Apparatus and method for inspecting containers by x-ray radiation

Abstract

Apparatus (1) for inspecting containers (10), with a transport device (2) which transports the containers (10) along a predefined transport direction, with at least a first radiation device (3) which emits high-energy radiation and in particular X-ray radiation onto the containers (10) that are to be inspected, and with a first sensor device (4) which is suitable and intended for receiving the radiation emitted onto the containers by the radiation device, wherein the transport device forms a support surface (20) which is movable in the transport direction and which supports the containers (10) at their container bases, characterized in that the support surface has a large number of carrier elements (22) made of a plastic material and moreover has at least one guide device (24) for guiding these carrier elements (22), wherein this guide device has a metal.

Description

[0001] Device and method for inspecting containers with X-rays

[0002] Description

[0003] The present invention relates to a device and a method for inspecting containers, and in particular filled containers. A large number of devices and methods for inspecting containers are known from the prior art. Devices and methods are also known in which, in particular, the base regions or the bases of such containers, and in particular also filled containers, are inspected. For this purpose, it is known to carry out such inspections using X-rays. The biggest problem with this full bottle inspection using X-rays is the transport through the X-ray unit. It is known that containers are transported with two lateral belts and are therefore bottom-free. It is also known for the containers to be transported on a conveyor chain or conveyor belt.

[0004] For the measurement to work at the container bottom, the conveyor chain should be very homogeneous and preferably free of metal. For example, a special chain with solid plastic elements is known from the state of the art. The problem with these chains is that they are prone to wear; for example, the chain stretches or wears out quite quickly and therefore needs to be replaced frequently.

[0005] In addition, despite the special design, residual structures are still visible in the camera image because the plastic used absorbs a significant portion of the X-rays, creating a "ghost image" of the chain. Using a less absorbing plastic is not feasible in the current technology because it is too soft for the chain's function and stretches even faster, requiring replacement. This also leads to a short service life.

[0006] EP 2435344 B1 discloses an X-ray inspection system with a conveyor chain.

[0007] The present invention is therefore based on the object of providing a device and a method for inspecting containers that, on the one hand, exhibit minimal wear and, on the other hand, allow proper inspection using X-rays. This is achieved according to the invention by the subject matter of the independent patent claims. Advantageous embodiments and further developments are the subject matter of the dependent claims.

[0008] A device according to the invention for inspecting containers comprises a transport device that transports the containers along a predetermined transport direction. In addition, the device comprises at least one first radiation device that emits high-energy radiation, in particular X-rays, onto the containers to be inspected, as well as a first sensor device that is suitable and intended for receiving the radiation emitted by the radiation device onto the containers. The transport device comprises a support surface (and / or support device) that is movable in the transport direction and that drops the containers at their container bottoms and transports them in this manner.

[0009] According to the invention, the support surface comprises a plurality of support elements made of a plastic material and furthermore at least one guide device for guiding these support elements, wherein this guide device comprises a metal. The guide device can be made of a metal or comprise a metal, for example, a metal-reinforced plastic. The metal is preferably selected from a group of metals including iron, steel, and aluminum, but other metals are also possible.

[0010] The idea of ​​the invention is therefore to create a support element for the containers that is constructed in two parts. The areas that directly support the container are preferably made of a non-absorbent plastic, while the elements subject to high loads, such as the aforementioned guide elements, are made of a harder material, although this material also absorbs X-rays.

[0011] Preferably, the support surface is flexible, which is achieved in particular by the mobility of the individual support elements relative to one another. This flexibility preferably exists in a plane formed by the transport direction and a longitudinal direction of the transported containers.

[0012] Preferably, the transport device transports the containers in an upright position, with the bottoms of the containers standing in particular on the support surface.

[0013] This ensures, on the one hand, that the X-ray radiation is not absorbed in the area relevant for the inspection and thus the inspection is not impaired, but, on the other hand, that those elements of the transport device which are subject to high mechanical stress are made of a more stable material.

[0014] A plastic with very low X-ray absorption is therefore used as the material for the support elements for the containers. These support elements or plates are preferably guided by a guide device, such as a wide transport station, which, as described in more detail below, can have toothed belts, particularly steel and / or CFRP-reinforced toothed belts, as guide elements.

[0015] Preferably, the support elements are each fastened to the guide device (which can also be referred to as the support device).

[0016] The device particularly preferably comprises a shielding device for shielding against X-rays. This shielding device particularly preferably completely surrounds the device in the transport direction of the containers, in particular in the inspection area. This shielding device can have walls that prevent the passage of X-rays. In addition, this shielding device can also have a labyrinth-like structure that prevents the X-rays from escaping from the shielding device after being reflected once or preferably twice. The said support elements do not absorb the X-rays or absorb them only to a small extent. Although the guide device absorbs X-rays, it is preferably arranged outside the measuring field for the plastic containers and therefore does not influence the inspection.

[0017] Preferably, the support elements are arranged on the upper side of the support surface carrying the container bottoms and the guide devices are arranged on the underside of the support elements opposite this upper side.

[0018] Particularly preferably, the transport direction is rectilinear. The radiation, and in particular X-ray radiation, is preferably directed at least also onto the container bases and, in particular, passes through them. The receiver device or sensor device detects radiation that has passed through the containers.

[0019] In a preferred embodiment, the sensor device is suitable and intended for spatially resolved recording of the X-ray radiation. Particularly preferably, the sensor device is suitable for recording and / or outputting a spatially resolved image of the X-ray radiation impinging upon it.

[0020] Particularly preferably, the guidance device or components of the guidance device are not located in the beam path of the outgoing and received X-ray radiation.

[0021] In a further advantageous embodiment, the support elements have a parallelogram-shaped cross-section with respect to a plane extending perpendicular to the transport surface and in the transport direction. This preferably ensures that adjacent sides of adjacent support elements are inclined at an oblique angle with respect to the transport direction, and preferably the support elements overlap each other in the transport direction.

[0022] In a further preferred embodiment, the guide devices are arranged outside the transport area of ​​the transport device. This means that the containers to be transported are not arranged above the guide devices. In a further preferred embodiment, the transport device is operable such that containers to be inspected are transported through a curtain of electromagnetic radiation, wherein the curtain of electromagnetic radiation extends in a plane that intersects the plane of the support surface along a line that runs perpendicular to the transport direction.

[0023] Particularly preferably, the transport device has a transport length (in particular in the transport direction) which is greater than 1 m, preferably greater than 2 m, preferably greater than 3 m and preferably greater than 3.5 m. In a further advantageous embodiment, the transport device has a transport length in the transport direction which is less than 10 m, preferably less than 8 m, preferably less than 6 m and preferably less than 5 m.

[0024] In a further preferred embodiment, the support elements are designed in the form of webs or strips and preferably have a rectangular or parallelogram-like cross-section.

[0025] In a further preferred embodiment, the support elements have a first end section and a second end section, and the guide devices are arranged and, in particular, fastened to these end sections. This allows, on the one hand, high stability to be achieved, and, on the other hand, prevents the guide devices from being located within a measuring range of the device.

[0026] In a further advantageous embodiment, the support elements are made of a plastic that does not absorb X-rays or only absorbs them to a minimal extent. Particularly preferably, the plastic material is selected from a group of plastic materials that includes PEEK, Teflon, and PET. In a further preferred embodiment, the support elements are made of a synthetic material that is permeable to high-energy radiation, in particular acetate resin or polypropylene.

[0027] Particularly preferably, two-sided guide and / or holding devices are provided for the support elements. It is possible for the support elements to be fixed to these guide devices. Particularly preferably, the (in particular lateral) guide devices are arranged at a distance from one another of at least 10 cm, preferably at least 20 cm, and preferably at least 25 cm. These guide devices are preferably spaced apart by less than 60 cm, preferably less than 50 cm, and preferably less than 40 cm. These distances have proven particularly advantageous, on the one hand, to ensure sufficient stability and, on the other hand, to keep the guide devices out of the measuring field of the device.

[0028] In a preferred embodiment, the at least one radiation device is arranged laterally of the transport station and / or transport device.

[0029] In a further advantageous embodiment, the transport device is a circulating transport device, in particular a circulating conveyor belt or a conveyor chain. Thus, the individual chain links are preferably composed of the guide devices and the support elements arranged thereon. The guides of this chain are thus arranged laterally or partially laterally with respect to the support elements, as mentioned above.

[0030] Preferably, the distance between the upper side of the conveyor belt running in the transport direction (which also forms the support surface at this moment) and the underside of the conveyor belt running opposite to the transport direction is greater than 10 cm, preferably greater than 20 cm, preferably greater than 30 cm. This distance between the upper side of the conveyor belt running in the transport direction and the underside running opposite to the transport direction is particularly preferably less than 100 cm, preferably less than 90 cm, preferably less than 80 cm, and preferably less than 70 cm.

[0031] In a further advantageous embodiment, at least one radiation device is arranged between the top and the bottom of the transport devices.

[0032] In a further advantageous embodiment, the guide device is a belt, in particular a toothed belt, or comprises a belt, in particular a toothed belt. In particular, this is a steel-reinforced toothed belt. As mentioned above, two guide devices, in particular two lateral toothed belts, are particularly preferably provided. The support elements can be attached to these.

[0033] In a further advantageous embodiment, the support elements have a thickness greater than 2 mm and preferably greater than 3 mm. In a further advantageous embodiment, the support elements have a thickness less than 10 mm, preferably less than 8 mm, and particularly preferably less than 6 mm. This thickness is particularly preferably substantially constant across the width of the support elements.

[0034] In a further advantageous embodiment, the support elements have a length running perpendicular to the transport direction that is greater than 10 cm, preferably greater than 20 cm, preferably greater than 25 cm. In a further preferred embodiment, the support elements have a length running perpendicular to the transport direction that is less than 100 cm, preferably 90 cm, preferably 80 cm, preferably 70 cm, preferably 60 cm, preferably 50 cm, preferably 40 cm, and particularly preferably less than 30 cm.

[0035] As mentioned above, these lengths are well chosen because, on the one hand, they still have sufficient stability and, on the other hand, they are wide enough to avoid disruptive influences.

[0036] Particularly preferably, the carrier elements have a distance from one another at the position at which the containers are located on them which is less than 10 mm, preferably less than 8 mm, preferably less than 6 mm, preferably less than 4 mm and preferably less than 3 mm.

[0037] In a further advantageous embodiment, the carrier elements have a width in the transport direction that is greater than 5 cm, preferably greater than 10 cm, and preferably greater than 15 cm. Particularly preferably, the carrier elements have a width in the transport direction that is less than 50 cm, preferably less than 40 cm, preferably less than 30 cm, and preferably less than 25 cm. These dimensions have also proven particularly advantageous for ensuring trouble-free operation of the device.

[0038] In a preferred embodiment, the device comprises at least one second (X-ray) radiation device and / or at least one second receiving device. Particularly preferably, at least one second (X-ray) radiation device and a second receiving and / or sensor device are provided. These can inspect the container to be inspected, preferably from different angles.

[0039] Particularly preferably, at least one X-ray device is arranged above the bottom of the containers, and particularly preferably, at least one X-ray device is arranged below the bottom of the containers. Particularly preferably, at least one sensor device is arranged above the bottom of the containers and / or at least one sensor device is arranged below the bottom of the containers. In this way, a comprehensive image of the bottom of the container can be recorded using the transmitted-light method.

[0040] Particularly preferably, at least one X-ray device and a sensor device, which records the radiation radiated by this X-ray device onto the containers, are arranged such that a beam path of the X-ray radiation runs obliquely with respect to a longitudinal direction of the containers to be inspected. Particularly preferably, this beam path also runs obliquely with respect to the transport direction of the containers. Particularly preferably, an angle between the longitudinal direction of the containers and the main beam direction of the X-ray device is more than 10°, preferably more than 15°, preferably more than 20°, preferably more than 25°, preferably more than 30°, and preferably more than 35°. Particularly preferably, this angle is less than 80°, preferably less than 70°, preferably less than 65°, preferably less than 60°, and particularly preferably less than 55°.

[0041] In a further preferred embodiment, at least one X-ray device and the sensor device, which records the radiation radiated by the X-ray device onto the containers, are arranged such that a beam path of the X-ray radiation runs obliquely with respect to a longitudinal direction of the containers to be inspected. In a preferred embodiment, the radiation device or devices are arranged laterally with respect to the transport device and can thus take the images through this plastic-air (and in particular PEEK-air) region. Preferred recording angles are, for example, 45° angles obliquely from above. The only dead zone here is the narrow belt, which is arranged far outside the container base.

[0042] In a preferred embodiment, the guide devices and / or sliding profiles within the measuring window are also made of plastic, in particular PEEK. Standard elements (e.g., made of steel and / or reinforced plastic) are again provided before and after this measuring window. In a further advantageous embodiment, the device has a discharge device that discharges the inspected containers from the transport device. A transfer device is preferably provided that transfers the containers from the transport device to the discharge device.

[0043] This transfer device is particularly preferably designed such that it transports the containers at an angle to the transport direction. A transport angle relative to the transport direction of more than 5°, preferably more than 10°, preferably more than 15°, and preferably more than 20° is particularly preferably provided. This angle is preferably less than 60°, preferably less than 50°, and preferably less than 40°.

[0044] Particularly preferably, the transfer device is a railing or has a railing, which particularly preferably transfers laterally downwards onto the discharge device, in particular a further transport device, such as a normal hinged belt chain.

[0045] Particularly preferably, a position detection device and / or a path tracking device is provided downstream of the radiation devices in the transport direction. This position detection device particularly preferably comprises at least one light barrier and preferably a light barrier array, in particular for FIFO (first in / first out) tracking. Particularly preferably, the device comprises at least one further position detection device and preferably several further position detection devices. These can be, for example, light barriers, as mentioned.

[0046] In a further advantageous embodiment, the device has a feed device which conveys the containers to the transport device, wherein this feed device preferably has a transport wheel conveying the containers or a transport screw conveying the containers.

[0047] It is also possible for the insertion, as mentioned above, to occur as a transfer from a normal conveyor belt. In this described embodiment, however, the containers are placed directly onto the conveyor by a sorting system, such as a transport wheel, and positioned centrally. This sorting system can, for example, be a slanted sorting screw, or an outlet star of a preceding rotary device, such as a filling device or a labeling machine, or even a belt station on one or both sides.

[0048] The present invention is further directed to a system for processing liquid containers. This system preferably comprises a filling device, and in particular also a labeling or printing device for printing the containers. Downstream of this device, a device according to the invention, as described above, for inspecting the containers is arranged. In a further advantageous embodiment, the present invention is used in a system for filling cans.

[0049] The present invention is further directed to methods for inspecting containers, wherein the containers are transported along a predetermined transport direction by a transport device and at least one first X-ray radiation device emits X-ray radiation onto the containers to be inspected and a first sensor device detects radiation emitted by the X-ray radiation device onto the containers or radiation resulting therefrom (or radiation radiated onto the containers by the radiation device and transmitted by the containers), wherein the transport device forms a support surface which is movable in the transport device and supports the containers on their container bottoms and thus transports them.

[0050] According to the invention, the support surface comprises a plurality of support elements made of a plastic material (and in particular a plastic material that does not absorb X-rays or absorbs X-rays only slightly) and furthermore at least one guide device for guiding these support elements, wherein this guide device is reinforced and / or comprises a metal and / or an X-ray absorbing material.

[0051] The containers are preferably filled and, in particular, labeled and / or printed containers. In particular, the containers are containers sealed with container closures or filled, sealed beverage cans.

[0052] Preferably, the containers are transported by the transport device such that they are spaced apart from one another in the transport direction. This distance between the containers is preferably greater than 2 mm, preferably greater than 3 cm, preferably greater than 4 cm, and preferably greater than 5 cm. This distance is preferably less than 30 cm, preferably less than 20 cm, and preferably less than 15 cm.

[0053] In a further preferred method, the containers are transported in a straight line during their inspection and / or after their inspection at least also perpendicular to the transport direction.

[0054] In another preferred method, the containers are fed to the transport device via a conveyor belt or a rotary conveyor, a dividing screw, or a belt station on one or both sides. Particularly preferably, the containers are removed after inspection via another conveyor belt.

[0055] In a further preferred method, the sensor device records a spatially resolved image of the transported containers.

[0056] Particularly preferably, the bottoms of the containers are inspected. Particularly preferably, the sensor device detects radiation emitted by the X-ray device and transmitted by the containers.

[0057] Particularly preferably, the X-rays pass through the carrier elements between the radiation device and the sensor device.

[0058] Within the scope of the invention, it is preferably proposed to use a plastic, in particular Lexan or PET, as the carrier element.

[0059] Within the scope of the invention, it is therefore particularly preferred to use a plastic, in particular PEEK, as the support element. PEEK is virtually invisible in a camera image and has almost the same absorption as air at the X-ray-specific wavelength. This also makes it possible for the support elements to be designed without an extremely narrow gap and without an air gap.

[0060] A further advantage arises from the above-described, particularly lateral, loading and / or unloading of the containers, particularly in the inlet and / or outlet areas. This simultaneously provides X-ray protection in the transport direction of the device.

[0061] If, as described above, an outlet starwheel of a rotary conveyor is used in the inlet area, it is possible to design the entire inspection device very compactly and, in particular, to mount it on or integrate it into a guide machine. The service life of the transport device is also preferably significantly longer than that of a conventional conveyor chain.

[0062] Further advantages and embodiments can be seen from the attached drawings:

[0063] Fig. 1 A schematic representation of a device according to the invention;

[0064] Fig. 2 is a side view of the device shown in Fig. 1;

[0065] Fig. 3 a detailed view of the X-ray inspection; and

[0066] Fig. 4 shows another detailed view of the X-ray inspection.

[0067] Figure 1 shows a schematic representation of an apparatus 1 according to the invention for inspecting containers 10. Reference numeral 2 denotes a transport device, such as a conveyor belt or a conveyor chain, which transports the containers 10 in the transport direction P. Reference numeral 14 denotes a shield which serves to shield against X-ray radiation. Reference numeral 5 schematically denotes the actual X-ray inspection device, which is described in more detail below. After inspection, the containers 10 are conveyed by a transfer device 16 to another transport device or a discharge device 8, which can again be a conveyor belt. It can be seen that the transfer device 16 transports the containers not only in the transport direction P, but also perpendicular thereto.Reference numeral 30 denotes a feed device, such as a transport star, which deposits the containers 10 essentially centrally on the transport device 2. Reference numeral 20 denotes the support surface that supports the containers during their transport.

[0068] Figure 2 shows a partial side view of the device shown in Figure 1. Deflection rollers 26, 28 are provided, which guide the transport means (i.e., in particular, the support surface and the guide devices) in a circumferential direction. Here, too, the support surface 20 is shown, but only on the top side. This support surface 20 is composed of a plurality of support elements (described in more detail below).

[0069] Figure 3 shows a further view of the actual inspection unit 5. Reference numeral 3 refers to a first X-ray device, and reference numeral 12 to a second X-ray device. These X-ray devices each illuminate the support surface and, in particular, the individual carrier elements 22. Reference numerals 4 and 14 denote sensor devices that detect the radiation directed by the radiation device onto the containers, particularly with spatial resolution. These sensor devices can comprise cameras that are sensitive to X-ray radiation.

[0070] It can be seen that the support element 22 has two lateral guide devices 24. Reference numerals 22A and 22B indicate the end sections of the support elements, which are carried by the guide device 24. The guide devices 24 are made of a material that also absorbs X-rays. However, as shown in Figure 3, the areas of the container base and the support element 22 detected by the sensor devices are outside the areas in which the guide devices 24 are located.

[0071] Figure 4 shows a further illustration of an inspection unit in a further embodiment. In this configuration, only one X-ray device 3 is provided, which, however, preferably radiates in multiple directions. This X-ray device 3 is preferably arranged below the containers.

[0072] Furthermore, two sensor devices 4 and 14 are provided here, which are preferably both arranged above the transport device and / or above the bottoms of the containers. The transport device is designed in the same way as in the embodiment shown in Fig. 3.

[0073] The applicant reserves the right to claim all features disclosed in the application documents as essential to the invention, provided they are novel, individually or in combination, over the prior art. It is further noted that the individual figures also describe features that may be advantageous in and of themselves. The skilled person will immediately recognize that a particular feature described in a figure may be advantageous even without the adoption of further features from that figure. Furthermore, the skilled person will recognize that advantages may also arise from a combination of several features shown in individual or different figures.

Claims

Device and method for inspecting containers with X-rays Claims. Device (1) for inspecting containers (10) comprising a transport device (2) which transports the containers (10) along a predetermined transport direction, comprising at least one first radiation device (3) which emits high-energy radiation, and in particular X-rays, onto the containers (10) to be inspected, and comprising a first sensor device (4) which is suitable and intended for receiving the radiation emitted by the radiation device onto the containers, wherein the transport device forms a support surface (20) movable in the transport direction which supports the containers (10) at their container bottoms, characterized in that the support surface comprises a plurality of support elements (22) made of a plastic material and further comprising at least one guide device (24) for guiding these support elements (22), wherein this guide device comprises a metal.Device (1) according to claim 1, characterized in that the support elements are designed as webs or strips and preferably have a rectangular or parallelogram-shaped cross-section. Device (1) according to at least one of the preceding claims, characterized in that the support elements have a first end section (22a) and a second end section (22b), and the guide elements (24) are arranged on these end sections (22a, 22b). Device (1) according to at least one of the preceding claims, characterized in that the support elements are made of a plastic material which does not absorb X-rays or absorbs them only to a small extent, wherein the plastic material preferably selected from a group of plastic materials which includes PEEK, Teflon and PET. Device (1) according to at least one of the preceding claims, characterized in that the transport device is a circulating transport device and in particular a conveyor belt or a transport chain. Device (1) according to at least one of the preceding claims, characterized in that the guide device is a belt and in particular a toothed belt. Device (1) according to at least one of the preceding claims, characterized in that the support elements have a thickness greater than 2 mm and preferably greater than 3 mm and / or the support elements have a thickness less than 10 mm, preferably less than 8 mm and particularly preferably less than 6 mm.Device (1) according to at least one of the preceding claims, characterized in that the device comprises at least one second radiation device (12) and / or at least one second sensor device (14). Device (1) according to at least one of the preceding claims, characterized in that at least one X-ray beam device and the sensor device, which receives the radiation emitted by the X-ray beam device onto the containers, are arranged such that a beam path of the X-ray radiation runs obliquely with respect to a longitudinal direction of the containers to be inspected. Device (1) according to at least one of the preceding claims, characterized in that the device (1) comprises a discharge device (8) which discharges the inspected containers from the transport device, preferably a transfer device. Device (16) is provided which transfers the containers (10) from the transport device to the discharge device (8). Device (1) according to the preceding claim, characterized in that this transfer device (16) is designed such that it transports the containers obliquely to the transport direction. Device (1) according to at least one of the preceding claims, characterized in that the device has a feed device (18) which conveys the containers to the transport device (2), wherein this feed device preferably comprises a transport wheel (18a) conveying the containers, or a transport wheel or a transport screw conveying the containers.Method for inspecting containers (10), wherein the containers are transported by a transport device (2) along a predetermined transport direction, and at least a first radiation device (2) emits high-energy radiation, and in particular X-rays, onto the containers (10) to be inspected, and a first sensor device (4) detects radiation emitted by the radiation device onto the containers, wherein the transport device forms a support surface (20) movable in the transport direction, which supports the containers (10) at their container bottoms, characterized in that the support surface has a plurality of support elements (22) made of a plastic material and furthermore at least one guide device (24) for guiding these support elements (22), wherein this guide device has a metal.Method according to claim 13, characterized in that the containers are filled and preferably also labelled and / or printed containers. Method according to claim 13 or 14, characterized in that the containers are transported in a straight line during their inspection and / or are transported at least also perpendicular to the direction of transport after their inspection.

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