APPARATUS FOR APPLYING A MULTI-COMPONENT VISCOUS MATERIAL TO WORKPIECES

Abstract

An apparatus for applying a multi-component viscous material to workpieces includes a metering unit having a number of metering valves corresponding to the number of components of the material, as well as a coupling device, and having a mixing unit having a material inlet at a first end, and a coupling part releasably connected to the coupling device, and, at a second end, a mixing tube having an exit opening for the material, as well as a mixing structure arranged in the tube, for mixing the components as they are passed through the tube from the inlet to the exit. A needle valve releases and closes the exit opening and has a valve needle extending in a longitudinal direction from the material inlet to the exit opening that releases the exit opening in a release position, and closes it in a closed position, by contacting a valve seat.

Claims

1. An apparatus for applying a multi-component viscous material to workpieces, having a metering unit (12) that has a number of metering valves that corresponds to the number of components of the viscous material, as well as a coupling device (16), and having a mixing unit (20), which has a material inlet (28), and a coupling part (26) releasably connected to the coupling device (16) at a first end (24), and, at a second end (32), a mixing tube (22) that has an exit opening (34) for the viscous material, as well as a mixing structure (36) arranged in the mixing tube (22), for mixing the components as they are passed through the mixing tube (22) from the material inlet (28) to the exit opening (34), the apparatus further comprising a needle valve (40) for releasing and closing the exit opening (34), wherein the needle valve has a valve needle (42) that extends in a longitudinal direction (38) that runs from the material inlet (28) to the exit opening (34), wherein the valve needle releases the exit opening (34) in a release position, and closes the exit opening in a closed position, by making contact with a valve seat (46).

2. The apparatus according to claim 1, wherein the mixing structure (36) has an inner tube (48), which is arranged in the mixing tube (22), and through which tube the valve needle (42) extends, and from which tube a mixing spiral (50) projects away radially.

3. The apparatus according to claim 2, wherein the valve needle (42) projects out of the inner tube (48) at a front end (52) of the inner tube, wherein the front end faces the valve seat (46), and is conducted to be sealed off at the front end (52), by means of a sealing element (54).

4. The apparatus according to claim 1, wherein the mixing unit (20) is produced in one piece, by means of 3D printing.

5. The apparatus according to claim 1, wherein the mixing unit (20) has different materials.

6. The apparatus according to claim 1, wherein the mixing tube (22) and the mixing structure (36) are produced from a first material, and the valve seat (46) is produced from a second material.

7. The apparatus according to claim 1, wherein the mixing tube (22) and the mixing structure (36) are produced from a first material, and the valve seat (46) and the sealing element (54) are produced from a second material or from different second materials.

8. The apparatus according to claim 1, wherein the needle valve (40) has a drive unit (44) for moving the valve needle (42).

9. The apparatus according to claim 8, wherein the drive unit (44) is a pneumatic drive unit.

10. The apparatus according to claim 8, wherein the drive unit (44) is releasably connected to the metering unit (12).

11. The apparatus according to claim 8, wherein the valve needle (42) can be moved, by means of the drive unit (44), into the closed position in the longitudinal direction (38), and into the release position counter to the longitudinal direction (38).

12. The apparatus according to claim 8, wherein the valve needle (42) can be moved, by means of the drive unit (44), into the release position in the longitudinal direction (38), and into the closed position counter to the longitudinal direction (38).

13. The apparatus according to claim 1, wherein the mixing structure (36) is accommodated so as to rotate in the mixing tube (22), about a rotational axis that runs in the longitudinal direction (38), preferably motor driven.

14. The apparatus according to claim 1, wherein the mixing tube (22) and the mixing structure (36) are produced from a polylactide (PLA) or an acrylonitrile butadiene styrene copolymer (ABS).

15. The apparatus according to claim 1, wherein the valve needle (42) is produced from a metal or a hard metal.

16. The apparatus according to claim 1, wherein the valve needle (42) is produced together with the mixing unit (20), by means of 3D printing.

17. The apparatus according to claim 1, further comprising a device for producing a vacuum in the mixing tube.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

[0014] In the drawings,

[0015] FIG. 1 shows an apparatus for applying a viscous material, in a schematic representation, in section;

[0016] FIG. 2A shows a mixing unit for an apparatus according to FIG. 1, according to a first embodiment, in section;

[0017] FIG. 2B shows an enlargement of the detail F in FIG. 2A;

[0018] FIG. 3A show a mixing unit for an apparatus according to FIG. 1, according to a second embodiment, in section; and

[0019] FIG. 3B shows an enlargement of the detail B in FIG. 3A.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0020] The application apparatus 10 shown in the drawing serves for applying a multi-component viscous material to workpieces, in accordance with the present exemplary embodiment of a two-component viscous material, for example of an adhesive that is mixed from two components, namely a base component and a hardener. It has a metering unit 12, which has a feed channel 14 for each of the components, by way of which channel the component is supplied, in each instance. Each of the feed channels 14 can be blocked and released by means of a metering valve not shown in the drawing, so that each component can be supplied in a metered manner. The metering unit 12 furthermore has a coupling device 16, to which a mixing unit 20 is releasably attached. The mixing unit 20 has a mixing tube 22, at the first end 24 of which a coupling part 26 is arranged, which serves for a releasable connection to the coupling device 16. Likewise, a material inlet 28 is arranged at the first end 24 of the mixing tube 22, into which inlet the feed channels 14 open. In the exemplary embodiment shown here, the material inlet 28 has two material inlet channels 30, wherein one of the feed channels 14 opens into each of the material inlet channels 30. Of course, this principle can also be applied to the application of a viscous material composed of more than two materials, wherein a number of metering valves and feed channels that corresponds to the number of components is always provided in the metering unit 12, which channels and valves open into the material inlet 28, which can then also have a number of material inlet channels that corresponds to the number of components.

[0021] At the second end 32 of the mixing tube 22, the tube has an exit opening 34 from which the viscous material produced by mixing of the components exits for application to workpieces. In the mixing tube 22, a mixing structure 36 is arranged, which serves for mixing the components on their way from the material inlet 28 to the exit opening 34 as homogeneously as possible. A valve needle 42 of a needle valve 40 extends in the longitudinal direction 38, which extends from the material inlet 28 to the exit opening 34. The needle valve 40 furthermore has a pneumatic drive unit 44 releasably connected to the metering unit 12, by means of which unit the valve needle 42 can be moved in and counter to the longitudinal direction 38, in a limited manner. A valve seat 46 is arranged at the exit opening 34, wherein the valve needle 42 closes off the exit opening 34 in a closed position, by means of contact with the valve seat 46, and releases it in a release position, in which it is lifted up from the valve seat 46. In this regard, the valve needle 42 is moved into the release position counter to the longitudinal direction 38, and into the closed position in the longitudinal direction 38, in the first exemplary embodiment shown in FIGS. 2A, 2B. In contrast, in the case of the second exemplary embodiment according to FIGS. 3A, 3B, the needle valve 40 is configured as a snuff back valve, and the valve needle 42 is moved into the release position in the longitudinal direction 38, and into the closed position counter to the longitudinal direction 38.

[0022] In the case of both exemplary embodiments, the mixing unit 20 has an inner tube 48 arranged in the mixing tube 22, through which inner tube the valve needle 42 extends. A mixing spiral 50 extends radially away from the inner tube 48, which spiral extends all the way to the mixing tube 22, and forms a spiral-shaped surface that is inclined toward the exit opening 34, over which surface the components flow down and mix as they flow down. The valve needle 42 stands at a front end 52 of the inner tube 48, which end faces the exit opening 34 and is arranged at a distance from it, and projects out of the tube. Furthermore, a circumferential sealing element 54 that lies against the valve needle 42, forming a seal, is arranged in the inner tube 48 at the front end 52 of the inner tube 48, which element prevents penetration of the viscous material into the inner tube 48.

[0023] In the case of the present exemplary embodiments, the mixing unit 20 is produced using 3D printing, in each instance. In this regard, the mixing tube 22 and the mixing structure 36 are produced in one piece, from the same material, which is a polylactide (PLA) or an acrylonitrile butadiene styrene copolymer (ABS) in the present exemplary embodiment. The valve seat 46 and the sealing element 54 are generally produced from a more wear-resistant material, but are also formed on the mixing tube 22 and/or on the inner tube 48 by means of 3D printing. The valve needle 42 can also be produced, using the 3D printing method, along with the production of the mixing unit 20, wherein metal or hard metal are particularly preferred as materials. In particular when the needle valve 40 is configured as a snuff back valve, production of the valve needle 42 by means of a 3D printing method is advantageous, because the valve needle 42 cannot be introduced into the mixing unit 20 in the longitudinal direction 38. Another possibility, however, is a two-part configuration of the valve needle 42, in which one part is introduced into the mixing unit 20 in the longitudinal direction 38, and one part is introduced by way of the exit opening 34, counter to the longitudinal direction 38, and both parts are then firmly connected to one another. Furthermore, it is apparent that the invention also covers application apparatuses 10 that have a mixing unit having a different mixing structure. Furthermore, the mixing structure 36 can also be able to rotate relative to the mixing tube 22, about its longitudinal center axis.

[0024] In summary, the following should be stated:

[0025] The invention relates to an apparatus 10 for applying a multi-component viscous material to workpieces, having a metering unit 12 that has a number of feed channels 14 that corresponds to the number of components of the viscous material, for one of the components, in each instance, which channels can be blocked and released by means of metering valves, as well as a coupling device 16, and having a mixing unit 20, which has a material inlet 28, into which the feed channels 14 open, at a first end 24, and a coupling part 26 releasably connected to the coupling device 16, and, at a second end 32, a mixing tube 22 that has an exit opening 34 for the viscous material, as well as a mixing structure 36 arranged in the mixing tube 22, for mixing the components as they are passed through the mixing tube 22 from the material inlet 28 to the exit opening 34. According to the invention, a needle valve 40 is provided for releasing and closing the exit opening 34, which valve has a valve needle 42 that extends in a longitudinal direction 38 that runs from the material inlet 28 to the exit opening 34, which needle releases the exit opening 34 in a release position, and closes it in a closed position, by making contact with a valve seat 46.

[0026] Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.