun according to claim 1
characterized in that
in a first air funnel (61), the first air passage cross section (68) is formed from a double channel system (68a) (68b) and in a second air funnel (62) the second air passage cross section (69) is formed from a single channel (69a). Paint spray gun according to claim 1 or 2
characterized in that
an elongated longitudinal axis of the first air passage cross section (68) having an elongated longitudinal axis of the second air passage cross section (69) with the longitudinal axis of a sprayed ink jet substantially forms an intersection. Paint spray gun according to one of the preceding claims
characterized in that
the air flow gate (4) has a preferably centrally arranged ink passage opening (40), in particular in cooperation with a valve needle (24) as a paint metering device. Paint spray gun according to one of the preceding claims
characterized in that
the air cap (3) is preferably pierced centrally by a Farbdosiervorrichtung. Paint spray gun according to one of the preceding claims
characterized in that
the air funnels (61), (62) are designed as separate, preferably attachable individual elements which can be fastened to the air cap (3). Paint spray gun according to one of the preceding claims
characterized in that
the air cap (3) is rotatable about the air flow direction (10) or about a longitudinal axis of the gun body (2) and / or the air flow gate (4) can be inserted in the gun body (2), preferably using defined insertion positions is trained. Paint spray gun according to one of the preceding claims
characterized in that
the air flow gate (4) has a paint passage opening (40), at least one air passage opening on a first radius (41) around the paint passage opening (40) and at least one second air passage opening on a second radius (42) around the paint passage opening (40). Paint spray gun according to claim 8
characterized in that
at least one air passage opening (46) comprises both the first radius (41) around the color passage opening and the second radius (42) around the color passage opening. Paint spray gun according to claim 8 or 9
characterized in that
at least one forced ventilation opening (43) between two working air openings (44), (45) is provided on the first radius (41) around the color passage opening (40), and at least one working air opening (49) between two forced ventilation openings (47) is provided on the second radius (42) ), (48) are provided. Paint spray gun according to one of the preceding claims
characterized in that
the air flow gate (4) has an inner air flow-through area (55) about a preferably central ink passage opening (40). Paint spray gun according to one of the preceding claims
characterized in that
the air cap (3) has a centric flow opening (60). Paint spray gun according to one of the preceding claims
characterized in that
the air cap (3) on a first radius (63) at least one air passage opening, preferably four pairwise mirror-symmetrically arranged air passage openings (64), (65), (66), (67). Paint spray gun according to one of the preceding claims
characterized in that
the first air funnel (61) and the second air funnel (62) are arranged opposite one another, preferably radially symmetrically between further air passage openings (64), (65), (66), (67). Paint spray gun according to one of the preceding claims
characterized in that
at least one air passage opening, preferably at least one air funnel (61), (62), on the air cap (3) with at least one air passage opening (43), (44), (45), (46), (47), (48), (49) on a radius (41) (42) to the color passage opening (40) on the air flow gate (4) to bring in such a coincidence that a continuous air passageway is formed.

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