METHOD AND DEVICE FOR FILLING HOLLOW PROFILE STRIPS

Description

[0001] The invention relates to a method for filling hollow profile strips, in particular hollow profile strips which are legs of spacer frames or closed spacer frames, wherein free-flowing filling material, in particular a hygroscopic material such as molecular sieve, is introduced into the hollow profile strip from a storage container.

[0002] The invention further relates to a device with which the method according to the invention can be carried out.

[0003] Methods and devices for filling hollow profile strips, in particular hollow profile strips that serve as spacers in insulating glass, are known in various embodiments.

[0004] AT 383 581 B discloses a device for filling spacer frames for insulating glass units with hygroscopic material, wherein the spacer frames have corners produced in one piece by bending. The device comprises holders for the spacer frame to be filled and at least one multi-processing tool, which has a device for creating an opening in the outer wall of the spacer frame, a nozzle for filling the hygroscopic material into the spacer frame, and a nozzle for closing the filling opening.

[0005] Another device for filling spacer frames for insulating glass is known from AT 383 582 B. A device for filling spacer frames for insulating glass with hygroscopic granules is described, in which the line connecting a storage container to the outlet opening for the granules has a section with a larger cross-section and a section with a smaller cross-section, which is deflected upwards and whose axis is offset upwards relative to the axis of the section with a larger cross-section. This device is used, for example, in a machine for filling spacer frames for insulating glass, which has two processing arrangements with which holes can be created in the legs of the spacer frame, filled with granules, and the holes can be closed again.The machining assemblies have a plate against which the respective leg of the spacer frame rests and in which a hole for a drill bit, as well as the openings for the granulate line and a channel for the sealing compound, are arranged. To successively align the legs of the spacer frame, which are gripped by clamping devices, with the hole for the drill bit and the openings for the channels, the clamping devices and the plate are movable relative to each other.

[0006] Methods and devices for filling spacer frames with filling material (hygroscopic material, such as molecular sieve) are known from AT 388 548 B, AT 390 606 B, EP 0 349 519 A1 and EP 0 376 926 A2.

[0007] DE 44 02 450 A1 (= EP 0 615 046 A2) discloses a spacer frame consisting of a hollow profile strip bent three times and still open at the fourth corner, with one leg being longer than the other leg leading to the open corner, and which is filled with granular desiccant via a probe inserted into the leg. The front end of the probe protrudes into the leg to the desired fill level. As soon as the desiccant in the leg reaches the probe, the flow of desiccant stops. This is detected by a sensor. The sensor triggers the withdrawal of the probe. A negative pressure is applied to the probe via a line to prevent any more desiccant from escaping from the probe.

[0008] EP 0 430 924 A1 (= AT 399 587 B) discloses a bulk flow detector for a line through which granular, hygroscopic material, to be filled into spacer frames for insulating glass, is fed from a storage container to a filling head. The bulk flow detector has a light source connected to the line, which emits a light beam traversing the line. A sensor responsive to the light emitted by the light source is arranged opposite the light source. Upon exposure to the light from the light source, the sensor transmits a signal to a controller, which in turn transmits a signal if no signal from the sensor is received within a preselected period of time after the last signal emitted by the sensor.

[0009] EP 3 477 037 A1 discloses a device and a method for filling a spacer frame leg or spacer frame with hygroscopic filling material, wherein an indirect determination of the quantity of filling material filled into a spacer frame leg or spacer frame is to be possible by determining the weight loss of a storage container filled with filling material.

[0010] WO 2017 / 037288 A1 discloses a device for filling a spacer frame with a filler for producing an insulating glazing unit. The device comprises at least a) calculating the filling time for the spacer frame; b) inserting the spacer frame into a filling device with scales and frame holders, with the spacer frame suspended from suspension devices; c) filling the spacer frame during the calculated filling time; and d) weighing the spacer frame and determining the fill level. When the fill level is > 90%, the filling of the spacer frame is terminated.

[0011] DE 37 10 694 A1 discloses a method and device for filling straight hollow profile bars for spacer frames for insulating glass with a granular desiccant. In this known method, a predetermined amount of desiccant is introduced into the hollow profile bar using compressed air. The hollow profile bar is sealed at one end to prevent the desiccant from escaping. The compressed air used as a propellant is designed to escape through holes in the profile bar.

[0012] A disadvantage of the known measures for determining the degree of filling of hollow profile strips, in particular of spacer frames for insulating glass, is the use of weighing devices, since the low specific weight of the usual filling material requires highly precise scales.

[0013] Weighing using precision scales is not always possible due to various influences in practical operation, especially in systems for the production of insulating glass (dust, air draft, etc.).

[0014] Determining the degree of filling of a hollow profile strip, in particular a spacer frame for insulating glass, with the aid of a probe that has to be inserted into the hollow profile strip, for example into the frame leg of a spacer frame, and then pulled out again, has also proven to be disadvantageous.

[0015] Due to the presence of burrs inside hollow profile strips, there is a risk that complete filling of a hollow profile strip, especially a spacer frame, cannot be guaranteed.

[0016] The invention is based on the object of specifying a method and a device for carrying out the method, with which the filling of hollow profile strips, in particular hollow profile strips which serve as spacers in insulating glass, is possible in a simple and reliable manner, wherein the desired degree of filling can be achieved in a simple and reliable manner.

[0017] This object is achieved according to the invention with a method having the features of claim 1.

[0018] The problem underlying the invention, as far as the device is concerned, is solved by a device which has the features of the independent claim 6 directed to the device.

[0019] Preferred and advantageous embodiments of the method and device according to the invention are the subject of the subclaims.

[0020] In the method according to the invention, the fill level of the fill material in the storage container (storage) is precisely determined before filling the hollow profile strip, such as a spacer frame or a leg for a spacer frame, begins. A constant (pneumatic) pressure is applied to the surface of the fill material in the storage container via a piston. This pressure ensures that a defined contact area of ​​the fill material is present, which allows for precise recording of the fill level in the storage container and any changes therein.

[0021] By removing fill material from the storage tank, a hollow profile bar is filled until the piston in the storage tank stops moving. The volume decrease of the fill material in the storage tank is determined by measuring the distance the piston has moved (distance difference ΔH).

[0022] The method according to the invention makes it possible to determine whether the actually desired filling level of the hollow profile strip, in particular of the spacer frame, has been achieved by comparing the target value for the filling level of the frame (which results from the frame geometry) and the actual value of the volume reduction of the filling material in the storage container.

[0023] In practice, the method according to the invention can be implemented, for example, by inserting a spacer frame into a frame holder below the filling device and suspending it. Holes are then drilled to fill the frame. Finally, granular desiccant, which in this case is the filler material, is filled into the storage container via the filling device.

[0024] In one embodiment of the invention, a line is provided that opens into the container and is connected to a vacuum pump. The negative pressure generated by the pump assists the filling of filler material into the storage container or makes filling possible in the first place, for example, if the storage container is positioned higher than a storage container (barrel) from which filler material (such as desiccant) is to be poured into the storage container.

[0025] The exact fill level of the fill material in the storage container is determined before filling the spacer frame begins by placing a piston with constant (pneumatic) pressure on the surface of the fill material in the storage container. When fill material is drained from the storage container and a hollow profile bar or spacer frame is filled, the piston moves as it follows the surface of the fill material in the storage container. As soon as the piston stops moving, the hollow profile bar or spacer frame is completely filled. The amount of fill material filled into the spacer frame is determined by measuring the piston stroke (path difference ΔH). A comparison between the target value and the actual value determines whether the desired fill level of the hollow profile bar of the spacer frame has actually been achieved, thus enabling simple quality control.

[0026] The amount of filling material removed from the storage tank corresponds to the product of the cross-sectional area of ​​the storage tank (= area of ​​the piston) and the stroke (Δ H) of the piston.

[0027] In the invention, the amount of filling material filled into a hollow profile strip is determined volumetrically - and not gravimetrically as in the prior art.

[0028] This makes it easy to adjust the fill level—that is, the extent to which the cavity in the hollow profile strip is filled—to a predetermined value. For example, the invention can be used to achieve fill levels other than the (conventional) fill levels above 90%, such as 80%, 70%, etc.

[0029] Once the spacer frame is filled to the desired level, especially completely (> 90%), the further flow of fill material from the filling line leading from the outlet opening of the storage tank is stopped. This allows the drilled holes in the spacer frame serving as filling openings to be easily closed.

[0030] If the filling line is at least partially an elastic hose, the filling line can be closed by applying compressed air in the manner of a pinch valve.

[0031] Alternatively, a line capable of being subjected to negative pressure can be connected to the filling line, particularly in the area of ​​its end connected to the hollow profile strip, to prevent further flow of filling material. Additionally, a sealing plug that can be adjusted to a closed position can be attached to the free end of the filling line.

[0032] In a preferred embodiment, there is play between the outside of the piston and the inside of the wall of the storage container so that fine dust does not hinder / prevent the movements of the piston in the storage container.

[0033] Within the scope of the invention, it is also contemplated to use several filling devices in order to fill several spacer frames simultaneously or one spacer frame via several filling openings.

[0034] Further details and features of the invention will become apparent from the following description of preferred embodiments with reference to the drawings. It shows: Fig. 1 schematically shows a storage tank in its initial position, Fig. 2 the storage tank from Fig. 1 after filling a spacer frame, Fig. 3 a system for carrying out the method according to the invention and Fig. 4 another system for carrying out the method according to the invention.

[0035] In a Fig. 1 und 2 The schematically shown storage container 5 stores filling material 20 (e.g. desiccant in the form of molecular sieve) which is to be filled into a spacer frame 11 for insulating glass.

[0036] As in Fig. 1 As shown, a piston 12 rests on the top side of the filling material 20, which is pressed onto the surface of the filling material 20 with a predetermined force F.

[0037] After filling a spacer frame 11, the piston 12 has moved downwards by the distance Δ H ( Fig. 2 ). From the distance Δ H by which the piston 12 has moved and the area of ​​the piston 2, the amount of filling material 20 (e.g. molecular sieve) actually introduced into the spacer frame 11 can be determined.

[0038] For this purpose, it can be provided, for example, that the stroke of the piston 12, i.e. the distance Δ H, is recorded with the aid of a measuring device, as will be described below.

[0039] At the Fig. 3 In the system (device) shown for filling a spacer frame 11, two storage containers 5 are provided. A piston 12 is provided in each of the storage containers 5, which is pressed onto the top of the filling material 20. For this purpose, the piston 12 is connected to a piston rod of a pneumatic cylinder 1, so that the piston 12 is pressed onto the filling material 20 in the storage container 5.

[0040] A measuring ruler 2 is provided to measure the distance (ΔH) traveled by the piston 12 when removing filling material 20 from the storage containers 5. Instead of a measuring ruler 2, any device can be provided that directly or indirectly measures the movements of the piston.

[0041] Lines leading to a vacuum pump 3 are connected to the storage tanks 5, allowing negative pressure to be generated in the storage tanks 5. This negative pressure facilitates the supply of filling material 20 (in particular, free-flowing or pourable granules in the form of a hygroscopic substance, such as a molecular sieve) via a line 4.

[0042] At the bottom of the storage containers 5, an outlet opening 6 is provided, to which a line 7 in the form of a hose is connected. Filling material 20 is introduced into a spacer frame 11 through the line 7 by inserting the line 7 into filling openings previously created in the outer wall of a spacer frame 11 made of hollow profile strips or a hollow profile strip bent into a frame. The free end 10 of the line 7 can be closed with the aid of a nozzle 9 in the manner of a pinch valve if compressed air is supplied to the nozzle 9 via a compressed air hose 8. In this way, the line 7 can be closed once the filling of a spacer frame 11 has been completed. This allows the spacer frame 11 to be removed and the openings in the spacer frame 11 to be closed by introducing a plastic, hardening mass.

[0043] The Fig. 4 The embodiment of a plant for carrying out the method according to the invention shown corresponds to the one shown in Fig. 3 shown embodiment.

[0044] Vacuum lines 25 extend from the lines 7 in the area of ​​their free ends 10, which are connected to them when used to fill spacer frames 11. Filters 26 are provided in the vacuum lines 25. The vacuum lines 25 are connected to - in Fig. 4Jet pumps 27, shown only symbolically, are connected in the area of ​​constrictions 28. In the medium flowing through the jet pumps 27 (for example, air), a negative pressure is created in the area of ​​the constriction 28, which causes no more filler material 20 (desiccant) to escape from the free ends of the lines 7. Once this is achieved, the spacer frame 11 can be removed from the system. In addition, the escape of filler material 20 from the lines 7 is prevented by sealing plugs 30 when these have been pushed forward with the aid of their drives 31 into their closed position, in which they rest against the ends 10 of the lines 7.

[0045] In summary, an embodiment of the invention can be described as follows: A device for filling spacer frames 11 made of hollow profile strips has a storage container 5 for free-flowing, hygroscopic filling material 20, such as molecular sieve. A line 7 extends from the storage container 5, leads to the spacer frame 11 to be filled and opens into a filling opening in the wall of the spacer frame 11. The amount of filling material 20 filled into the spacer frame 11 is determined by detecting the amount of filling material 20 removed from the storage container 5. The amount of filling material 20 removed from the storage container 5 is detected by measuring the travel (ΔH) of a piston 12 resting under pressure on the filling material 20 in the storage container 5.The degree of filling is checked by comparing the amount of filling material 20 removed from the storage container 5 with the predetermined amount of filling material 20 to be filled into the spacer frame 11.

Claims

1. Method for filling hollow-section strips, in particular hollow-section strips in the form of legs of spacer frames (11) or in the form of spacer frames (11), wherein free-flowing fill material (20), in particular a hygroscopic material, such as a molecular sieve, is introduced from a storage tank (5) into the hollow-section strip, wherein the quantity of fill material (20) introduced into the hollow-section strip is detected by detecting the quantity of fill material (20) removed from the storage tank (5), characterized in that the change in the level of fill material (20) in the storage container (5) is detected, in that pressure is exerted on the upper side of the fill material (20) contained in the storage tank (5) by means of a piston (12) that can be displaced in the storage tank (5), and in that the drop in the level of the fill material (20) in the storage tank (5) is determined by detecting the travel of the piston (12) in the storage tank (5).

2. Method according to claim 1, characterized in that the piston (12) is loaded pneumatically.

3. Method according to claim 1 or 2, characterized in that the degree of filling of the hollow-section strip is verified by a calculated threshold value for the degree of filling of the hollow-section strip being compared to the amount of the fill material (20) removed from the storage tank (5) as an actual value.

4. Method according to one of claims 1 to 3, characterized in that underpressure is generated in the storage tank (5) in order to suction off fill material (20) in the storage tank (5).

5. Method according to one of claims 1 to 4, characterized in that fill material (20) is prevented from exiting from the outlet opening after the filling process is completed by closing the lines (7) in the manner of a pinch valve.

6. Device for carrying out the method according to one of claims 1 to 5, characterized by a storage tank (5) for fill material (20), by a piston (12) displaceably accommodated in the storage tank (5), by a system (1) for loading the piston (12) with a preset pressure, by a line (7) connecting the storage tank (5) to the hollow-section strip to be filled, and by a system (2) for detecting the travel distance traveled by the piston (12) in the storage tank (5) when fill material (20) is removed.

7. Device according to claim 6, characterized in that a line (4) to which underpressure can be applied is connected to the storage tank (5) for generating underpressure in the storage tank (5).

8. Device according to claim 6 or 7, characterized in that a line (7) is connected to the outlet opening (6) of the storage tank (5) and in that the line (7) is assigned to a shut-off valve.

9. Device according to one of claims 6 to 8, characterized in that there is play between the piston (12) and the inside of the wall of the storage tank (5).

10. Device according to one of claims 6 to 9, characterized in that the piston (12) stands still when the actual amount of the fill material (20) has been poured into the hollow-section strip.

11. Device according to one of claims 6 to 10, characterized in that the system for detecting the travel distance (ΔH), by which the piston (12) is moved in the storage tank (5), is a measuring guide (2).

12. Device according to one of claims 6 to 11, characterized in that the line (7), which runs from the storage tank (5) to the hollow-section strip that is to be filled, is a flexible hose, and in that the free end (10) of the fill line (7) can be closed in the manner of a pinch valve.

13. Device according to claim 12, characterized in that a nozzle (9) to which compressed air can be applied is provided in order to close the line (7) in the manner of a pinch valve.

14. Device according to one of claims 6 to 11, characterized in that an underpressure line (25) is connected to the line (7), which underpressure line runs to a source for underpressure, in particular a jet pump.

15. Device according to claim 14, characterized in that a filter (26) is provided in the underpressure line (25).

16. Device according to one of claims 6 to 15, characterized in that two storage tanks (5) are provided that are connected in parallel and in that a line (7) for filling a spacer frame (11) extends from each storage tank (5).