METHOD FOR PRESERVING CAVITIES, MIXING NOZZLE UNIT AND CAVITY-PRESERVING DEVICE HAVING A MIXING NOZZLE UNIT OF THIS TYPE

Abstract

A method for preserving cavities by applying a protective layer to the interior of a hollow body. The method uses a mixing nozzle unit coupled to a rotor unit. The mixing nozzle unit is rotated about an axis of rotation and has a mixing nozzle. The mixing nozzle unit has two supply channels for the cavity preservative and for gas for atomizing the cavity preservative. The supply channels run in the direction of the axis of rotation and conduct cavity preservative and atomizing gas separately to the mixing nozzle. The mixing nozzle unit is inserted into the hollow body in the direction of the axis of rotation through an opening in the hollow body. The cavity preservative is discharged in atomized form, and the mixing nozzle unit is rotated about the axis of rotation relative to the hollow body during the discharging or between a plurality of discharging phases.

Claims

1. A method for preserving cavities of a motor vehicle part with the following features: a. the method serves for the application of a protective layer of a cavity preserving agent on the inner side of a motor vehicle part which is configured as a hollow body, and, b. for the purpose of the application, a mixing nozzle unit is used which is coupled with a proximal end to a rotor unit, by which it can be rotated about a rotational axis, the mixing nozzle unit having, at a distal end, a mixing nozzle which is oriented radially with respect to the rotational axis, and c. the mixing nozzle unit has two separate feed channels which extend in the direction of the rotational axis for the cavity preserving agent and for gas for the purpose of the atomization of the cavity preserving agent, the cavity preserving agent and the atomization gas being conducted separately through the feed channels as far as the mixing nozzle, and d. the mixing nozzle unit is inserted in the direction of the rotational axis through an opening of the hollow body into the hollow body, with the result that at least the mixing nozzle is situated within the hollow body, and e. the cavity preserving agent is discharged in atomized form by the mixing nozzle, and is deposited on the inner side of the hollow body, the mixing nozzle unit being rotated about the rotational axis with respect to the hollow body during the discharge or between a plurality of discharge phases.

2. The method for preserving cavities as claimed in claim 1 with the following additional feature: a. while the mixing nozzle unit is rotated, the feed of cavity preserving agent to the mixing nozzle is varied, with the result that the quantity of cavity preserving agent which is discharged in an angular region of constant size is heterogeneous in a manner which is dependent on the rotational position.

3. The method for preserving cavities as claimed in claim 1 with the following additional feature: a. while the mixing nozzle unit is rotated, the feed of cavity preserving agent is interrupted in phases, with the result that no cavity preserving agent is discharged in a part region of the circumference.

4. The method for preserving cavities as claimed in claim 1 with the following additional feature: a. the mixing nozzle unit is rotated at a varying rotational speed, with the result that the quantity of cavity preserving agent which is discharged in an angular region of constant size varies in a manner which is dependent on the rotational position.

5. The method for preserving cavities as claimed in claim 1 with the following additional feature: a. an atomization is brought about by way of the feed of gas, which atomization leads to a nebulization of the cavity preserving agent.

6. A mixing nozzle unit for the discharge of cavity preserving agent in atomized form, with the following features: a. the mixing nozzle unit has an elongate stem, at the proximal end of which a coupling device for attaching to a rotor shaft is provided, and which elongate stem extends along a rotational axis which is defined by way of the coupling device, and, b. in the region of a distal end, the mixing nozzle unit has a mixing nozzle which is oriented transversely with respect to the rotational axis, with the result that the atomized cavity preserving agent can be output by the mixing nozzle in a radial discharge direction in relation to the rotational direction, and c. the mixing nozzle unit has two separate feed channels which extend in the direction of the rotational axis for the cavity preserving agent and for gas for the purpose of atomization, through which feed channels the cavity preserving agent and the atomization gas are conducted separately as far as the mixing nozzle, and d. the feed channels have, in a manner which is separate from one another, deflection sections, in which the fed cavity preserving agent and the fed gas are deflected from an axial flow direction for the purpose of the subsequent atomization into a radial flow direction.

7. The mixing nozzle unit as claimed in claim 6 with the following additional features: a. the mixing nozzle has at least two outlet openings, of which one is connected to the feed channel for gas, and of which one is connected to the feed channel for cavity preserving agent, and b. the outlet openings are oriented in such a way that the exiting cavity preserving agent is atomized downstream of the two outlet openings in the case of gas which exits at the same time.

8. The mixing nozzle unit as claimed in claim 6 with the following additional feature: a. the mixing nozzle unit has an orientation marking at the proximal end, with the result that the orientation of the mixing nozzle can be seen from the outside even in the case of a mixing nozzle unit which is inserted partially into the opening of the hollow body.

9. The mixing nozzle unit as claimed in claim 6 with the following additional feature: a. the mixing nozzle unit has a scale or markings along its elongate stem, with the result that a dipping depth of the mixing nozzle unit into the hollow body can be seen from the outside.

10. A cavity preserving device for the application of a protective layer consisting of a cavity preserving agent on the inner side of a hollow body with the following features: a. the cavity preserving device has a discharge device with a rotor unit which can be rotated about a rotational axis, and b. the cavity preserving device has a mixing nozzle unit as claimed in claim 6, and c. the coupling devices of the rotor unit and the mixing nozzle unit are configured for coupling to one another.

11. The cavity preserving device as claimed in claim 10 with the following additional feature: a. the discharge device has supply channels for supplying the mixing nozzle unit with gas and with cavity preserving agent.

12. The cavity preserving device as claimed in claim 11 with the following additional feature: a. the discharge device has at least one controllable valve, by which the feed of gas and/or cavity preserving agent to the mixing nozzle unit can be controlled.

13. The cavity preserving device as claimed in claim 10 with the following additional feature: a. the discharge device has an electric drive, by means of which the mixing nozzle unit can be rotated about the rotational axis.

14. The cavity preserving device as claimed in claim 10 with the following additional feature: a. the cavity preserving device has a robot with a robot arm, to which the discharge device is coupled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Further advantages and aspects of the invention result from the claims and from the following description of preferred exemplary embodiments of the invention which are described in the following text on the basis of the figures.

[0035] FIGS. 1 to 3 show a discharge device according to the invention with a mixing nozzle unit according to the invention in different perspectives.

[0036] FIGS. 4 and 5 show the discharge device of the above figures in a partially sectioned and sectioned illustration, respectively.

[0037] FIGS. 6 to 8 show further sections, from which the fluid feed to the mixing nozzle unit can be seen.

[0038] FIG. 9 shows a cavity preserving device with a robot for handling the discharge device.

[0039] FIG. 10 clarifies the method of function of the discharge device in operation.

[0040] FIGS. 11 to 13 show a discharge of cavity preserving agent, which discharge is variable in a rotational angle-dependent manner.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0041] FIG. 1 shows a discharge device 20 which is the core component of a cavity preserving device 10. In the case of the present exemplary embodiment, said discharge device 20 is provided for coupling to a robot arm 14 and, for this purpose, has a coupling device 24 which also comprises supply and control lines in a way which is still to be described in the further text.

[0042] The discharge device 20 has a rotational drive unit 30 with an internal electric motor (not shown in FIG. 1) which is provided for the purpose of it being possible for a rotatable rotor unit 50 to be rotated about a rotational axis 2. Here, the electric motor 32 can rotate the rotor unit 50 not only to a limited extent between two end positions, but rather freely about 360° and further in an endless manner.

[0043] For the purpose of the discharge of cavity preserving agent, the discharge device 20 has a mixing nozzle unit 60 which is attached by means of a nut 58 fixedly to the rotor unit 50 for conjoint rotation. The mixing nozzle unit 60 has an elongate stem 66, the proximal end 60A of which is fixed by way of the nut 58. A mixing nozzle 80 is provided at the distal end 60B of the mixing nozzle unit 60, which mixing nozzle 80 is oriented in the radial direction, with the result that fluid which is discharged here is discharged in a discharge direction which encloses approximately an angle of 90° with respect to the rotational axis 2. Depending on the application, smaller angles can also be provided, for example 60° and more.

[0044] With reference to FIG. 2, the coupling device 24 can be seen clearly. It is provided in the abovementioned way with connectors 26, through which cavity preserving agent, compressed air, electric energy and control signals are transmitted.

[0045] FIGS. 4 and 5 show the discharge device 20 and the mixing nozzle unit 60 in an enlarged and sectioned illustration. In the region of the mixing nozzle unit 60, the discharge device 20 has the rotational drive unit 30 which comprises an electric motor 32 (shown merely diagrammatically in FIG. 4). Said electric motor 32 is provided for driving the rotor 50 which, at its upper end, has a thread, by means of which the nut 58 is screwed fixedly to the rotor 50. As can be seen in FIG. 4, the nut 58 has a conical inner side in a manner which corresponds to a likewise conical coupling device 62 on the part of the mixing nozzle unit 60. The rotor unit 50 is mounted rotatably by means of an anti-friction bearing 52 on a base of the discharge unit 20.

[0046] In addition to the mixing nozzle 80 itself, the mixing nozzle unit 60 consists of three main constituent parts, namely an outer pipe 64A, an inner pipe 64B and a nozzle receptacle 64C, in which the mixing nozzle 80 is fastened. This design allows simple reconfiguration of the mixing nozzle unit, by the components 64A, 64B being swapped for components of a different length. As a result, mixing nozzle units with a differing maximum dipping depth can be used. A feed channel 70 for feeding the cavity preserving agent extends within the inner pipe 64B and in a continued manner as far as into the component 64C. At its distal end, said feed channel 70 has a deflection 70A, at which inflowing cavity preserving agent is deflected out of an axial flow direction into a radial flow direction. In a similar way, a feed channel 72 is also provided between the outer side of the inner pipe 64B and the inner side of the outer pipe 64A, which feed channel 72 likewise continues as far as into the component 64C and is deflected there in the radial direction in a deflection region 72A. Both fluids, the cavity preserving agent and the gas which is used for atomization, therefore pass to the mixing nozzle 80 in a manner which is already deflected in the radial direction, where, in the case of that embodiment of the mixing nozzle 80 which is shown, they are conducted to separate outlet openings 82, 84, at which they are output under pressure. As is indicated by way of the arrows 94, the discharged cavity preserving agent 92 is atomized in the process and forms a fine protective agent mist 96.

[0047] The supply of said feed channels 70, 72 takes place by way of the rotor unit 50 which, for this purpose, has a central cavity preserving agent channel 54 and, surrounding this, gas channels 56 in the way which can also be seen in the following FIGS. 6 to 8. As can be seen on the basis of FIG. 4, but also, in particular, on the basis of FIGS. 7 and 8, rotary leadthroughs 43, 47 are provided in each case, by means of which the channels 54, 56 are connected permanently to corresponding channels 42, 46 of the base. Said channels 42, 46 are supplied by said connectors 26 on the coupling device 24, a switching valve 44 being provided in the channel 42 for the cavity preserving agent, by means of which switching valve 44 the feed of cavity preserving agent can be interrupted comparatively close to the discharge opening 84. Here, the valve 44 is provided as a pneumatically switchable valve.

[0048] FIG. 9 shows the main use as intended of a discharge device in accordance with the preceding figures. It can be seen that the discharge device 20 is attached by way of its coupling device 24 to a robot arm 14, by means of which the discharge device can be moved flexibly in three dimensions, in order, in particular, to be moved with respect to a vehicle chassis and to be moved into a working position. FIG. 10 shows a working position of this type. In the working position, the mixing nozzle unit 60 is inserted into a hollow body 100 partially through an opening 102. Here, as intended, the mixing nozzle unit 60 is rotated by means of the rotor unit 50 and the electric motor 32 with a protective agent mist being produced at the same time. Therefore, the spray mist 94 which is produced can be applied in different directions and onto all inner surfaces of the hollow body 100.

[0049] FIGS. 11 to 13 clarify this further. Here, FIG. 11 shows an orientation of the mixing nozzle in the direction of extent of the elongate hollow body 100. A particularly great quantity of protective agent mist is required in this direction, since the inner faces which are arranged in this direction are comparatively large. FIG. 12 shows an orientation at a 90° angle with respect to that of FIG. 11. In this orientation, the mixing nozzle is directed onto a comparatively near wall, with the result that the areas to be coated in this angular region are smaller. Therefore, a smaller quantity of cavity preserving agent per unit of angle is also required. FIG. 13 shows an orientation, in which no discharge at all of cavity preserving agent is desired.

[0050] There are a plurality of possibilities for achieving this result. For instance, in one variant of the method, the valve 44 can remain opened over the predominant part of a 360° rotation of the mixing nozzle unit 60, and can be closed only in the orientation of FIG. 13. In order for it, additionally to be possible for the different cavity preserving agent quantity to be discharged in an angle-dependent manner in accordance with FIGS. 11 and 12, it can be provided that, at a constant rotational speed of the mixing nozzle unit 60, the valve 44 or some other electrically operated valve decreases the flow of the cavity preserving agent in the angular position of FIG. 12 in comparison with the position of FIG. 11. As an alternative, the rotational speed of the mixing nozzle unit can be considerably greater in the angular position of FIG. 12 than in the angular position of FIG. 11. Although, in the case of a procedure of this type, the mixing nozzle outputs the same quantity of cavity preserving agent per unit time in the rotational positions of FIGS. 11 and 12, the quantity of the cavity preserving agent per unit of angle is influenced by way of this variable speed.