DE102011102191B4 - Method and plant for painting compressed gas cylinders - Google Patents

Abstract

A process for painting compressed gas cylinders, comprising: a) a main area, b) a neck having a diameter smaller than the diameter of the main area, c) a shoulder forming the transition between the main area and the neck; Neck-mounted shoulder collar, which includes a cavity in the region of the neck and the shoulder, in which liquid in step e) can penetrate, the method comprising the following steps: e) the compressed gas cylinder is pretreated with a treatment liquid, in particular degreased and / or Zn g) the dried compressed gas cylinder is painted, characterized in that the step f) of drying comprises local inductive heating of the shoulder collar (5) and the adjoining portion of the shoulder (2) For this purpose, an inductor (16) is used with an effective range (31) whose shape to the shape of Schulterkra gens (5) and the adjacent region of the shoulder (2) is adjusted, and the inductor (16) is brought into a position in which the effective region (31) in a suitable for inductive heating small distance from the shoulder collar (5) and the adjacent to this region of the shoulder (2).

Description

The invention relates to a method for painting compressed gas cylinders according to the preamble of claim 1 and to a system for painting compressed gas cylinders according to the preamble of claim 2.

Compressed gas cylinders generally have a construction in which the neck, which has a smaller diameter than the main area, shrunk off a shoulder collar, which in turn carries an external thread for a bottle cap. The shoulder collar surrounds a cavity bounded by it, a portion of the shoulder and the neck. Compressed gas cylinders must be subjected to pre-treatment before the painting process using liquid treatment media. These pretreatments include, in particular, degreasing and optionally Zn-phosphating. These pretreatments can be carried out both by a dipping process and by high-pressure spraying.

All these pretreatment processes have in common that liquid treatment medium can penetrate into said cavity, in particular if different bath temperatures are used. If, in such a case, the compressed gas cylinder is painted while the gap between shoulder collar and shoulder initially closed and evaporated over time, the liquid treatment medium, it comes to flaking off the paint or rusting in the neck region of the compressed gas cylinder over time. To prevent this, in known methods and systems of the type mentioned, the compressed gas cylinders are heated with directly gas-heated convection oven. This heating is carried out untargeted over the entire volume of the compressed gas cylinder. For the subsequent painting, for example with powder coating, the entire compressed gas cylinder must be cooled down again accordingly.

Furthermore, goes from the DE 19703489 A1 a method of applying an inorganic coating to an electrically conductive body. Here, the surface area of the body to be coated is inductively heated to a reaction temperature or a preheating temperature. However, this does not pose the problem that the electrically conductive body has a cavity that would first have to be dried before the coating process.

DE 29517738 U1 describes an arrangement for heating sheet metal frames along an axial narrow area. For this purpose, a longitudinal inductor is used, which is displaced relative to the axial region of the sheet metal frames to be heated.

Object of the present invention is to provide a method or a system of the type mentioned, with or can be handled with less energy and faster the entire painting process.

This object is achieved, as far as the method is concerned, in that the step f) of drying comprises a local inductive heating of the shoulder collar and the adjoining region of the shoulder, for which purpose an inductor with an effective area is used whose shape conforms to the shape is adapted to the shoulder collar and the adjacent region of the shoulder, and the inductor is brought into a position in which the effective region is located in a suitable for inductive heating small distance from the shoulder collar and the adjoining region of the shoulder.

According to the invention, therefore, the entire compressed gas cylinder is no longer brought to the temperature required for expelling the liquid treatment medium; Rather, the heating is limited locally to the region in which liquid treatment medium preferably accumulates, namely on the shoulder collar and the adjacent region of the shoulder. This local limitation can be realized particularly favorable by inductive heating according to the invention. In experiments, it was found that, for example, 30 seconds are sufficient to reach local temperatures of over 120 ° C. This ensures a rapid and complete evaporation of the liquid treatment medium in the cavity.

• h) die Trockenstation einen Induktor umfasst, der aus einer Stromversorgung gespeist ist und einen Wirkbereich aufweist, dessen Form an die Form des Schulterkragens und des angrenzenden Bereiches der Schulter angepasst ist, derart, dass der Induktor in eine Position gebracht werden kann, in welcher sein Wirkbereich einen zur induktiven Erwärmung geeigneten kleinen Abstand von dem Schulterkragen und dem an diesen angrenzenden Bereich der Schulter besitzt.

The above object is, as far as the plant is concerned, solved by

• h) the drying station comprises an inductor fed from a power supply and having an effective area whose shape is adapted to the shape of the shoulder collar and the adjacent area of the shoulder such that the inductor can be brought into a position in which Effective range has a suitable for inductive heating small distance from the shoulder collar and adjacent to this region of the shoulder.

The advantages of the system according to the invention correspond mutatis mutandis to the above-mentioned advantages of the method according to the invention.

In an advantageous embodiment of the invention, the inductor is held by a holding device, which is designed such that the Effective range of the inductor with a relative to the axis of the shoulder collar axially directed component of motion can be placed on the gas cylinder. In this way, in the drying station inductor and compressed gas cylinder can be largely automated brought into the relative position required for drying. An attachment in the axial direction is required because of the special shape of the compressed gas cylinder in the shoulder transfer and the shoulder in order to realize the required for inductive heating small distance.

It may also be expedient if the inductor is held by a holding device, which is designed so that the effective range of the inductor can be placed on the compressed gas cylinder with a radially directed with respect to the axis of the shoulder collar movement component, including the effective range of the inductor a lateral Gap has. Moving the inductor sideways towards the bottle allows the active region of the inductor to be positioned axially in alignment with the pressurized gas bottle, even when suspended by a handrail or rope. The support bar or rope then penetrates through the gap in the active region of the inductor during the lateral movement. Subsequently, then the axial movement of the active region, which brings them in the vicinity of the shoulder collar and the shoulder of the compressed gas cylinder.

A particularly favorable embodiment of the invention is characterized in that the holding device comprises a pivoting frame which is connected at its lower end by at least one lever rotationally connected to a rotatable shaft, and hingedly connected at a distance from its lower end with at least one further lever is, in turn, hinged to a stationary part. With this embodiment of the holding device, the desired combined axial and radial movement of the inductor can be generated from a pure rotational movement, namely that of the shaft.

• 1 im Schnitt den oberen Bereich einer Druckgasflasche;
• 2 perspektivisch eine Trockenstation zum Trocknen einer Druckgasflasche in einer ersten Arbeitsposition;
• 3 eine Ansicht, ähnlich der 2, in der sich jedoch die Trockenstation in einer zweiten Arbeitsposition befindet;
• 4 die Seitenansicht der Trockenstation in der in 2 gezeigten Arbeitsposition;
• 5 die Seitenansicht der Trockenstation in der in 3 gezeigten Arbeitsposition;
• 6 in größerem Maßstab die Seitenansicht eines Induktors, wie er in der Trockenstation der 2 bis 5 verwendet wird;
• 7 die Stirnansicht des Induktors;
• 8 die Draufsicht auf den Induktor.

An embodiment of the invention will be explained in more detail with reference to the drawing; show it:

• 1 in section, the upper portion of a compressed gas cylinder;
• 2 in perspective, a drying station for drying a compressed gas cylinder in a first working position;
• 3 a view similar to the one 2 in which, however, the drying station is in a second working position;
• 4 the side view of the drying station in the in 2 shown work position;
• 5 the side view of the drying station in the in 3 shown work position;
• 6 on a larger scale, the side view of an inductor, as in the drying station of the 2 to 5 is used;
• 7 the front view of the inductor;
• 8th the top view of the inductor.

First, on the 1 With reference to which the problem is addressed, with which the present invention is concerned. The total with the reference numeral 1 marked gas cylinder has in the upper part of a shoulder 2 over which the major diameter major area 3 in a neck 4 smaller diameter passes (see also the 2 to 5 ). On the neck 4 is a shoulder collar 5 Shrunk, having an external thread 6 for a bottle cap (not shown) carries. The shoulder collar 5 lies with a lower edge 7 on the outside of the shoulder 2 more or less close. The neck 4 has an internal thread 42 ,

When the raw gas cylinder 1 To be painted, various wet chemical pretreatments are required, for example in a degreasing. For Zn-phosphating the entire compressed gas cylinder 1 also sprayed from the outside with high pressure. In these processes, in particular due to different used bath temperatures in heated and unheated process steps, liquid bath medium is in the cavity 8th sucked in, between the throat 4 , the shoulder 2 and the shoulder collar 5 lies.

In the subsequent painting process, the gap between the edge 7 the shoulder collar 5 and the outer surface of the shoulder 2 closed by the paint. Now, if the paint dried, evaporated in the cavity 8th enclosed bath medium, causing the popping of the paint or rusting in the corresponding area of the compressed gas cylinder 1 leads. Therefore, the bath medium before the painting reliably from the cavity 8th be removed.

This happens in a drying station, as in the 2 to 5 is shown and the total reference numeral 10 wearing. The drying station 10 includes a floor frame 11 , which are essentially four vertical columns 12 that up through cross struts 13 connected to each other. Further cross struts 14 at the bottom of the columns 12 stiffen the floor frame 11 in a known manner.

With the floor frame 11 is a serving as a holding device swing frame 15 connected in a manner as explained in more detail below becomes. The swing frame 15 carries an inductor in the upper area 16 which also explained in more detail below and drying the neck area of the compressed gas cylinder 1 is used.

The connection between the swing frame 15 and the floor frame 11 is as follows:

The two longitudinal spars 17 . 18 of the swing frame 15 are, at a distance from their lower ends, over two levers 19 . 20 on two opposite cross struts 13 hinged. Articulated is both the connection between the levers 19 . 20 and the longitudinal bars 17 . 18 as well as the connection between the lower ends of the levers 19 . 20 and the crossbars 13 , The levers 19 . 20 are to stiffen each other via a crossbar 21 and at the bottom over a pivot shaft 22 connected.

Also at the lower ends of the spars 17 . 18 of the swing frame 15 is a lever 23 hinged. The opposite ends of the lever 23 are with a pivot shaft 25 connected, in turn, on two opposite transverse struts 14 is stored. The pivot shaft 25 can be with the help of an electric geared motor 27 also on one of the cross struts 14 is fixed, twist in both directions of rotation.

On the levers 23 opposite side of the pivot shaft 25 is, at some distance from this, a balance weight 28 arranged.

The inductor 16 in the upper part of the swing frame 15 is held in a special way both to the shape of the compressed gas cylinder 1 as well as the construction of the drying station described above 1 customized. For a more detailed explanation is now on the 6 to 8th Referenced.

The inductor 16 includes two parallel power supplies 29 . 30 and one of these power supplies 29 . 30 fed effective range 31 , The effective range 31 First of all, it can roughly be described as referring to the shape of the transitional area between the shoulder 2 and the shoulder collar 5 the compressed gas cylinder 1 is adapted, so it can be brought relatively close to the corresponding surfaces. A second special feature of the effective range 31 is that he's at the of the feeders 29 . 30 opposite side a gap 40 due to which the effective range 31 from the side over a holding bar 43 can be pushed, where the compressed gas cylinder 1 suspended and by a not shown in detail power-and-free conveyor through the drying station 1 and possibly through the whole plant is promoted.

In principle, the effective range 31 a coil with turns of different diameters, although the various turns are not connected to each other in the manner of a normal helix. Rather, leads the supply line 29 first over a bow 32 (see in particular 7 ) in the uppermost turn 33 , This bow 32 limits the gap 40 on one side. The turn 33 is over another, the gap 40 on the other side bounding arc 34 with the lowest turn 35 connected. This in turn is over a rising area with a section of the second bottom turn 36 in turn, in turn, with the second highest turn 37 connected is. This stands with a second section of the second bottom turn 36 in connection. The latter in turn is over a descending range 38 especially in 6 it can be seen with the feeder 30 connected. The described construction allows the above-mentioned gap 40 the sphere of action 31 of the inductor 16 to realize.

The inductor 16 is in known manner with a power supply in combination, which includes an optionally cooled generator with rectifier, intermediate circuit and inverter, and an adapter with capacitors and transformer and need not be described in detail here. This power supply can, for example, on a body frame 41 be placed on the top of the floor frame 11 is mounted.

The drying station described above 1 works as follows:

The compressed-gas cylinder to be dried on the Power-and-Free conveyor from the pretreatments 1 will, as in the 1 and 4 shown at a small distance and in a substantially vertical orientation in front of the swing frame 15 the device 1 arranged. The swing frame 15 is moved away from the vertical, as in the 2 and 4 is shown, so that the effective range 31 of the inductor 16 slightly above the shoulder collar 5 and the shoulder 2 located to the side of these.

The effective range 31 is now on the shoulder collar 5 and the shoulder 2 created by that with the help of the engine 27 the pivot shaft 25 is twisted. This twist has the consequence that the spars 17 . 18 of the swing frame 15 be pulled down. Due to the leadership of the swing frame 15 through the two upper levers 19 . 20 at the upper cross struts 13 are articulated, while the swing frame 15 in a vertical plane. When moving the swing frame 15 from the into the 2 and 4 position shown in the position of 3 and 5 the effective range is moving 31 of the inductor 16 from the side on the compressed gas cylinder 1 too and lowers at the same time. The handrail 43 penetrates into the gap 40 the effective range 31 one. This lateral movement of the inductor 16 is a vertical, downward movement superimposed. At the end of the described sequence of movements is the effective range 31 of the inductor 16 as required in the transition area between the shoulder 2 and the shoulder collar 5 at a small distance from their outer surfaces.

Now the inductor 16 energized, causing in the shoulder collar 5 and the shoulder 2 Eddy currents are generated. These eddy currents heat the corresponding area of the compressed gas cylinder 1 essentially selective, with the other areas of the compressed gas cylinder 1 not heated significantly. Selective heating drives those in the cavity 8th between shoulder collar 5 and neck 4 as well as shoulder 2 trapped liquid in a short time. Experiments have shown that with appropriate parameters in a very short time and reliable complete drying of the gas cylinder 1 can be achieved, the energy consumption is very low and subsequent cooling can be omitted.

Claims (5)

A method of painting compressed gas cylinders comprising: a) a main area; b) a neck having a diameter smaller than the diameter of the main region; c) a shoulder forming the transition between the main area and the neck; d) a shoulder collar secured to the neck which encloses a cavity in the region of the neck and the shoulder in which liquid can penetrate in step e); the process comprising the following steps: e) the compressed gas cylinder is pretreated with a treatment liquid, in particular degreased and / or Zn-phosphated; f) the pretreated compressed gas cylinder is dried; g) the dried compressed gas cylinder is painted; characterized in that the step f) of drying comprises a local inductive heating of the shoulder collar (5) and of the adjoining region of the shoulder (2), for which purpose an inductor (16) having an effective region (31) is used whose shape is adapted to the shape of the shoulder collar (5) and the adjacent region of the shoulder (2), and the inductor (16) is brought into a position in which the effective region (31) in a suitable for inductive heating small distance from the Shoulder collar (5) and the adjacent to this region of the shoulder (2). Plant for painting compressed gas cylinders, comprising: a) a main area; b) a neck having a diameter smaller than the diameter of the main region; c) a shoulder forming the transition between the main area and the neck; d) a shoulder collar attached to the neck; the plant comprising: e) one or more treatment stations in which the compressed gas cylinder is pretreated with a treatment liquid, in particular degreased and / or Zn-phosphated; f) a drying station in which the pretreated compressed gas cylinders are dried; g) a painting station in which the dried compressed gas cylinders are painted; characterized in that h) the drying station comprises an inductor (16) powered by a power supply and having an effective area (31) the shape of which is adapted to the shape of the shoulder collar (5) and the adjacent area of the shoulder (2) in that the inductor (16) can be brought into a position in which the effective region (31) is located in a small distance, suitable for inductive heating, from the shoulder collar (5) and the region of the shoulder (2) adjoining it , Plant after Claim 2 , characterized in that the inductor (16) by a holding means (15) is held, which is formed so that the effective region (31) of the inductor (16) with respect to the axis of the shoulder collar (5) axially directed component of motion the compressed gas cylinder (1) can be placed. Plant after Claim 2 or 3 , characterized in that the inductor (16) by a holding device (15) is held, which is formed so that the active region (31) of the inductor (16) with respect to the axis of the shoulder collar (5) radially directed component of motion the compressed gas cylinder (1) can be placed, for which purpose the effective region (31) of the inductor (16) has a lateral gap (40). Plant after Claim 4 , characterized in that the holding device comprises a pivot arm (15) which is connected at its lower end via at least one lever (23) rotationally connected to a rotatable shaft (25) and at a distance from its lower end with at least one further lever (15). 19, 20) is hinged, which in turn is articulated to a stationary part (13).

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