APPLICATION NOZZLE

Description

[0001] The invention relates to an application nozzle for applying a viscous material to workpieces according to the preamble of claim 1.

[0002] Well-known application nozzles of this type are widely used for applying viscous materials such as adhesives, sealants, insulation materials or thermal pastes to workpieces. In the automotive industry in particular, such materials are applied to workpieces such as car body components. For this purpose, the application nozzle is moved relative to the workpiece by a robot, and a dosing system feeds the viscous material under pressure into the application channel, through which it flows and exits the application nozzle at the material outlet opening and is applied to the workpiece in question. So-called round nozzles with a circular material outlet opening are usually used, so that a material strand with an approximately circular cross-section leaves the application nozzle. The material strand applied to the workpiece in question then has a height that roughly corresponds to its width.Particularly when applying adhesive to workpieces to join two parts together, an excessively high material strand can be detrimental. Less stable workpieces, in particular, cannot be pressed against each other with sufficient force to flatten the adhesive strand.

[0003] Application nozzles according to the preamble of claim 1 are known from US 3,334,792 A. A plunger constricting the cross-section of the application channel is arranged in the application channel of the application nozzle according to US 3,334,792 A, the cross-section of which increases towards the material outlet opening. Further application nozzles are known from US 6,062,492 A and from DE 10 2016 008 643 A1. The application nozzle known from US 6,062,492 A has a plastic insert inserted into the nozzle body, which lines the nozzle body all around and thus narrows the cross-section of the application channel. In the application nozzle according to DE 10 2016 008 643 A1, the nozzle body is lined with an inner tube through which the application channel extends.

[0004] The object of the invention is to further develop an application nozzle of the type mentioned at the outset in such a way that it has a simpler construction.

[0005] This object is achieved according to the invention by an application nozzle having the features of claim 1. Advantageous developments of the invention are the subject of the dependent claims.

[0006] The invention is based on the idea of ​​creating an air pocket in the material strand by means of at least one filler arranged in the application channel and extending to the material outlet opening, so that the material strand applied to the workpiece is partially hollow. The hollow space can be enclosed by the material strand or open to a surface of the material strand. This measure makes the material strand significantly easier to compress and, when two workpieces are pressed together, can be flattened more easily and with less force, thus achieving a lower height for the material strand.

[0007] According to the invention, the at least one filler body has a cross-section that increases from the first end to the second end. It is preferred that the cross-section of the at least one filler body increases continuously, at least in sections, from the first end to the second end. These measures are advantageous from a fluidic perspective, since abrupt cross-sectional changes within the application channel adversely affect the flow behavior of the viscous material in the application channel.

[0008] According to the invention, the at least one filler body directly adjoins the nozzle body over its entire length and is formed integrally with the nozzle body. This allows the air pocket or cavity in the material bead to be open at its edges. The material bead can then be applied to the workpiece either with the open edge of the air pocket facing the workpiece, thus delimiting the air pocket on one side by the viscous material and on the other side by the workpiece, or with the open edge facing away from the workpiece.

[0009] According to an advantageous development of the invention, two filler bodies, preferably identical in size, are arranged at a distance from one another in the application channel. In this way, two separate cavities are created in the material strand. According to a preferred embodiment, the cross-sections of the application channel and the filler body(ies) at the material outlet opening add up to form a semicircular area. In particular, if two filler bodies are present in the application channel, this can lead to an M-shaped cross-section of the application channel at the material outlet opening. If two filler bodies are present in the application channel, they are expediently arranged mirror-symmetrically with respect to a central plane, so that the M-shaped cross-section of the application channel is also mirror-symmetrical at the material outlet opening.

[0010] It is preferred that the application channel is angled between the material inlet opening and the material outlet opening such that a longitudinal center axis of an initial section extending from the material inlet opening and a longitudinal center axis of an end section of the application channel extending to the material outlet opening enclose an acute or right angle, in particular an angle between 30° and 60°. Such a nozzle geometry is used in particular when the application nozzle is moved in a pulling motion during material application, i.e., when it is moved in a direction of movement that is opposite to the application direction in which the viscous material exits the material outlet opening.

[0011] According to an advantageous development, at least one heating element for heating the viscous material is arranged in the application channel. This measure takes into account the fact that it is advantageous to heat the viscous material during application in order to reduce its viscosity and facilitate application. In known application nozzles, this is achieved by surrounding the nozzle body with a heating element. For space reasons, however, the heating element cannot then extend as far as the nozzle tip, where the material outlet opening is located. If a heating element is arranged in the application channel, the viscous material can be heated up to the point where it exits the material outlet opening. In particular, if at least one filler body is present in the application channel, the heating element can be arranged in the filler body.

[0012] It can also be advantageous to add an additive to the viscous material when it is applied to the workpiece. In particular, this can be a heat-conducting additive. Viscous materials such as adhesives have poor heat conductivity and require a longer cooling phase after application to a workpiece. The cooling time can be shortened by adding a heat-conducting additive. However, such additives are often abrasive, so their addition leads to increased wear on the application nozzle and / or the supply lines and / or the dosing system for the viscous material. To reduce wear, it can therefore be provided that at least one supply line for the application of an additive is arranged in the application channel, leading into the material outlet or into the application channel. The supply line can be made of a more resistant material so that it does not wear as quickly.In particular, the dosing system for the viscous material is not supplied with the additive if it is only added at or shortly before the material outlet opening. Just like the heating element, the at least one supply line can advantageously run through the at least one filler. For example, the supply line can run through one filler, while a heating element is arranged in a second filler. However, it is also possible to incorporate the supply line for the additive into the application channel if there is no filler present.

[0013] According to an advantageous development, the at least one heating element and / or the at least one supply line are detachably connected to the nozzle body. The heating element or the supply line can then be accommodated in the application nozzle as wear parts and can be replaced.

[0014] The invention will be explained in more detail below with reference to an embodiment shown schematically in the drawing. Fig. 1 a, 1b shows an application nozzle in front view and in side view; Fig. 1c shows section A from Fig. 1a ; Fig. 2a, 2b show a material bead applied to a workpiece in cross section when using one filler or when using two fillers, and Fig. 3a to 3d show four different shapes of a material bead in a fold in cross section.

[0015] The application nozzle 10 shown in the drawing has a nozzle body 12 in which an application channel 18 extends from a material inlet opening 14 to a material outlet opening 16. The application nozzle 10 is used to apply viscous material to workpieces. It is moved relative to the workpieces, and the viscous material is introduced under pressure via the material inlet opening 14 into the application channel 18 and leaves it again at the material outlet opening 16. The application channel 18 has an initial section 20 extending from the material inlet opening 14, which has a constant cross-section and extends parallel to a first longitudinal central axis 22.It also has an end section 24 opening into the material outlet opening 16, which in turn has a linear extension parallel to a second longitudinal central axis 26, which runs at an acute angle to the first longitudinal central axis 22. The cross-section of the application channel 18 decreases from the initial section 20 to the end section 24. Between the initial section 20 and the end section 24, the application channel 18 is curved.

[0016] Two filler bodies 28 are arranged in the application channel 18, which are formed in one piece with the nozzle body 12 and narrow its cross-section in the end section 24. Each of the filler bodies 28 extends from a first end 30, which is arranged at a distance from the material inlet opening 14 as well as at a distance from the material outlet opening 16, to a second end 32, which is arranged at the material outlet opening 16. Both filler bodies 28 have identical dimensions and are arranged next to one another at a distance and parallel to one another. They are also arranged symmetrically with respect to a center plane 34, which is perpendicular to the plane of the drawing of the Fig. 1a, c and parallel to the plane of the Fig. 1b and which is a plane of symmetry of the application nozzle 10. The cross-section of the filler bodies 28 increases continuously from the first end 30 to the second end 32. At the material outlet opening 16, the cross-sections of the application channel 18 and the filler bodies 28 add up to form a semicircular area.

[0017] The application nozzle 10 is particularly suitable for applying a strand of material to a workpiece, wherein the application nozzle 10 is moved in a pulling manner. This means that the material exits the material outlet opening 16 in an application direction 36, while the application nozzle 10 is simultaneously moved in a direction of movement 38 that is opposite to the application direction 36 or at least has a directional component that runs opposite to the application direction 36. A material bead 40 emerges from the material outlet opening 16, which is essentially M-shaped in cross section, wherein the tips of the M are rounded, and which has two cavities 42 that approximately correspond in cross section to the filler bodies 28. The material bead can, as in Fig. 2a shown, applied to a workpiece 44 such that the cavities 42 are enclosed between the viscous material and the workpiece 44.

[0018] In principle, the application nozzle 10 can be realized with only one filling body extending up to the material outlet opening 16 in the application channel 18 instead of with two parallel filling bodies 28. As an example, Fig. 2b a corresponding material bead 40' in cross-section, which encloses only a cavity 42 with the workpiece 44. Such a material bead 40' can be applied in particular when there is a risk of it slipping off the workpiece 44 in one direction. It has a thicker main region 40'a and a support region 40'b that prevents slipping.

[0019] Fig. 3a bis d show schematically application examples in which the material bead 140a to 140d is applied in reverse to the respective workpiece 44, i.e. with the cavities 42 facing away from the workpiece 44. Fig. 3a to c show three different embodiments, in each of which a filling body 28 is used to form a cavity 42, while Fig. 3d shows an embodiment in which according to the application nozzle 10 according to Fig. 1a bis c Two filler bodies 28 are used to form two cavities 42. By appropriately selecting the cross-section of the filler bodies 28, the geometry of the material bead 140a to 104d can be influenced and adapted to the respective conditions and requirements. In Fig. 3a bis d the material bead 140a to 140d each fills a fold 46.

[0020] According to further developments not shown in the drawing, the filler elements 28 can perform additional functions. For example, it is possible for an electrically heatable heating cartridge to be inserted into at least one of the filler elements for heating the viscous material in the end section 24, which heating cartridge is held there permanently or removably. It is also possible for a supply line, particularly for an abrasive additive, to extend through at least one of the filler elements 28, opening either into the end section 24 or into the material outlet opening 16. The supply line can also be permanently integrated into the respective filler element 28 or arranged therein in a removably manner so that it can be replaced when it becomes worn.

[0021] In summary, the invention relates to an application nozzle for applying a viscous material to workpieces (44), comprising a nozzle body (12) and an application channel (18) for the viscous material, said application channel extending in the nozzle body (12) from a material inlet opening (14) to a material outlet opening (16), wherein at least one filler body (28) is arranged in the application channel (18), narrowing the cross-section of the application channel (18) and extending from a first end (30) arranged at a distance from the material inlet opening (14) to a second end (32) arranged at the material outlet opening (16), wherein the at least one filler body (28) has a cross-section which increases from the first end (30) to the second end (32), and wherein the at least one filler body (28) directly adjoins the nozzle body (12) over its entire length.

[0022] According to the invention, it is provided that the at least one filling body (28) is formed integrally with the nozzle body (12).

Claims

1. Application nozzle for application of a viscous material to workpieces (44), having a nozzle body (12) and having an application channel (18) for the viscous material that extends in the nozzle body (12) from a material inlet opening (14) all the way to a material outlet opening (16), wherein at least one filler body (28) that narrows the cross-section of the application channel (18), extending from a first end (30) arranged at a distance from the material inlet opening (14) all the way to a second end (32) arranged at the material outlet opening (16) is arranged in the application channel (18), wherein the at least one filler body (28) has a cross-section that increases in size from the first end (30) to the second end (32) and wherein the at least one filler body (28) borders on the nozzle body (12) directly over its entire length, characterized in that the at least one filler body (28) is configured in one piece with the nozzle body (12).

2. Application nozzle according to claim 1, characterized in that the cross-section of the at least one filler body (28) increases in size continuously from the first end (30) to the second end (32), at least in certain sections.

3. Application nozzle according to one of the preceding claims, characterized in that two filler bodies (28) that are preferably identical in their dimensions are arranged in the application channel (18) at a distance from one another.

4. Application nozzle according to one of the preceding claims, characterized in that the cross-sections of the application channel (18) and of the filler body or bodies (28) add up to a semicircular surface at the material outlet opening (16).

5. Application nozzle according to claim 3 or 4, characterized in that the cross-section of the application channel (18) is M-shaped at the material outlet opening (16).

6. Application nozzle according to one of claims 3 to 5, characterized in that the two filler bodies (28) are arranged with mirror symmetry with reference to a center plane (34).

7. Application nozzle according to one of the preceding claims, characterized in that the application channel (18) is angled away between the material inlet opening (14) and the material outlet opening (16), in such a manner that a longitudinal center axis (22) of an initial section (20) proceeding from the material inlet opening (14) and a longitudinal center axis (26) of an end section (24) of the application channel (18) that extends toward the material outlet opening (16) enclose an acute or right angle, in particular an angle between 30° and 60°.

8. Application nozzle according to one of the preceding claims, characterized in that at least one heating element for heating the viscous material is arranged in the application channel (18).

9. Application nozzle according to claim 8, characterized in that the at least one heating element is arranged in the at least one filler body (28).

10. Application nozzle according to one of the preceding claims, characterized in that at least one feed line for the application of an additive, which line opens into the material outlet opening (16) or into the application channel (18), is arranged in the application channel (18).

11. Application nozzle according to claim 10, characterized in that the at least one feed line runs through the at least one filler body (28).

12. Application nozzle according to one of claims 8 to 11, characterized in that the at least one heating element and / or the at least one feed line is releasably connected with the nozzle body (12).

13. Method for application of a viscous material to workpieces (44), using an application nozzle (10) according to one of the preceding claims, wherein the viscous material exits from the material outlet opening (16) in an application direction (36), characterized in that the application nozzle (10) is moved, during material application, in a movement direction (38) that is opposite to the application direction (36) or at least has a component that runs counter to the application direction (36).

14. Method for application of a viscous material to workpieces (44), using an application nozzle (10) according to one of claims 1 to 12, in particular the method according to claim 13, wherein the viscous material exits from the material outlet opening (16) in an application direction (36) and forms a material bead (40, 40', 140a, 140b, 140c, 140d) that extends in the application direction (36), and wherein the material bead (40, 40', 140a, 140b, 140c, 140d) has a number of cavities (42) that are open at the edge and extend in the application direction (36), which number corresponds to the number of filler bodies (28).

15. Method according to claim 14, characterized in that the material bead (40, 40', 140a, 140b, 140c, 140d) is applied with the cavity (42) facing the respective workpiece (44) or with the cavities (42) facing the respective workpiece (44), respectively.

16. Method according to claim 14, characterized in that the material bead (40, 40', 140a, 140b, 140c, 140d) is applied in particular in a fold (46) of the respective workpiece (44), with the cavity (42) facing away from the workpiece (44) or with the cavities (42) facing away from the workpiece (44), respectively.