DE60201380T2 - Apparatus and method for powder coating with inductive heating - Google Patents

Abstract

Provided is an apparatus (1) for powder coating which includes a coat-applying station (9) for applying a powder coating (P) on a work (3) to be coated, and a high frequency induction heating apparatus (47) for heating the work (3) covered with the powder coating (P) under the effect of high frequency wave and baking the powder coating (P) on the work at the interface defined between the powder coating and the work. Use of the apparatus (1) provides a uniform and strong coating film without any unevenness more efficiently with the relatively compact apparatus. <IMAGE>

Description

Field of invention

The The present invention relates to an apparatus and a method for powder coating, the one uniform and strong coating film without any unevenness on workpieces Provide complex design, such as a pipe fitting of ferrous material and a powder coating applicator to run derselbigen. More particularly, the present invention relates to a Device and a method for powder coating, which the Reinforce adhesive properties of the coating film with respect to the workpieces, thereby the efficiency of the coating process by switching off the degreasing step improving and improving their productivity.

background the invention

at the coating application process according to the prior art (see GB 110113, for example) are used after a degreasing step for Removing the impurity such as grease, affecting that on the surface the workpieces to be coated adheres, a cleaning step, a dripping step and a drying step also performed. Then, a coating application step, a dry and a Heating step by irradiation with rays in the extreme infrared and a cooling step carried out.

Should however, the workpieces complex design by irradiation with radiation in the extreme infrared range dried and heated, so the surface of the Coating to excessively heated to become and the adherent surface of the coating tends to, shorter to be heated as required, so that the uneven coating can train. Furthermore, the process of drying and heating by irradiation with extreme infrared radiation a time consuming process. If provided, by irradiation uniform with radiation in the extreme infrared range dry, the must Coating application device inevitably be increased, so that the Room and the costs required to set up the device also significantly enlarged or elevated become.

Of another must at the above mentioned Procedure for coating the degreasing process to be made, before a coating of the workpieces takes place. In the case, in which the heat is supplied by irradiation with radiation in the extreme infrared range from outside of the workpiece, brings an impurity such as between the workpiece and the Coating interposed grease the disadvantage of sticking or a separation between the workpieces and the coating film with himself. It is therefore reasonable perform a degreasing on each workpieces. The degreasing process However, it is very expensive and is an obstacle the improved efficiency of the coating process.

at the coating process, a hanger is used, in which several workpieces suspended are. While Repeated Coating processes adheres to the distributed around the hanger Coating material on it and strongly adheres to it through the Effect of the heating process. It was therefore necessary to have an extra process to peel off the adherent coating material from the hanger.

Summary the invention

• eine Beschichtungsauftragstation zum Auftragen einer Pulverbeschichtung auf eine Oberfläche eines durch elektrostatische Beschichtung zu beschichtenden Werkstücks;
• eine Heizstation zum Aufheizen der aufgetragenen Pulverbeschichtung, aufweisend ein Paar an Hochfrequenzinduktionsspulen, die einander gegenüberliegend und voneinander getrennt angeordnet sind und die bei Zufuhr eines hochfrequenten Stroms das mit der Pulverbeschichtung bedeckte Werkstück heizen;
• einen Aufhänger mit mehreren Anbringstangen für Haken, an denen Haken montiert sind, die aus einem Material hergestellt sind, das durch Hochfrequenzinduktionsheizen nicht erwärmt werden kann; und
• eine Transfereinrichtung für Aufhänger zum sequentiellen Transportieren des Aufhängers zu jeder Station, wobei die Transfereinrichtung für Aufhänger den Aufhänger zwischen den gegenüberliegenden Hochfrequenzinduktionsspulen führt.

According to a first aspect of the present invention, there is provided a high frequency induction heating type powder coating apparatus comprising:

• a coating application station for applying a powder coating on a surface of a to be coated by electrostatic coating workpiece;
• a heating station for heating the applied powder coating, comprising a pair of high-frequency induction coils arranged opposite to each other and separated from each other, which heat the powder-coated workpiece upon supplying a high-frequency current;
• a hanger having a plurality of attachment bars for hooks on which hooks made of a material that can not be heated by high-frequency induction heating are mounted; and
• a hanger transfer means for sequentially transporting the hanger to each station, the hanger transfer means guiding the hanger between the opposed high frequency induction coils.

Preferably is the hanger made of copper.

Preferably the apparatus further comprises a support for displacing the workpieces a circular, horizontal transfer line.

Preferably the hook has a mounting member bent to the inverted "U" shape and an arm which extends from one end of the mounting member and wherein the Mounting bar for Hook is provided with a plurality of vertically extending recesses, in the longitudinal direction of the element are spaced apart to releasably the mounting member of the Hakens to capture.

at the coating application device of the above construction may be the hook with the mounting bar for Hooks are connected by mounting the mounting member of the hook on the pole, with each selected, vertical one Recess. Therefore, the hook can be stably by the engagement of the mounting member be held with the recess. The hook can also easily through Pulling the mounting member are removed from the recess.

Thereby the hook on the mounting element for hooks can only by a Process mounted or detached from this. In this context can the at the mounting rod for Hook-mounted hook quickly replaced by another type hook be in agreement with the shape or size of the too coating workpiece. The number of hooks mounted on the pole can be light in accordance be changed with the shape or size or size of the workpiece to be coated. The spacing between the hooks may be in accordance with the shape or size of the too coating workpiece can be easily varied. Furthermore, a process can be effected over the the distance between workpieces and the high frequency induction coils is adjustable.

The Hook for workpieces are preferably made of a material to which the powder coating does not adhere, such as a phosphor bronze wire. If the mounting member is formed in a clip-shaped configuration is, the hook can continue stable on the mounting rod for hooks be held.

Preferably are the mounting element and the arm of the hook of a wire circular cross-section formed, runs the upper end of the arm of the mounting element down and is a hook portion with arrowhead shape for suspending the workpiece on the attached to the upper end of the arm. In this context, the disorder due to the footprint of the hook on the stream of injected coating material be prevented by making the height of the hook longer as the dimension of the workpiece, measured from the hook hole to its upper end, i. by positioning the entire workpiece below the mounting bar for Hook. The disorder can further be prevented or mitigated when the mounting element and the arm of the hook are made of a thin wire. This can eliminate the problem of uneven coating become.

at the practical execution of the present invention the two coils are separated in their circle. The means for energy supply these coils can however, be simplified by connecting both circles and union the circles with a wire material in which no induction current is induced.

Preferably is the pair of high-frequency induction coils each on Spulentragsockeln carried, the pedestals offset in opposite directions can be so that the widened or narrowed between the coil sockets limited distance can be and provides a control device for the coil position is to control the offset of the bobbin base.

at Such an arrangement may be the distance between coils and the distance between each spool and the workpieces can be adjusted so that the Distance between coils can be extended during transfer or transporting the hanger in the heating station and then you can the coils are shifted to the optimum position in the heating operation. In this connection can workpieces edited various sizes and the heating conditions can in accordance with the type of workpieces changed become.

Preferably, the apparatus comprises a tag for storing position control data of the pair of high-frequency induction coils or data representative thereof, which is adapted to be mounted on the hanger, the data being changed in accordance with the workpieces attached to the hangers and / or the powder coating covering the workpieces, a data read circuit for reading the data stored in the tag, a processor generating a control signal based on the data read from the data read circuit, and a control circuit for controlling the position of the coils based on the control signal.

Accordingly, the Position of the spools relative to the workpieces, i.e., the one to be controlled Condition for realizing the optimum heating with respect to the kind the workpieces or the property of the coating material is automatically adjusted will be in accordance with the control data or the representative one previously stored in the mark Dates.

• eine Datenleseschaltung zum Lesen der in der Marke gespeicherten Daten,
• einen Prozessor, der ein Steuersignal basierend auf den von der Datenleseschaltung gelesenen Daten generiert; und
• eine Steuerschaltung zum Steuern der Vorrichtung basierend auf dem Steuersignal.

Preferably, the apparatus further comprises a tag for storing control data or data representative thereof for controlling the plurality of displacements of a spray gun of the heating station, the amount of coating to be sprayed by the spray gun, and / or the time for heating by means of the high frequency induction coil which is designed to be mounted on the hanger, the data being changed in accordance with the workpieces attached to the hangers and / or the powder coating covering the workpieces,

• a data read circuit for reading the data stored in the tag,
• a processor that generates a control signal based on the data read by the data read circuit; and
• a control circuit for controlling the device based on the control signal.

Accordingly, the Device are set automatically in accordance with the control data or the representative Data previously stored in the tag, out of the several move operations the spray gun, the amount of coating material to be applied and / or the time for heating by means of the high frequency induction coils, i.e., at least one of the states to be controlled for the realization of the optimal coating application or the optimal Heating in relation to the type of workpieces or the property of the Coating material.

As can be seen from the above, one or more of the influencing conditions in the coating application process or the quality of the heated Coating to be controlled automatically, as well as optimally in relation on the type of workpieces and the coating material. This makes the inefficient process such as stopping the line and / or adjusting the position of the coils, which is conventionally required to to change the state to be controlled if the type of workpieces changed turned off.

With Help of the present invention may be the coating application process the hanger be made under optimal process conditions in accordance with their own control data and the representative data, so that itself hanger smaller single lots can be optimally processed.

The Method for storing data can be either the method for Save the control data to be in the mark or the procedure for Storing the concrete control data of each workpiece in the data file and storing only the representative Data, such as identifying the workpiece in the mark Number. Provided that the SID-TAG SYSTEM for a use is provided, the latter method can be used become.

• einen Beschichtungsauftrageschritt zum Auftragen einer Pulverbeschichtung auf einer durch elektrostatische Beschichtung zu beschichtenden Oberfläche eines Werkstücks;
• einen Heizschritt zum Ausheizen der aufgetragenen Pulverbeschichtung, unter Verwendung eines Paares an Hochfrequenzinduktionsspulen, die einander gegenüberliegend und voneinander beabstandet angeordnet sind und die bei Zufuhr eines Hochfrequenzstroms das mit der Pulverbeschichtung bedeckte Werkstück heizen;
• wobei das Werkstück an einen Aufhänger gehängt ist, der mehrere Anbringstangen für Haken aufweist, an denen Haken montiert sind, wobei der Aufhänger aus einem Material hergestellt ist, das nicht durch Hochfrequenzinduktionsheizen erwärmt wird; und
• wobei der Aufhänger sequentiell zu jeder Station transportiert und zwischen den gegenüberliegenden Hochfrequenzinduktionsspulen geführt wird.

According to a second aspect of the present invention, there is provided a powder coating method using high-frequency induction heating, comprising the steps of:

• a coating application step of applying a powder coating on a surface of a workpiece to be electrostatically coated;
• a heating step of annealing the applied powder coating using a pair of high frequency induction coils disposed opposite to each other and spaced apart from each other and heating the workpiece coated with the powder coating upon application of a high frequency current;
• wherein the workpiece is hung on a hanger having a plurality of hook mounting bars on which hooks are mounted, the hanger being made of a material that is not heated by high frequency induction heating; and
• wherein the hanger is transported sequentially to each station and guided between the opposite high-frequency induction coils.

Summary the drawings

Examples The present invention will now be described in detail below Reference to the attached Drawings in which:

1 a perspective view is showing the powder coating applicator of the first embodiment of the present invention;

2 a top view is shown in FIG 1 shown powder coating applicator;

3 a vertical cross-sectional side view is the one in FIG 1 shown powder coating applicator, wherein the station for coating the workpieces with powder is shown;

4 a schematic block diagram is shown in FIG 1 shown powder coating applicator;

5 a schematic perspective view is showing the configuration of the coating and heating stations of the other embodiment, obtainable by modifying the first embodiment of the present invention;

6 a plan view showing the general arrangement of the powder coating applicator of the second embodiment of the present invention;

7 FIG. 4 is a perspective view showing the essential portion of FIG 6 the powder coating applicator shown;

8th an enlarged perspective view is shown in the in the 6 shown powder coating applicator used hanger;

9 an enlarged, detailed perspective view is shown in the manner of attachment of the workpieces to be coated on the hooks;

10 a side view is in representation of the attached to the hook workpiece;

11 an enlarged perspective view is in illustration of the heater of in 6 shown powder coating applicator;

12 an enlarged side view is in illustration of the heater of in 6 shown powder coating applicator;

13 an enlarged perspective view is in representation of the brand socket, which is provided on the hanger, in the in 6 shown powder coating applicator is used; and

14 a schematic block diagram is shown in FIG 6 shown powder coating applicator used control system.

detailed description

A powder coating device 1 According to the first embodiment of the present invention will now be with reference to the 1 - 4 described.

The powder coating apparatus 1 The present invention can be used to provide a coating on an iron workpiece 3 complex design apply, such as the pipe fittings made of iron material.

Concretely, the powder coating apparatus has a cylindrical processing chamber 5 which is subdivided into six processing stations 7 . 9 . 11 . 13 . 15 and 17 , as well as a variety of accessories for each to be carried out in the stations processing, as well as a carrier assembly 19 to hold the workpieces 3 and as in the 1 and 2 shown their carriage in the chamber.

The transfer station 7 serves to the workpieces 3 to be taken up by the sponsor 21 from outside the chamber were conveyed and to the coated workpieces in the conveyor 21 respectively. The chamber also has a central spindle shaft 23 and six arms 25 extending radially from the top of the spindle shaft 23 extend. The number of arms shown in the figure is for illustrative purposes only and does not limit them. The spindle shaft 23 is designed to rotate using a drive motor 27 for one arm, via a suitable drive mechanism 29 such as a chain or a timing belt.

The poor 25 have hangers at their free ends 31 for hanging the workpieces 3 on. The hangers 31 are rotatable, for example, 180 degrees about the reverse operation of the engine 33 arranged. The hanger 31 has a vertically extending suspension bar 35 and a plurality of suitably spaced apart retaining arms 37 which are fixed to the rod so as to extend horizontally therefrom. The hanger 31 may be made of a material such as copper that can not be heated under the action of a high frequency wave.

The above-mentioned carrier arrangement 19 consists of the spindle shaft 23 , to the poor 25 , the drive motor 27 , the drive mechanism 29 , the hanger 31 and the sponsor 21 ,

In the direction of workpiece transfer is a coating application station 9 , at the transfer station 7 adjacent, provided and a coating application station 11 is at the coating application station 9 provided adjacent. The coating application stations 9 and 11 Whose structure is substantially identical are designed to be tandemly provided to make it possible to produce many kinds and small quantities of products. A chamber-like spray nozzle 41 a coating application device 39 is toward the interior of each coating applicator 9 and 11 directed. The coating application device 39 is outside the processing chamber 5 positioned.

The coating application device 39 is a device that uses the powder coating P on the surface of the workpiece 3 is applied under the action of electrostatic induction. The reason why the powder coating P is used is that the solvent contained in the liquid paint is one of the causes of environmental pollution.

Also, each of the coating application stations 9 and 11 with a vacuum line 45 Mistake. The vacuum line 45 is at the recovery device 43 connected to the recovery of the excess amount of powder coating (agent) P, which does not occur when coating the workpieces 3 Use found. In the direction of workpiece transfer is a heating station 13 for heating or heating and solidifying or heating the powder coating P, applied to the workpieces, at the coating application station 9 adjacent, provided.

A high frequency induction coil 49 "U" -shaped cross section, which is part of the high frequency induction heating 47 is inside the heating station 13 provided in a position in which the spaced open side of the "U" shape is directed upward, so that the workpieces 3 and the hanger 31 can be passed through there. In such a position, the slot defined between the legs of the "U" shape is directed toward the workpiece transfer.

An electric current is supplied by the energy source 53 supplied for the induction heating, which is part of the high-frequency induction heating 47 forms, namely to the high-frequency induction coils 49 for generating the induction current through the workpieces 3 , which heats the powder coating P applied to the workpieces at the interface between the workpieces and the coating. A cooling passage (not shown) for suppressing overheating of the high frequency induction coils 49 is provided within the coil of limited channel.

As recognizable from the above, the powder coating P is designed such that she heated and can be heated up from the interface between the Coating and the workpiece via inductive heating with the help of a high frequency wave. An impurity such as a small amount of material located on the surface of the workpiece Grease is heated and evaporates and loses itself from the interface between the Coating and the workpiece, so that one poor close contact between the coating and the workpiece turned off can be. Of course can also be required in the prior art process of degreasing eliminated.

The on the hanger 31 remaining powder coating P can not be heated and can remain in the mold as it was because the hanger 31 is made of a material such as copper, which can not be heated under the influence of high frequency wave or radiation. This can be done on the hanger 31 remaining powder coating easily be blown off with the help of a jet of compressed air.

An air blower station 15 for blowing off the powder coating P on the surface of the coating film on the workpiece 3 and the hanger 31 is left, is at the heating station 13 adjacent, in the direction of workpiece transfer, provided. jets 57 of the air blower 55 are in the direction of the air blower station 15 directed. An additional heating station 17 for additional heating of the surface of the workpiece 3 Trained coating is at the air blower station 15 provided adjacent in the direction of workpiece transfer. The additional heating station 17 is with several lamps 59 for extreme infrared radiation of 2 kW power, to ensure that the coating can be uniformly heated without any irregularities. The one in the additional heating station 17 with the help of the lamps 59 For heating in the extreme infrared range caused heating is provided only as an additional means, since the heating process can be completed by the effect of high frequency induction heating.

The transfer station 7 , which serves to connect the chamber to the outside, is at the additional heating station 17 adjacent, in the direction of workpiece transfer, provided. The coated workpieces 3 be in the transfer station 7 transferred and to the sponsor 21 transferred to the front of the transfer station 7 is provided. The workpiece and the coating thereon are passed through the cooling fan 61 cooled, which is on the delivery side of the conveyor 21 is provided.

The processing steps used in the powder coating applicator 1 will now be described sequentially.

Workpiece adoption process

The hanger 31 and the workpieces attached to it 3 be over a predetermined distance on the conveyor 21 transported and then to the transfer station 7 transmitted by any suitable transfer mechanisms. When transferring to the transfer station 7 becomes the upper end of the suspension rod 35 of the hanger 31 with the free end of the arm 25 coupled. This allows the workpieces within the processing chamber 5 be transmitted on the circular, horizontal transfer line.

Beschichtungsauftragevorgang

The in the processing chamber 5 through the transfer station 7 transferred workpieces 3 be at a predetermined angle in the coating application station 9 or 11 added. In the coating application station 9 or 11 becomes the powder coating P from the nozzles 41 the coating applicator 39 injected and adheres to the surface of the workpieces 3 under the influence of electrostatic induction on.

The hanger 31 is there by the angle of 180 degrees about the reverse motion of the engine 33 turned around so that the powder coating P thoroughly on the surface of the workpieces 3 on the hanger 31 distributed or can be attached to it. The excess amount of powder coating that does not adhere to the workpieces can be removed by means of the recovery device 43 be recovered.

Hochfrequenzinduktionsheizvorgang

Then the workpieces are 3 in the heating station 13 conveyed and inside the slot 51 the high-frequency induction coil 49 positioned. The workpieces 3 are heated under the influence of high frequency radiation from the high frequency induction coil 49 was generated, which is operated by the energy source 53 for induction heating. The on the surface of the workpiece 3 applied powder coating P is designed so that it is heated and heated over the interface between the coating and the workpiece. At the same time, impurities such as on the surface of the workpiece 3 adhering fat also heated or heated, evaporated and turned off. The temperature at which the fat is evaporated is less than the temperature at which the powder coating P is heated or solidified, so that the vaporized impurities such as grease entwei can pass through the voids between particles of the powder coating P, even after the powder coating on the workpieces 3 was applied.

The vaporized and fumed contaminants such as Fat, can Adsorbed by any suitable absorption device (not shown) and filtered. This allows pure air without pollution removed from the chamber become.

air blowing

The workpieces 3 with a coating film formed by the above-mentioned high-frequency induction heating process are introduced into the air blower station 15 in which the excess powder coating P adhering to the surface of the coating film is conveyed by the air blower 55 emitted air stream can be dusted. At the same time, the powder coating P adhering to the hanger can also be dusted off.

Additional heating process

The workpieces 3 are then in the additional heating station 17 moved or transported and irradiated by the lamps 59 for radiation in the extreme infrared range to be subjected to the additional heating process. This can ensure that the coating can be uniformly heated without any irregularities.

Produktausliefervorgang

The workpieces 3 then go to the transfer station 7 promoted and on to the conveyor 21 which is located outside the processing chamber, transmitted by any suitable transfer mechanism. The coated workpieces are passed through the cooling fan 61 on the conveyor 21 cooled and delivered as finished products.

As can be seen from the above, the hangers become 31 with the workpieces attached to it 3 , one by one in the processing chamber 5 from the conveyor 21 accepted, processed in the context of the above-mentioned processes, back to the conveyor 21 transported and then transported as finished products.

5 Fig. 13 is a view showing the structural relationship of the hooks for suspending the workpieces and the elements of the coating application device 1 ,

The workpieces to be coated are designed so that they can be transported sequentially through the coating application station, the heating station and the cooling station. As mentioned above, the coating application stations are 9 and 11 provided with a spray gun f, with the help of the nozzle 41 the statically charged powder coating P can be delivered. The nozzle 41 can move back and forth in the vertical direction. The heating station 13 is with the high frequency induction coil 49 provided, which is formed by a bent to "U" shape elongated coil and the cooling station is connected to the cooling fan 61 and the like provided.

The hanger 31 comprises a vertically extending stand h, a plurality of equidistantly spaced, horizontally extending attachment rods i for hooks which are fixed to the stand and a plurality of workpiece holding hooks j mounted on the attachment rods i for hooks. The hook mounting bars i are also provided with a plurality of bolt holes k which are aligned along the longitudinal direction of each bar. The workpiece holding hook j is formed by bending the rectangular piece of strip into a substantially "L" shape. The length of the vertically extending leg of the workpiece holding hook can be substantially identical to the width of the hooking rod i for hooks. Also, the vertically extending leg is provided with a bolt hole. The workpiece holding hook can be mounted on the hook attaching rod by screwing a bolt m through the bolt hole of the hook and through the bolt hole k, and fastening the nut P to the bolt. Two or three hooks can be mounted in each branch of the pole extending from the stand.

The distal end of the horizontal leg of the hook is pointed in the form of an arrowhead. The workpieces are designed so that they pass through Introduce each pointed tip in the hook hole q corresponding workpieces to the Hook attached can be.

When transferring the hanger 31 in the coating application station 9 the spray gun f sprays the powder coating P in the vertical direction on reciprocation. This allows the powder coating P on the workpieces 3 be applied under the action of electrostatic induction.

The hanger 31 is then transferred to the space between the left and right halves g-1 and g-2 of the high-frequency induction coil 49 and then the workpieces 3 heated from the inside. The temperature of the heated workpieces is such that it is controlled within the range between 250⎕ and 280⎕. This allows the on the workpieces 3 applied powder coating P are heated from the interface between the workpiece and the coating ago.

at the embodiment described above The coating is the interface between the workpiece and the Coating under the influence of High frequency induction ago heated. In this connection, the coating can be heated uniformly be without unevenness, the for the time required to heat up the coating can be reduced and the coating applicator can be miniaturized become.

The contamination such as on the surface of the workpieces 3 Adhering fat is vaporized and disappears under the influence of high-frequency induction heating, so that the degreasing operation, which is inevitably required in the prior art, can be avoided. This leads to the substantial improvement of the operating efficiency.

Also, the problem of environmental pollution caused by the solvent contained in the liquid paint can be avoided because the powder coating P is used in the present coating application process. The excess amount of at the hanger 31 adhering powder coating can not be heated and therefore can not adhere firmly. This is because the hanger is made of a material such as copper, which can not be heated by high-frequency radiation. This allows the powder coating to be easily dusted off the hanger.

While that first embodiment of the present invention has been described in detail for the It will be apparent to those skilled in the art that a wide variety of changes and modifications in the design can be made without to depart from the spirit and scope of the invention.

Although in the above-mentioned embodiment, the coating application stations 9 and 11 have substantially identical structure and are provided in tandem, can be dispensed with both stations or it can be added one or more additional coating application stations.

Furthermore, it would be possible to provide a structure in which the width of the slot 51 the high-frequency induction coil 49 can be controlled. In such a construction workpieces can 3 can be accommodated in a variety of sizes and the temperature of the workpieces can be controlled and / or unified in the Hochfrequenzinduktionsheizvorgang.

Under the condition that the excess amount of powder coating should not adhere to the surface of the coated film, the air blower operation using the air blower can be performed 55 be waived.

Further, if the uniform coating without inequalities can be formed only by the high-frequency induction heating process, the additional heating operation with the aid of the lamps can also be performed 59 be dispensed with radiation in the extreme infrared range.

Although the transfer process of the workpieces 3 to or from the processing chamber 5 in the above embodiment by a transfer station 7 can be effected, a receiving station 63 only for holding the workpieces and a conveyor station 65 only for conveying the workpieces, as in 4 (a) be shown provided.

The path for transporting the workpieces 3 in the processing chamber 5 may be a rotating system as mentioned in the first embodiment and in FIG 4 (a) is shown and can be a linear alignment system, as well as a as in 4 (b) shown carriage system.

The offset of the workpieces 3 is not limited to the above-described discreet operation and the workpieces 3 can also be put into a continuous operation by changing the size of each station and the useful length. If the hanger 31 coated with PTFE, the cleaning of the hanger can be simplified.

A powder coating device 101 According to the second embodiment of the present invention will now be with reference to the 6 - 14 described.

The powder coating apparatus 101 has a structure in which predetermined processing stations are arranged along a circular transfer path.

A workpiece to be coated 103 is a pipe joint of iron material with a hook hole 103a at about its central section. Of course, the workpiece 103 just one example of a variety of workpieces that in the powder coating device 101 can be treated.

A. hanger (see 6 - 10 . 12 and 13 )

A hanger 105 for hanging the workpiece 103 during transport will be detailed with reference to the 8th - 10 described.

The hanger 105 has a vertical stand 106 square cross section, a plurality of equidistant, horizontally extending mounting rods 107 for hooks attached to the stand 106 are fastened, several workpiece holding hooks 108 , detachable to the mounting rods 107 for hooks are mounted, a pair of suspension kits 109 which is horizontal from the upper section of the stand 106 preside and a brand or day 110 , These elements of the hanger are made of a material such as phosphor bronze, which can not be affected by the high frequency radiation.

The mounting bar 107 for hooks is an element of relatively narrow sheet material. One end of the element is bent at right angles relative to its remaining portion. The mounting bar 107 for hooks can be attached to the stand 106 be mounted by bolting the one end of the element to the stand, so that it stands horizontally away from it.

The mounting bar 107 for hooks is on its two surfaces with several vertically extending recesses 107a V-shaped cross-section, which are spaced apart in the longitudinal direction of the element at a predetermined pitch or pitch. The position of each recess provided on the front surface of the member corresponds to that of the rear surface, that is, a pair of front and rear recesses (hereinafter referred to as a pair of recesses) are provided at the same position on the member.

The on one side of the stand 106 provided mounting rods 107 for hooks are aligned with those on the other side of the stand, ie several pairs of hook attaching rods are aligned on both sides of the stand 106 symmetrical.

A catch 108 for the workpiece to be coated comprises a mounting element 108a , an arm 108b and a hook portion 108c , The mounting element 108a and an arm 108b are formed by bending a wire of phosphor bronze circular cross-section. The mounting element 108a has a deep U-shape. The distance between the legs of the "U" is substantially equal to the thickness of the mounting bar 107 for hooks in each recess pair. The arm 108b extends from the mounting element 108a in the shape of the quadrant forward and backward. The hook section 108c is at the top of the arm 108b attached. The hook section 108c is formed in a shape of an arrowhead or isosceles triangle. The arm is configured to be insertable into a hole provided at the base of the hook portion opposite the apex of the triangle and welded thereto.

The hooks 108 are designed so that they are detachable on the mounting rod 107 are mounted for hooks by holding the rod between the legs of the "U" s of the mounting element 108a at each recess pair. The hooks can be attached to the mounting bar 107 for hooks by engagement between the hook mounting element 108a and held the recess pair.

Although usually two or three hooks 108 on every mounting rod 107 are mounted for hooks (in 6 and 7 There are two hooks mounted in each pole and in 8th if three hooks are mounted in each bar), the number of hooks can be changed in accordance with the shape or size of the workpieces to be coated.

To support the hanger on a hanger support bar described below, the stand points 106 the suspension kits 109 extending through the upper end portion of the stand in a direction parallel to the mounting bars 107 for hooks.

The stand 106 is also in a position above those of the approaches 109 provided, with a short cylindrical. marker base 110 (please refer 8th ) runs horizontally from there. The marker base is designed to receive a marker or marker to be described in detail below.

Various hangers whose number is different from the mounting rods 107 for hooks, can also be used in the coating application device 101 Find use. The hooks can be changed in terms of the number, shape and height of the arms 108b and the size of the hook section 108c , These hooks are common with the shape and size of the mounting element 108 ,

B. Processing chamber (see 6 . 7 . 11 and 12 )

It is a processing chamber 121 provided by substantially cylindrical polygonal configuration. The chamber surrounded by a cylindrical outer wall may be maintained in a substantially airtight state. Around the chamber are provided various necessary additional facilities.

A vertical main shaft assembly section 122 hexagonal cross-section is through the central section of the processing chamber 121 provided through. The one between the processing chamber 121 and the space defined to the main shaft arranging section can be divided into six sectors of substantially the same size. Each of the boundaries between the sectors is provided with a respective partition wall. An intended in each partition hanger 123 is designed so that it transfers the hanger 105 is opened and closed from one sector to the adjacent sector.

The sectors are called transfer station 124 , two coating application stations 125 . 125 ' , a heating station 126 , a heat balance station 127 and a cooling station 128 used. These stations are arranged in the clockwise direction as mentioned above. The transfer station 124 is provided adjacent to the workpiece feed station described below.

The transfer station 124 serves to accommodate the hanger 105 from the workpiece feed station and the promotion of the hanger 105 in the workpiece feed station. In the coating application stations 125 . 125 ' the powder coating P is applied to the workpieces 103 applied, in the heating station 126 will be on the workpieces 103 applied powder coating P heated under the influence of Hochfrequenzinduktionsheizens, in the heat balance station 127 the unevenness of the temperature of the workpieces is switched off and in the cooling station 128 become the hot workpieces 103 cooled. Both coating application stations 125 . 125 ' can be used in accordance with the coloring of the coating to be applied to the workpieces.

B-1. Hanger Transfer Mechanism (See 6 and 7 )

A vertical main shaft 131 is within the main shaft assembly section 122 arranged. The main shaft 131 can be absent with the help of a turning mechanism 132 to be rotated in the clockwise direction at the 60 degree center angle.

Radial and horizontal six suspension suspension poles 133 , which define the angle of 60 degrees between adjacent rods, are at the top of the main shaft 131 provided and protrude through the upper wall of the processing chamber 121 , A hanger holding member (not shown) having a holding portion for holding the hanger lug 109 of the hanger 105 is at the free end of each hanger support bar 133 intended. The hanger holding member can by means of the rotating mechanism 134 to be turned around. The hanger holding element is turned around the hanger 105 for example, to turn 180 degrees.

The additional rotation of the main shaft 133 can be controlled so that it stops to hang gertragstangen 133 at the substantially central position of the stations 124 - 128 to arrange.

The hanger 105 to which the workpieces to be coated 103 can be added and checked at the transfer station 124 on the hanger holding member of the hanger support bar 133 to hang from this. Then the hanger goes along the circular path through the processing chamber 121 emotional. This allows you to hang on the hanger 105 attached workpieces over the coating application station 125 or 125 ' , the heating station 126 , the heat balance station 127 and the cooling station 128 be treated.

B-2. Coating application station (see 6 . 7 and 14 )

A spray gun displacer 141 and an associated powder feeder 142 are on the outside of every coating application station 125 and 125 ' arranged. The spray gun offset 141 has a chain 143 in the vertical direction (see 14 ) is a motor 144 to drive the chain and a spray gun 145 for spraying the powder coating P on. The spray gun 145 is with the chain 143 connected. The spray gun 145 has a comb-like shape with multiple nozzles that are in the predetermined width, a little wider than the width of the hanger 105 are arranged. The spray gun is just in front of the hanger 105 within the coating application stations 125 and 125 ' arranged. One with the spray gun 145 connected line passes through a vertical slot which is bounded by the peripheral wall of the processing chamber 121 and is with the chain 143 connected.

The motor 144 switches the direction of rotation in a predetermined period of time to the offset direction of the spray gun 145 to change. During the upward and downward movement, the powder coating P of the spray gun 145 fed and from there in the direction of the workpieces 103 pushed out. To get out of the spray gun 145 discharging ejected powder coating P with static electricity is means for charging the coating material, for example, the friction tube or the corona discharge plug to the coating material supply system or the end of the nozzles of the spray gun 145 intended.

B-3. Heating station (see 6 . 7 . 11 and 12 )

The heating station 126 is with a pair of high frequency induction coils 151 and 151 ' Mistake. Each of these high-frequency induction coils 151 and 151 ' is formed by winding the wire on a plane to define an elongated swirl, so that the coils, unlike the high frequency induction coil 149 , have no bending section. The dimensions of the high-frequency induction coils 151 and 151 ' are essentially identical to those of the hanger 105 , The coils are within a pair of coil housings 152 each recorded in an upright position.

As can be seen from the above, the high-frequency induction coils 151 and 151 ' independent from each other. However, the coils are over a strand of wire 153 made of copper material connected together. In this connection, the coils are integrally connected together in a circuit. The material used to form the coils is a thin copper tube through which the coolant can flow. The channels confined within the tubes are fitted with an elastic tube 15 connected.

A pair of sliding blockers 155 attached to the bottom surface of each coil housing 152 are provided, are designed such that they can be brought into engagement with a pair of guide rails 156 at the bottom of the heating station 126 lie so that the high-frequency induction coils 151 and 151 ' can be moved to each other.

The lower end portion of the bobbin case 152 is with a mother 157 provided, which has a right-handed screw thread and the lower end portion of the other coil housing 152 is with a mother 157 provided that has a left-handed screw thread. These nuts 157 are engaged with a threaded shaft 158 , The thread shaft 158 is designed so that it by means of a stepping motor 159 is rotatable. As a result, by pressing the stepper motor 159 the coil housing 152 offset in opposite directions so that the distance between the coil housings 152 can be increased or decreased.

B-4. Heat balance station and cooling station (See 6 )

The heat balance station 127 is with several heaters 161 a radiation in the extreme or ho infrared range of 1-9 kW.

The cooling station 128 is with a cooling fan 162 Mistake.

C. Workpiece feed station (See 6 )

The workpiece feed station 171 is in front of the transfer station 124 the processing chamber 121 intended. The workpiece feed station 171 has an endless feed chain 173 on, which runs horizontally at a predetermined height. The chain 173 is with a plurality of equally spaced hanger holding members for holding the hanger 109 of the hanger 105 Mistake. The chain 173 repeated movement and stop. That means that the chain 173 stops when a hanger a predetermined position with respect to the transfer station 124 has reached and moves later again.

The hanger 105 with the workpieces 103 can be on the chain 173 at a predetermined position at the workpiece feed station 171 be attached. The hanger 105 is then through the task chain 173 in the direction of the processing chamber 121 moved and then by means of a transfer robot (not shown) to the suspension support bar 133 at the transfer station 124 promoted. After the hanger 105 through the processing chamber 121 transported and the transfer station 124 has reached, the hanger with the help of the transfer robot (not shown) to the task chain 173 promoted and then from the task chain 173 removed and transported away.

D. Control System (See 14 )

The for the Powder coating apparatus used according to the present invention Tax system is basically defined as the SID-TAG or SID-BRAND system.

In 14 is a tax system 181 shown with the number of offsets of the spray gun 145 , the relative position of the high frequency induction coils 151 and 151 ' and which can be controlled by the coil-induced heating time.

reference numeral 182 is associated with a circuit which is the drive of the spray gun offset motor 144 serves.

reference numeral 183 is associated with a coating valve built into the coating feed system and with the spray gun 145 connected is. The coating valve 183 has a control mechanism with which the size of the opening passing therethrough is changeable in accordance with the electrical command. The control mechanism is configured to pass through the coating valve control circuit 184 is controllable.

reference numeral 185 is associated with a circuit which serves to drive the motor to offset the coils and the reference numeral 186 is assigned to a position sensor, such as a proximity switch for detecting the origin of the offset or the waiting position of the bobbin case 152 , The position sensor is designed so that it emits a signal when the bobbin case by the in 12 shown with two-point line defined position.

reference numeral 187 is associated with a Spulenanregeschaltung, with which the amount of electricity is controllable, the high-frequency induction coils 151 and 151 ' is supplied. The Spulenanregeschaltung has a timer 187a on.

reference numeral 188 is associated with a tag and the reference number 189 the data read circuit. The data at the position number of the workpiece is written into the mark by means of writing means (not shown) 188 read in and stored in it. The mark 188 is designed so that it is detachable on the base 110 can be mounted.

The one in the brand 188 stored data can be from one at the mark 188 provided antenna are sent to an antenna connected to the data read circuit 186 is provided and with the help of the data read circuit 189 be read out.

reference numeral 190 is associated with a processor having a control data file identifying the control data of the workpieces identified by the position number indexed thereon, such as For example, the number of offsets of the spray gun 145 , the degree of divergence of the coating valve 183 , the color of the coating to be applied, the number of rotations of the stepper motor 159 , which determines the distance between the coils and the workpieces and the length of time during which the high frequency induction coils 151 and 151 ' are excited, as well as a program data file in which the control data corresponding to the position number obtained by means of the data read circuit 189 has been read from the control data file and the predetermined control signals of each control circuit 182 . 184 . 185 . 197 be issued.

Part of the contents of the control data file is shown in Table 1:

The structure of the powder coating applicator 101 is as described above.

E. The method of use and the effect

The method of using the powder coating apparatus 101 and the resulting effect.

E-1. preparation

In front The beginning of the coating process will be the data of each workpiece, such as for example, the empirically determined optimal control data and the data of the color to be used by the SID-TAG system in written the control data file.

Will the workpiece to be coated on the hanger 105 Hanged, so will the type and number of attaching rods 107 for hooks to be mounted 108 suitably selected. To put it more practically, the height H of the arm should be 108b (please refer 10 ) be longer than the distance between the hook hole 103a and the upper end of the workpiece. Although the hook 108 the above-mentioned embodiment can be used for the workpiece, which can be supported by only a portion, a hook with two arms 108b be used for a workpiece that must be supported by two sections. If a workpiece with a larger size are attached, so are on each mounting rod 107 Two hooks are provided for hooks and if the workpieces of smaller size are to be attached to each mounting bar 107 for hook three hooks provided.

Should the workpieces due to the differences in their positions with respect to the radio frequency coils 151 and 151 ' can be heated unequal, so the hook of the longer arm 108b for the lower heating rate workpieces to enhance the effect of high frequency induction.

After the predetermined type and number of hooks on the mounting rods 107 is mounted for hooks, the workpieces to be coated are attached thereto by firmly inserting the hook portion 108c of the hook 108 in the hook hole 103a of the workpiece 103 , The workpieces attached to the hanger should be of the same type.

The mark 188 to which the position number of the checked workpieces is written is in the mark base 110 introduced.

The hanger 105 can at the task chain 173 be attached.

E-2. coating application

Has the hanger 105 with the workpieces 103 the predetermined position near the transfer station 124 achieved, that will be on the mark 188 written or stored data from the data read circuit 189 receive. The processor 190 reads, from the data file, the control data and the color data of the coating corresponding to the data on the position number obtained from the data read circuit 189 received, converts the data into predetermined control signals and outputs the signal to the corresponding control circuit. The signal is output sequentially at a timing which is in synchronization with the signal for controlling the rotation of the main shaft 131 ,

The hanger 105 then becomes the hanger-carrying bar 133 transported in a position in which the mounting rods 107 are for hooks parallel to the straight line circumscribing the circle defined by the geometric location of the free end of the hanger support bar 133 ,

After the carriage in the processing chamber 121 took place, the hanger becomes 105 further into the coating application station 125 transported and in front of the spray gun 145 stopped. Provided that the color to be applied to the workpieces coincides with the color to be applied in this station, the coating application process is performed. If the paint to be applied to the workpieces does not match the color to be applied in that station, the hanger will continue to be conveyed to the next coating application station 125 ' and then the coating application process is performed. The coating application process is controlled as mentioned below.

The spray gun 145 is designed so that it the powder coating P in the direction of the hanger 105 injecting, vertically displacing or moving up and down predetermined times in accordance with the control signal from the processor 190 to the spray gun offset 141 and the associated powder feeder 142 , The amount of powder coating P is determined by the degree of divergence of the coating valve 183 which is controlled in accordance with the control signal. The hanger 105 and the workpieces 103 are covered on one side with the powder coating P.

If it is necessary to coat both sides of the workpieces and after the coating operation on one side of the workpieces has been completed, the hanger can be rotated 180 ° and the coating process on the other side of the workpieces is restarted. The mounting bar 107 for hooks does not interfere with the coating process because the entire body of each workpiece is below the mounting bar 107 is positioned for hooks. Furthermore, the arm is disturbing 108b of the hook 108 the coating process not because the arm is made of the fine wire material.

E-3. Heating etc.

After in the coating application station 125 or 125 ' the powder coating was applied, becomes the hanger 105 in the heating station 126 promoted. Before the hanger in the heating station 126 is transported, the coil housing 152 put on hold to increase the space in between. This allows the hanger 105 lightly in the space between the coil housings 152 to get promoted.

After the hanger 105 has been moved to such a position, the processor gives 190 the control signal in the circuit 185 to drive the Spulenversatzmotors from. The stepper motor 159 rotates in a predetermined amount in accordance with the control signal to the coil housing forward, in the predetermined position in the direction of the hanger 105 to move. Once the coil housing has reached the predetermined position, a signal is sent to the Spulenanregeschaltung 189 delivered and the high-frequency induction coils 151 and 151 ' are stimulated.

The workpieces themselves generate heat under the influence of induction heating via the coils 151 and 151 ' and the powder coating P adhering to the surface of the workpieces is heated. However, the hanger does not generate heat because the hanger is made of phosphor bronze which is unaffected by high frequency radiation. As a result, the powder coating P heats up on the hanger 105 not up.

After a predetermined period of time, the high-frequency induction coils 151 and 151 ' energetically degraded and become, put back in their waiting position.

After completion of the heating process, the hanger 105 into the heat balance station 127 transported to reduce the unevenness of the temperature of the workpieces and further into the cooling station 128 transported to cool the workpieces and then in the transfer station 124 promoted and to the task chain 173 promoted.

The on the hanger 105 adherent powder coating P can be dusted off by means of a blower (not shown) placed inside the heat balance station 127 is provided and recovered or recycled by the vacuum line.

In the above-mentioned embodiment, the replacement operation or the position change operation of the hook 108 be carried out easily and the disorder in terms of spraying the coating on the workpiece 103 can be reduced.

Furthermore, in the above-mentioned embodiment, the heating effect by the high-frequency induction coils 151 on all workpieces 103 attached to the hanger 105 attach, become uniform. The distance between each coil and the workpiece 3 can be controlled.

moreover can at the above mentioned embodiment the for the quality the coating essential processes or processes, such as the coating application process or the heating process automatically be controlled according to previous Setting in the unit of the hanger. This is the coating application device according to the above-mentioned embodiment good in terms of operational efficiency.

According to the present Invention can be a uniform and strong coating film without any unevenness formed more effectively with the relatively compact device become.

Claims (9)

Apparatus for powder coating of high-frequency induction type, marked by a coating application station for application a powder coating on a surface of a by electrostatic Coating to be coated workpiece; a heating station for heating the applied powder coating, comprising Pair of high-frequency induction coils facing each other and are arranged separately from each other and the supply of a high-frequency current, heat the workpiece coated with the powder coating; one hanger with several mounting rods for Hooks on which hooks are mounted, made of a material are not heated by high frequency induction heating can; and a hanger for sequentially transporting hanger of the hanger to each station, wherein the transfer device for hanger the hanger between the opposite High frequency induction coils leads. Apparatus according to claim 1, wherein the hanger is made Copper is made. Apparatus according to claim 1 or 2, further a carrier for moving the workpiece on a circular, having horizontal transfer line. Device according to one of the preceding claims, wherein which has the hook a mounting element that is bent to the reverse "U" shape and an arm, the extends from one end of the mounting member, and wherein the Mounting bar for Hook provided with a plurality of vertically extending recesses is that in the longitudinal direction of the element are spaced apart to releasably the mounting member of the Hakens to capture. Apparatus according to claim 4, wherein the mounting element and the arm of the hook is formed of a wire of circular cross-section are, the upper end of the arm of the mounting element down extends and a hook portion with an arrowhead shape for suspending the workpiece attached to the upper end of the arm. The apparatus of claim 1, wherein the pair of high frequency induction coils are each supported on coil support sockets, wherein the sockets can be displaced in opposite directions, so that the distance between the bobbin sockets limited can be widened and narrowed and wherein a control means for the bobbin position is provided to control the displacement of the bobbin support base. The device of claim 6, further comprising: a A marker for storing position control data of the pair of high frequency induction coils or in this regard representative Data adapted to be mounted on the hanger, wherein the data changed will be in accordance with the on the hangers attached workpieces and / or the workpieces covering powder coating; a data reading circuit for Reading the data stored in the mark, a processor that a control signal based on that read by the data read circuit Data generated and a control circuit for controlling the position the coils based on the control signal. Device according to one of the preceding claims, of further comprising: a mark for storing control data or in this regard representative Data for controlling the multiple displacements of a spray gun of Heating station, the amount of sprayed from the spray gun Coating and / or time for heating by means of the high-frequency induction coil designed is to hang on the hanger to be mounted, the data being changed in accordance with the workpieces, the on the hangers attached be and / or the workpieces covering powder coating, a data reading circuit for Switching the data stored in the mark, a processor, a control signal based on that of the data read circuit generated data generated; and a control circuit for controlling the device based on the control signal. Powder coating process using high-frequency induction heating, characterized by the steps: one Coating application step for applying a powder coating on a to be coated by electrostatic coating surface a workpiece; one Heating step for heating the applied powder coating, using a pair of high frequency induction coils, the opposite each other and spaced from each other and the supply of a High-frequency current heating the workpiece covered with the powder coating; in which the workpiece to a hanger hanged is having a plurality of attachment bars for hooks on which Hooks are mounted, with the hanger made of a material is not heated by high-frequency induction heating; and the hanger is transported sequentially to each station and between the opposite high-frequency induction coils guided becomes.