Flatbed embossed-printing machine and embossing plate

Abstract

The invention relates to a flat bed embossing machine (1) comprising a tool plate (20) with a tool side (36) for receiving at least one embossing tool and with a tool plate rear side (35) which lies opposite the tool side (36), further a base plate (10) with a tool plate side (12) which faces the tool plate rear side (35) and with a base plate rear side (11) which is lies opposite the tool plate side (12), for transmitting an embossing force which is exerted upon the tool plate (20), between the tool plate side (12) and the base plate rear side (11), as well as an induction heating appliance (3) for heating the at least one embossing tool (23). The induction heating appliance (3) comprises an inductor (16), the design of which and its arrangement between the tool plate side (12) and the base plate rear side (11) being such that a magnetic alternating field (19) which on the tool plate side (12) reaches beyond the base plate (19) and is for the inductive heating of an inductively heatable tool plate (20) can be produced beyond of the tool plate side (12) and outside the base plate (10).

Claims

1. A flat bed embossing machine comprising: at least one embossing tool; an inductively heatable tool plate with a tool side on which the at least one embossing tool is arranged and with a tool plate rear side which lies opposite the tool side; at least one base plate with a tool plate side which faces the tool plate rear side and with a base plate rear side which lies opposite the tool plate side, for transmitting an embossing force which is exerted upon the tool plate, between the tool plate side and the base plate rear side; and an induction heating appliance with at least one inductor for heating the at least one embossing tool, wherein the heating appliance is arranged on a side which is facing the tool plate rear side, and wherein the at least one inductor is designed and is arranged between the tool plate side and the base plate rear side of the at least one base plate and is recessed into the at least one base plate such that the heating appliance by means of the inductor produces a magnetic alternating field which at the tool plate side of the at least one base plate reaches beyond the at least one base plate for the inductive heating of the tool plate which is arranged beyond the tool plate side of the at least one base plate and outside the at least one base plate.

2. A flat bed embossing machine according to claim 1, wherein the at least one inductor and the at least one base plate together form part of a heating module.

3. A flat bed embossing machine according to claim 1, wherein the at least one inductor is designed as a wound electrical conductor with curvatures which are arranged in a plane parallel to the tool plate side.

4. A flat bed embossing machine according claim 1, wherein field conducting elements with ferrimagnetic characteristics are arranged between the at least one inductor and the base plate rear side.

5. A flat bed embossing machine according to claim 4, wherein the field conducting elements are recessed into the at least one base plate.

6. A flat bed embossing machine according to claim 1, wherein an extensive shielding element consisting of or comprising an electrically conductive material is arranged on the base plate rear side, wherein the shielding element shields the machine in a region facing the base plate rear side at least partly from the magnetic alternating field.

7. A flat bed embossing machine according to claim 1, wherein the at least one base plate consists of a carrier material which is electrically non-conductive.

8. A flat bed embossing machine according to claim 7, wherein the carrier material of the at least one base plate is a fiber-reinforced plastic.

9. A flat bed embossing machine according to claim 1, wherein the tool plate forms a heating zone which is inductively heatable by the at least one induction heating appliance.

10. A flat bed embossing machine according to claim 9, wherein the tool plate forms a continuous base region in a region facing of the tool plate rear side, and the continuous base region is part of the heating zone.

11. A flat bed embossing machine according to claim 10, wherein the tool plate comprises a multitude of recesses which are open to the tool side and which end at the continuous base region of the tool plate rear side.

12. A flat bed embossing machine according to claim 1, wherein the flat bed embossing machine comprises a plurality of individually operable heating modules each with one of the at least one base plate and with one of the at least one inductor which are arranged next to one another over the tool plate rear side, each of the heating modules designed for individually heating a part-zone of the tool plate.

13. A flat bed embossing machine according to claim 1, wherein the induction heating appliance comprises a temperature measuring device for determining a temperature of the tool plate.

14. A flat bed embossing machine according to claim 13, wherein the temperature measuring device comprises at least one temperature sensor for measuring at least one temperature of the tool plate.

15. A flat bed embossing machine according to claim 14, wherein the temperature measuring device comprises a movement mechanism, by way of which the at least one temperature sensor is fastened to the at least one base plate in a movable manner relative to the at least one base plate and is movable toward the tool plate rear side and in the opposite direction of the moving direction toward the tool plate rear side.

16. A flat bed embossing machine according to claim 15, wherein the at least one temperature sensor, by way of the movement mechanism, is movable between a measuring position, in which the at least one temperature sensor forms a measuring contact with the tool plate rear side, and a configuring position in which the at least one temperature sensor is not in contact with the tool plate rear side.

17. A flat bed embossing machine according to claim 13, characterised by a control device for controlling the temperature of the tool plate via the induction heating appliance on the basis of temperature values which are detected by the temperature measuring device.

Description

DESCRIPTION OF THE DRAWINGS

(1) The subject-matter of the invention is hereinafter explained in more detail by way of embodiment examples which are shown in the accompanying drawings. In each case in a schematic manner are shown in:

(2) FIG. 1 a cross-sectional view of a flat bed embossing machine with an induction heating appliance;

(3) FIG. 2 an enlarged detail of FIG. 1 from the region of the induction heating appliance;

(4) FIG. 3 a cross-section view of the embossing region;

(5) FIG. 4 a perspective representation of an inductor as a would electrical conductor;

(6) FIG. 5a a plan view of the base plate for receiving an inductor according to FIG. 4;

(7) FIG. 5b the base plate according to FIG. 5a with an inductor and with ferrimagnetic elements;

(8) FIG. 6 a plan view of an arrangement of four adjacent heating modules, each with a base plate for a tool plate of a continuous web machine;

(9) FIG. 7 a plan view of an arrangement of six adjacent heating modules, each with a base plate for a tool plate of a sheet-fed machine;

(10) FIG. 8a a cross-sectional view of a first embodiment of a temperature measuring device;

(11) FIG. 8b a perspective view of the temperature measuring device according to FIG. 8a;

(12) FIG. 9 a cross-sectional view of a second embodiment of a temperature measuring device.

(13) Basically, the same parts are provided with the same reference numerals in the figures.

DETAILED DESCRIPTION

(14) Certain features, for example features which are not essential to the invention are not represented in the drawings, for a better understanding of the invention. The described embodiment examples are exemplary of the subject-matter of the invention or serve for its explanation and have no limiting effect.

(15) FIG. 1 shows a schematic representation of a flat bed embossing machine 1.

(16) The machine (press) 1 comprises a flat bed press 4 with a printing table 8 and with a press head 7. The printing table 8 comprises a back-pressure plate 9.

(17) A base plate 10 of an induction heating appliance 3 is arranged on the press head 7. The base plate 10 comprises a plate rear side 11 with a first support surface, and a tool plate side 12 which lies opposite the plate rear side 11 and which has a second support surface. The base plate 10 bears with the support surface of the plate rear side 11 on a fastening component of the press head 7 in an extensive (surfaced) manner and is mechanically connected to this.

(18) The press head 7 moreover comprises a tool plate 20. This forms a plate rear side 35 with a first support surface, and a tool side 36 which lies opposite the plate rear side 35 and which has tool receiving surface (see also FIG. 2).

(19) On operation, the tool plate 20 bears with the support surface of the plate rear side 35 on the support surface of the tool plate side 12 of the base plate 10. The tool plate 20 is thereby releasably fastened to the press head 7.

(20) Embossing tools 23 are releasably fastened on the tool side 36 of the tool plate 20.

(21) The tool plate 20 is designed as a honeycomb mount and for fastening the embossing tools comprises a honeycomb region 22 which forms a fastening zone, with a plurality of blind holes 31 which run transversely to the support surface. The blind holes 31 are delimited to the plate rear side 35 by a continuous base region 21.

(22) Likewise schematically represented is a feed device 41 for the flat material 5 as well as a leading-away device 42 for the flat material 5

(23) If the flat bed embossing machine 1 is designed as a sheet-fed machine, then the flat material 5 is present as a sheet 5.1. In this case, the feed device 41 comprises a feeder and the leading-away device 42 a delivery means.

(24) If the flat bed embossing machine 1 is designed as a continuous web machine, then the flat material 5 is present as a continuous web 5.1. The feed device 41 in this case comprises a winding-off unit and the leading-away device 42 a winding-up unit.

(25) Both variants are schematically represented in FIG. 1.

(26) The flat bed embossing machine 1 moreover comprises a foil web guide 2 for guiding an embossing foil web 6 through the embossing region between the tool plate 20 and the back-pressure plate 9.

(27) The flat bed embossing machine 1 moreover comprises a machine control 43 for the control of the flat bed press 4 as well as of the foil web guide 2 and of the feed device and leading-away device 41, 42.

(28) The heating appliance 3 moreover comprises a regulating device 44 for the regulation of the temperature of the tool plate 20. Here, the regulating device 44 is integrated into the machine control 43.

(29) For carrying out an embossing procedure, the embossing foil and the flat material 5 are inserted between the tool plate 20 and the back-pressure plate 9 and are positioned. The embossing foil can likewise be inserted in the process direction X or counter to the process direction X whilst the flat material 5 is introduced in the process direction X.

(30) The flat material 5 lies on the back-pressure plate 9. The embossing foil 6 is arranged between the flat material 5 and the tool plate 20.

(31) The back-pressure plate 9 is pressed onto the stationary tool plate 20 amid the application of an embossing pressure, by way of moving up the printing table 8 (see arrows). The printing table 8 with the back-pressure plate 9 is moved downwards again after completion of the embossing procedure. The printing table 8 therefore executes an embossing stroke or lift H. The embossed flat material 5 is subsequently moved further in the process direction X.

(32) A compressed air device 40 for producing a blowing airflow for the purpose of separating the embossed flat material 5 from the foil web 6 is arranged at the exit side of the embossing region considered in the process direction X (see FIGS. 3, 6 and 7). The compressed air device 40 e.g. is a blower.

(33) However, the embossing tools 23 need to be heated to an embossing temperature prior to carrying out the embossing procedure.

(34) For this, the base plate 10 is part of an induction heating 3. An inductor 16 in the embodiment of a flat coil (see also FIG. 4) is recessed into the base plate 10 and is arranged between the tool plate side 12 and the plate rear side 11. For this, the inductor 16 is inserted from the plate rear side 11 into slot openings 33 in the base plate 10 and is e.g. bonded in this with an adhesive or moulded into it with a moulding material. The slot openings 33 are accordingly open to the plate rear side 11. The flat coil 16 is arranged in a planar-parallel manner to the support surface on the tool plate side 12.

(35) FIG. 5a shows a plan view of the base plate 10 towards the plate rear side 11 for this. Amongst other things, the plate rear side 11 shows the slot openings 33 for the flat coil 16 as well as a through-opening 34 for the sensor unit 26 which is yet described further below.

(36) The carrier material 13 of the base plate 10 is a plastic which is reinforced with glass fibres and accordingly is not electrically conductive, but is permeable to the produced magnetic alternating field 19.

(37) For starting operating of the induction heating appliance 3, the inductor 16 is now fed with an alternating current by way of a power unit (not shown). A magnetic alternating field 19 is now produced due to the design and arrangement of the inductor 16 and this alternating field penetrates into the base region 21 of the tool plate 20 and inductively heats this.

(38) Moreover, ferrimagnetic bodies 18 are arranged in the base plate 10, between the support surface of the plate rear side 11 and the inductor 16. The ferrimagnetic bodies 18 are recessed in the base plate 10 from the plate rear side 11. The ferrimagnetic bodies 18 serve for deflecting the magnetic alternating field towards the tool plate 20 and thus also for shielding the remaining press head 7 at the plate rear side 11.

(39) For this, FIG. 5b shows the plan view of a heating module with a viewed direction onto the rear side 11 of the base plate 10. The heating module comprises the flat coil 16 which is inserted into the slot openings 33 of the base plate, as well as the ferrimagnetic bodies 18 which are mentioned above and which are likewise arranged in deepenings of the base plate 10 between the flat coil 16 and the support surface of the plate rear side 11.

(40) Moreover, a shielding element 17 in the form of an aluminium sheet with a thickness of e.g. 0.2 mm bears on the rear side 11 of the base plate 10 (FIG. 2). The shielding element 17 serves for shielding the remaining press head 7 from the magnetic alternating field. An inductive heating of the remaining press head 7 is to be prevented by way of this. The shielding element 17 can otherwise likewise be part of the heating module.

(41) The thermal energy which is inductively produced in the base region 21 of the tool plate 20 is now led towards the tool side 36 by way of thermal conduction and from there is led into the embossing tools 23. The thermal conduction within the continuous base region 21 parallel to the support surface of the plate rear side simultaneously ensures a homogeneous temperature of the entire extension of the tool plate 20.

(42) FIG. 6 shows a particular embodiment of an induction heating appliance for a continuous web machine with four heating modules, each with a base plate 10.1 to 10.4 and with an inductor. The four heating modules are arranged successively in the process direction X on the rear side of the tool plate 20. The tool plate 20 is yet drawn in a dotted manner in FIG. 6 for the sake of completeness. The tool plate 20 has a length L in the process direction X and a width B transverse to the process direction X. Likewise drawn are a compressed air device 40 which is arranged at the entry side and outlet exit side, for producing a blowing airflow.

(43) The division of the heating zone of the tool plate 20 into several part-zones which are each heated by a heating module permits the individual heating of individual part-zones of the tool plate 20.

(44) FIG. 7 shows an embodiment of a sheet-fed machine with in total six heating modules 10.1 to 10.6. Four heating modules 10.3 to 10.6 are arranged next to one another transversely to the process direction X at the inlet side. Two further heating modules 10.3 to 10.6 are arranged next to one another transversely to the process direction X at the outlet side.

(45) Likewise drawn are two compressed air devices 40 which are arranged at the outlet side and are for producing a blowing airflow.

(46) If for example, as is represented in FIGS. 6 and 7, blowing air is blown in at the outlet side and possibly also at the inlet side of the embossing region by way of a compressed air device 40, then the inlet-side or outlet-side part-zone cools down more rapidly than the middle part-zones of the heating zone.

(47) The outlet-side and possibly also the inlet-side part-zone can now be heated to a greater extent than the middle part-zones thanks to the present arrangement of several heating modules according to FIGS. 6 and 7. A homogeneous temperature of the tool plate 20 over all part-zones can be ensured by way of this, despite the differently large heat losses over the surface extension of the tool plate.

(48) Each heating module comprises a temperature sensor 25.1 to 25.4 (FIG. 6) or 25.1 to 25.6 (FIG. 7), with which the temperature in the respective part-zone can be measured, in order to detect the different temperatures in the individual part-zones.

(49) FIG. 3 shows a schematic cross-sectional view through the embossing region of a flat bed embossing machine with a tool plate 20 and, arranged next to one another on the rear side of this tool plate, two heating modules each with a base plate 10.1, 10.2. The heating modules can be individually operated, so that considered in the process direction X, a front and rearward part-zone of the heating zone formed by the base region 21 are heatable independently of one another.

(50) The respective heating module each comprises a temperature measuring device with a temperature sensor 25.1, 25.2 (see also FIG. 8a, 8b), so that the temperature of the base region 21 of the tool plate 20 in the part-zones and consequently the temperature of the embossing tools 23 can be regulated via the temperature regulation device 44 (see also FIG. 8a, 8b).

(51) FIGS. 8a and 8b show a first embodiment of a temperature measuring device 24 with a sensor unit 26. The sensor unit 26 comprises a temperature sensor 25 which is attached to one end of a movable sensor carrier 30 and is directed towards the support surface of the base plate 10. The sensor carrier 30 is present as a sleeve and forms the moving part of the sensor unit 26. The sensor unit 26 moreover comprises a housing 32, in which the sensor carrier 30 together with the temperature sensor 25 is displaceably guided along a movement axis between a measuring position S1 and a configuring position S2 by way of a sliding guide. A tension spring 27 acts as a restoring element and leads the sensor carrier 30 together with the temperature sensor 25 back into the configuring position S2 or holds it in this.

(52) The above-mentioned elements together form a movement mechanism for displacing the sensor carrier 30 with the temperature sensor 25.

(53) The sensor unit 26 is recessed in a through-opening 34 in the base plate 10, wherein the temperature sensor 25 is directed towards the tool plate side 12.

(54) The movement mechanism is driven by a pneumatic drive 28. A gas pressure is hence built up in the cavity of the sensor carrier 30 via a pneumatic conduit. If the pressing force which is exerted upon the sleeve by the gas pressure exceeds the restoring force of the tension spring 27, then the sensor carrier 30 is moved out of the configuring position S2 into the measuring position S1.

(55) If the gas pressure is relieved again, then the tension spring 27 on account of its restoring force pulls the sensor carrier 30 and consequently the temperature sensor 25 back again into the configuring position S2 as soon as the restoring force exceeds the gas pressure force.

(56) The control of the pneumatic drive 28 and thus of the position of the temperature sensor is effected e.g. via the machine control 43.

(57) A sensor lead 59 which is led from the temperature sensor 25 through the cavity of the sensor carrier 30 to the outside is provided for transmitting the sensor measuring data to the temperature regulation device 44.

(58) In particular, the temperature measuring device which is described above is designed for flat bed embossing machines, concerning which the tool plate is led up to the base plate with a lateral movement component on assembly after the (re-)configuration, so that the tool plate could damage a protruding temperature sensor on assembly, e.g. by way of shearing it off.

(59) The second embodiment of a temperature measuring device which is shown in FIG. 9 differs from a first embodiment according to FIGS. 8a and 8b in that this does not comprise a pneumatic device for the controlled moving of the sensor carrier in the base plate.

(60) The temperature measuring device 54 comprises a sensor unit 56. The sensor unit 56 comprises a temperature sensor 55 which is attached to the end of a movable sensor carrier 60 and is directed towards the support surface on the tool plate side of the base plate. The sensor carrier 60 is present in the form of a sleeve and forms the moving part of the sensor unit 56. The sensor unit 56 moreover comprises a housing 62, in which the moving sensor carrier 60 with the temperature sensor 55 is movably guided along a movement axis A via a sliding guide.

(61) The sensor unit 56 is recessed in a through-opening in the base plate, wherein the temperature sensor 55 is directed towards the tool plate side.

(62) The sliding guide is formed by a guide sleeve 61 which is arranged in the housing 62 in a stationary manner. For this, the movable sensor carrier 60 in particular forms a cylinder-shaped sliding section, via which the sensor carrier 60 is slidingly guided along an in particular cylinder-shaped sliding section of the sliding sleeve 61. In particular, the sliding sections are shaped in a circularly cylindrical manner. The sliding section of the movable sensor carrier 60 thereby engages over the sliding section of the sliding sleeve 61 or—as is shown in FIG. 9—engages into this.

(63) The sliding sections of the two sleeves 60, 61 are encompassed by a compression spring 57 in the form of a helical spring. The compression spring 57 bears with one end on a stop on the sensor carrier 60 and with another end on a stop on the guide sleeve 61.

(64) The compression spring 57 serves as a restoring element which moves the pressure-relieved sensor carrier 60 together with the temperature sensor 55 into the configuring position and holds it in this. In the configuring position, the end-section of the sensor sleeve 60 with the temperature sensor 55 projects beyond the support surface of the base plate, e.g. by about 0.5 mm (see FIG. 9).

(65) The temperature measuring device which is described above is particularly suitable for flat bed embossing machines, concerning which the tool plate is led onto the base plate perpendicularly to the support surface of the base plate on assembly after the (re-)configuration, so that the tool plate cannot damage a protruding temperature sensor on assembly, but in contrast presses this back into the base plate. A sufficient pressing pressure of the temperature sensor onto the tool plate is ensured in the operational position by way of this, for the purpose of forming a measuring contact.

(66) A sensor lead 59 which is led from the temperature sensor 55 through the cavity of the sensor carrier 60 and of the sliding guide 61 to the outside is provided for transmitting the sensor measurement data to the temperature regulating device 44.