Method for applying corrosion protection wax to conservation areas of a surface to be conserved

Abstract

Method for applying corrosion protection wax to conservation areas of a surface to be conserved, with the following characteristics: a. The discharge is carried out by means of a robot tool (20) attached to a robot arm (12) of a robot (10) with the following features: - the robot tool (20) comprises a nozzle unit (50) which is designed for the selective discharge in one discharge direction of unatomized corrosion protection wax without the supply of compressed air in the form of a thin jet (90) and of corrosion protection wax atomized with compressed air in the form of a spray cone (92), and - the nozzle unit (50) is connected to a supply channel (70) for compressed air and to a supply channel (72) for corrosion protection wax, and - the nozzle unit (50) has an internal nozzle (59) for generating the thin jet (90) of corrosion protection wax, wherein the internal nozzle (59) is supplied via the supply channel (72) for corrosion protection wax, and - the nozzle unit (50) has an external nozzle (53) for generating the spray cone (92) of atomized corrosion protection wax, and - an atomizing chamber (74) is provided between the inner nozzle (59) and the outer nozzle (53), wherein the supply channel (70) for the compressed air opens into the atomizing chamber (74), and - the inner nozzle (59) is aligned in the discharge direction with the outer nozzle (53), so that the corrosion protection wax exiting through the inner nozzle (59) in the form of a jet (90) can be discharged as a jet through the atomization chamber (74) and the outer nozzle (53) when the atomization chamber (74) is not supplied with compressed air, and - the atomizing chamber (74) is designed to atomize the jet exiting the inner nozzle (59) by means of the supplied compressed air when the atomizing chamber (74) is supplied with compressed air, and b. the discharge is carried out for coating at least a first preservation area (18) in the form of an unatomized jet (90) of corrosion protection wax, and c. The discharge is carried out to coat at least a second preservation area (16) in the form of a spray cone (92) with corrosion protection wax atomized by means of compressed air.

Description

SCOPE OF APPLICATION AND STATE OF THE ART

[0001] The invention relates to a method for applying corrosion protection wax to preservation areas of a surface to be preserved.

[0002] Robotic tools for dispensing corrosion protection wax are generally known. This document concerns robotic tools that apply a jet of corrosion protection wax to workpieces, particularly body parts for motor vehicles. This wax remains on the relevant surface areas and prevents corrosion there throughout the vehicle's service life.

[0003] Two different techniques are known in this context. To achieve an application of corrosion protection wax in the form of narrow lines, the corrosion protection wax is applied unatomized through a nozzle of the robot tool, typically at a pressure between 3.0 × 10 5 Pa and 5.0 × 10 6The wax is applied using a Pa spray. It does not mix with air, so the corrosion protection wax hits the workpiece as a relatively thin, unatomized jet. However, applying corrosion protection wax to larger areas with such robotic tools is problematic, as it is quite time-consuming to fill these areas with narrow lines of wax.

[0004] For the application of corrosion protection wax to workpieces over a wide area, other robotic tools are typically used, designed to atomize the corrosion protection wax in the nozzle area. These robotic tools usually have a mixing chamber located away from the dispensing nozzle and connected to it via lines. The corrosion protection wax and compressed air are introduced into this chamber, creating a liquid-air mixture that is then fed to the dispensing nozzle. This nozzle produces a cone-shaped spray jet of atomized corrosion protection wax, enabling rapid, even application.

[0005] These conventional robot tools are particularly well-suited when the workpieces require application exclusively in the form of narrow lines or exclusively in an area. However, if the same workpiece requires both linear and area application, existing robot tools are not ideally suited. Either a robot tool designed for unatomized application must trace the areas with a linear application of the corrosion protection wax, or a change of robot tool is necessary. Both solutions are disadvantageous for the desired cycle times in the automotive industry.

[0006] Document US 3796376 A discloses a spray gun supplied with a dispensing medium and with air, whereby air is always expelled during dispensing. However, the device allows the spray pattern to be influenced by the relative displacement of a dispensing nozzle for the medium on the one hand and air nozzles on the other.

[0007] Further prior art documents relating to devices and methods for applying viscous coating media using nozzles, in particular using compressed air for atomization, are US 5102051 A, DE 102010034921 A1, US 4597526 A, DE 9011965 U1, DE 102013207021 A1, DE 102009052654 A1, US 2002 / 0104900 A1 and DE 6806920 U. TASK AND SOLUTION

[0008] The object of the invention is to provide a method that makes it possible to combine short cycle times and flexible discharge shapes for the dispensing of corrosion protection wax.

[0009] The problem is solved by a method according to claim 1 using a robot tool.

[0010] The robot tool includes a nozzle unit designed for the selective discharge in one discharge direction of unatomized corrosion protection wax in the form of a thin jet and of corrosion protection wax atomized with compressed air in the form of a spray cone.

[0011] The nozzle unit is connected to a compressed air supply channel and a supply channel for corrosion protection wax. It features an inner nozzle for generating a jet of corrosion protection wax, supplied via the wax supply channel. It also features an outer nozzle for generating a spray cone of atomized corrosion protection wax. An atomization chamber is located between the inner and outer nozzles, with the compressed air supply channel opening into this chamber.

[0012] The inner nozzle is aligned with the outer nozzle in the discharge direction, so that the corrosion protection wax emerging through the inner nozzle in the form of a jet can be discharged as a jet through the atomization chamber and the outer nozzle when the atomization chamber is not supplied with compressed air.

[0013] The atomizing chamber is designed to atomize the jet exiting the inner nozzle by means of the supplied compressed air when the atomizing chamber is supplied with compressed air.

[0014] The robot tool is designed to both dispense corrosion protection wax unatomized without the supply of compressed air to achieve narrow applications of corrosion protection wax, and to allow atomized dispensing of the corrosion protection wax with the aid of compressed air.

[0015] The described nozzle unit configuration is designed for this purpose. Corrosion protection wax and compressed air can be supplied to this nozzle unit via the supply channels. If only corrosion protection wax, but no compressed air, is supplied, the wax is dispensed as a thin, unatomized jet. If compressed air is also supplied, atomization occurs, and the corrosion protection wax is dispensed as a spray cone consisting of compressed air and atomized corrosion protection wax.

[0016] The nozzle unit features two nozzles: an inner nozzle and an outer nozzle. These two nozzles are aligned with each other. If no compressed air is supplied to the nozzle unit, the inner nozzle produces an unatomized jet of corrosion protection wax, which, due to their alignment, is carried unimpeded through the atomization chamber and the outer nozzle. If compressed air is supplied to the nozzle unit, the jet emitted through the inner nozzle is swirled and atomized in the atomization chamber and then discharged through the outer nozzle in the form of the aforementioned spray cone.

[0017] The system can switch between these two discharge methods by adjusting the supply and withdrawal of compressed air. Additionally, it may be advantageous to adjust the pressure at which corrosion protection wax is applied.

[0018] The robot tool is therefore suitable for applying corrosion protection wax to workpieces section by section in a linear fashion and section by section over a larger area, all with short cycle times. This eliminates changeover times between robot tools.

[0019] The inner nozzle and the outer nozzle can be spaced variably apart from each other, whereby increasing the distance between them increases the volume of the atomizing chamber.

[0020] The variable spacing between the inner and outer nozzles allows this distance to be adjusted to the selected operating mode. For a linear application, the inner and outer nozzles should be close together so that the jet emitted by the inner nozzle is not negatively affected by the outer nozzle. For a broadcast application of atomized corrosion protection wax, increasing this distance is recommended. This also enlarges the atomization chamber, resulting in a more homogeneous mixture of air and corrosion protection wax.

[0021] The variable spacing allows the nozzle unit to be ideally configured for the two operating modes.

[0022] The inner and outer nozzles can be permanently forced towards each other by a nozzle spring. The inner and outer nozzles can also be forced away from each other by the supply of compressed air.

[0023] Alternatively, it is also possible to effect the displacement of the inner nozzle and the outer nozzle relative to each other using a linear actuator or the like.

[0024] However, a design is advantageous in which the compressed air itself increases the small distance between the inner and outer nozzles when at rest. The nozzle spring constantly exerts a spring force that moves the inner and outer nozzles closer together. Only the compressed air shifts the inner and outer nozzles relative to each other, resulting in the desired enlarged atomization chamber. When the compressed air supply is interrupted, the nozzle spring acts again, reducing the size of the atomization chamber so that the unatomized jet of corrosion protection wax can once again be discharged completely unimpeded.

[0025] The nozzle assembly can have two assemblies movable relative to each other: an inner nozzle assembly and an outer nozzle assembly. The inner nozzle assembly can comprise at least one channel section of the supply channel for corrosion protection wax leading to the inner nozzle, as well as the inner nozzle itself. The outer nozzle assembly can comprise at least one jacket wall surrounding the atomization chamber, as well as the outer nozzle.

[0026] The inner nozzle assembly and the outer nozzle assembly can be mounted so that they can slide against each other in the discharge direction.

[0027] This design has proven to be very reliable and structurally simple. The assembly containing the inner nozzle is surrounded by the assembly containing the outer nozzle, which also provides a casing wall that surrounds the atomization chamber. The aforementioned nozzle spring acts between the two assemblies, pressing them together.

[0028] The compressed air supply channel and the corrosion protection wax supply channel can be designed, at least in sections, as concentrically arranged supply channels with respect to their cross-section. The corrosion protection wax supply channel can be located internally, and the compressed air supply channel externally. These supply channels can thus transition directly into the aforementioned nozzle unit with its internal nozzle assembly and external nozzle assembly. It is particularly advantageous if the internal nozzle assembly is fixed to the walls of the supply channels, which can be formed, in particular, by two concentric pipes.

[0029] The problem is also solved by a robot for dispensing a corrosion protection wax, in particular for the purpose of coating body parts for motor vehicles, according to claim 6.

[0030] The robot has a robot arm and a robot tool of the type described attached to it.

[0031] The robot is controlled by a control unit that regulates not only the robot's movements but also the supply of compressed air. This controls the desired operating mode, i.e., the dispensing of unatomized corrosion protection wax and the dispensing of atomized corrosion protection wax. The pressure at which the corrosion protection wax is supplied can also be adjusted by the control unit to ensure the ideal pressure for both operating modes.

[0032] The invention consists of a method for applying corrosion protection wax to preservation areas of a surface to be preserved.

[0033] The discharge is carried out using a robot tool of the type described.

[0034] The application process involves coating at least one initial preservation area with an unatomized jet of corrosion protection wax, and coating at least one second preservation area with corrosion protection wax atomized by compressed air. The two operating modes of the described tool are used for this purpose.

[0035] The corrosion protection wax is preferably applied unatomized at a rate between 3.0 × 10 6 Pa and 5.0 × 10 6 Pa. However, pressures up to 1.2 × 10 are also possible. 7 Pa possible. For the purpose of atomized application, the corrosion protection wax preferably occurs between 8.0 × 10 6 Pa and 1.2 × 10 7 Pa from the inner nozzle.

[0036] This process is used particularly for vehicle body parts, such as car doors. The described robot tool enables short cycle times and ideally adapted discharge shapes in both atomized and non-atomized form. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further advantages and aspects of the invention will become apparent from the claims and the following description, which are explained below with reference to the figures. These show: Fig. Figure 1 shows a robot with a robot tool for dispensing corrosion protection wax. Fig. Figure 2 shows the robot tool of the robot according to Fig. 1 in separate illustration. Fig. Figure 3 shows the nozzle unit of the robot tool. Fig. 2 as an exploded view. Fig. 4a and Fig. Figure 4b shows the nozzle unit of the robot tool in two different operating modes. Fig. Figure 5 shows an alternative design of a nozzle unit. DETAILED DESCRIPTION OF THE EXECUTION EXAMPLES

[0038] Fig. Figure 1 shows a robot tool for a method according to the invention. This robot tool 20 is provided on the robot arm 12 of a robot 10 and is positioned in the Fig. 1. Non-removable, it is supplied with corrosion protection wax and compressed air via lines. Its purpose is to coat a workpiece, in this case a car door 14, with corrosion protection wax.

[0039] As an example, 14 different areas on the car door, which are to be treated with corrosion protection wax, are shown with dashed lines. These areas include a flat area 16 with a diameter of several centimeters, as well as linear areas 18 where corrosion protection wax is to be applied only in the form of a relatively narrow line.

[0040] Given such requirements, it is advantageous to apply the corrosion protection wax in the case of area 16 by means of compressed air atomization in order to be able to provide large areas with corrosion protection wax at high speed, while the narrow linear areas 18 are preferably to be provided with unatomized corrosion wax.

[0041] The robot tool 20 is designed to be able to apply corrosion protection wax to both planar areas 16 and linear areas 18 without longer changeover times.

[0042] Fig. Figure 2 shows the robot tool 20 in a more detailed view, with a nozzle unit 50 shown again separately enlarged.

[0043] The robot tool 20 has a base 22 equipped with a coupling device for attaching it to the robot arm 12. Connections for supplying the robot tool 20 with compressed air and corrosion protection wax are also provided in the area of ​​the base 22, though these connections are not shown in detail.

[0044] The robot tool 20 has the aforementioned nozzle unit 50 with a discharge opening 34, which is simultaneously the outlet side of an external nozzle 53 described below. The nozzle unit 50 is connected to the base 22 via two concentric tubes 30, 32, with the outer tube 32 being Fig. 2 is partially obscured for easier comprehension. The inner tube 30 provides an internal supply channel 72 for corrosion protection wax. The annular space between the inner tube 30 and the outer tube 32 also provides a supply channel 70 for compressed air. In this way, the nozzle unit 50 can be supplied with corrosion protection wax and compressed air.

[0045] The nozzle unit 50 comprises two assemblies movable relative to each other, namely an inner nozzle assembly and an outer nozzle assembly, which are slidably guided against each other. Referring to Fig. 2 The inner nozzle assembly is only identifiable by the connecting part 64. The outer nozzle component 52, the atomization chamber wall 54 and an adjoining sleeve component 56 are part of the outer nozzle assembly.

[0046] The entirety of the components can be seen in the exploded view of the Fig. As can be seen in Figure 3. The outer pipe 30 and the inner pipe 32 are connected to the aforementioned connection piece 64. A fixed channel component 62 is provided for this purpose. This, in turn, is fixedly connected via an intermediate component 57 to an inner nozzle component 58, which itself has the inner nozzle 59. The outer nozzle assembly comprises the end-facing outer nozzle component 52 with the outer nozzle 53 provided therein. In the assembled state, it is fixedly connected to the atomization chamber wall 54 and to the sleeve component 56.

[0047] The nozzle spring 60 is supported, as in Fig. 4a and 4b also illustrate that the force is applied to the assemblies at a stop on the atomization chamber wall 54 on the one hand and on the intermediate component 57 on the other.

[0048] The Fig. 4a and Fig. Figure 4b shows the nozzle unit in operation, whereby Fig. 4a shows the operating mode in which no compressed air is supplied and the corrosion protection wax is dispensed in the form of a thin, unatomized jet 90°. Fig. Figure 4b shows the second operating mode, in which compressed air is supplied in addition to the corrosion protection wax, which atomizes the corrosion protection wax and creates a spray cone 92 of atomized corrosion protection wax.

[0049] In the first operating mode, which is in Fig. As shown in Figure 4a, corrosion protection wax is supplied through the supply channel 72, which is located within the inner tube 32 and the pipe section 62, in the manner already described. The corrosion protection wax thus reaches the inner nozzle component 58 and the inner nozzle 59 therein. It is dispensed in the form of a jet that passes through the outer nozzle 53 without the outer nozzle 53 influencing the discharge characteristics. In this operating mode, the corrosion protection wax can be applied to the workpiece in the form of fine lines, i.e., with reference to the car door of the Fig. 1 in areas 18.

[0050] The second operating mode, which in Fig. The process shown in Figure 4b is identical with respect to the supply of the corrosion protection wax through the supply channel 72. However, the protective wax, which is discharged in the form of a jet through the inner nozzle 59, first enters the atomization chamber 74. This atomization chamber 74 is significantly larger in the second operating mode than in the first operating mode. This is due to the supply of compressed air at a pressure of 2.0 × 10 5 Pa up to 6.0 × 10 5 Pa is achieved. This compressed air pushes the external assembly and with it the external nozzle 53 against the force of the nozzle spring 60 to the right, as shown in the illustration. The significantly enlarged atomizing chamber 74 thus allows complete atomization, resulting in a very homogeneous air-liquid mixture, which is emitted as a cone-shaped atomized spray jet 92. As soon as the compressed air supply through the supply channel 70 ceases, the nozzle unit 50 returns to its first operating mode according to Fig. 4a over.

[0051] Fig. Figure 5 shows an alternative design of the nozzle unit 50. The operating principle is identical in that this design also provides an inner nozzle 59 and an outer nozzle 53. When corrosion protection wax is supplied without compressed air, the unatomized spray jet emitted through the inner nozzle 59 can also be emitted through the outer nozzle 53 without interference. If compressed air is additionally supplied through the supply channel 70, atomization occurs again in the area of ​​the atomization chamber 74, resulting in the emission of corrosion protection wax in a form atomized by the compressed air.

[0052] The difference between the design of the Fig. 5 and the design according to Fig. 2 to 4b therefore primarily lies in the fact that the atomization chamber 74 according to Fig. 5 has no variable volume. The construction method according to Fig.Although option 5 is considered disadvantageous, it is structurally simpler and therefore has its place.

Claims

[1] Method for applying corrosion protection wax to conservation areas of a surface to be conserved, having the following characteristics: a. The discharge is carried out by means of a robot tool (20) attached to a robot arm (12) of a robot (10) with the following features: - the robot tool (20) comprises a nozzle unit (50) which is designed for the selective discharge in one discharge direction of unatomized corrosion protection wax without the supply of compressed air in the form of a thin jet (90) and of corrosion protection wax atomized with compressed air in the form of a spray cone (92), and - the nozzle unit (50) is connected to a supply channel (70) for compressed air and to a supply channel (72) for corrosion protection wax, and - the nozzle unit (50) has an internal nozzle (59) for generating the thin jet (90) of corrosion protection wax, wherein the internal nozzle (59) is supplied via the supply channel (72) for corrosion protection wax, and - the nozzle unit (50) has an external nozzle (53) for generating the spray cone (92) of atomized corrosion protection wax, and - an atomizing chamber (74) is provided between the inner nozzle (59) and the outer nozzle (53), wherein the supply channel (70) for the compressed air opens into the atomizing chamber (74), and - the inner nozzle (59) is aligned in the discharge direction with the outer nozzle (53), so that the corrosion protection wax exiting through the inner nozzle (59) in the form of a jet (90) can be discharged as a jet through the atomization chamber (74) and the outer nozzle (53) when the atomization chamber (74) is not supplied with compressed air, and - the atomizing chamber (74) is designed to atomize the jet exiting the inner nozzle (59) by means of the supplied compressed air when the atomizing chamber (74) is supplied with compressed air, and b. the discharge is carried out for coating at least a first preservation area (18) in the form of an unatomized jet (90) of corrosion protection wax, and c. The discharge is carried out to coat at least a second preservation area (16) in the form of a spray cone (92) with corrosion protection wax atomized by means of compressed air. [2] Method according to claim 1 comprising the feature: a. the pressure at which the corrosion protection wax is supplied is between 8.0 × 10 immediately beyond the inner nozzle (59) 6 Pa and 1.2 × 10 7 Pa. [3] Method according to claim 2 comprising the feature: a. the robot tool (20) has the following additional feature: - the inner nozzle (59) and the outer nozzle (53) are variably spaced apart from each other, whereby the volume of the atomizing chamber (74) can be increased by increasing the distance. [4] Method according to claim one of the preceding claims having the feature: a. The robot tool (20) has the following additional features: - the inner nozzle (59) and the outer nozzle (53) are permanently forced towards each other by a nozzle spring (60), and - the inner nozzle (59) and the outer nozzle (53) can be subjected to force moving away from each other by the supply of compressed air. [5] Method according to claim 3 or 4 above, comprising the feature: a. The robot tool (20) has the following additional features: - the nozzle unit (50) has two assemblies movable relative to each other, namely an inner nozzle assembly and an outer nozzle assembly, and - the internal nozzle assembly comprises at least one channel section (30) of the supply channel (72) for corrosion protection wax leading to the internal nozzle, as well as an internal nozzle component (58) on which the internal nozzle (59) is provided, and - the external nozzle assembly comprises at least one jacket wall (54) surrounding the atomization chamber (74) and an external nozzle component (52) on which the external nozzle (53) is provided, and - the inner nozzle assembly and the outer nozzle assembly are slidably mounted against each other in the discharge direction (2). [6] Method according to any one of the preceding claims having the features: a. The robot tool (20) has the following additional features: - the supply channel (70) for compressed air and the supply channel (72) for corrosion protection wax are designed, at least in sections, as supply channels (70, 72) arranged concentrically with respect to the cross-section, and - the supply channel (72) for the corrosion protection wax is located inside and the supply channel (70) for the compressed air is located outside. [7] Use of the method according to any of the preceding claims for the coating of body parts (14) for motor vehicles.

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