Apparatus with a heating station and a forming station.

p0001The invention relates to a device having a heating station and a forming station for producing a shaped part from a flat, three-dimensionally deformable workpiece, which consists of thermoplastic material or includes such a plastic.

p0002Devices of the type mentioned for the manufacture of thin-walled molded parts made of thermoplastics such as automotive interior trim parts and the like. Are known in large numbers and work more or less satisfactorily. The disadvantage is in most cases that too much waste is produced, it is carried out at too high temperatures, causing potentially toxic fumes that the energy consumption is relatively large and that the devices for certain moldings have to be specially designed and retrofitted difficulties leave etc.

p0003The invention is therefore based on the object to provide a device for producing thin-walled moldings consisting of thermoplastic resins, or at least contain thermoplastics, this device compared with known devices of the aforementioned type having improvements in the above-mentioned disadvantages.

p0004To achieve this object, the invention provides that in the heating station at least one heating device is arranged and that at least one heating device is also movable as a carrier for the workpiece in the forming station.

p0005The use of a heating device which in the forming station is movable or moved from the heating station to heat the workpiece in the least possible way, since it is no longer cools during the transport to the forming station, but is maintained at its optimum temperature allowed. While the thin and most extensive work to date in the forming station to a considerable extent lost heat during the transfer from the heating station, this is no longer the case when using a movable from the heating station to the forming station heater. This entails lower best temperatures to which the workpiece has to be heated further lower energy expenditure and ultimately a lower release of noxious fumes and gases exiting workpiece containing from the heated, thermoplastic materials in the result.

p0006Preferably located in the heating a bottom heater and a top heater, between which the sheet workpiece is positioned for heating.

p0007In the invention, the upper heater also serves as a movable support for the workpiece to be formed, especially when in the forming a lower mold is arranged on the sheet-like workpiece can be stored.

p0008In principle, it is also possible to provide all the parts associated with the transportation and the deformation of the workpiece such that the lower heating device is used as a carrier when a top mold is then provided in the forming station, which for example by means of grippers or with the aid of suction air, the heated workpiece accepts.

p0009It is particularly expedient, finally, if at least one of the two heating devices with at least two media, namely electrical power for heating and hot air works for heating an open-cell or air-permeable workpiece. Such a heating device is in fact able to heat both homogeneous workpieces and air-permeable workpieces, and further is advantageous if at least one of the two heating devices additionally has a cooling means eg in the form of water channels. The additional arrangement of such cooling devices, it is in fact possible to set both heaters within close tolerances to exact temperatures and also to regulate the desired heat transfer to be heated workpiece exactly. From this eventually results still the advantage that both heaters operate at different temperatures, so that it is possible to suspend multilayer workpieces on both outer sides of different temperatures. In particular, when various layers of the thin-walled workpiece composed of different materials, such as the one hand, is made of a homogeneous, thermoplastic material with a melting temperature of X degrees Celsius and on the other hand of an open cell, thermoplastic material with a melting temperature of Y degrees Celcius, so it is possible using the heaters according to the invention to suspend such a workpiece on both sides different temperatures and various heat effects.

p0010According to applicable grippers are provided finally optionally, which detect the workpiece heated in the forming station with needles and hold at least before the molding operation. This needle gripper require edge on each workpiece on the order of at most 30 to 40 mm material to hold the respective workpiece can. This means that you can work with already close tolerance blanks and thus the resultant waste is extraordinarily low.

p0011Furthermore, a close tolerance work with blanks is possible if the blank is stored accurately and precisely positioned in the heating station. It is also expedient if the cutting of the edges arranged frame and is held in the forming station a vacuum forming takes place.

p0012Further features of the invention are apparent from dependent claims in connection with the description and the drawing.

p0013The invention will be described below with reference to embodiments which are illustrated in the drawing. They show:<dl id="dl0001"><dt>To FIG. 1.</dt><dd>a schematic diagram of the group consisting of heating station and molding station apparatus with open heating station;</dd><dt>Fig. 2:</dt><dd>a schematic diagram as in Figure 1 but with a closed heating station.</dd><dt>Fig. 3:</dt><dd>a schematic diagram as shown in Figures 1 and 2 with a traversed from the heating station into the molding station heating means. </dd><dt>Figure 4-6.:</dt><dd>Simplified diagrams with further stages of operation of the device;</dd><dt>Fig. 7:</dt><dd>a schematic diagram of a device with a modified forming station;</dd><dt>Fig. 8:</dt><dd>in section and on a larger scale, a schematic diagram of essential parts of a heater;</dd><dt>Fig. 9:</dt><dd>in plan view and in a different scale, a schematic diagram of a framework for the movable heater;</dd><dt>Fig. 10:</dt><dd>a schematic diagram of a gripping device on a different scale;</dd><dt>Fig. 11:</dt><dd>a side view of the gripping device according to FIG. 10;</dd><dt>Fig. 12:</dt><dd>a modified gripping device in a first working position and</dd><dt>Fig. 13:</dt><dd>the gripping device according to FIG. 12 in a second operating position.</dd></dl>

p0014A device 1 for producing a shaped part 2 of a flat, three-dimensionally deformable, single or multilayer workpiece 3, which is made of thermoplastic Kusntstoff or contains 1 comprises according to FIG. A heating station 4 and a forming station 5. In the heating station 4 there is at least a heater 6 and there are there according to the embodiment shown in the figures arranged two cooperating and between the workpiece 3 heated heaters. 6 and 7 The lower heater 7 is by means of a lifting device 8, for example in the form of a spindle drive from a lower position as shown in FIG. 1 in an upper position shown in FIG. 2 can be raised, so that the static on the lower heater 7 or stored there workpiece 3 as close to the upper heater 6 can be moved or comes into direct contact with the upper heater. 6

p0015The upper heating means 6 serves not only for heating of workpieces 3, but it is also from the heating station 4 in the forming station 5 can be moved or on reels 9 there movable and thus at the same time serves as a support and transport means for transporting the heated workpiece 3 from the heating station 4 5. in the forming station purpose, the heater 6 further suitable retaining means for the embodiment according hanging under your workpiece 3. This holding means for example can work with suction.

p0016Once the Heizeinrichtng has 6 the workpiece 3 from the heating station 4 transported into the forming station 5 according to FIG. 3, the workpiece 3 is there taken over by one or several gripping devices 10, 11 and held in a stretched state. This is indicated by means of arrows a in FIG. 3, showing the direction of pull of the gripping means 10, 11.

p0017As soon as the gripping devices have 10, 11 over the workpiece 3 and the heater has 6 leave the workpiece 3, it moves back into the heating station 4. There is now on the back lowered, lower heater 7 is another, yet cool workpiece 3 'been filed , The workpieces 3 and 3 'can be either by hand or with the aid of a transport device to enter the heating station 4, or they may also rest in the heating station 4 on a perforated conveyor belt 12 which for the automatic feeding of the heating station in the direction of arrow b (Figure . 1 and 3) is provided. When perforated conveyor belt 12, for example, is a Teflon tape.

p0018In the forming station 5 are suitable moldings. These are referred to in FIGS. 1 - illustrated embodiment 6 a lower mold 13 and an upper mold 14. The gripping means 10 and 11 hold the workpiece 3 after the takeover of the heater 6 between the lower mold 13 and the upper mold 14, and as soon as carrier and carrier serving heater 6 has left the forming station 5 again, driving the lower mold 13 and the upper mold 14 together for the purpose of deformation of the workpiece 3 and the production of the desired three-dimensionally shaped molding. 2

p0019Figure 4 shows this operation, which according to the embodiment, the lower mold 13 is moved upward against the standing there overmould 14th When the lifting device 15 for the lower mold 13 as a piston-cylinder device is provided. Furthermore, it is ensured that the gripping means 10, 11, the workpiece 3 release time if the deformation process between the lower mold 13 and upper mold 14 starts.

p0020Once the deformation process is completed, the lower mold 13 and upper mold 14 are separated again and it moves according to the embodiment, the lower mold 13 back into its lower starting position according to FIG. 5. The molding 2, meanwhile, suspended or under the upper mold 14 by means of a suitable holding means for example in the form of pivotable holders 16 is held at a level above the traversable in the forming station 5 heater 6th

p0021Once then the heater has 6 moves to the next, sufficiently heated workpiece 3 'in the forming station 5 (Fig. 5), the molding 2 is passed by the upper mold 14 to the movable heater 6 or placed on the upper side 17 (Figure . 5). For this purpose, the upper mold 14 separately in the vertical direction according to the arrow c in Fig. 5 is movable, or the holder 16 enter the molded part 2 is only released so that it falls by gravity from a small height on the top 17 of the Heizeinrichtng 6th It is understood that the upper side 17 of the heating device 6 has a sufficiently low temperature so that not takes place a re-heating of the mold part second

p0022The heater 6 is also in accordance with the FIG. 5 operation in the forming station 5 shown that brought workpiece 3 'to the gripping means 10, 11 and then travels with the rest on their molding 2 in the heating station 4 back, as shown in FIG. is shown. 6 There, the mold part 2 can then be removed manually or transported by means of handling devices, while 'takes place in the forming station 5, the deformation of the workpiece 3 to form a mold part 2 by means of the lower mold 13 and the upper mold fourteenth

p0023The two heaters 6 and 7 may be the same or different. The heating may be effected electrically inductively, with hot water, hot oil or with hot air or with combinations of these media. If to be heated workpiece 3 is multilayered and the individual materials different temperature and / or material properties as for example with an existing plastic substrate and cover material made of velor, needle felt or terry, the layers thus made homogenous or more or less inhomogeneous materials, on the one hand slides and on the other hand non-woven materials or made with an open surface, so it is appropriate that the operating temperatures of the two heating devices are separately controllable so that both heaters 6, 7 can also be operated at different temperatures.

p0024The two heaters 6 and 7 expediently comprise a respective contact heating 18 and 19, as a basic element. This contact heating 18, 19 are, for example, electrically inductive heating and consist for example of an upper, relatively thin, the actual contact surface 20 forming, metal plate 21, an electrically heatable heating strip 22 and a further metallic plate 23, as well as from FIG. 8 shows , If the material properties of each to be heated workpiece 3 permit, the workpiece 3 touch the heaters 6, 7 with their contact surfaces 20 immediately. Further, the flow channels are 24 for air in, but expediently in two contact heating 18, 19 and end there at their respective contact surface 2o. These flow channels 24 are also separately with the aid of locking elements 25 can be shut off. The flow channels 24 in the lower and / or upper Kontakheizplatte 18, 19 respectively in the lower and / or upper heating means 6, 7 can be acted upon with suction air and / or compressed air, with room temperature-tasting and / or tempered, then preferably heated air what they are connected to 26 producing with an optional pressure and / or vacuum blower. For the generation of negative pressure at the upper heater 6, which is required for the heater 6 can serve as a support for a hanging below it workpiece 3, the upper heater 6 is connected according to the embodiment via a line 27 to the blower 26th The line 27 is flexible and can be moved in the forming station 5 heater 6 follow. The conduit 27 can also serve as a conduit for compressed air, is that help is effected or supported the release of the workpiece 3 by serving as a support 6 heater. 6

p0025Further, the fan 26 also via a line 28 to the lower heater 7 and the flow channels 24 is connectable to air, there to generate a positive pressure or a negative pressure. A switched on and off the heater 29 may be integrated in the pressure line 28th

p0026The supply of places throughout the, the workpiece 3 facing surface flow channels 24 in the lower contact heating 19 with hot air via the fan 26 and the heater 29 is for heating or heating of air-permeable workpieces 3. They can be by means of contact heating only heat in the region of their surfaces and only to a relatively small workpiece depth. During the interaction of an upper heating means 6 and a lower heater 7 by using heated air, this flows from the flow channels 24 of the lower heater 7 through the air-permeable workpiece 3 in the upper heating means 6 and the located there flow channels 24 and then through the vacuum line 27 for blower 26. the blower 26, the hot air generator 29, the lower heater 7 and the upper heater 6 and the left between the two heaters 6, 7 workpiece 3 form a self-contained circuit for the heated air. This self-contained cycle is so long maintained until the air-permeable workpiece 3 has reached the required temperature for 5 deformation in the forming station also in its interior.

p0027In order to achieve an optimal distribution of hot air over the entire surface 30 of the workpiece 3 in the lower heater 7, the lower heater 7 is preferably provided with a hot air distribution manifold 31st This hot air manifold 31 is for example a lattice work or a filter mat, which causes the numerically limited from comparatively provided flow channels 24 in the contact surface 20 exiting air can be distributed over the whole, to be heated surface 30 of the workpiece. 3

p0028When using a hot air manifold 31 that can rest in accordance with the embodiments illustrated in the figures directly on the contact surface 2o.

p0029Finally, the lower heater 7 a abutting the edge 32 to be heated workpiece 3 frame 33. Essentially this frame surrounds the 33 hot air manifold 31 and protrudes slightly above the workpiece side surface 34th This creates between the bottom of the workpiece 3 and the surface 34 of the hot air manifold 31 is a shallow chamber 35, located in the under overpressure standing hot air. From here the hot air flows either directly into the air-permeable workpiece 3 or even first by the strongly perforated conveyor belt 12 and finally into the upper heater 6, which sucks the emerging from the top surface 30 of the workpiece 3 hot air. To ensure a uniform absorption of exiting from the top 30 of the workpiece 3 hot air, the upper heater 6 with a hot air manifold 31 of the lower heater 7 corresponding, identically shaped collector 36 is provided. Further, a frame surrounds 37 of the framework 33 to the collector 36th

p0030Once the air-permeable workpiece is brought 3 in the heating station 4 to the required temperature, the hot air circuit is turned off and the upper heater 6 is pressurized by the fan 26 only contributes with vacuum or with a permanent vacuum, so that the heater 6 as a carrier an air-permeable workpiece 3 can be used.

p0031A reliable temperature control of the heaters 6 and 7 is only guaranteed when a cooling device 38 is provided there in addition. It is for clarity in Figures 1-6 are not shown. This cooling device 38 comprises in the lower and / or upper heater 6, 7 and in the contact heating 18, 19 disposed channels 39 for a coolant. This coolant can be water, oil or the like..

p0032The channels 39 for the cooling agent in the contact heating and the 18, 19 are suitably controlled or controlled individually. Thereby, it is possible to regulate the temperature in individual areas of contact heating 18 and 19 on different heights.

p0033Also the and the frame 33, 37 can serve to ensure that the edge or the edges 40 of the workpiece 3 protected against warming. The workpiece 3 is thus not only between the two heaters 6, 7 with the aid of the respective frames 33, 37 fixed at a distance of the hot air distributor 31 and collector 36, but the frame 33, 37 also have a further function in that the edge 40 of the workpiece 3 is less heated and thereby also greater strength reserves than the other parts of the workpiece 3. This higher strength is desirable in many cases, namely when the workpiece 3 in the forming station 5 of the present there gripping means 10, 11 is adopted.

p0034If the workpiece 3 is warmed or heated, it shrinks. To compensate for this shrinkage effect, the contact heating 18, 19 move again to another and for this purpose are preferably in the figures springs not shown mounted. The contact heating 18, 19 can be slow to feather each other. The springs are also preferably relatively soft.

p0035All above-mentioned machine parts are housed in a suitable machine frame 41 and 42, together with its bearings and drives. These machine elements are known in principle and are not shown for clarity in the figures.

p0036The embodiment of FIG. 7 differs from the first described embodiment only in that in the molding station 5 for a suitable pure vacuum forming device 50 is arranged in place of a lower mold 13 and an upper mold. This device 50 consists of a female mold or the male mold 51, a vacuum box 52 and a frame 53 which can be lowered on the free edge 54 of the vacuum box 52 and there serves for fixing the heated workpiece third The Vakkumverformung occurs in the device 50 in a manner basically known.

p0037As well as the workpiece 3 from the heating device 6 in which, in connection with Figs. 1 - described embodiment 6 transported in the forming station 5, and is passed on to the gripping means 1o, 11, this place the workpiece 3 onto the free edge 54 of the vacuum box 52, whereupon an appropriate adjustment device 55 to frame 53 drops from a located above the level of the movable heater 6 rest position according to FIG. 7 and the workpiece 3 presses with its edge 40 on the free end 53 of the vacuum box 52. Thereafter, the die or male mold 51 in known manner is acted upon by means of a fan 56 with vacuum so that the atmospheric air pressure, the workpiece 3 pressed onto the surface of the die or male die 51 and thus causing the desired deformation.

p0038Even with overpressure working pressers or the like are. Used in principle.

p0039The two gripping means 10, 11 is preferably needle gripper 60 according to FIGS. 10 and 11 or by needle grippers 9o shown in FIGS. 12 and 13. Each of the needle gripper 60 has at least one needle 61, but preferably a plurality of needles 61, as shown in Fig. 10. The needles 61 are arranged on a needle carrier 62nd Further, the needles 61 are straight and relatively short. However, the needle gripper 60 further comprising at least one, according to embodiment two adjusting elements 63 and 64. The two adjusting elements 63, 64 an end 65 or 66 at a fixed point 67 and 68 are each at their pivotably articulated. Furthermore, the two adjusting elements 63, 64 are telescopic and its length is variable. Finally, the two adjusting elements 63, 64 also connected at their other ends 69, 7o via a spacer 71 to each other, said spacer 71 is hinged 69,7o pivoted at the respective ends. The length of the spacer 71 istgrundsätzlich rigid for adjustment but also changeable. The distance of the two articulation points or fixed points 67, 68 is, as Fig. 11 shows, somewhat greater than the length of the spacer 71. Also, the distance of the two fixed points 67 and 68 from one another is for the purpose of setting changeable and in the respective operating position by means of a Einstellschuhes 72 and by means of screws 73 on a carrier 74 fixed.

p0040The support 74 rests on springs 74a supported longitudinally displaceably on guide rods 74b, which are arranged on the bottom side on a shoe 74c, which engages in a dovetail guide 74d. There, the shoe 74c is fastened by means of screws. The carrier 74 is therefore zuammen with the two adjusting 63 and 64 along the dovetail guide also 74d adjustable.

p0041On the carrier 74 finally is still a support 75 arranged with an adjustable stop 76 of an adjustment element 64 limits the possible swivel movement around the fixed point 68 between two attachment points 77 and 78th

p0042The two adjusting elements 63 and 64 are in the rest position shown in FIG. 11 approximately parallel but slightly acute angle to each other and together with the articulated spacer 71 and the fix or pivot points 67, 68 a trapezoid that between the points 77, 78 of stopper 76 is movable. The points 77, 78 are advantageously formed by means of adjustable screws.

p0043The two adjusting elements 63, 64 are preferably piston-cylinder means, said cylinder with its piston rods 79, 80 opposite ends are hinged to the fix or pivot points 67, 68th

p0044The one adjustment 64 and the corresponding piston-cylinder device carries at the free, telescoping end 70 a bearing piece 81 carrying the needle carrier 62 freely pivotable. With its axis 82 of the needle carrier 62 is displaced in the bearing piece 81 in the axial direction. Further, on the bearing piece 81 supporting spring loaded 83 the needle carrier 62, so that it is moved by the spring 83 in a normal position, from this basic position against the force of spring 83 but relative to the perpendicular to the axis 82 stationary axle 84 of the adjustment element 64 or . the corresponding piston-cylinder device is displaced. The needle gripper can therefore follow in tension on the workpiece 3 occurring deformations or changes in position in the lateral direction with its needle carrier 62nd

p0045The needle carrier 62 is finally connected to arms or a fork formed by these also with the spacer 71, which is articulated at the free end 69 of the other adjusting element 63 or on the piston rod 79 of the respective piston-cylinder device in a joint 86th The location of the free end 69 of the adjustment element 63 and the respective position of the joint 86 therefore also determines the position and inclination of the needle carrier 62 and its needles 61. A caused by the adjustment element 63 change in position of the joint 86 causes a corresponding change in position or inclination of the the needle carrier 62 and the needles 61st

p0046the possible adjustment and change in position of the joint 86 by a fork 87 at the free end 70 of the adjustment is limited 64. The fork 87 serves as a stop for the spacer 71, which FIG. 11 is referred in a slot of the fork 87.

p0047The cylinders of the two adjusting elements 63 and 64 are controlled separately, so that the two piston rods 79, 80 individually or jointly adjustable are. In addition, the stroke of the two piston rods 79, 80 differently, and finally the actuation of the adjusting elements 63, 64 is also such that the piston rods 79, 80 may move at different speeds. For this purpose, 64 required throttle and controls are in the pressure supply lines for the adjustment 63 is provided, which are known in principle.

p0048To accept a workpiece 3 by the movable heater 6, the needles so that the needle carrier 62 about the axis 82 counterclockwise 61 pressed on the needle carrier 62 from the bottom up in the workpiece 3, whereupon the piston rod 79 of the adjustment element 63 is slightly retracted, and further pivots the needle carrier 62 carrying it along with the adjustment element 64 in Fig. 11 is moved to the left. The needling is thus effected by extending the piston rods 79, 80 and then retracting the piston rod 79th

p0049Once the workpiece is 3 needled, both piston rods 79, 80 are retracted until the adjustment is 64 from the attachment point 78 of the stop 76 from moving further. The necessary stroke of the piston rod 79 is greater than that of the piston rod 80 in total at each operation.

p0050For discharging the workpiece in turn the needle carrier 62 is pivoted with the aid of the adjustment element 63 and further, both piston rods 79, 80 so far retracted or extended again, that the respectively desired level is reached.

p0051The frame 37 on the movable heater 6 is expediently adapted to the needling of the workpiece 3 by the needle carrier 62nd It has for this purpose as shown in FIG. 9 on the outside at its periphery recesses 89th These recesses 89 impart to the frame 37, a comb-shaped contour and allow the needles 61 to penetrate a small distance from the outer edge into the material of the workpiece third To this end, the needles engage initially through the workpiece and then lie with their tips in the recesses 89th

p0052Gripping devices 10 and 11 and needle gripper 60 are arranged in the forming station 5 on all sides of the workpiece 3, wherein the needle carrier 62 can be moved in a total of three, at the same time intersecting directions X, Y and Z.

p0053The needle gripper 9o shown in FIGS. 12 and 13 has only a telescopic or changed in its length adjustment 91 and not two adjusting elements such as needle grippers 6o. The adjustment element 91 is again preferably a piston-cylinder device. At one, axially in the direction of the double arrow A (Fig. 13) adjustable end 92 of the adjustment element 91 carries one or more needles 93, which is angled 95 in the tensioning direction relative to the axis 94, the movement causing the piston rod. A eingenadeltes workpiece can not become detached therefore.

p0054The adjusting element 91 is at its second end 96, that is mounted pivotably at the lower end of the cylinder device 97 about an axis 98th Close to the lower end 96 protrudes further away an arm 99 of the cylinder device 97 and has an adjusting 1oo on.

p0055The adjustment element 91 can carry about its bearing point or to the bottom side disposed axis 98 pivoting movements on molds 1o1 and 1o2 to and away. When driving this is an inflatable and deflatable hose 1o3 and a restoring element 1o4 eg in the form of a pressure membrane 1o4, which engages the arm 99th

p0056The serving as pivot drive for the adjustment 91 tubing 1o3 is partly on the adjustment element 91 and is supported on the other hand from the lower mold 1o2 and is preferably secured there. The tubing 1o3 is a hose piece and can have any desired length so that it bears not only on a single adjusting element 91, but at multiple and possibly even on multiple sides of the mold 1O2.

p0057The adjustment element 91 is arranged substantially upright near the perimeter of the lower mold 1o5 1o2 and pivotable only within a small angular range, as is apparent from corresponding Fig. 13 the two representations in solid and in dashed lines. The stroke in the pivoting direction is limited by the pressure membrane 1o4, which may also be a rubber buffer o. Like., For example, and. By the adjustment 1oo arm 99, which cooperates with the pressure membrane 1o4 when setting the Schwenkhubes

p0058The needle 93 is slightly inclined from the molds 1o1 and 1o2 with its tip in the Einnadelposition FIG. 12. The storage of the lower end 96 of the adjustment element 91 and the arrangement of the pressure membrane 1o4 place, for example to a base plate 1o6 of the lower mold 1o2.

p0059The tubing 1o3 can be arranged in a recess on the periphery 1o7 1o5 of the lower mold 1o2 partially submerged. The control and supply of the hose 1o3 with a pressure medium are not shown in the figures because it is here to basically familiar elements.

p0060The invention is not limited to the embodiments shown in the figures, there still manifold modifications may be made without departing from the fundamental inventive idea.