EP3486058B1 - Suction head of a roofing tile device and method for mounting a suction head - Google Patents

Description

The invention relates to a roof tile press and a method for operating such a roof tile press.

A roof tile press is used to shape a roof tile and to compress the base material of the roof tile. Typically, roof tiles are made from clay and loam. A pressed blank is made from a plastic blank in a roof tile press. For this purpose, the blank is placed in a lower mold and then pressed to form a blank by means of an upper mold which is arranged on a press ram. The molding is then removed from the tile press at a removal point. This is typically done by means of a suction head, which combines the functions of piercing and suction: The molding is separated from the press waste by means of a knife frame of the suction head and removed from the lower mold. The pressed molding is then placed on a molding carrier by swiveling and / or moving the suction head. The molding carrier is used to transport the brick moldings in the further process.

The geometry of the suction heads for cutting out, vacuuming and depositing is adapted to the brick model to be produced and connected to the machine via a carrying unit. A vacuum is applied to the suction head to suck and hold the molding. It is deposited using a pneumatic cylinder moving plate and additional compressed air ejection nozzles. The suction heads have appropriate media connections for this.

The suction heads have a significant influence on the brick quality. Your position determines the cut, i.e. the outer geometry of the molding and thus the brick. The lateral position (x-direction) describes the position of the suction heads parallel to the direction of the drum axis. The y-direction describes the position on the drum surface, perpendicular to the drum axis and tangential to the drum surface. The z position describes the position perpendicular to the named x-y plane and also the position of the shelf height above the frame track. A visible offset of the cut to the brick surface in the x-y plane is considered a defect. There is therefore a need to align and position the suction heads as precisely as possible in the x-y plane. The pretensioning of the knives also has an influence on the cutting pattern. In order to be able to apply sufficient cutting force, the connection of the nursing heads to the associated support units is preloaded via spring assemblies. In order to always be able to apply the same cutting forces, the distance to the drum in the z direction must be set correctly and corrected if necessary.

The suction heads and their knives are subject to a certain amount of wear due to regular contact with the clay material. Wear of the knives affects the surface of the cut. The cut must be as smooth as possible. For this reason and also because of the individual design for each brick model, there is a need to change the suction heads at regular intervals or to remove them for maintenance purposes. For this purpose, the suction heads are separably connected to their support units. For this purpose, a mounting plate or an adapter plate are attached to the support units and the suction heads. The adapter plate is always on top of the suction heads. The suction head therefore hangs on the respective support unit or on its separate mounting plate, with the cutting edge of the knife frame pointing downward.

In such a scenario, the suction head must always be raised against gravity for attachment. Because of the limited space, the suction head cannot be gripped by its adapter plate. Rather, it is placed on a soft surface with the circumferential cutting edge of the knife frame and then brought into position. The knife frame is able to carry the weight of the suction head. However, larger forces must be avoided in order not to damage the knife frame. The application of additional assembly forces, for example for pressing the suction head onto the carrying unit, is therefore ruled out.

The adapter plate of the suction head is connected to the mounting plate of the support unit via coupling means which, in the prior art, comprise screws, hydraulic pivoting clamping cylinders or other clamping elements. In addition to the mechanical attachment, the lines for the media such as vacuum and compressed air and possibly other lines must be connected to the suction head. Replacing the suction heads is very time-consuming, since the position can rarely be reproduced with the necessary accuracy during the clamping process. After attaching the suction heads, extensive adjustment work is necessary to correctly align the suction head relative to the lower shape of the brick. This adjustment time means a significant loss of production.

The publication DE 94 07 086 U discloses a suction head device of a roof tile press according to the preamble of claim 1.

The invention has for its object to further develop a generic suction head device and a roof tile press with such a suction head device such that the attachment and / or removal of a suction head from the support unit is facilitated.

This object is achieved by a suction head device with the features of claim 1 and also by a roof press with such a suction head device.

The invention is further based on the object of specifying a simpler and faster method for mounting a suction head device.

This object is achieved by a method with the features of claim 8.

The invention is based initially on the knowledge that conventional zero point clamping systems appear attractive at first glance because of the simplicity of the locking process and because of the positioning accuracy in all three spatial directions, but they are not readily suitable for connecting a suction head to its associated carrying unit. According to the prior art, zero point clamping systems comprise a clamping bolt and a clamping unit for receiving and locking the clamping bolt. During the locking process, the clamping bolt is inserted axially into the unlocked clamping unit, the clamping bolt being guided in the clamping unit without play in all radial directions. This provides an exact positioning in a plane perpendicular to the axial direction of the clamping bolt or in an xy plane. In addition, however, an exact axial positioning or positioning in the z direction must now also be carried out so that on the one hand the clamping unit can grip the clamping bolt at all and on the other hand the desired relative axial positioning of the two modules to be connected is achieved. The locking can only take place in the desired axial target position. The slightest deviations from this mean that gripping and locking does not take place at all. In the prior art, the assembly with the clamping bolt is therefore brought into abutment with the assembly comprising the clamping unit, which on the one hand brings about the correct execution of the locking process and on the other hand also brings about the desired axial positioning. However, such a procedure is not possible with a suction head, since a suction head standing on the knife frame cannot be driven forcefully against a stop without endangering the knife frame. Avoiding such a stop, however A sufficiently precise axial positioning is not possible such that reliable locking takes place on the zero point clamping system.

Proceeding from this, the invention is based on the further partial knowledge that, despite the above disadvantages, the other advantages of a zero-point clamping system can then be used in a roof tile press for suction head assembly and disassembly if certain modifications and accompanying measures are introduced.

According to the invention, provision is accordingly made for the coupling means to have at least one zero-point clamping system and a device for determining the position of the suction head relative to the carrying unit. The zero point clamping system comprises a clamping bolt and a clamping unit for receiving and locking the clamping bolt, the clamping bolt and the clamping unit being matched to one another in such a way that they have an axial gripping tolerance with respect to one another during the locking process. The axial gripping tolerance is advantageously greater than or equal to one millimeter, is preferably in the range from one to three millimeters and is in particular approximately two millimeters. The device for determining the position is designed to determine the axial relative positioning of the clamping bolt and clamping unit within the specified axial gripping tolerance during the locking process.

In the associated method according to the invention for assembling the suction head device, the suction head and the carrying unit are brought closer to one another and the clamping bolt is threaded into the clamping unit. The approach continues until the device for determining the position signals that the clamping bolt and the clamping unit are within the axial gripping tolerance relative to one another. The zero point clamping system is then locked in this position.

The invention enables the suction head device to be assembled and disassembled considerably more easily. The comparatively large gripping tolerance does not require a particularly precise positioning. In particular, positioning with mechanical aids can be carried out, for example, via the machine control and without manual intervention by the operator, which also includes automated positioning. One or more suction heads can be provided, for example, on a suitable carrier, which aligns the suction head (s) in a defined manner using dowel pins or similar positioning elements. The carrier equipped in this way can be positioned over a carriage or over the conveyor of the molded carriers and then locked in the change position. The latter can be lowered to bring the lower suction head and upper support unit closer together. Alternatively or additionally, the carrier equipped with the suction head can be lifted from below. With regard to the suction head, however, this positioning is limited to forces that result solely from the movement. As a result of the axial gripping tolerance and the position determination within this axial gripping tolerance, no mechanical stop is used. There are no pressure forces that could damage the suction head, its knife frame or other components. The lack of a mechanical stop is compensated for by the device for determining the position, which despite the large gripping tolerance signals when the relative positioning is in the catching area and consequently a secure locking can be carried out. Overall, the suction heads can be attached quickly, easily, securely and reproducibly. Disassembly is carried out in the reverse order and direction, with the same advantages.

In an advantageous further development, the coupling means have a total of two zero point clamping systems for one carrying unit and one suction head each. This enables exact positioning and locking in all six spatial degrees of freedom (displacement in three spatial axes and rotation around three spatial axes) with little effort.

It may be sufficient that the axial gripping tolerance is maintained as an axial play even in the locked state. However, the zero point clamping system is preferably designed and used in the operating method to ensure that the clamping unit during Locking process grips the clamping bolt within the axial gripping tolerance and then axially fixed while canceling the axial gripping tolerance. When locking, there is therefore an axial bracing, so that an exactly reproducible position positioning is guaranteed in the axial direction or in the z direction.

The zero point clamping system can be operated manually, for example via a lever mechanism, or remotely, for example electromechanically. It preferably has a pneumatic actuation, which is locked in particular without pressure and unlocked when compressed air is applied. By applying simple pressure pulses, reliable locking and unlocking can be achieved with little effort, which incidentally can also be automatically coupled to the signal of the device for determining the position.

The device for determining the position can be an ultrasound or touch sensor or the like and preferably comprises a proximity sensor which is matched to the size of the axial gripping tolerance, in particular in the form of an inductive proximity switch. This eliminates the effort of an exact position or distance measurement. Rather, a simple on / off signal is generated, which indicates whether a sufficient approach has been reached or not. The proximity sensor does not need exact adjustment, calibration or the like. Rather, positioning in the accuracy range of the axial gripping tolerance is sufficient to indicate, as desired, that when the switch is triggered a relative position is reached which is within the gripping tolerance and therefore enables secure locking.

Fig. 1

in einer perspektivische Übersichtsdarstellung eine erfindungsgemäß ausgeführte Dachziegelpresse,

Fig. 2

in einer Seitenansicht einen Vertikalschnitt durch die Dachziegelpresse aus Fig. 1 mit weiteren Details,

Fig. 3

in einer perspektivischen Frontansicht die Dachziegelpresse nach den Fig. 1 und 2 mit Einzelheiten zum Einsatz von Saugkopfvorrichtung bei der Ablage von Formlingen auf einem Förderer,

Fig. 4

in einer vergrößerten Detailansicht die Anordnung nach Fig. 3 mit weiteren Einzelheiten zur Saugkopfbefestigung,

Fig. 5

in einer perspektivischen Einzelansicht eine Saugkopfvorrichtung nach den vorherigen Figuren mit abgekoppeltem Saugkopf, und

Fig. 6

in einer vergrößerten Längsschnittdarstellung die mit axialer Greiftoleranz vorpositionierte, aber noch nicht verspannte Saugkopfvorrichtung nach Fig. 5.

An embodiment of the invention is explained below with reference to the drawing. Show it:

Fig. 1

a perspective overview representation of a roof tile press designed according to the invention,

Fig. 2

in a side view a vertical section through the roof tile press Fig. 1 with further details,

Fig. 3

in a perspective front view of the roof tile press according to 1 and 2 with details on the use of a suction head device when depositing moldings on a conveyor,

Fig. 4

in an enlarged detail view of the arrangement Fig. 3 with further details on the suction head attachment,

Fig. 5

in a perspective individual view of a suction head device according to the previous figures with a decoupled suction head, and

Fig. 6

in an enlarged longitudinal sectional view the pre-positioned but not yet braced suction head device with axial gripping tolerance Fig. 5 .

Fig. 1 shows a roof tile press 1 designed in accordance with the invention. In the roof tile press 1, a molding 22 is produced from a plastic blank 2 made of clay or clay. The blank 2 is conveyed on a conveyor belt 21 to the roof tile press 1. The finished molding 22 is removed by a conveyor 16 from the roof tile press 1 for further processing.

As in Fig. 2 shown, the molding 22 is produced by pressing the blank 2 between an upper mold 4 and a lower mold 6 at a pressing point 7 of the roof tile press 1. The shapes can vary depending on the type of brick and regional preferences. For example, they can comprise an aluminum body with a plastic insert and a rubber membrane or a rubber blanket, or they can be made from a steel body. In the exemplary embodiment shown, both the upper mold 4 and the lower mold 6 comprise one Aluminum body and a plaster inlay arranged in it. The upper mold 4 is attached to the lower end of a press ram 3. The press ram 3 is mounted so that it can move back and forth in the vertical direction. The press ram 3 can be pressed down by means of a cam plate 23 of the roof tile press 1.

The lower mold 6 is arranged on a movement device 5. In the exemplary embodiment, the movement device 5 is a drum. However, it can also be provided that the movement device is a swivel-mounted table and the lower mold is arranged on a surface of the table. The drum in the exemplary embodiment is rotatably mounted about a longitudinal axis 90. The longitudinal axis 90 runs horizontally. In a section perpendicular to the longitudinal axis, the peripheral surface of the drum forms an equilateral hexagon. Four sub-molds 6 are arranged on each side of the hexagonal peripheral surface, so there are a total of twenty-four sub-molds 6. Corresponding to the number of lower molds 6 located on a drum surface, the roof tile press has the same number, in this case four upper molds 4.

In operation, the roof tile press 1 carries out several processing steps on different blanks 2 and moldings 22 simultaneously. The roof tile press 1 comprises various processing points for processing the blank 2 and the blank 22. The processing points include a filling point 12 for filling the lower mold 6 with a blank 2 to be pressed, the press point 7 already mentioned for pressing the blank 2 between the upper mold 4 and the blank Lower mold 6, a removal point 8 with a suction head device 60 for removing the pressed molded article 22 from the lower mold 6 and for depositing it on a molded carrier 20, and a discharge point 11 for removing any content 19 which may remain in the lower mold 6 unintentionally. The movement device 5 moves the lower mold 6 in a direction of movement 100 cyclically from one processing point to the next. In the exemplary embodiment, the direction of movement 100 is circular in a clockwise direction around the longitudinal axis 90 of the drum. The direction of movement 100 runs in the direction from the tapping point 8 via the filling point 12 to the pressing point 7 and from the pressing point 7 back to the tapping point 8. The drum rotates clockwise in its circumferential direction. The drum is driven by a rotary or detent gear. In the exemplary embodiment, the rotary or detent gear is a Geneva gear, not shown. As a result, the lower mold 6, which is arranged on a side surface of the drum, is rotated by a specific angle of rotation about the longitudinal axis 90 of the drum during operation of the roof tile press 1 and then remains in a position for a specific time. The drum and thus also the lower mold 6 arranged on the side surface is then rotated further about the longitudinal axis 90 by the angle of rotation. In the exemplary embodiment, the angle of rotation is 60 °. After a certain number of rotations, the lower mold 6 and the movement device 5 return to their initial state. In the exemplary embodiment, this happens after six rotations.

Fig. 3 shows a perspective front view of the roof tile press according to the 1 and 2 in the area of the removal point 8. Corresponding to the number of sub-molds 6 located on a drum surface ( 1, 2 ), the roof tile press 1 has the same number, here four suction head devices 60. By means of the suction head device 60, the pressed moldings 22 are reworked in the working step Fig. 2 taken from their respective lower mold 6, trimmed in their contours and according to Fig. 3 stored on shaped carriers 20. The molding carriers 20 are in turn located on a conveyor 16, by means of which the molding carriers 20 and the moldings 22 placed thereon are transported away and fed for further processing.

Fig. 4 shows the arrangement in an enlarged detail view Fig. 3 with further details of the suction head devices 60. An individual suction head device 60 each comprises a support unit 61, a suction head 24 and coupling means for exchangeable connection of the suction head 24 to the support unit 61 described in more detail below. In the exemplary embodiment shown, the support unit 61 comprises a base body 69 and a receiving plate 70, the receiving plate 70 against a spring force is vertically resiliently mounted on the base body 69. The suction head 24 comprises an adapter plate 71 corresponding to the receiving plate 70 and a circumferential knife frame 72 extending downward therefrom for separating excess material from the molding 22. For this purpose, during operation the suction head 24 is attached to the lower mold 6 ( 1, 2 ) moved up so that the knife frame 72 penetrates the material of the molding 22, trims it to a certain outline and thereby defines the outer contour of the roof tile that will later become. The previously described elastic flexibility of the receiving plate 70 with respect to the base body 69 allows a certain compensatory movement.

Further details on the structural design and on a method sequence according to the invention during the assembly of the suction head device 60 shown result from the overview of the 5 and 6 : There is a single suction head device 60 according to the previous figures is shown in individual views, but the suction head 24 is still separated from the support unit 61 and is not locked or braced with this.

As already mentioned, the connection of the suction head 24 to the carrying unit is designed to be detachable in order to enable the suction head 24 to be replaced if necessary. For this purpose, coupling means are provided according to the invention, which according to the 5 and 6 have at least one zero-point clamping system 63, here a total of two zero-point clamping systems 63 for one carrying unit 61 and one suction head 24 each, and a device for determining the position 66 of the suction head 24 relative to the carrying unit 61. Each of the zero point clamping systems 63 comprises a clamping bolt 64 and a clamping unit 65 for receiving and locking the clamping bolt 64. In the exemplary embodiment shown, the clamping units 65 are fastened to the support unit 61, specifically to their mounting plate 70, while the associated clamping bolts 64 are attached to the suction head 24, here are attached to the adapter plate 71. However, reverse attachment can also be considered. In any case, the clamping units 65 are designed to receive and lock the assigned clamping bolts 64, with which a locking of the suction head 24 is associated with the support unit 61. The device for determining the position 66 of the suction head 24 relative to the support unit 61 is designed in the exemplary embodiment shown as a proximity sensor, more precisely as an inductive proximity switch 68. The inductive proximity switch 68 is inserted from above into the mounting plate 70 of the support unit 61 and fastened there in such a way that its detection area is oriented downward towards the suction head 24. Of course, here too, reverse mounting on the suction head 24 is possible.

A method according to the invention for assembling the suction head device 60, that is to say for releasably fastening and locking the suction head 24 to the carrying unit 61, now results from the overview of the 5 and 6 as follows: First, the suction head 24 and the support unit 61 are brought closer together, as shown in FIG Fig. 5 is shown. For this purpose, in the exemplary embodiment, the suction head 24 stands with the lower cutting edge of its knife frame 72 on a support (not shown) and is positioned there exactly below the receiving openings of the associated clamping units 65 in relation to the axial direction of the clamping bolts. The mutual approach is now continued in the above-mentioned axis direction by lowering the support unit via the machine control, not shown. The tensioning bolts 64 thread themselves into the receiving openings of the associated tensioning units 65 in accordance with Fig. 6 a. Of course, it can also be possible to leave the carrying unit in place and to lift the suction head 24 in the process. A combined movement of the two assemblies is also conceivable within the scope of the invention.

From the longitudinal section of the Fig. 6 it also follows that the longitudinal axis of the clamping bolt 64 specifies a z direction, which in the assembled state is radial to the longitudinal axis 90 of the movement device 5 or the drum ( Fig. 2 ) lies. Perpendicular to this is a parting plane between the mounting plate 70 and the adapter plate 71 with an x-direction, which in the assembled state is parallel to the longitudinal axis 90 ( Fig. 2 ) lies, and with a y-axis perpendicular to it, that is, in the assembled state, perpendicular to the longitudinal axis 90 and thereby tangential to the surface of the said drum corresponding to the direction of movement 100 ( Fig. 2 ) lies. The tensioning bolts 64 and the tensioning units 65 are matched to one another in such a way that the tensioning bolts 64 automatically thread into the tensioning units and are then guided in the engaged state with virtually no play in the x-direction and in the y-direction, which facilitates guidance and exact relative positioning Suction head 24 and support unit 61 in these same directions. Since there are also two of the zero point clamping systems mentioned, there can be no relative rotation about the z axis.

However, the clamping bolts 64 and the clamping unit 65 are also coordinated with one another in such a way that they have an axial gripping tolerance a against one another during the locking process. For explanation is in Fig. 6 shown that the approach of the suction head 24 and the support unit 61 in the z-direction has been advanced so far that the desired target position is almost reached within the framework of a machine-controlled rough positioning, but that there is still a gap between the suction head 24 and the support unit 61. The clamping bolt 64 is not fully inserted into the clamping unit 65, so there is no stop between the suction head 24 and the carrying unit 61 in the context of the rough positioning mentioned. With its gap dimension in the z direction, the mentioned gap corresponds to the axial gripping tolerance a measured in the z direction, within which, on the one hand, there remains a residual mobility of the suction head 24 relative to the support unit 61 in the z direction, but on the other hand also the zero point clamping system 63 can be reliably locked. The axial gripping tolerance is preferably at least one millimeter and is in particular in the range from one to three millimeters. In the preferred exemplary embodiment shown, it is approximately two millimeters.

Whether an axial relative positioning of the clamping bolt 64 and the clamping unit 65 has occurred within the mentioned axial gripping tolerance a is determined by means of the position determining device 66, that is to say by means of the inductive proximity switch 68. This is set in such a way that, with sufficient approximation, however gives a signal without going to the stop. This signal indicates that an axial relative positioning within the gripping tolerance a has been achieved. This can be a light signal and / or an acoustic signal, as a result of which the machine personnel now locks using the zero point clamping systems 63. Alternatively, fully automatic locking is of course also conceivable. In any case, the locking now carried out brings about a reliable, but if necessary also releasable, attachment of the suction head 24 to the carrying unit 61, the remaining degrees of freedom of a relative movement now being determined at least with sufficient accuracy. In the preferred embodiment shown here, the zero point clamping system 63 is also designed such that the clamping unit 65 grips the clamping bolt 64 within the axial gripping tolerance a during the locking process and then fixes it axially while canceling the axial gripping tolerance a. An axial bracing takes place, in which the gap between the suction head 24 and the support unit 61 disappears, that is to say, therefore, the adapter plate 71 of the suction head 24 comes to rest on the mounting plate 70 of the support unit 61. This also results in a play-free fixation in the z direction, which also applies to tilting movements about the x-axis and the y-axis that are now excluded.

Conversely, a carrier can be provided for disassembly and moved close to the suction head 24. A proximity sensor can also be used for this. After loosening the zero point clamping systems 63, the suction head lowers gently on the carrier and can then be removed without overloading.

In the preferred embodiment shown, the zero point clamping systems 63 used have a pneumatic actuation 67, which is only indicated schematically here, with locking or unlocking being effected by means of compressed air. For this purpose, the zero point clamping systems 63 are designed to be pressure-free. In other words, they are in the locked state without the application of compressed air. This lock is released when a pulse of compressed air is applied. Related to the assembly and Locking process means that first a rough positioning into the axial gripping tolerance a is carried out, while the zero point clamping system 63 is unlocked by means of pressurization by the pneumatic actuation 67. As soon as the axial gripping tolerance a is reached and this is recognized by means of the inductive proximity switch 68, the pressure is removed, so that a lock occurs as a result.

Claims (8)

1. Suction head device for a roofing tile press (1), comprising a supporting unit (61), a suction head (24) and coupling means for releasably connecting the suction head (24) to the supporting unit (61),
   characterised in that the coupling means comprise at least one zero point clamping system (63) and a device for position detection (66) of the suction head (24) relative to the supporting unit (61), wherein the zero point clamping system (63) comprises a clamping pin (64) and a clamping unit (65) for the accommodation and locking of the clamping pin (64), wherein the clamping pin (64) and the clamping unit (65) are matched to each other in such a way that they have a mutual axial gripping tolerance (a) in the locking process, and wherein the device for position detection (66) is designed to determine in the locking process the axial relative positioning of the clamping pin (64) and the clamping unit (65) within the axial gripping tolerance (a).
2. Suction head device according to claim 1,
   characterised in that the coupling means have a total of two zero point clamping systems (63) of a supporting unit (61) each and a suction head (24) each.
3. Suction head device according to claim 1 or 2,
   characterised in that the axial gripping tolerance (a) is at least one millimetre, being preferably in the range of one to three millimetres and in particular approximately two millimetres.
4. Suction head device according to any of claims 1 to 3,
   characterised in that the zero point clamping system (63) is designed for the clamping unit (65) to grip the clamping pin (64) in the locking process within the axial gripping tolerance (a) and then to fix is axially while cancelling the axial gripping tolerance (a).
5. Suction head device according to any of claims 1 to 4,
   characterised in that the zero point clamping system (63) has a pneumatic actuation (67).
6. Suction head device according to any of claims 1 to 5,
   characterised in that the device for position detection (66) comprises a proximity sensor matched to the magnitude of the axial gripping tolerance (a), in particular in the form of an inductive proximity switch (68).
7. Roofing tile press with a suction head device according to any of claims 1 to 6.
8. Method for installing a suction head device according to any of claims 1 to 6, comprising the following procedural steps:

   - The suction head (24) and the supporting unit (61) are brought close to each other while the clamping pin (64) is threaded into the clamping unit (65).

   - The approach process is continued until the device for position detection (66) signals that the clamping pin (64) and the clamping unit (65) are within the axial gripping tolerance (a) relative to each other.

   - In this position the zero pint clamping system (63) is locked.

   - The clamping unit (65) optionally fixes the clamping pin (64) axially in the locking process while cancelling the axial gripping tolerance (a).

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