DE8817247U1 - Sprayer - Google Patents

Description

Description :

The invention relates to a spraying device for applying fluid media, in particular adhesives, dyes, etc., to an object according to the preamble of claim 1.

Adhesives, glues, varnishes or similar flowable substances which harden or dry out after being applied to an object place special demands on spray guns used for application, because there is a risk that the substances to be processed will harden in the spray gun during any work breaks, particularly in the nozzle bore.

Spraying devices are already known which are intended to prevent the described drying out of the spray head. On the one hand, a high-pressure and movable nozzle needle is arranged in the nozzle bore for this purpose.

However, this requires the supply of control compressed air. Another disadvantage is that the nozzle needle is complex to manufacture and can only be installed in nozzles with a correspondingly large nozzle bore. In addition, there are natural limits to the cycle frequency of such a nozzle needle. Such spray guns can therefore only be used to a limited extent. It is also known to rinse the nozzle bores of the nozzles during work or cycle breaks. It has proven to be disadvantageous that rinsing liquid remains in the nozzle bore, which mixes with the material to be applied during the work cycle following the work or cycle break, or even gets onto the object unmixed. The object can then no longer be used.

is Based on this, the invention is based on the object of creating a spraying device with which, despite work interruptions (cycle or work breaks), a reliable application of easily hardening or drying substances (varnishes, paints or adhesives) is possible, in particular hardening or sticking of the substance is avoided.

This task is solved in terms of the device by a spray gun according to claim 1. The movable closing element ensures a simple but effective closure of the nozzle bore or several nozzle bores of the spray gun during a work or cycle break. When the spray gun is in operation, the closing element is moved in such a way that the nozzle bore or the nozzle bores are released for the application of glue, dye, etc. The movement of the closing element thus switches the operating position of the spray gun from a work or cycle break to a working position and vice versa.

According to a further proposal of the invention, the switching of the closing element takes place in at least one direction, i.e. from a covering position to an opening position of the same or vice versa, pressure-operated by a corresponding movement element. In the case of pressure-operated movement in only one direction, a

The closing element is moved spring-loaded, preferably from the open position into the covering position of the closing element. As a result, the spray gun according to the invention is self-sufficient with regard to closing the nozzle bore or the nozzle bores, i.e. the closing takes place automatically. In the event of a fault, this ensures that the nozzle bore or nozzle bores are closed, i.e. protected from drying out. Alternatively, it can be useful, especially in the case of larger spray guns that require greater movement forces of the closing element, to move it in both directions using pressure medium.

In a particularly advantageous embodiment of the invention, the closing element is designed as a sliding closing plate assigned to the underside of the housing. This has the advantage that the closing plate does not make the compact housing even more complex. In addition, this arrangement has the advantage that the closing plate rests under the nozzle, namely on the outlet side of the nozzle bore from the spray gun. This seals the nozzle bore or bores in the covering position of the closing plate exactly where the greatest risk of drying out or hardening of the paint, adhesive or the like occurs.

It is also proposed to arrange at least one seal between the closing plate and the associated outlet side of the nozzle or nozzles or the housing. This ensures that, particularly when the closing plate is in the covering position, the contact surface of the same on the housing is sealed off from the nozzle bore or bores in an airtight and moisture-tight manner.

In a preferred embodiment of the spray gun, a channel system is arranged in the closing plate, which in the cover position of the same is connected to the nozzle bore or the nozzle bores. This channel system enables the nozzle or nozzles to be kept moist in the cover position of the closing plate. In addition, the nozzle or nozzles can also be cleaned in this way by

Dissolving or washing liquid is passed through the nozzle bore or bores.

Further subclaims relate to the structural design of the locking plate, the seal and the pressure medium elements for actuating the locking plate.

An embodiment of the spray device according to the invention is explained in more detail below using the drawing. In it:

Fig. 1 a vertical section through the spray gun in the area of two nozzles in a working position,

Fig. 2 shows the spray gun of Fig. 1 in a cycle or work break,

Fig. 3 a horizontal section through the spray gun in the area of a drive for a closing plate,

Fig. 4 a vertical section through the spraying apparatus along the line IV - IV in Fig. 3,

Fig. 5 a horizontal section through the locking plate along the line V - V in Fig. 1, and

Fig. 6 is a section according to Fig. 3 through a spray head composed of two spray modules.

The spray gun shown here is used in particular for the portion-wise application of adhesives of any kind (hot glue, cold glue or similar), dyes (varnishes, paints, stains or similar) or other flowable substances. In the following example of the spray gun shown, it is assumed that it is used for the point-like or drop-like application of an adhesive to an object not shown.

The spray gun shown in the figures has a plurality of nozzles 11 housed in a common housing 10. In the spray gun shown, these are arranged in two parallel rows of nozzles 12 in the housing 10, whereby the distance between adjacent nozzles 11 in each row of nozzles 12 is approximately the same, but the nozzles 11 of different rows of nozzles 12 are offset from one another, namely "with a gap".

&iacgr;&ogr; The nozzles 11 in the spray gun shown here are fed by metering valves 13 of commercially available design. For this purpose, a metering valve 13 is arranged above each nozzle 11 in such a way that each nozzle 11 and the metering valve 13 assigned to it lie on a common (vertical) longitudinal center axis 14.

Each dosing valve 13 has a piston (not shown in the figures) which can be moved up and down in a pulsating manner by means of a suitable magnetic drive. With each working cycle, this piston pumps the adhesive entering the dosing valve 13 through an annular chamber into an (upper) inlet opening 15 of a dosing tube 16. The latter is connected to the nozzle 11 assigned to it in such a way that a (lower) end section 17 of the dosing tube 16 projects into the upper area of the nozzle 11. A central dosing bore 18 in the dosing tube 16 merges into a central nozzle bore 19 of the nozzle 11. The nozzle bore 19 and the dosing bore 18 are thus arranged one above the other on the common longitudinal center axis 14. In the area of the transition from the dosing bore 18 to the nozzle bore 19, a seal (not shown in the figures) is expediently arranged between the dosing tube 16 and the nozzle 11.

Each of the nozzles 11 opens with a (lower) front side 20 on a lower side 21 of the housing 10. In the area of the front side 20, from which the metering holes 18 emerge from the nozzles 11, a constriction is provided in the present embodiment, such that the diameter of the metering holes 18 decreases in stages here.

The closing element, namely a reciprocating closing plate 22, is assigned to the underside 21 of the housing 10 in the embodiment of the spray gun according to the invention shown here. The closing plate 22 has an upper side 23 that rests against the underside 21 of the housing 10. As can be seen from Figs. 1 _, 2 and 4, recesses 24 are arranged in the closing plate 22, the number and grid distribution of which corresponds to the nozzles 11 arranged in the housing 10, so that each nozzle 11 has a recess 24.

xo is assigned. Each recess 24 consists here of a (short) cylinder shoulder 25 directed towards the top 23 of the closing plate 22 and a (conical) funnel 27 enlarging towards the bottom 26 of the closing plate 22. In the working position of the spray gun shown in Fig. 1

Each recess 24 is concentric with the longitudinal center axes 14. As a result, the recesses 24 release the nozzle bores 19 of the nozzles 11 in the working position of the spray gun, which corresponds to the open position of the closing plate 22.

Furthermore, the closing plate 22 has a plurality of connection holes 28, which are connected to a channel system 29, which is also housed in the closing plate 22. Each nozzle 11 is again assigned a connection hole 28, which opens into the top 23 of the closing plate 22, the grid of which corresponds to that of the nozzles 11 or the recesses 24, but is offset from the recesses 24 by approximately half the pitch of neighboring nozzles 11, i.e. is approximately in the middle between two neighboring recesses 24. As can be seen from Fig. 2, in the cover position of the closing plate 22 intended for work or cycle breaks of the spray gun, the connection holes 28 are in a concentric position to the longitudinal center axes 14 of the nozzles 11. As a result, the connection holes 28 cover the

3s Nozzle holes 19 in the covering position of the locking plate 22.

As can be seen from Fig. 4, all connection holes 28 are connected to one another by a large number of (horizontal) holes 30 running in a zigzag shape through the locking plate 22

to form the channel system 29. At the beginning 31 of the channel system there is a feed hole that is similar in design to the connection holes 28 and also opens into the top 23 of the locking plate 22. In an equivalent manner, an output hole 34 is assigned to the end 33 of the channel system.

The feed bore 32 and the outlet bore 34 serve to supply the channel system 29 and the connection bores 28 with a liquid that serves to close the nozzle bores 18 in the cover position.

Both the feed bore 32 and the outlet bore 34 of the channel system 29 are for introducing or pumping the liquid through the same, not shown in the figures.

is assigned to feed or disposal nozzles, which correspond in principle to the nozzles 11 and to which a feed or disposal valve is also assigned, which in turn corresponds to the metering valves 13. In this way, the channel system 29 can be supplied with liquid in a targeted manner and can also be disposed of. By pumping in liquid through the feed valve and the feed nozzle, a liquid pressure can be built up in the channel system 29 when the drain valve is blocked, which reliably closes the metering holes 18 of the nozzles 11 in the cover position and can also be used to flush the nozzles 11 or the metering holes 18 of the same if necessary.

Seals 35 are provided between the underside 21 of the housing 10 and the top side 23 of the closing plate 22. Each nozzle 11 and the feed and outlet nozzles (not shown) are assigned a seal 35. Each seal 35 surrounds the end section 17 of the respective nozzle 11. The seal 35 is housed in the housing 10, in an annular channel 36 arranged therein, which surrounds the cylindrical end section 17 of each nozzle and is formed by a through hole 37 in the housing 10, the diameter of which is larger than that of the end section of the offset nozzles 11. Each seal 35 is formed from an O-ring 38, which rests on the top side 23 of the closing plate 22.

The O-ring 38 is pressed against the top 23 of the closing plate 22 by a compression spring 39 housed in the ring chamber 35, which is supported on an upper collar 40 of the respective nozzle 11. To equalize the pressure force exerted by the compression spring 39 on the elastically deformable O-ring 38, a (non-deformable) ring 41 is arranged between the latter and the underside of the compression spring 39 and can be moved up and down in the ring chamber 36. Due to the preload of the O-ring 38, which is in

&iacgr;&ogr; the cover position of the locking plate 22 not only surrounds the dosing holes 18 but also the connection holes 28 in the locking plate 22, a seal is created in the area of the contact of the upper side 23 of the locking plate with respect to the underside 21 of the housing 10. This ensures that

In the channel system 29, no liquid can get between the nozzle holes 19 and the connection holes 28, but on the other hand, no air can be supplied from the contact surface of the closing plate 22 on the housing 10 to the nozzle holes 19.

From Figs. 3 and 4, a drive 42 can be seen for the back and forth movement of the closing plate 22 relative to the housing 10 into the open position and cover position and vice versa. In the present case, the drive 42 consists of a pressure medium-operated cylinder, namely a pneumatic cylinder 43, and a return element operatively connected to it, namely a compression spring 44. Both the pneumatic cylinder 43 and the compression spring 11 are housed in the housing 10, in the area between the rows of nozzles 12, which run parallel to one another at a distance. A (cylindrical) piston 45 of the pneumatic cylinder 43 can be moved back and forth in a cylinder bore 46 arranged in the housing 10 using compressed air. The compression spring 44 is also mounted in the housing 10 in a bore 47 of approximately the same size opposite the cylinder bore 46. The compression spring is connected here to a piston 48 which can also be moved back and forth in the bore 47.

■ *

As can be seen in particular from Fig. 4, both the compressed air-operated piston 45 and the piston 48 moved by the compression spring 44 are firmly connected to the closing plate 22, namely on the one hand by a cylindrical pin 49 protruding from the housing 10 s and by additional screws not shown in the drawings.

The drive 42 is connected in such a way that by actuating the pneumatic cylinder 43 the locking plate 22 is moved into its

&iacgr;&ogr; opening position, i.e. the working position of the spray gun, while simultaneously pre-tensioning the compression spring 44. By opening the outlet valve on the pneumatic cylinder 43, the compression spring 44 automatically moves the

The locking plate 22 is in its covering position.

Fig. 6 shows a spray head that has a modular design, namely it is made up of spray modules 50 and 51. Each of these spray modules 50 and 51 has eight nozzles 11, which have a grid distribution that corresponds to that in Fig. 3. Furthermore, each of the spray modules 50 and 51 has an independent drive 42 for the closing plates 22 (not shown), which are also made up of modules. Alternatively, it is possible to assign a drive 42 to only one of the spray modules 50 or 51 and use this to move both closing plates 22 or a common (one-piece) closing plate back and forth.

By using additional spray modules, a spray gun of any size can be assembled depending on the intended use. The diagonally opposite nozzles can be used as feed nozzles 52 and as outlet nozzles 53 for the liquid to be guided through the channel system of the locking plates.

When assembling a spray gun from more than three modules, it is recommended to use end modules with a feed nozzle on the one hand and an outlet nozzle on the other hand, as well as nozzles 11 for the adhesive and

(medium) spray modules that only have nozzles 11 for the adhesive supply.

Finally, it can be seen from Fig. 6 that the front sides 54 and 55 of the adjacent injection modules 50, 51, which serve to connect them, have a stepped profile, which makes it easy to position the individual injection modules 50 and 51 together in an exact position. In addition, this design of the front sides 54, 55 prevents the injection modules 50, 51 from being assembled in the wrong relative position.

Ref.: G 88 17247.3

Note: Alfred Schütze

Apparatebau GmbH

19 May 1995/7119 SCU-17G-DE

List of synonyms :

10 Housing

11 Nozzle

12 nozzle rows

13 Dosing valve

14 Longitudinal center axis

15 Entrance opening

16 dosing tubes

17 End section

18 Dosing hole

19 Nozzle bore

20 Front side

21 Bottom

22 Locking plate

23 Top

24 Recess

25 cylinder head

26 Bottom

27 funnels

28 Connection hole

29 Channel system

30 Bore

31 Canal system start

32 Feed hole

33 channel system end

34 Exit hole

35 poetry 36 Ring chamber 37 Through hole 38 O-ring 39 Compression spring 40 Federation 41 ring 42 drive 43 Pneumatic cylinder 44 Compression spring 45 Pistons 46 Cylinder bore 47 drilling 48 Pistons 49 Zylli ndersti ft 50 Spray module 51 Spray module 52 Food nozzle 53 Outlet nozzle 54 Front side 55 Front side

Claims (19)

Expectations: 1. Spraying device for applying flowable substances, in particular adhesives, dyes, etc. to an object with at least one nozzle arranged in a housing, which has a (central) nozzle bore for the outlet of the flowable substance characterized in that the nozzle bore (19) or several nozzle bores (19) arranged in a housing (10) can be closed by at least one movable closing element (closing plate 22) assigned to the nozzle (11) or the nozzles (11). 2. Spray apparatus according to claim 1, characterized in that the closing member (closing plate 22) can be moved back and forth between a covering position closing the nozzle bore (19) and an opening position exposing the nozzle bore (19). 3. Spraying apparatus according to claim 1 or 2, characterized in that the closing member (closing plate 22) can be brought by pressure medium at least into the opening position corresponding to the working position of the nozzle (11). 4. Spraying apparatus according to one or more of claims 1 to 3, characterized in that the closing member (closing plate 22) can be brought from the opening position into the covering position by a resilient return member. 5. Spray apparatus according to claim 1 and one or more of the further claims, characterized in that the closing member (closing plate 22) is designed as one of the undersides (21) of the housing (10) directed towards the mouth of the nozzle (11). is associated with a displaceable locking plate (22). 6. Spray apparatus according to claim 5, characterized in that the closing plate (22) is assigned at least one recess (24) for the nozzle bore (19), such that in the open position of the closing plate (22) the recess (24) exposes the nozzle bore (19). 7. Spray apparatus according to claim 5 or 6, characterized in that at least one channel, in particular a channel system for keeping at least the mouth of each nozzle bore (19) moist in the covering position, is arranged in the closing plate (22). 8. Spray apparatus according to claim 7, characterized in that the channel system (29) has a connection bore (28) emerging from the upper side (23) of the closing plate (22) directed towards the housing (10), which connection bore (28) covers the nozzle bore (19) in the covering position of the closing plate (22). as 9. Spraying apparatus according to claim 5 and one or more of the further claims, characterized in that the nozzle (11) is sealed with respect to the closing plate (22). •*■ 10. Spray apparatus according to claim 9, characterized in that a seal (35) enclosing the nozzle bore (19) is arranged between the underside (21) of the housing (10) and the upper side (23) of the closing plate (22) abutting thereon in order to seal the nozzle (11). 11. Spray apparatus according to claim 10, characterized in that the seal (35) is located in a cylindrical annular chamber (36) between a (lower) end section (17) of the nozzle (11) and &iacgr;&ogr; is mounted on the housing (10). 12. Spray apparatus according to claim 11, characterized in that the seal (35) can be pressed against the upper side (23) of the closing plate (22) facing the housing (10) and resting thereon. it is. 13. Spray apparatus according to claim 11 or 12, characterized in that the seal (35) can be pressed against the closing plate (22) by a compression spring (39) arranged in the annular chamber (36), wherein a ring (41) which can be displaced in the annular chamber (36) is preferably arranged between the seal (35) and the compression spring (39). 14. Spray apparatus according to claim 10 and one or more of the further claims, characterized in that the seal (35) has an O-ring (38). 15. Spraying apparatus according to claim 3 and one or more of the further claims, characterized in that in the housing (10) a pressure cylinder (pneumatic cylinder 43) connected to the closing plate (22) is arranged. 16. Spraying apparatus according to claim 15, characterized in that the pressure medium cylinder (pneumatic cylinder 43) is designed to be single-winding and is in operative connection with the resilient return element, in particular consisting of a compression spring (44), which is also arranged in the housing (10). 17. Spraying apparatus according to claim 16, characterized in that the compression spring (44) designed as a resilient return element is associated with a piston (48) which is arranged longitudinally displaceably in the housing (10) and which is connected to the closing plate (21). is. 18. Spraying apparatus according to claim 1 and one or more of the further claims, characterized by a plurality of nozzles (11) arranged in a grid in the housing (10), to which &iacgr;&ogr; a common locking plate (22) is assigned. 19. Spraying apparatus according to claim 1 and one or more of the further claims, characterized in that the channel system (29) in the closing plate (22) on the inlet side is and/or on the output side a nozzle (11) arranged in the housing (10) is assigned, such that at least in the covering position of the closing plate (22) the nozzle bores (19) of the nozzles (11) assigned to the channel system (29) can be provided with a moisturizing or dissolving liquid through the channel system (29).