Base body for a spray gun, spray guns, spray gun set and method for converting a spray gun

Description

[0001] The invention relates to a spray gun, in particular a paint spray gun, according to the preamble of claim 1, a method for converting a spray gun, in particular a paint spray gun, according to the preamble of claim 11 and a method for converting a spray gun, in particular a paint spray gun, according to the preamble of claim 13.

[0002] According to the prior art, a spray gun, in particular a paint spray gun, in particular a compressed air atomizing paint spray gun, has a paint nozzle on its head which is screwed into the gun body. The paint nozzle often has a hollow cylindrical plug at its front end, from whose front opening the material to be sprayed emerges when the spray gun is operated. However, the paint nozzle can also be conical in its front area. The gun head usually has an external thread via which an air nozzle ring with an air cap arranged therein is screwed onto the gun head. The air cap has a central opening whose diameter is larger than the outer diameter of the paint nozzle plug or the outer diameter of the front end of a conical paint nozzle. The central opening of the air cap and the plug or the front end of the paint nozzle together form an annular gap.From this annular gap emerges the so-called atomizing air, which, in the nozzle arrangement described above, creates a vacuum at the front of the paint nozzle, sucking the material to be sprayed out of the paint nozzle. The atomizing air strikes the paint jet, tearing the paint jet into threads and bands. Due to their hydrodynamic instability, the interaction between the rapidly flowing compressed air and the ambient air, and aerodynamic disturbances, these threads and bands break up into droplets, which are then blown away from the nozzle by the atomizing air.

[0003] The air cap often also has two horns which are diametrically opposed to one another and project beyond the aforementioned annular gap and the material outlet opening in the outflow direction. Two supply bores, i.e. horn air supply channels, run from the rear of the air cap to horn air bores in the horns. As a rule, each horn has at least one horn air bore, but preferably each horn has at least two horn air bores from which the horn air exits. The horn air bores are usually oriented such that they point towards the longitudinal axis of the nozzle in the outlet direction after the annular gap, so that the so-called horn air exiting from the horn air bores can influence the air that has already escaped from the annular gap or the paint jet or the paint mist that has already at least partially formed.This compresses the paint jet, or spray jet, with its originally circular cross-section (round jet), on the sides facing the horns and extends it in a perpendicular direction. This creates a so-called broad jet, which allows for a higher surface painting speed. In addition to shaping the spray jet, the horn air also serves to further atomize the spray jet.

[0004] Air ducts are generally incorporated into the gun body, i.e. the base body of the spray gun, with air from one of the ducts being directed to the said annular gap for use as atomizing air, as described above, and air from another duct being directed to the said horn air openings for use as horn air, as described above. For this purpose, the air ducts open into an end face of the head of the gun body and are directed to the annular gap or horn air holes via an air distributor arrangement. The air distributor arrangement frequently comprises an air distributor ring which separates the atomizing air region and the horn air region from one another. Such a nozzle arrangement or air distributor arrangement is disclosed, for example, in DE 20 2010 012 449 U1 and in the Chinese utility model specifications ZL 2014 2 0431026.7 and ZL 2016 2 0911120.1.

[0005] A disadvantage of the prior art described above, namely the air distribution arrangement comprising an air distribution ring, is that the air distribution ring must be manufactured by the manufacturer of the spray gun as a separate component and installed by the manufacturer or user of the spray gun. The user must clean and replace the separate component. Furthermore, there is a risk of losing the air distribution ring, rendering the spray gun unusable until the user has procured a replacement. To achieve a simple seal between the atomizing air area and the horn air area, the air distribution ring is made of plastic. However, this makes it susceptible to damage. Furthermore, the air distribution rings according to the prior art are relatively complex.

[0006] US 2007 / 0262169 A1 cites Taiwanese utility model TW 510253, which discloses a gun head structure, wherein the gun head has two annular grooves defined by three circumferential walls on the gun head. The described nozzle structure includes a sealing disc b, a connecting part c, a nozzle d, a spray head d, and a screw nut f.

[0007] Both the gun head structure according to the prior art cited in the US document and the arrangement described in the cited US document itself comprise a large number of individual parts with the disadvantages described above. Some of the individual components are relatively delicate. If one of the components is damaged, there is a risk that the seal between the atomizing air area and the horn air area is no longer present, which has a negative impact on the spray jet. Furthermore, the gun head is relatively long due to the large number of components stacked on top of one another. US6612506B1 also shows a spray gun, and DE69827994T2 shows a method for converting a spray gun according to the prior art.

[0008] The object of the present invention is therefore to provide a spray gun, in particular a paint spray gun, which is less susceptible to damage and functionally reliable.

[0009] A further object of the present invention is to provide methods for converting a spray gun, in particular a paint spray gun, by means of which a spray gun, in particular a paint spray gun, with a first nozzle internal pressure can be easily converted to a spray gun, in particular a paint spray gun, with a second nozzle internal pressure and back.

[0010] The first object is achieved by a spray gun, in particular a paint spray gun, which has at least one base body, a nozzle with at least one material nozzle, an air cap, a first air-conducting region and a second air-conducting region, wherein the first air-conducting region carries air that is used to atomize material to be sprayed, and the second air-conducting region carries air that is used to influence a spray jet, wherein the base body has at least one head region for attaching a nozzle arrangement, wherein the head region has at least one inner wall, an outer wall and a central wall arranged therebetween, wherein the walls are formed circumferentially and integrally with the base body, wherein the front end of the central wall is set back along an axis relative to the front end of the outer wall,wherein the first air-conducting region and the second air-conducting region are separated from one another at least in regions by the central wall of the base body, a disc element arranged integrally on the material nozzle, at least one baffle plate arranged on the material nozzle, in particular one arranged captively, and by at least a portion of the air cap, and wherein the inner wall, the central wall, and the outer wall are each circular and arranged concentrically to one another. Due to the described design, a separation or sealing between the first and second air-conducting regions is possible using only existing parts, i.e., parts that also fulfill a function other than separating the two regions. No additional sealing element is required, which allows the number of individual parts to be kept low in order to overcome the aforementioned disadvantages and realize the aforementioned advantages.

[0011] The air used to atomize the material to be sprayed and guided by the first air-conducting area is often referred to as atomizing air. The air used to influence a spray jet and guided by the second air-conducting area is often referred to as horn air. These areas are often referred to as the atomizing air area and the horn air area, respectively. The disc element can be considered part of the material nozzle, so that a deflector disc actually arranged on the disc element can also be considered arranged on the material nozzle. The fact that the deflector disc is "captively" arranged on the material nozzle means that the deflector disc cannot be removed from the material nozzle or only with considerable effort, and removal is not intended. For example, the deflector disc can be pressed, glued, riveted, or welded to the material nozzle.A strong snap connection or strong screwing can also make the impact disc "captive".

[0012] The nozzle arrangement which can be attached to the head region can comprise, for example, a material nozzle, which is often also referred to as a paint nozzle and serves at least for the outlet of the material to be sprayed, an air cap for the outlet of air and an air nozzle ring for connecting the air cap to the base body.

[0013] In the present case, a wall can be understood to mean, in particular, a web or a partition with a thickness of a few millimeters, which extends essentially parallel to the central or longitudinal axis of the head region of the base body or to the central or longitudinal axis of the material nozzle that can be arranged in or on the base body. This can also be a central or longitudinal axis of an upper part of the base body and / or the central or longitudinal axis of a receiving opening for receiving a material quantity regulating device. The wall is preferably essentially perpendicular to a surface, for example a front surface of the head of the base body, which runs essentially perpendicular to the above-mentioned central or longitudinal axes.The terms "inner", "middle" and "outer" wall are to be understood in such a way that, when viewed from the front onto the gun head, the inner wall is closer in the radial direction to the center of the gun head than the middle wall, which in turn is closer to the center of the gun head than the outer wall.

[0014] The walls are circular and preferably have a constant thickness.

[0015] The term "integrally formed" with the base body means that the walls and the remaining base body were manufactured from one piece, for example by casting, machining, 3D printing or other processes.

[0016] This means that the walls and the base body do not have to be manufactured separately and then joined together. This reduces the number of individual parts. The base body is preferably first forged from a bent solid bar and then machined using a drill, milling cutter, or a combination of these.

[0017] In this context, "along an axis" refers to the central or longitudinal axis of the head region of the base body or the central or longitudinal axis of the material nozzle that can be arranged in or on the base body. "Front" refers to the spray direction or the side of the base body on which the material nozzle is or can be arranged, while "rear" refers to the opposite side or opposite direction, where, for example, a material flow control device is or can be arranged.

[0018] The above-mentioned last-mentioned object is achieved by a method for converting a spray gun, in particular a paint spray gun, with a first internal nozzle pressure to a spray gun, in particular a paint spray gun, with a second internal nozzle pressure, wherein the first internal nozzle pressure is greater than the second internal nozzle pressure, wherein the method comprises, in particular, as a step, the removal of a high-pressure nozzle arrangement from or out of a base body of the spray gun, wherein the high-pressure nozzle arrangement has at least one nozzle with a material nozzle having a hollow section for the passage of the material to be sprayed and a material outlet opening, and wherein the method comprises, as a further step, the arrangement of a low-pressure nozzle arrangement in or on the base body of the spray gun,wherein the low-pressure nozzle arrangement comprises at least one nozzle with a material nozzle having a hollow section for passing the material to be sprayed and a material outlet opening, wherein the nozzle of the high-pressure nozzle arrangement, which is removed from or from the main body of the spray gun, further comprises a disc element arranged on the outer circumference of the hollow section and at least one first baffle plate, wherein the first baffle plate is arranged on the side of the disc element facing away from the material outlet opening and has an inner and an outer circumference, and wherein the nozzle of the low-pressure nozzle arrangement, which is arranged in or on the main body of the spray gun, further comprises a disc element arranged on the outer circumference of the hollow section and at least one first baffle plate, wherein the first baffle plate is arranged on the side of the disc element facing away from the material outlet opening,has an inner and an outer circumference, and a second baffle plate arranged on the side of the first baffle plate facing away from the material outlet opening, wherein the outer circumference of the first baffle plate of the nozzle of the low-pressure nozzle arrangement is smaller than the outer circumference of the first baffle plate of the nozzle of the high-pressure nozzle arrangement.

[0019] The object is further achieved by a method for converting a spray gun, in particular a paint spray gun, with a first internal nozzle pressure to a spray gun, in particular a paint spray gun, with a second internal nozzle pressure, wherein the first internal nozzle pressure is lower than the second internal nozzle pressure, wherein the method comprises, in particular, as a step, the removal of a low-pressure nozzle arrangement from or out of a base body of the spray gun, wherein the low-pressure nozzle arrangement has at least one nozzle with a material nozzle with a hollow section for conducting the material to be sprayed and a material outlet opening, and wherein the method comprises, as a further step, the arrangement of a high-pressure nozzle arrangement in or on the base body of the spray gun,wherein the high-pressure nozzle arrangement comprises at least one nozzle with a material nozzle having a hollow section for conducting the material to be sprayed and a material outlet opening, wherein the nozzle of the low-pressure nozzle arrangement, which is removed from or from the main body of the spray gun, further comprises a disc element arranged on the outer circumference of the hollow section and at least one first baffle plate, wherein the first baffle plate is arranged on the side of the disc element facing away from the material outlet opening, has an inner and an outer circumference, and has a second baffle plate arranged on the side of the first baffle plate facing away from the material outlet opening, and wherein the nozzle of the high-pressure nozzle arrangement, which is arranged in or on the main body of the spray gun, further comprises a disc element arranged on the outer circumference of the hollow section and at least one first baffle plate,wherein the first baffle plate is arranged on the side of the disc element facing away from the material outlet opening and has an inner and an outer circumference, wherein the outer circumference of the first baffle plate of the nozzle of the high-pressure nozzle arrangement is larger than the outer circumference of the first baffle plate of the nozzle of the low-pressure nozzle arrangement.

[0020] Spray guns, especially paint spray guns, operate using various pressure processes. Conventional spray guns operate at relatively high spray pressures of several bar. In so-called HVLP guns, the internal nozzle pressure is a maximum of 10 psi or 0.7 bar, which allows for transfer rates well over 65%. Compliant spray guns, on the other hand, have an internal nozzle pressure of more than 10 psi or 0.7 bar, but also achieve a transfer rate of more than 65%.

[0021] According to the state of the art, HVLP spray guns differ structurally from compliant spray guns in particular in that additional throttle tubes are inserted into the air duct openings in the head of the base body of HVLP spray guns. This requires additional manufacturing steps, and a spray gun designed as an HVLP spray gun or a base body designed for use with an HVLP spray gun cannot be converted into a compliant spray gun or a compliant spray gun base body, or can only be converted with difficulty, because the throttle tubes must be firmly inserted, for example, pressed, into the air duct openings to prevent accidental release.

[0022] The advantage of the first method according to the invention for converting a spray gun, in particular a paint spray gun, with a first internal nozzle pressure to a spray gun, in particular a paint spray gun, with a second internal nozzle pressure, wherein the first internal nozzle pressure is greater than the second internal nozzle pressure, is that the base body of the spray gun can remain unchanged if, for example, a compliant spray gun is to be converted to an HVLP spray gun. The spray gun can be converted to a spray gun with a lower internal nozzle pressure simply by replacing the nozzle. The production of separate throttle tubes and their insertion into the base body of the spray gun can be dispensed with.

[0023] The advantage of the second method according to the invention for converting a spray gun, in particular a paint spray gun, with a first internal nozzle pressure to a spray gun, in particular a paint spray gun, with a second internal nozzle pressure, wherein the first internal nozzle pressure is lower than the second internal nozzle pressure, also lies in the fact that the base body of the spray gun can remain unchanged if, for example, an HVLP spray gun is to be converted to a compliant spray gun. The spray gun can be converted to a spray gun with a higher internal nozzle pressure simply by replacing the nozzle. The difficult removal of the throttle tubes incorporated into the base body of the spray gun can be dispensed with.

[0024] In both methods according to the invention for converting a spray gun, in particular a paint spray gun, a further advantage is that the conversion is still easy even after the spray gun has been delivered to the customer.

[0025] The internal nozzle pressure of the spray gun is the pressure prevailing in the air cap of the spray gun. The atomizing air area is often separated from the horn air area and the pressure in the atomizing air area can be different than in the horn air area. However, the pressures in the atomizing air area and the horn air area can also be the same. The internal nozzle pressure can be measured, for example, using a so-called test air cap. This is a special air cap that is attached to the spray gun instead of the usual air cap. The test air cap usually has two pressure gauges, one of which is connected to the atomizing air area via a hole in the test air cap and the other to the horn air area via another hole in the test air cap.

[0026] The terms low-pressure nozzle arrangement and high-pressure nozzle arrangement are not intended to imply that the respective nozzle arrangement is only used in classic low-pressure or high-pressure spray guns, or that the use of the respective nozzle arrangement turns the spray gun into a classic low-pressure, in particular HVLP, spray gun, or a classic high-pressure gun. Rather, it is only to be understood that the spray gun, when equipped with the high-pressure nozzle arrangement, has a higher internal nozzle pressure than when equipped with the low-pressure nozzle arrangement. Preferably, the spray gun equipped with the low-pressure nozzle arrangement or the base body equipped with the low-pressure nozzle arrangement meets the criteria of an HVLP spray gun, and the spray gun or the base body equipped with the high-pressure nozzle arrangementThe base body equipped with the high-pressure nozzle arrangement meets the criteria of a compliant spray gun.

[0027] In addition to a nozzle comprising at least one material nozzle with other components optionally arranged thereon, the nozzle arrangement can also have an air cap and an air nozzle ring. All of these components can be designed differently in the low-pressure nozzle arrangement than in the high-pressure nozzle arrangement; however, the differences can also be limited to one or some of the components, while the other components are the same in the low-pressure nozzle arrangement and the high-pressure nozzle arrangement. The differences preferably lie in the material nozzle or the components arranged thereon and in the air cap. The differences in the nozzle, the material nozzle orThe advantages of the components arranged thereon can be, in particular, that the nozzle of the low-pressure nozzle arrangement has an additional baffle plate compared to the nozzle of the high-pressure nozzle arrangement, and that the first baffle plate of the nozzle of the low-pressure nozzle arrangement has a smaller outer circumference than the first baffle plate of the nozzle of the high-pressure nozzle arrangement. The additional baffle plate can act as an additional throttle that limits the flow area of ​​air. However, the additional baffle plate can also alternatively or additionally perform the functions of the first baffle plate described above, such as air conduction, air deflection, homogenization, and / or air distribution.Furthermore, both the disk element of the nozzle of the low-pressure nozzle arrangement and the disk element of the nozzle of the high-pressure nozzle arrangement can have through-openings, in particular through-bores, for air, but these can be designed differently or present in a different number in the nozzle of the high-pressure nozzle arrangement than in the nozzle of the low-pressure nozzle arrangement. The same applies to the baffle disks. The differences in the air cap preferably lie in the fact that the central opening of the air cap of the low-pressure nozzle arrangement has a larger diameter than the central opening of the air cap of the high-pressure nozzle arrangement.As a result, with the outer diameter of the front end of the material nozzle remaining essentially the same, the annular gap formed by the outer surface of the front area of ​​the material nozzle and by the wall defining the central opening in the air cap, and from which the atomizing air exits, is larger in the low-pressure nozzle arrangement than in the high-pressure nozzle arrangement.

[0028] Advantageous embodiments are the subject of the subclaims.

[0029] Preferably, the front end of the middle wall is set back by 2 mm to 4 mm along the axis relative to the front end of the outer wall.

[0030] Preferably, the inner wall and the middle wall of the base body delimit a first air distribution chamber and the middle wall and the outer wall delimit a second air distribution chamber. This means that they define such air distribution chambers, preferably with other walls or surfaces of the base body or walls or surfaces of other components. The air distribution chambers are preferably not closed, but have inlets, outlets and / or passages. Preferably, the air distribution chambers are substantially annular, but can also have other shapes if this appears advantageous. Preferably, the chambers are circumferential, i.e. extend over 360°, but they can also be limited to a smaller area. The purpose of the air distribution chambers can be to distribute air which flows from at least one opening into the air distribution chamber over a larger area, preferably over 360°.The air distribution chamber between the inner and middle walls can be referred to as the "inner air distribution chamber," and the air distribution chamber between the middle and outer walls can be referred to as the "outer air distribution chamber." The inner air distribution chamber can be the air distribution chamber for atomizing air, and the outer air distribution chamber can be the air distribution chamber for horn air.

[0031] A first front surface is preferably arranged between the inner wall and the middle wall, and a second front surface is arranged between the middle wall and the outer wall, wherein the first front surface has a first distance along the aforementioned axis from the front end of the outer wall, at least in some regions, and the second front surface has a second distance along the aforementioned axis from the front end of the outer wall, at least in some regions, and wherein the first distance is greater than the second distance. In the present case, the aforementioned axis is again the central or longitudinal axis of the head region of the base body or the central or longitudinal axis of the material nozzle that can be arranged in or on the base body. The term "front surface" is intended to express that the surface of the above definition points "forward", in particular in the spray direction. They are therefore essentially perpendicular to the aforementioned central or longitudinal axis.Longitudinal axis and perpendicular to the walls between which they are arranged. The front surfaces can form a type of base surface of the above-mentioned air distribution chambers and are preferably surfaces of the base body. The first front surface is, at least in some areas along the aforementioned axis, further away from the front end of the outer wall than the second front surface. However, the distances do not have to be constant over the entire length of the front surface. Rather, the front surfaces can also have slopes, steps, depressions, shoulders, or similar features.

[0032] Preferably, the first distance, i.e. the distance of the front surface between the inner and middle wall to the front end of the outer wall along the axis is 9 mm to 11 mm and the second distance, i.e. the distance of the front surface between the middle and outer wall to the front end of the outer wall along the axis is 4 mm to 6 mm. Due to the different distances, the inner air distribution chamber can have a greater depth and thus, despite a smaller base area, a larger volume than the outer air distribution chamber. If the air distribution chambers were each viewed as closed chambers, with the demarcation being formed by the base area, the two adjacent walls and by an imaginary cover surface which is arranged parallel to the base area on the lower of the two walls, the volume of the inner air distribution chamber would particularly preferably be between 1,000 mm³ and 1,000 mm³.500 mm 3< and the volume of the outer air distribution chamber between 400 mm 3< and 900 mm 3<.

[0033] Preferably, at least the first front surface and / or the second front surface have a groove at least in some areas; particularly preferably, at least the second front surface has a groove with a bottom surface at least in some areas, wherein the bottom surface of the groove has a third distance from the front end of the outer wall along the aforementioned axis, in particular the above-mentioned central or longitudinal axis of the head region of the base body or the central or longitudinal axis of the material nozzle that can be arranged in or on the base body, and wherein the third distance is smaller than the first distance from the first front surface to the front end of the outer wall. The bottom surface of the groove therefore lies along the axis between the first front surface and the second front surface. The said third distance is made up of the distance from the second front surface to the front end of the outer wall plus the distance between the bottom surface of the groove and the second front surface, i.e.the depth of the groove.

[0034] The width of the groove in the first or second front surface preferably corresponds substantially to the width of the first front surface or the second front surface. The groove in the first front surface particularly preferably has substantially the same width as the first front surface, and the groove in the second front surface particularly preferably has substantially the same width as the second front surface. The width of the groove or of the front surface is understood to mean the extent in the radial direction of the head region of the base body or the distance between the inner and middle wall or between the middle and outer wall in the radial direction.

[0035] Particularly preferably, the groove extends in the circumferential direction over 25% to 75%, in particular over 45% to 55%, of the circumference of the first front surface or the second front surface. The first front surface preferably has at least one inner air outlet opening, in particular two inner air outlet openings, and the second front surface has at least one outer air outlet opening, in particular two outer air outlet openings. At least one air outlet opening, in particular one outer air outlet opening, is particularly preferably located within the groove in the front surface. As a result of this and in particular as a result of the groove extending over 25% to 75%, in particular over 45% to 55%, of the circumference of the respective front surface, an even better distribution of the air flowing out of the at least one air outlet opening over the circumference of the air distribution chamber is achieved.If the corresponding front surface extends over 360°, the groove preferably extends over 90° to 270°, in particular over 162° to 198°. The designations "inner" and "outer" air outlet opening serve merely to distinguish between the air outlet openings. Preferably, the at least one "inner" air outlet opening is located further inward in the radial direction, i.e., closer to the central or longitudinal axis of the head region of the base body, than the at least one "outer" air outlet opening. However, they can also be at the same distance from the central or longitudinal axis of the head region of the base body.

[0036] Particularly preferably, the first front surface has two inner air outlet openings and the second front surface has two outer air outlet openings, wherein the outer air outlet openings in the second front surface are located within a groove, and wherein the groove extends over approximately 50% of the circumference of the second front surface.

[0037] The at least one inner air outlet opening of the first front surface preferably extends at least in regions over at least 85% of the width of the first front surface and the at least one outer air outlet opening of the second front surface preferably extends at least in regions over at least 85% of the width of the second front surface.

[0038] As already mentioned above, it is particularly preferred to have two air outlet openings in each of the first front surface and the second front surface. The air outlet openings are, in particular, holes, and it is advantageous for the hole diameter to be as large as possible to achieve the greatest possible air volume. The space for the holes is limited by the walls, which is why the holes, or the air outlet openings in general, should extend as far as possible across the width of the front surfaces.

[0039] Preferably, the base body has at least two atomizing air ducts extending from the first front surface into a round, wide-jet air distribution chamber, and / or the base body has at least two horn air ducts extending from the second front surface into a round, wide-jet air distribution chamber, wherein the atomizing air ducts are spaced apart from one another in the region of the first front surface and at least partially overlap in the region of the round, wide-jet air distribution chamber, and / or wherein the horn air ducts are spaced apart from one another in the region of the second front surface and at least partially overlap in the region of the round, wide-jet air distribution chamber. In other words, the first front surface has two spaced-apart atomizing air duct openings, and the second front surface has two spaced-apart horn air duct openings.The round, wide-jet air distribution chamber now only has one atomizing air duct opening and one horn air duct opening. The outer contour of each opening can have the shape of an "8." This results in the total cross-sectional area of ​​the two air ducts increasing from the round, wide-jet air distribution chamber to the front surfaces.

[0040] In a preferred embodiment, the front end of the inner wall is set back from the front end of the central wall along the aforementioned axis, in particular the central or longitudinal axis of the head region of the base body or the central or longitudinal axis of the material nozzle that can be arranged in or on the base body. Particularly preferably, the front end of the inner wall is set back from the front end of the central wall by 0.4 mm to 0.6 mm along the axis.

[0041] The fact that the front end of the inner wall is set back from the front end of the middle wall along the aforementioned axis means that the front edge of the inner wall is set back from the front edge of the middle wall at least in some areas along the axis. The front edge of the middle wall does not have to be located in front of the front edge of the inner wall along its entire length. Rather, the front edge of the middle wall can also be located behind the front edge of the inner wall in some areas. This also means that the walls do not have to have a constant height along their entire length. Rather, the walls can have steps, ledges, ramps, or similar features. Preferably, however, the walls have a constant height along their entire length, and the front edge of the inner wall is set back from the front end of the middle wall along its entire length along the axis.

[0042] The walls—i.e., the inner, middle, and outer walls—are each circular and arranged concentrically to one another. This makes the mold easier to manufacture because it can be realized relatively simply and quickly by turning or using a rotationally symmetrical tool. This can preferably be done in a single step if the contour of the tool corresponds to the contour of the front head region of the base body or represents a negative of the contour. The nozzle or nozzle arrangement arranged in or on the head region can also be designed to be at least partially rotationally symmetrical.

[0043] Preferably, the inner wall has an outer diameter of 13 mm to 15 mm, the middle wall has an outer diameter of 22 mm to 24 mm, and the outer wall has an outer diameter of 33 mm to 35 mm.

[0044] The inner wall can have an inner diameter of 11 mm to 13 mm, the middle wall an inner diameter of 20 mm to 22 mm, and the outer wall an inner diameter of 31 mm to 33 mm.

[0045] Preferably, the inner wall has an internal thread at least in some areas and the outer wall has an external thread at least in some areas. For example, a nozzle, in particular a material nozzle, optionally with further components arranged thereon, can be screwed into the internal thread of the inner wall. For example, an air nozzle ring can be screwed onto the external thread of the outer wall. The threads can be metric threads, trapezoidal threads or other threads. The internal thread of the inner wall is intended to ensure that the nozzle fits tightly in the base body and, if necessary, to seal between the material and air-conducting areas. The external thread of the outer wall is intended primarily to enable quick attachment and removal of the air nozzle ring to and from the base body, but also to seal the air-conducting area from the environment.Preferably, the internal thread of the inner wall is a pointed thread and the external thread of the outer wall is a quick-action thread, in particular a trapezoidal thread.

[0046] The method according to the invention for converting a spray gun, in particular a paint spray gun, with a first internal nozzle pressure to a spray gun, in particular a paint spray gun, with a second internal nozzle pressure, wherein the first internal nozzle pressure is greater than the second internal nozzle pressure, preferably comprises, as a first step, the removal of a high-pressure air cap arranged on the base body via an air nozzle ring, wherein the high-pressure air cap has at least one central opening with a first diameter, and, as a further step, the arrangement of a low-pressure air cap that can be arranged on the base body via an air nozzle ring, wherein the low-pressure air cap has at least one central opening with a second diameter and wherein the second diameter is greater than the first diameter of the high-pressure air cap.Because the central opening of the air cap of the low-pressure nozzle assembly has a larger diameter than the central opening of the air cap of the high-pressure nozzle assembly, the annular gap between the material nozzle and the air cap, through which the atomizing air exits, is larger in the low-pressure nozzle assembly than in the high-pressure nozzle assembly, while the outer diameter of the front end of the material nozzle remains essentially the same. This also means that the pressure in the air cap is lower in the low-pressure nozzle assembly, and the volume flow of the exiting air is higher than in the high-pressure nozzle assembly.

[0047] The method according to the invention for converting a spray gun, in particular a paint spray gun, with a first internal nozzle pressure to a spray gun, in particular a paint spray gun, with a second internal nozzle pressure, wherein the first internal nozzle pressure is smaller than the second internal nozzle pressure, preferably comprises as a first step the removal of a low-pressure air cap arranged on the base body via an air nozzle ring, wherein the low-pressure air cap has at least one central opening with a first diameter, and as a further step the arrangement of a high-pressure air cap that can be arranged on the base body via an air nozzle ring, wherein the high-pressure air cap has at least one central opening with a second diameter and wherein the second diameter is smaller than the first diameter of the low-pressure air cap.

[0048] The method according to the invention for converting a spray gun, in particular a paint spray gun, can also be regarded as a method for converting a base body of a spray gun, in particular a paint spray gun.

[0049] The methods according to the invention for converting a spray gun can comprise, as a further step, the delivery of the spray gun to a customer and / or the use of the base body or the spray gun.

[0050] The statements regarding the base body, the spray gun according to the invention and the method according to the invention for converting a spray gun, in particular the statements regarding the components, can apply across the board, ie the statements regarding the base body can also apply to the spray gun according to the invention or to the method according to the invention, etc.

[0051] The spray gun according to the invention, in particular a paint spray gun, can be used to spray not only paint but also adhesives or varnishes, in particular base and clear coats, both solvent-based and water-based, as well as liquids for the food industry, wood preservatives, or other liquids. The spray gun according to the invention can, in particular, be a hand-held spray gun or an automatic or robotic gun. Hand-held spray guns are primarily used by craftsmen, in particular painters, carpenters, and varnishers. Automatic and robotic guns are generally used in conjunction with a painting robot or a painting machine for industrial applications. However, it is certainly conceivable to integrate a hand-held spray gun into a painting robot or a painting machine.

[0052] The spray gun according to the invention and the methods according to the invention can be used for all types of spray guns, but in particular for air-atomizing, in particular compressed air-atomizing, spray guns.

[0053] The spray gun according to the invention can, in particular, comprise or be equipped with the following additional components: handle, upper gun body, compressed air connection, paint needle, trigger for opening an air valve and for moving the paint needle out of the material outlet opening of the material nozzle, round-to-wide jet regulator for adjusting the ratio of atomizing air and horn air to shape the paint jet, air micrometer for adjusting the spray pressure, material flow regulator for adjusting the maximum material flow rate, material connection, paint channels for directing the material to be sprayed from a material inlet to the material outlet opening, suspension hook, and / or analog or digital pressure measuring device. However, it can also comprise other components from the prior art.The paint spray gun can be designed as a gravity-feed gun with a paint cup arranged above the gun body, from which the material to be sprayed flows into and through the paint channels essentially by gravity and by negative pressure at the front end of the material nozzle. However, the spray gun can also be a side-feed gun, in which the paint cup is arranged on the side of the gun body, and in which the material is also fed to the gun by gravity and by negative pressure at the front end of the material nozzle. However, the spray gun can also be designed as a suction or suspended cup gun with a paint cup arranged below the gun body, from which the material to be sprayed is sucked out of the cup essentially by negative pressure, in particular by utilizing the Venturi effect.It can also be designed as a pressure-cup gun, in which the cup is positioned below, above, or to the side of the gun body and is pressurized, forcing the material to be sprayed out of the cup. It can also be a pressure-feed gun, in which the material to be sprayed is fed to the spray gun via a hose from a paint container or via a pump.

[0054] The invention is explained in more detail below using 18 figures as examples. These figures show: Fig. 1 a partially exploded view of a spray gun with an air distribution ring according to the prior art disclosed in Chinese utility model publication ZL 2014 2 0431026.7; Fig. 2 a plan view of a head portion of a main body of a spray gun according to the prior art disclosed in the aforementioned Chinese utility model publication; Fig. 3 a sectional view of a head portion of a spray gun according to the prior art disclosed in Chinese Utility Model Publication ZL 2016 2 0911120.1; Fig. 4 an exploded view of an embodiment of a spray gun according to the invention; Fig. 5 a sectional view of an embodiment of a base body for a spray gun; Fig. 6 a sectional view of the head region of an embodiment of a base body for a spray gun; Fig. 7 a perspective view of the head region of an embodiment of a base body for a spray gun; Fig. 8 a perspective view of an embodiment of a nozzle for use in an embodiment of a spray gun according to the invention; Fig. 9 a perspective view of the embodiment of a nozzle from Fig. 8 from another side; Fig. 10 a rear view of the embodiment of a nozzle from Fig. 8 ; Fig. 11 a sectional view of the embodiment of a nozzle from Fig. 8 ; Fig. 12 a sectional view of the head region of an embodiment of a spray gun according to the invention with the embodiment of a nozzle from Fig. 8 ; Fig. 13 a perspective view of a second embodiment of a nozzle for use in an embodiment of a spray gun according to the invention; Fig. 14 a perspective view of the embodiment of a nozzle from Fig. 13 from another side; Fig. 15 a rear view of the embodiment of a nozzle from Fig. 13 ; Fig. 16 a sectional view of the embodiment of a nozzle from Fig. 13 ; Fig. 17 a sectional view of the head region of an embodiment of a spray gun according to the invention with the embodiment of a nozzle from Fig. 13 ; and Fig. 18 a perspective view of a part of an embodiment of a base body.

[0055] The Fig. 1 The part of a spray gun 100, in particular a paint spray gun, according to the prior art shown in FIG. 1, comprises a base body 102 with various attachments. Shown is an air distribution ring 104, which can be arranged on the head region 103 of the base body 102. For this purpose, the air distribution ring 104 has at least one, in the present example two, retaining pins 106a and 106b, which are inserted into two blind holes 108a and 108b corresponding to the retaining pins 106a and 106b, which are in Fig. 2 are shown, in order to fasten the air distribution ring 104 to the gun head or to the head area 103 of the base body 102 in such a way that the wall 107 of the air distribution ring 104 lies sealingly against the front surface 110 of the head area 103 of the base body 102, which in Fig. 3 shown. The Fig. 3 The head portion 103 shown is disclosed in Chinese utility model ZL 2016 2 0911120.1. An atomizing air outlet opening 114 in the front surface 110 of the head portion 103 of the base body 102 lies within the wall 107 of the air distribution ring 104. Atomizing air flows from the atomizing air outlet opening 114 into an inner air distribution chamber 116, which is formed by the air distribution ring 104 and the base body 102. A horn air outlet opening 112 in the front surface 110 of the head region 103 of the base body 102 lies outside the wall 107 of the air distribution ring 104. Horn air flows from the horn air outlet opening 112 into an outer air distribution chamber 118 of the air distribution ring 104.

[0056] On a surface within the wall 107, the air distribution ring 104 has a plurality of passages 120 distributed over its circumference, through which the atomizing air flows from the inner air distribution chamber 116. From the passages 120, the atomizing air flows to a plate 124 arranged integrally on the paint nozzle 122, which sealingly rests against a wall 109 of the air distribution ring 104, wherein the wall 109 is arranged on the side of the air distribution ring 104 facing away from the front surface 110 of the head region 103 of the base body 102. The plate 124 has a plurality of through-bores 126 distributed over its circumference. The air flowing through the through-holes 126 then flows through an annular gap 130 between the central opening of the air cap 132 and the front end of the paint nozzle 122, which may be designed in the form of a suppository.

[0057] The outer air distribution chamber 118 of the air distribution ring 104, together with an outer wall 134 on the head region 103 of the base body 102, forms a gap through which the horn air flows from the outer air distribution chamber 118. From there, the air flows into the horn air supply channels in the air cap 132 and then into the horn air bores 136, from whose openings the air exits.

[0058] Fig. 4 shows an exploded view of an embodiment of a spray gun 1 according to the invention. The spray gun 1 can have a cup 3 for receiving and dispensing the material to be sprayed, wherein the cup comprises a lid 3b with a valve plug 3a, a cup body 3c, and a plug-in sieve 3d. Furthermore, the spray gun 1 can comprise a material quantity regulating device 11, an air micrometer 13, a round-to-wide jet regulating device 9, a trigger system 7 consisting of a trigger and fastening means, and an air connection, which can be designed as a standard connection 4a or as a swivel connection 4b. A nozzle arrangement consisting of a nozzle 24, which can comprise a material nozzle 40, can be arranged on the head region 6 of the base body 2. The nozzle arrangement can also comprise an air cap 76, which can be fastened, in particular screwed, to the head region 6 via an air nozzle ring 74.The head region 6, the nozzle 24, and the air cap 76 with air nozzle ring 74 are arranged or can be arranged coaxially along an axis Z, which in the present case represents the above-mentioned central or longitudinal axis of the head region 6 of the base body 2, the central or longitudinal axis of the material nozzle 40, the central or longitudinal axis of the upper part of the base body 2 and the central or longitudinal axis of a receiving opening for receiving the material quantity regulating device 11.

[0059] In Fig. 5 is a sectional view of the embodiment of a base body 2 for a spray gun from Fig. 4 shown, with the section from top to bottom through the Z axis consisting of Fig. 4 The base body 2 has a plurality of bores; in the upper part of the base body 2, in particular, a plurality of bores along an axis Z, which in the present case represents the above-mentioned central or longitudinal axis of the head region 6 of the base body 2. In the present exemplary embodiment, this axis is the same as the central or longitudinal axis of the material nozzle 40 arranged in or on the base body 2. Fig. 4 and equal to the central or longitudinal axis of the upper part of the base body 2 and equal to the central or longitudinal axis of a receiving opening 82 for receiving a Fig. 4 material quantity regulating device 11 shown as an example.

[0060] When it is described above that the front end of one wall is set back along an axis relative to the front end of another wall, the term along an axis refers to the Z axis. As in Fig. 5 As can be seen, the middle wall 12 is clearly set back from the outer wall 14. The "front" is considered to be the spray direction or the side of the base body 2 on which the material nozzle 40 is Fig. 4 can be arranged, the opposite side or opposite direction, here the side with the receiving opening 82, is referred to as "rear". The fact that the front end of the middle wall 12 is "set back" along an axis Z relative to the front end of the outer wall 14 means that the front end of the outer wall 14 is further forward than the front end of the middle wall 12.

[0061] In the present embodiment, the inner wall 10 is only slightly set back from the middle wall 12.

[0062] In the Fig. 5 Only a single atomizing air duct 64 is visible, along with a horn air duct 66, which intersects with a second horn air duct. The sectional view also shows part of a round, wide-jet air distribution chamber 68.

[0063] Fig. 6 shows a sectional view of a part of the embodiment of a base body 2 for a spray gun 1, which in Fig. 5 shown in a different sectional view. The Fig. 6 The section shown was again taken through the Z axis from Fig. 4 , but along a cutting plane which corresponds to the Fig. 5 perpendicular to the applied cutting plane. In the present Fig. 6 It can be seen that the inner wall 10 of the head region 6 of the base body 2 of the spray gun 1 is set back from the middle wall 12 by a distance d4 along the Z axis. The middle wall 12, in turn, is set back from the outer wall 14 by a distance d3 along the Z axis. In other words, the outer wall 14 projects beyond the middle wall 12, which in turn projects beyond the inner wall 10. The inner wall 10 and the outer wall 12 delimit a first air distribution chamber 60, and the middle wall 12 and the outer wall 14 delimit a second air distribution chamber 62. Towards the front, i.e. in the spraying direction, the air distribution chambers 60 and 62 are open; towards the rear, they are delimited at least in regions by a first front surface 16 and a second front surface 18, respectively.In the present exemplary embodiment, a groove 19 is introduced into the second front surface 18, the bottom surface of which partially delimits the air distribution chamber 62 to the rear instead of the second front surface 18. The air distribution chamber 62 is therefore partially delimited to the rear by the second front surface 18 and partially by the bottom surface of the groove 19. The distance d5, i.e. the depth of the groove 19, i.e. the distance between the second front surface 18 and the bottom surface of the groove 19, can be, for example, approximately 1.5 mm to 3.0 mm. The distance d1 between the first front surface 16 and the front end of the outer wall 14 is preferably between 8 mm and 12 mm, particularly preferably between 9 mm and 11 mm. The distance d2 between the second front surface 18 and the front end of the outer wall 14 is preferably between 4 mm and 6 mm. In this case, the middle wall 12 is spaced apart from the outer wall 14 along the axis Z by a distance d3, which is preferably approximately2 mm to 4 mm. The inner wall 10 is preferably only set back by 0.1 mm to 1.0 mm relative to the middle wall 12. This is the distance d4. The distance shown in . Fig. 6 The embodiment of a head region 6 of a base body shown has a counter sealing surface 84 for a Fig. 6 nozzle seal (not shown). The distance d6 between this counter sealing surface 84 and the first front surface 16 is preferably approximately 1.5 mm to 3.0 mm. The first front surface 16 is set back from the second front surface 18 along the Z axis. In the present exemplary embodiment, the distance d7 by which the front surface 16 is set back from the second front surface 18 is approximately 4 mm to 6 mm. The dimensions or combinations of dimensions mentioned have proven advantageous for good atomization quality in spray tests.

[0064] In Fig. 7 is a perspective view of a part of the embodiment of a base body 2 from Fig. 5 und Fig. 6 shown. In particular, the groove 19 in the second front surface 18 is clearly visible here. The width of the groove 19 is approximately the same width as the second front surface 18. The width of the groove 19 or the second front surface 18 is to be understood as the extent in the radial direction of the head region 6 of the base body 2 or also the distance between the middle wall 12 and the outer wall 14 in the radial direction. In the circumferential direction, the groove 19 extends over approximately 50% of the circumference of the second front surface 18, ie in the present case over approximately 180%.

[0065] The inner wall 10, the middle wall 12 and the outer wall 14 are each circular and arranged concentrically to each other and coaxially to the axis Z from the previous drawings. The axis Z runs through the axis of rotation of the walls, the walls run parallel to the axis Z. The inner wall 10 has an internal thread 70 in this case, into which a Fig. 7 A nozzle (not shown), in particular a material nozzle, which is often also referred to as a paint nozzle, can be screwed in. The outer wall 14 has an external thread 72, via which a Fig. 7 An air nozzle ring (not shown) with an air cap can be screwed onto the head region 6 of the base body 2. The middle wall 12 has no thread in the present case. However, it is conceivable that the middle wall 12 can also have an internal or external thread. Furthermore, it is conceivable that the outer wall 14 has an internal thread for screwing in a component, in particular an air cap, and the inner wall 10 has an external thread for screwing on a component, in particular a nozzle.

[0066] The first front surface 16 has two inner air outlet openings 20a and 20b, and the second front surface 18 has two outer air outlet openings 22a and 22b. The diameter of the air outlet openings 20a, 20b, 22a, and 22b corresponds almost to the width of the front surfaces 16, 18 or the groove 19 into which they are inserted. This allows the available space to be utilized for maximum air throughput. Fig. 8 shows a perspective view of an embodiment of a nozzle 24 for use in an embodiment of a spray gun according to the invention or also for use in a method according to the invention. The nozzle 24 can have at least one material nozzle 40 with a material outlet opening 28 and a section for applying a tool, in this case an external hexagon profile 41, as well as a disk element 32 with a front surface 34 and a conical surface 35. The front surface 34 has in this case several, preferably 7 to 9, through openings 36 distributed over the circumference. Material nozzle 40 and disk element 32 are preferably designed as one piece. Arranged thereon, preferably captively arranged, particularly preferably pressed on, is a first baffle plate 30. Arranged on this, in turn, preferably arranged as one piece, is a Fig. 9 recognizable second baffle plate 42. This is arranged on the side of the first baffle plate 30 facing away from the material outlet opening 28. Like the first baffle plate 30, the second baffle plate 42 is also annular with an inner and an outer circumference. In the radial direction, the inner circumference of the second baffle plate 42 does not reach as far as the external thread 46 of the material nozzle 40, so that a gap exists between the inner circumference of the second baffle plate 42 and the external thread 46 of the material nozzle 40. Along one axis, i.e. along the central or longitudinal axis of the nozzle 24, the second baffle plate 42 is spaced from the through-openings 36. In the radial direction, the second baffle plate 42 almost completely covers the through-openings 36, as in Fig. 10 is clearly visible. In Fig. 10 Also visible are the material outlet opening 28 and the impact surface 30a of the first impact plate 30. Preferably, the plate element 32 has a recess or groove on its side facing away from the material outlet opening 28, in which the through-openings 36 are arranged. This increases the distance between the side of the plate element 32 facing away from the material outlet opening 28 and the side of the second impact plate 42 facing this side, and the air flowing into this area has more volume available for distribution.

[0067] Fig. 11 shows the structure of the nozzle 24 in a sectional view. It can be seen that the material nozzle 40 with its material outlet opening 28 and the disk element 32 are designed as a single piece. On its side facing away from the material outlet opening 28, the disk element 32 has a circumferential groove 33 which enables or facilitates the pressing of the first baffle plate 30 onto the disk element 32. The first baffle plate 30 has an inner circumference and an outer circumference, wherein the outer circumference of the first baffle plate 30 is larger than the outer circumference of the disk element 32. The inner circumference of the first baffle plate 30 extends approximately as far as the through-openings 36 of the disk element 32. The second baffle plate 42 is arranged as a single piece on the first baffle plate 30. A collar 43 can be arranged between them. The first baffle plate 30, the second baffle plate 42 and, if applicable, the collar 43 form a Z-shape in the present case.The first baffle plate 30 can have a recess on its side facing the material outlet opening 28, in particular in the region of the inner circumference, so that a stepped shape is formed, which can form the contact area between the first baffle plate 30 and the plate element 32. In the present case, the plate element 32 also has a step on its side facing away from the material outlet opening 28, in particular in the region of the outer circumference, which forms the contact area between the first baffle plate 30 and the plate element 32.

[0068] The material nozzle 40 is equipped with an air guide disc 38, which is also captively connected to the material nozzle 40, in particular, it can be pressed on. Furthermore, the present nozzle 24 has a nozzle seal 44, the purpose of which is explained further below. The nozzle seal 44 is preferably made of plastic and is preferably replaceably connected to the material nozzle 40. Fig. 11 the external thread 46 of the material nozzle 40 is also indicated.

[0069] Fig. 12 shows a sectional view of the head region 6 of an embodiment of a spray gun according to the invention with the embodiment of a nozzle 24 from Fig. 8 bis Fig. 11 in the assembled state. The nozzle 24, which in this case is a unit comprising the material nozzle 40 with the disc element 32, the first baffle plate 30, the second baffle plate 42, the air guide plate 38, and the nozzle seal 44, is screwed into the base body or its head region via the threads described above. The stop is formed by the first baffle plate 30, in particular its baffle surface 30a, and the central wall 12 of the head region 6 of the base body. The baffle surface 30a of the first baffle plate 30 acts as a sealing surface, and the central wall 12, in particular the front end of the central wall 12, acts as a counter-sealing surface against which the baffle surface 30a bears in a sealing manner. Alternatively or additionally, the outer surface of the second baffle plate 42 or the outer surface of the collar 43 between the first baffle plate 30 and the second baffle plate 42 can also be in sealing contact with an inner surface of the central wall 12.

[0070] When the nozzle 24 is screwed in, the nozzle seal 44 is against a counter sealing surface 84 which is Fig. 6 shown, presses and seals the material-carrying area of ​​the spray gun, in particular the transition area between the paint channel in the base body and the hollow section of the material nozzle 40 for conveying the material to be sprayed, against the air-carrying area of ​​the spray gun.

[0071] In the installed state, the first baffle plate 30 forms a gap 86 with the outer wall 14, which preferably represents an annular gap with a substantially constant width. The second baffle plate 42 forms a further gap 88 with the inner wall 10, which also preferably represents an annular gap with a substantially constant width.

[0072] The air nozzle ring 74 can be arranged on the head region 6 of the base body via the threads already mentioned above. The air cap 78 is arranged in the air nozzle ring 74, wherein the air cap 78 is fixed in a first direction by means of a flange 90, which rests against a projection on the inner surface of the air nozzle ring 74. In the opposite direction, the air cap 78 is limited by a retaining ring 89, which lies in a groove 91 in the air cap 78 and in a recess in the inner surface of the air nozzle ring 74. Merely for better visibility, the retaining ring 89 is shown in the present Fig. 12 outside the groove 91, whereby the retaining ring 89 does not have to be completely located in the groove 91. For example, the retaining ring 89 can be polygonal in shape so that it only partially lies in the circular groove 91.

[0073] As in Fig. 7 As can be seen, the first front surface 16 between the inner wall 10 and the middle wall 12 and the second front surface 18 between the middle wall 12 and the outer wall 14 in the present embodiment of the base body each have two air outlet openings 20a and 20b and 22a and 22b respectively. Referring again to Fig. 12 It can be seen that the air flowing out of the two inner air outlet openings 20a and 20b between the inner wall 10 and the middle wall 12 first strikes the second baffle plate 42. Due to the constriction in the form of the gap 88, the air is distributed over the circumference of the air distribution chamber between the inner wall 10 and the middle wall 12. The air flows through the gap 88 and is thereby throttled before flowing through the through-openings 36 of the plate element 32. The air exiting the through-openings 36 in a somewhat "punctuated" manner strikes the air guide element 38, whereby the air is distributed more evenly, homogenized, and slightly throttled again by the slight constriction between the air guide element 38 and the inner surface of the air cap 78.From the air cap chamber 80 between the air cap 78 and the material nozzle 40, the air then flows through a gap, in particular an annular gap, which is created by the front end of the material nozzle 40 protruding from the inside into the central opening 79 in the air cap 78. The material to be sprayed, flowing from a material feed device through the paint channel in the base body of the spray gun and the hollow section of the material nozzle 40, is atomized by the air flowing out of the gap, thereby forming the so-called spray jet. The air with the path just described is therefore referred to as atomizing air. The two inner air outlet openings 20a and 20b between the inner wall 10 and the middle wall 12 can be referred to as atomizing air outlet openings, the air channels behind them as atomizing air channels, and the air distribution chamber delimited by the inner wall 10 and the middle wall 12 can be referred to as the atomizing air distribution chamber.The area through which the atomizing air flows can be referred to as the atomizing air area.

[0074] The air flowing from the two outer air outlet openings 22a and 22b, which are located in the Fig. 12 shown embodiment of the base body is present, but in Fig. 7 can be seen particularly well, escaping air first strikes the first baffle plate 30. Due to the constriction in the form of the gap 86, the air is distributed over the circumference of the air distribution chamber between the middle wall 12 and the outer wall 14. The air flows through the gap 86 and is thereby throttled. Advantageously, the air then flows into an intermediate chamber 92 and into the horn air supply channels 78a in the horns of the air cap 78. From here, the air flows out of the horn air bores 78b and strikes the above-mentioned spray jet, deforming it. In particular, the so-called horn air flowing out of the horn air bores 78b in the diametrically opposed horns of the air cap 78 compresses the spray jet, which originally has a circular cross-section, on two opposite sides, creating a so-called broad jet. The amount of horn air flowing out of the horn air holes 78b, orThe amount of air flowing out of the outer air outlet openings 22a and 22b, which can be referred to as horn air outlet openings, can already be controlled via an example shown in . Fig. 4 The round-wide jet control device 9 shown can be adjusted. If the horn air is reduced to zero or almost zero, the spray gun produces a so-called round jet with a circular cross-section. The air channels behind the so-called horn air outlet openings can be referred to as horn air channels, the air distribution chamber defined by the central wall 12 and the outer wall 14 can be referred to as the horn air distribution chamber, and the area through which the horn air flows can be referred to as the horn air area. To seal the horn air area from the environment, a sealing element 87 can be provided between the air nozzle ring 74 and the head area 6.

[0075] So-called control openings 79a can be incorporated into the front surface of the air cap 78, radially outside of the central opening 79. The air exiting the control openings 79a influences the horn air, in particular, it mitigates the impact of the horn air on the spray jet. Furthermore, the so-called control air protects the air cap 78 from contamination by carrying paint droplets away from the air cap 78. It also contributes to the further atomization of the spray jet. The control air also acts on the circular jet, causing a slight pre-deformation and, here too, additional atomization.

[0076] As in Fig. 12 As can be clearly seen, the separation, in particular the sealing, between the atomizing air region and the horn air region is achieved by the central wall 12, the first baffle plate 30, the plate element 32 and by the air cap 78, in particular by a preferably circumferential web 78c of the air cap 78. The web 78c in this case has a conical region which bears against the conical surface 35 of the plate element 32. This also centers the air cap 78, ensuring that the air cap 78 and the material nozzle 40 are arranged concentrically to one another and that the above-mentioned gap, in particular the annular gap, between the front end of the material nozzle 40 and the air cap 78 for the outlet of the atomizing air has a constant width.

[0077] It is clear that, due to the special design of the base body and the spray gun according to the invention, no additional sealing element is necessary to seal between the atomizing air area and the horn air area. Because the front end of the middle wall 12 is set back from the front end of the outer wall 14, the middle wall 12 of the base body, which is important for sealing between the atomizing air area and the horn air area, is well protected from damage even when the nozzle 24 is unscrewed. Furthermore, this design allows the head area 6 of the base body to accommodate the first baffle plate 30, which therefore does not protrude beyond the outer wall 14. The gun head can therefore be designed very compactly.

[0078] In the Figs. 8 bis 12 The nozzle 24 shown is preferably a low-pressure or HVLP nozzle, or a nozzle for use in a low-pressure or HVLP nozzle arrangement, in particular for use in a method according to the invention for converting a spray gun, in particular a paint spray gun.

[0079] Fig. 13 shows a perspective view of a second embodiment of a nozzle for use in an embodiment of a spray gun according to the invention or also for use in a method according to the invention. In comparison to the nozzle shown in the Figs. 8 bis 12 In the first exemplary embodiment shown, the present nozzle 50 does not have an air guide disk, and the disk element 32 has a larger number of through-openings 36 in the front surface 34. Otherwise, the nozzle 50 also has a material nozzle 40 with a material outlet opening 28, and the disk element 32 has a conical surface 35. Preferably, the disk element 32 has a recess or groove on its side facing away from the material outlet opening 28, in which the through-openings 36 are arranged. As a result, when the nozzle 50 is installed, the distance between the side of the disk element 32 facing away from the material outlet opening 28 and the first front surface 16 of the head region 6 of the base body 2 increases, and the air flowing into this region has more volume available for distribution.

[0080] Only in Fig. 14 It can be seen that the first baffle plate 31 of the nozzle 50 is designed differently than the first baffle plate 30 of the previously described nozzle 24. The nozzle 50 does not have a second baffle plate, but instead has an inner collar 52 and an outer collar 53 with an intermediate baffle surface 31a.

[0081] In Fig. 15 , which shows a rear view of the nozzle 50, it is clear that the through-openings 36 are completely exposed, i.e., they are not covered or overhanging other components of the nozzle 50. The disc element 32 of the nozzle 50 preferably has a larger number of through-openings 36, in particular between 10 and 14.

[0082] The exposed through openings 36 are also in Fig. 16 , which is a sectional view of the nozzle 50. The material nozzle 40 with the integrally arranged disc element 32 and preferably replaceable nozzle seal 44 is essentially identical to the material nozzle 40 with the integrally arranged disc element 32 and preferably replaceable nozzle seal 44 of the previously described nozzle 24. The above statements regarding these components apply accordingly to the nozzle 50. The first baffle plate 31 with the inner collar 52, outer collar 53, and the intermediate baffle surface 31a differs from the first baffle plate 30 of the previously described nozzle 24.

[0083] Fig. 17 shows a sectional view of the head region 6 of an embodiment of a spray gun according to the invention with the embodiment of a nozzle 50 from the Figs. 13 bis 16 The basic body is the Fig. 12 shown embodiment. In particular, the head region 6 is designed the same, which is why reference can be made to the above explanations. It can be seen that the gap 86 between the outer wall 14 and the first baffle plate 31 is narrower than the gap 86 from Fig. 12 , which shows the head region 6 of the base body equipped with the previously described nozzle 24. Since it is the same base body with the same dimensions, in particular with the same inner diameter of the outer wall 14, it is clear that the first baffle plate 31 of the nozzle 50 has a larger outer diameter than the first baffle plate 30 of the nozzle 24. The remaining explanations regarding the in Fig. 12 The arrangement shown can also be used for the Fig. 17 shown arrangement applies.

[0084] Due to the lack of a second baffle plate and air guide plate in the nozzle 50 compared to the nozzle 24, the atomizing air is directed in the Fig. 17 shown arrangement, ie when using the nozzle 50, is less throttled than in the Fig. 12 shown arrangement, ie when using the nozzle 24. As a result, the nozzle internal pressure, ie in particular the pressure in the air cap chamber 81 between the air cap 78 and the material nozzle 40 when using the nozzle 50 is greater than the nozzle internal pressure, ie in particular the pressure in the Fig. 12 shown air cap chamber 80 between air cap 78 and material nozzle 40 when using nozzle 24.

[0085] In the Figs. 13 bis 17 The nozzle 50 shown is preferably a high-pressure or compliant nozzle, or a nozzle for use in a high-pressure or compliant nozzle arrangement, in particular for use in a method according to the invention for converting a spray gun, in particular a paint spray gun, with a first internal nozzle pressure to a spray gun, in particular a paint spray gun, with a second internal nozzle pressure.

[0086] Fig. 18 is a perspective view of a part of an embodiment of a base body, namely the area in which a Fig. 4 The circular wide-jet regulating device 9 shown as an example can be arranged. In particular, Fig. 18 the interior of the round-wide jet air distribution chamber 68 is at least partially visible. As described above, the base body 2, as in Fig. 7As can be seen, the head region 6 has two atomizing air outlet openings 20a, 20b and two horn air outlet openings 22a, 22b. In the head region 6, the two atomizing air outlet openings 20a, 20b are spaced apart from one another, as are the two horn air outlet openings 22a, 22b. The atomizing air ducts located behind the two atomizing air outlet openings 20a, 20b, i.e. the air ducts that end in the form of the atomizing air outlet openings 20a, 20b, extend into the round-wide jet air distribution chamber 68, converge on their way into the round-wide jet air distribution chamber 68 and meet at the latest at the intersection point with a wall of the round-wide jet air distribution chamber 68. The round-wide jet air distribution chamber 68 therefore has only a single atomizing air duct opening 20c. The horn air ducts located behind the two horn air outlet openings 22a, 22b, i.e.The air ducts which end in the form of the horn air outlet openings 22a, 22b extend into the round wide jet air distribution chamber 68, converge on their way into the round wide jet air distribution chamber 68 and meet at the latest at the intersection point with a wall of the round wide jet air distribution chamber 68. The round wide jet air distribution chamber 68 therefore also has only a single horn air duct opening 22c.

[0087] The outer contours of the atomizing air duct opening 20c and the horn air duct opening 22c in the round, wide-jet air distribution chamber 68 can have the outer contour of a horizontal figure-8. When the two atomizing air ducts and the two horn air ducts completely overlap upon entering the round, wide-jet air distribution chamber 68, the atomizing air duct opening 20c has substantially the same cross-sectional shape as at least one of the atomizing air outlet openings 20a and 20b, and the horn air duct opening 22c has substantially the same cross-sectional shape as one of the horn air outlet openings 22a, 22b.

[0088] Various round, wide-jet regulating devices are known in the prior art, for example from EP 0 706 832 B1 or EP 2 451 586 B1. Any type of round, wide-jet regulating device can be used for the present base body. Preferably, however, the round, wide-jet air distribution chamber 68 has a first chamber section and a second chamber section, the second chamber section having a larger diameter than the first chamber section. The horn air ducts of the base body 2 open into the first chamber section, i.e., the horn air duct opening 22c is located in the first chamber section. The atomizer air ducts of the base body 2 open into the second chamber section, i.e., the atomizer air duct opening 20c is located in the second chamber section.The sections form a step onto which a plate of a round-wide jet regulating device can rest in order to close the first chamber section and thus prevent the air supply to the horn air duct opening 22c and thus to the horn air ducts. In this case, when the spray gun is in operation, only the atomizing air duct opening 20c and thus the atomizing air ducts are supplied with air. The spray gun produces a round jet with an essentially circular cross-section, since no horn air acts laterally on the spray jet. For example, by means of a rotating mechanism, the plate of the round-wide jet regulating device can preferably be continuously moved away from the step between the first and second chamber sections of the round-wide jet air distribution chamber 68, so that the plate releases the air supply to the first chamber section and thus to the horn air duct opening 22c and to the horn air ducts in the base body 2.The further the plate is moved away from the step, the more air can flow through the horn air channels and thus out of the horn air holes and the more the spray jet is compressed laterally, creating an increasingly narrow wide jet.

[0089] Finally, it should be noted that the described embodiments describe only a limited selection of possible embodiments and therefore do not represent a limitation of the present invention.

Claims

1. Spray gun (1), in particular a paint spray gun, comprising at least one main body (2), a nozzle (24, 50) having at least one material nozzle (40), an air cap (76, 78), a first air-conducting region and a second air-conducting region, wherein the first air-conducting region conducts air that is used to atomize material to be sprayed, and the second air-conducting region conducts air that is used to influence a spray jet, wherein the main body (2) has at least one head region (6) for attaching a nozzle arrangement, wherein the head region (6) has at least one inner wall (10), one outer wall (14) and one middle wall (12) arranged therebetween, wherein the walls (10, 12, 14) are formed circumferentially and as a single piece with the main body (2), wherein the front end of the middle wall (12) is set back along an axis (Z) relative to the front end of the outer wall (14), and wherein the first air-conducting region and the second air-conducting region are separated from one another, at least in regions, by the middle wall (12) of the main body (2), a disk element (32) arranged as a single piece on the material nozzle (40), at least one baffle disk (30, 31, 42) arranged, in particular nondetachably arranged, on the material nozzle (40), and by at least a part of the air cap (76, 78), characterized in that the inner wall (10), the middle wall (12) and the outer wall (14) are each circular and arranged concentrically with one another.

2. Spray gun (1) according to claim 1, characterized in that the front end of the middle wall (12) is set back along the axis (Z) by 2 mm to 4 mm relative to the front end of the outer wall (14).

3. Spray gun (1) according to claim 2, characterized in that the inner wall (10) and the middle wall (12) delimit a first air distribution chamber (60) and the middle wall (12) and the outer wall (14) delimit a second air distribution chamber (62).

4. Spray gun (1) according to claim 2 or 3, characterized in that a first front surface (16) is arranged between the inner wall (10) and the middle wall (12) and a second front surface (18) is arranged between the middle wall (12) and the outer wall (14), in that the first front surface (16) is, at least in regions, at a first distance (d1) along the axis (Z) from the front end of the outer wall (14), in that the second front surface (18) is, at least in regions, at a second distance (d2) along the axis (Z) from the front end of the outer wall (14), and in that the first distance (d1) is greater than the second distance (d2), in particular in that the first distance (d1) is 9 mm to 11 mm and the second distance (d2) is 4 mm to 6 mm.

5. Spray gun (1) according to claim 4, characterized in that at least the first front surface (16) and / or the second front surface (18) have, at least in regions, a groove (19), the width of which preferably corresponds substantially to the width of the first front surface (16) or the second front surface (18) and / or which preferably extends in the circumferential direction over 25% to 75%, in particular over 45% to 55%, of the circumference of the first front surface (16) or the second front surface (18).

6. Spray gun (1) according to claim 5, characterized in that the second front surface (18) has, in at least regions, a groove (19) having a bottom surface, wherein the bottom surface of the groove (19) is at a third distance along the axis (Z) from the front end of the outer wall (14), and in that the third distance is smaller than the first distance (d1) of the first front surface (16) from the front end of the outer wall (14).

7. Spray gun (1) according to any of claims 4 to 6, characterized in that the first front surface (16) has at least one inner air-outlet opening (20a, 20b), in particular two inner air-outlet openings (20a, 20b) and in that the second front surface (18) has at least one outer air-outlet opening (22a, 22b), in particular two outer air-outlet openings (22a, 22b), wherein preferably the at least one inner air-outlet opening (20a, 20b) of the first front surface (16) extends, at least in regions, over at least 85% of the width of the first front surface (16) and the at least one outer air-outlet opening (22a, 22b) of the second front surface (18) extends, at least in regions, over at least 85% of the width of the second front surface (18).

8. Spray gun (1) according to any of claims 4 to 7, characterized in that the main body (2) has at least two atomization air channels (64) which extend from the first front surface (16) into a fan control air distribution chamber (68) and / or in that the main body (2) has at least two horn air channels (66) which extend from the second front surface (18) into a fan control air distribution chamber (68), wherein the atomization air channels (64) are spaced apart from one another in the region of the first front surface (16) and at least partially overlap in the region of the fan control air distribution chamber (68), and / or wherein the horn air channels (66) are spaced apart from one another in the region of the second front surface (18) and at least partially overlap in the region of the fan control air distribution chamber (68).

9. Spray gun (1) according to any of claims 2 to 8, characterized in that the front end of the inner wall (10) is set back along the axis (Z) relative to the front end of the middle wall (12), in particular in that the front end of the inner wall (10) is set back along the axis (Z) by 0.4 mm to 0.6 mm relative to the front end of the middle wall (12).

10. Spray gun (1) according to any of claims 2 to 9, characterized in that the inner wall (10) has an outer diameter of 13 mm to 15 mm and / or an inner diameter of 11 mm to 13 mm, the middle wall (12) has an outer diameter of 22 mm to 24 mm and / or an inner diameter of 20 mm to 22 mm, and the outer wall (14) has an outer diameter of 33 mm to 35 mm and / or an inner diameter of 31 mm to 33 mm.

11. Method for modifying a spray gun (1), in particular a paint spray gun, having a first internal nozzle pressure to form a spray gun (1), in particular a paint spray gun, having a second internal nozzle pressure, wherein the first internal nozzle pressure is greater than the second internal nozzle pressure, and wherein the method comprises at least the following steps: a. removing a high-pressure nozzle arrangement from or out of a main body (2) of the spray gun (1), wherein the high-pressure nozzle arrangement has at least one nozzle (50) having a material nozzle (40), which material nozzle (40) has a hollow portion for the passage of the material to be sprayed, and a material outlet opening (28); b. arranging a low-pressure nozzle arrangement in or on the main body (2) of the spray gun (1), wherein the low-pressure nozzle arrangement has at least one nozzle (24) having a material nozzle (40), which material nozzle (40) has a hollow portion for the passage of the material to be sprayed, and a material outlet opening (28), characterized in that the nozzle (50) of the high-pressure nozzle arrangement, which is removed from or out of the main body (2) of the spray gun (1), further comprises a disk element (32), arranged on the outer circumference of the hollow portion, and at least one first baffle disk (31), wherein the first baffle disk (31) is arranged on the side of the disk element (32) facing away from the material outlet opening (28) and has an inner and an outer circumference, and in that the nozzle (24) of the low-pressure nozzle arrangement, which is arranged in or on the main body (2) of the spray gun, further comprises a disk element (32) arranged on the outer circumference of the hollow portion and at least one first baffle disk (30), wherein the first baffle disk (30) is arranged on the side of the disk element (32) facing away from the material outlet opening (28), has an inner and an outer circumference, and has a second baffle disk (42) arranged on the side of the first baffle disk (30) facing away from the material outlet opening (28), wherein the outer circumference of the first baffle disk (30) of the nozzle (24) of the low-pressure nozzle arrangement is smaller than the outer circumference of the first baffle disk (31) of the nozzle (50) of the high-pressure nozzle arrangement.

12. Method according to claim 11, characterized in that the method comprises at least the following further steps: a. removing a high-pressure air cap (76) arranged on the main body (2) via an air cap ring (74), wherein the high-pressure air cap (76) has at least one central opening (77) which has a first diameter; b. arranging a low-pressure air cap (78) which can be arranged on the main body (2) via an air cap ring (74), wherein the low-pressure air cap (78) has at least one central opening (79) having a second diameter and wherein the second diameter is larger than the first diameter of the high-pressure air cap (76).

13. Method for modifying a spray gun (1), in particular a paint spray gun, having a first internal nozzle pressure to form a spray gun (1), in particular a paint spray gun, having a second internal nozzle pressure, wherein the first internal nozzle pressure is lower than the second internal nozzle pressure, wherein the method comprises at least the following steps: a. removing a low-pressure nozzle arrangement from or out of a main body (2) of the spray gun (1), wherein the low-pressure nozzle arrangement has at least one nozzle (24) having a material nozzle (40), which material nozzle (40) has a hollow portion for the passage of the material to be sprayed, and a material outlet opening (28); b. arranging a high-pressure nozzle arrangement in or on the main body (2) of the spray gun (1), wherein the high-pressure nozzle arrangement has at least one nozzle (50) having a material nozzle (40), which material nozzle (40) has a hollow portion for the passage of the material to be sprayed, and a material outlet opening (28), characterized in that the nozzle (24) of the low-pressure nozzle arrangement, which is removed from or out of the main body (2) of the spray gun (1), further comprises a disk element (32), arranged on the outer circumference of the hollow portion, and at least one first baffle disk (30), wherein the first baffle disk is arranged on the side of the disk element (32) facing away from the material outlet opening (28), has an inner and an outer circumference, and has a second baffle disk (42) arranged on the side of the first baffle disk (30) facing away from the material outlet opening (28), and in that the nozzle (50) of the high-pressure nozzle arrangement, which is arranged in or on the main body (2) of the spray gun, further comprises a disk element (32), arranged on the outer circumference of the hollow portion, and at least one first baffle disk (31), wherein the first baffle disk (31) is arranged on the side of the disk element (32) facing away from the material outlet opening (28) and has an inner and an outer circumference, wherein the outer circumference of the first baffle disk (31) of the nozzle (50) of the high-pressure nozzle arrangement is larger than the outer circumference of the first baffle disk (30) of the nozzle (24) of the low-pressure nozzle arrangement.

14. Method according to claim 13, characterized in that the method comprises at least the following further steps: a. removing a low-pressure air cap (78) arranged on the main body (2) via an air cap ring (74), wherein the low-pressure air cap (78) has at least one central opening (79) having a first diameter; b. arranging a high-pressure air cap (76) which can be arranged on the main body (2) via an air cap ring (74), wherein the high-pressure air cap (76) has at least one central opening (77) having a second diameter, and wherein the second diameter is smaller than the first diameter of the low-pressure air cap (78).