The invention relates to a method for the production of roofing tiles according to the preamble of claim 1 as well as to a device for the production of these roofing tiles according to the preamble of claim 16.
In the case of pitched roofs the major portion of the roof surface is covered with flat roofing tiles. However, for the roofing of certain regions of the roof and for satisfying specific technical functions, the flat roofing tiles are installed in combination with accessory tiles. Accessory tiles are, for example, the ridge and arris starting tiles to be installed in the ridge and arris regions as well as the hip caps. Among the accessory tiles with technical function are, in contrast, snow guard tiles, venting tiles and [foot-]standing tiles. Since accessory tiles have markedly more complex geometries compared to flat roofing tiles, the production of flat roofing tiles and accessory tiles prove to be highly different.
Flat roofing tiles are produced using extrusion molding, such as is described in the German [laid open] application DE 35 22 846 A1. Herein green cement is placed onto a continuous belt of bottom dies and pressed into the bottom die by means of a profiled roller such that a continuous belt of compacted green concrete is generated, whose cross sectional profile corresponds to that of the future flat roofing tile. The continuous belt is subsequently cut such that each bottom die bears a single molded flat roofing tile blank. While the extrusion molding method ensures the efficient production of the flat roofing tiles, however only simple geometries can be produced since the forming by means of a roller and a bottom die does not permit providing the flat molded roofing tile blank with contours extending transversely to the direction of extrusion. However, many accessory tiles require such contours.
An alternative method which permits a greater degree of freedom of the forming, is the core shooting method disclosed in EP 1 106 281 B1, in which by means of compressed air a molding material with delayed curing properties is injected into a core box and subsequently removed from it. To inject the molding material, the core box is substantially positioned in a perpendicular with respect to the longitudinal direction of the body to be formed and swivelled substantially into a horizontal for the removal of the molded body. The molding material described in EP 1 106 281 B1 can be a green concrete, whereby the invention can be employed in the production of roofing tiles.
In practice accessory tiles are produced manually which is time consuming and cost intensive. Ridge and arris starting tiles are produced using a two-part molding box, wherein the lower half of the molding box forms the underside and the upper half of the molding box the upper side of the ridge or arris starting tile. After placing the green concrete manually into the lower half, the upper half of the molding box is placed onto it and pressed against it. The densification of the green concrete subsequently takes place thereby that the molding box is placed onto a vibrating table. Depending on the dwelling time on the vibrating table, the densification of the green concrete yields different results such that the ridge and arris starting tiles vary with respect to their freeze-thaw cycling resistance.
The methods for the production of snow guard tiles, venting tiles and standing tiles are very similar. In the production of snow guard tiles, first, a rib serving as a snow barrier is formed from the green concrete, which rib subsequently is adhered in the foot-end region onto the top side of the flat roofing tile. The production of standing tiles takes place by prefabricating the bracket comprising the climbing step and adhering it onto the roofing tile. For the production of a venting tile, a venting opening is cut centrally out of the flat roofing tile, which opening is subsequently covered with a separately fabricated venting hood against the penetration of rain. For this purpose the venting hood is adhered onto the top side of the flat roofing tile. The adhesive bonding in such accessory tiles represents a mechanical weak spot, which tends toward the formation of cracks. Through the penetration of moisture, frost bursting can occur and the further weakening of the adhesive bond. Under the action of an external force, for example when a roofer walks on the roof during an inspection, there is the risk that the adhered joined part (snow barrier, bracket, venting hood) become detached from the flat roofing tile. Since the flat roofing tiles and the joined parts are produced separately, their color coatings are also carried out independently of one another. The color of the flat roofing tiles and that of the joined parts therefore vary such that the finished accessory parts also do not exhibit a uniform appearance. It is not possible to produce a faultless esthetic appearance even with an additional color coating of the finished accessory tile.
The present invention therefore addresses the problem of providing a method and an installation which make feasible the economically more efficient production of accessory roofing tiles and simultaneously the enhancement of the quality of the produced accessory structural tiles.
The problem addressed by the invention is resolved according to the features of patent claims 1 and 16.
The invention thus relates to a method for the production of roofing tiles by means of a core shooter [device]. Herein a core box is provided which includes in its interior a mold carrier. Through an injection opening of the core box green concrete is introduced into the core box. Venting the core box takes place via at least one screen nozzle disposed in the mold carrier. The roofing tile generated in the core box is removed from the core box and transferred to a cutting device, where projecting burrs of the roofing tile are cut off
According to the invention the green concrete is shot or injected at high kinetic energy via a compressed air percussion into the molding box of a core shooter for the production of accessory tiles, whereby a compaction is attained that is markedly higher than is the case when using the conventional densification of the green concrete on a vibrating table. Due to the higher compaction of the green concrete, the accessory tiles have a lesser porosity and therewith a higher freeze-thaw cycling resistance (according to DIN EN 490, tested according to DIN EN 491).
Since the cavity of the molding box receiving the green concrete corresponds to the finished accessory tile, monolithic accessory tiles are generated. The separate production and the time-consuming adhesion of flat roofing tiles and joined parts become superfluous, and the accessory tile accordingly also no longer has a weakening adhesive bond.
After the injection step, the molding box can be removed from the core shooter and be disassembled. The accessory tile is subsequently removed from the molding box and transferred promptly to a coating station, such that the color application takes place on the still wet green concrete of the not yet cured accessory tile. This process is referred to as wet coating. Color variations, such as were previously unavoidable due to the separate color coating of the flat roofing tiles and of the joined parts, are in this way avoided. Wet coating, moreover, permits the optimal cross-linking of the coloring agent, which conventionally is a polymer dispersion coloring agent, with the surface of the accessory tile such that improved adhesion and durability of the color coating is attained. A single color application is sufficient for an esthetic appearance of the accessory tile.
Several embodiments of the invention will be explained in conjunction with the Figures and explained in the following in further detail. In the drawing depict:
The mixture has the following composition:
sand (type 0/3, Producer: CWS) 45 to 75 wt %, especially preferred 54.13 wt %,
sand (type 0.5/2, producer: CWS): 0 to 24 wt %, especially preferred 11.4 wt %,
quartz sand (type L 55, producer: Quarzwerke): 0 to 30 wt %, especially preferred 5.7 wt %,
cement (type CEM II 52.5, producer: Holcim): 18 to 25 wt %, especially preferred 20.89 wt %,
additive (type FK 61, producer: MC Bauchemie): 0.2 to 1.4 wt %, especially preferred 0.47 wt %,
additive (type BWA 22, producer: MC Bauchemie): 0.2 to 0.8 wt %, especially preferred
coloring agent (type granite, producer: Lanxess): 0.3 to 1.0 wt %, especially preferred 0.5 wt %.
The pot life of the green concrete mixture is approximately 20 minutes. After this time its processing property is impaired, which can have a negative effect on the product quality. The pot life is thus the time between mixing a multi-component substance and the end of its processibility, thus the time interval in which the substance can still be “removed from the pot” and processed. The end of the pot life is most frequently indicated by a marked viscosity rise, which prevents further processing. It is therefore recommended to produce each time only a small green concrete quantity of approximately 50 to 100 kg, which can be quickly used up. The produced green concrete is transferred from the mixer 14 to an extraction belt 15 and from it is supplied to a core shooter 16. The core shooter 16 is described in greater detail in
Injecting the green concrete into the core box 17 takes place through a compressed air percussion. Through the entering air stream the green concrete is herein converted into a two-phase mixture of compressed air and concrete particles. The concrete particles are entrained by the air stream via an injection opening, not visible here, into the core box 17, where they are strongly compacted due to their high kinetic energy. The high compaction leads to a porosity or bulk density of the accessory tiles of approximately 16% to 18% (measured according to DIN 52102), which lends high freeze-thaw cycling resistance to the accessory tiles. For the injection of the green concrete the compressed air should have a pressure of at least 4·105 Pa. Optimal results are achieved at pressures of approximately 6·105 Pa to 10·105 Pa. This pressure should at least be maintained for one second, however no longer than five seconds. The pressure is preferably maintained for one to three seconds.
Using a hydraulic lifting cylinder the filled core box 17 is lowered after the injection process into the core shooter 16. Since the green concrete has a lesser compaction in the region of the injection opening of the core box 17, the green concrete located in the injection channel must be re-pressed by means of a re-pressing unit. This re-pressing unit will be described in the context of
The handling station 22 includes a first receiving device 23, into which the robot unit 20 places the filled core box 17. After the placement, the robot unit 20 releases pneumatically the upper core box 19 and the lower core box 18. Such released core box comprised of a first lower core box 24 and a first upper core box 25 can be seen in
Before the accessory tile 26 can be removed from the first lower core box 24 located in the first receiving device 23, the burrs at the head- and foot-end margin of the accessory tile 26 are cut off the accessory tile 26 using cutting devices. These cutting devices will be described in detail in
To ensure high molding accuracy the lower core boxes and the upper core boxes are cleaned after every third injection process. As a rule, the length of an injection process is 45 seconds. The cleaning is completed using a compressed air jet or water vapor jet. Further, a parting agent is applied to avoid adhesions of the accessory tile in the core box. As parting agent can be utilized, for example, a bio-oil, with the application quantity being preferably approximately 1 g. This application can be carried out manually or by machine.
In the color coating installation 32 is already an accessory tile 33, which had been transported by the conveyor means 31 into a spray chamber 34 and been positioned beneath a movable nozzle arrangement. Since the accessory tile, seen in top view, only overlaps the mold carrier partially, the non-covered regions of the mold carrier are masked with the aid of a template in order for the mold carrier not to be contaminated with the coloring agent (
As soon as the drying chamber trolley 35 is completed loaded with accessory tiles, it is driven into a drying chamber 36 where the accessory tiles are cured over a dwelling time of 6 to 10 hours and at a temperature between 45° to 60° C. To attain complete hydration, to the drying chamber 36 water vapor is supplied at regular intervals during the curing process, which is indicated by an arrow 37. The relative air humidity is thereby kept in a range of 65 to 90%. At the end of the dwelling time the accessory tiles have a sufficiently high solidity permitting the detachment of the accessory tiles from the mold carrier.
Since the thus produced accessory tiles comprise monolithically only one material, they have the same surface quality everywhere. The cured accessory tile is now preferably manually detached from the mold carrier, the so-called pallet. This detachment of the accessory tile from the mold carrier is referred to as stripping. After they have been stripped from the mold carrier, the accessory tiles can be transferred to further work stations, not depicted in
Further can be seen in
Core box 56 is disposed on a support plate 60 of lifting cylinder 41. This support plate 60 is located on a cylinder 61 which is anchored in a base 62. The lifting cylinder 41 can be moved by means of an hydraulic force in the direction of arrows 63 and 64. Therewith it becomes feasible to move the core box 56 on the support plate 60 either in the direction toward the shooting unit 50 or to move the core box 56 away from this unit. The center part 43 as well as the machine stand 42 are each connected across conduits 65 to 67, for example pipes, with a pump device 69 driven by a motor 68. On the pumping device 67 can be seen two manometers 70, 71. By means of the pump device 69 it is possible to supply compressed air to the core shooter 16 via the conduits 65 to 67 or to extract this [air] again from the core shooter 16. As can be seen in
Furthermore can be seen in
In
The plate-shaped element 121 includes an opening 157 in its center. This opening 157 is encompassed by a border strip 162 provided with openings 158 to 161. This border strip 162 of opening 157 is encompassed by a frame 163 which is also provided with several openings 164 to 167. Compared to frame 163, the border strip 162 is thinner, such that this border strip 162 forms a support-plate surface for the plate-shaped part 144 of inset 120, whereas the frame 163 forms a support surface for receiver 119. The inset 120 rests subsequently on the border strip 162 such that the openings 153 to 156 are located precisely above openings 158 to 161.
The plate-shaped element 122 has in its central plateau 135 an opening 136 through which concrete from the core shooter 16 can reach a core box. This opening 136 is consequently the opening of the shooting unit 50. The element 122 comprises a margin section 137 with several connection elements 138 to 143 which can engage into the openings 158 to 161 of the plate-shaped element 121 and the superjacent openings 153 to 156 of inset 120, whereby the elements 121, 122 and inset 120 are firmly connected with one another.
The shooting unit 50 is formed by placing the receiver 119 onto the plate-shaped element 121 and introducing the connection elements 129 to 134 into openings 164 to 167 of frame 163. The shooting unit 50 can consequently be simply removed from cylinder 44 of the core shooter 16 and be disassembled. Maintenance of the shooting unit 50 is therefore simple.
For this purpose two cutting devices 171, 172 are disposed laterally of the receiving device 23, each of which cutting devices includes a cutting tool 184 and 196, respectively. The cutting tools 184, 196 are of different structure such that the cutting tool 184 working the head-end edge 185 carries out a simple straight cut and the cutting tool 196 working the foot-end edge 186 during the straight cut performs additionally a compaction of the cut edge.
The cutting device 171 has movable tracks 175 which can be moved via a lifting device 176 in the direction of arrows 173, 174. On the tracks 175 is visible a carriage 177 disposed on wheels, which can be moved in the direction of arrows 178, 179. The carriage 177 has, for example as in
At the end of carriage 177 is disposed a removable insert 183 for the exchangeable cutting tool 184. With this cutting tool 184 the burr on the head-end edge 185 of accessory tile 26 is removed. For this purpose through movement of the carriage 177 in the direction of arrow 179 the cutting tool 184 is disposed precisely above the site at which the burr adhering on the accessory tile 26 must be cut off. Subsequently the tracks 175 with the carriage 177 disposed thereon are lowered in the direction of arrow 174. The cutting tool 184 penetrates therein the end of the green concrete and cuts this from the accessory tile 26 proper. By moving the carriage 177 in the direction of arrow 178 the green concrete cut off the accessory tile 26 is removed from the lower core box 24.
The cutting device 172 has a similar constructional setup as the cutting device 171. In the case of cutting device 172 a carriage 189 movable in the direction of arrow 187, 188 is disposed on tracks 190. The carriage 189 includes wheels of which only wheels 191, 192 can be seen since the other two wheels which can not be seen, are oppositely located. The carriage 189 is connected with a driving mechanism 193 by means of which the carriage 189 can be moved in the direction of arrows 187 and 188.
On the end of carriage 189 facing the receiving device 23 (
By moving the carriage 189 in the direction of arrow 188 the cut-off green concrete is removed from the accessory tile 26 and pushed from the lower core box 24. Both cutting devices 171, 172 preferably operate synchronously. Once the green concrete is removed from the lower core box 24, the two cutting devices 171, 172 move back into the initial position as shown in
Although in
Thereby that during the cutting process the cutting tools 184, 196 are also pressed against the accessory tile 26, before they remove the cut-off green concrete from the lower core box 24, the cutting devices 171, 172 also serve for re-pressing the accessory tile.
The accessory tile 33 located on a mold carrier 232 has been transferred into the spray chamber 34 via the conveyor means 31. The rear wall 233 can be seen as well as the two side walls 234, 235 and the bottom 236 of the spray chamber 34. The conveyor means 31 is comprised of a T-shaped carriage 237 disposed on wheels, wherein in
Further can be seen walls 245, 246 extending parallel to both sides of the hood 237. At each of the upper front ends of these walls are disposed bearings for an articulation rod 249, 250. Of the bearings only bearings 247, 248 can be seen in
If the accessory tile 33 is now to be coated with polymer dispersion coloring agent, the covering 251 is moved in the direction of arrow 256 and the covering 252 in the direction of arrow 258. As soon as the template 253 masks the region of the mold carrier 232 not covered by the accessory tile, the robot unit 200 can carry out the coloring agent application by means of the nozzle arrangement 231.
The state in which the template 253 masks the region of the mold carrier 232 not covered by the accessory tile 33, is also shown in
Also seen is the conveyor means 31 with hood 242 with the through-hole 243. The tracks 240, 241 disposed beneath the hood 242 are also visible. At the end of this track line formed by the tracks 240, 241 is disposed stop bar 260. Walls 245 and 246, which at least partially overlap the hood 242, include bearings 248, 261 and 247, 262, respectively, in which are disposed the articulation rods 249 and 250, respectively.
The upper core box 78 of core box 56 has on the side facing away from the lower core box 79 several bracings 270 to 272. Further can be seen a side wall 273 which is in connection with the bracings 270 to 272. The lower core box 79 also includes several bracings 274 to 276, which are in connection with a side wall 277. The lower core box 79 has furthermore a prominence 278 as well as a notching 279. On the prominence 278 of the lower core box 79 rests a mold carrier 280. The mold carrier 280 includes two webs 281, 282, wherein the one web 281 encompasses the prominence 278 of the lower core box 78 and the other web 282 engages into the notching 279. The mold carrier 280 is thereby fixedly disposed on the lower core box 79. Between the mold carrier 280 and an indentation 283 of the upper core box 78 an injection channel 284 can be seen, which has its greatest extent in the region of web 281 of mold carrier 280 and opening 136 of shooting plate 52. This extent is denoted as terminating edge 285.
In the proximity of the milling-out 286, furthermore, a screen nozzle 287 is disposed as a part of the lower core box 78. This screen nozzle 287 includes several openings 288 to 291, through which the air can escape from the core box 56 when concrete is injected into it.
While the screen nozzle 287 in
The at least one opening of the screen nozzle 287 must herein have such diameter that air, however not concrete, can leave the core box 56. It is understood that the screen nozzle 287 can also be disposed on the lower core box 79 or that the screen nozzle is formed by the lower core box 79 as well as also by the upper core box 78.
The screen nozzles can be disposed on the end of the injection channel or laterally on the injection channel. Since the screen nozzles lead to exhaust markings on the accessory tile, they are so disposed in the core box that, with respect to the accessory tile, they are disposed in regions where they are later no longer visible once they are installed. Milling-out can be employed in addition to the screen nozzles. The cross section of a milling-out is less than the diameter of the concrete particles such that these cannot escape from the core box. However, such millings-out are not depicted in
The accessory tile 295 shown in
The lower core box 79 includes a lower part 305 on which an upper part 306 is disposed. On this upper part 306 is disposed the prominence 278, which includes the notching 279. This prominence 278 is so formed that on it the mold carrier 280 can be seated with accurate fit. The lower part 305 of the lower core box 79 further includes several openings 307 to 311, into which connection elements of the upper core box 78 can be introduced, wherein only the connection elements 312 to 314 of the upper core box 78 are evident. Furthermore is evident the milling-out 286 in the lower part 305. Through this milling-out 286 air can escape from the core box 56 via the screen nozzle 287 when green concrete is injected. The screen nozzle can also be disposed on walls 297 or 273. It is also feasible to provide several screen nozzles.
Here side walls 316 to 319 are also connected with one another via bracings 320 to 322. As the arrangement 299, this arrangement 315 also serves for purpose for the core box 56 to withstand the temperatures and pressures generated when concrete is injected. Via the two webs 281, 282 the mold carrier 280 is placed onto the prominence 278 with accurate fit. However, prominence 278 is not visible in
In
As already stated in the first embodiment example, it is feasible to dispose the screen nozzle 349 on the lower core box 331 or on the upper core box 332 as well as also on the lower core box 331.
In
The lower core box 401 also includes an arrangement 405 with several bracings 406 to 409 located between walls 410 to 413.
The mold carrier 403 includes on its underside several webs 414 to 417, which can engage into the notchings of a prominence disposed on the lower core box 401. However, in
The upper core box 402 includes moreover several connection elements 419 to 423 as well as openings 424, 425, via which the upper core box 402 can be firmly connected with the lower core box 401. The upper core box 402 includes an arrangement with several bracings similar to the arrangement 405 of the lower core box 401, which arrangement, however, is not visible in
It is understood that the arrangements 299, 315, 335, 354 and 405 shown in
The depicted notchings on the prominences of the lower boxes can also be implemented differently.
Based on
Number | Date | Country | Kind |
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10 2007 043 163.7 | Sep 2007 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2008/061946 | 9/9/2008 | WO | 00 | 2/24/2010 |