CN105937883A - Device and method used for detecting sealing piece - Google Patents

Abstract

The invention relates to a device and a method for testing a closure (14), wherein the closure (14) closes a container (12), wherein an analysis unit (23) is provided for determining a quality criterion (40, 47), in particular the size of the gap between the closure (14) and the container (12), wherein at least one sensor (18) for ascertaining the height profile of the closure (14) is provided, Wherein, at least one output signal of the sensor (18) is sent to the analysis and processing unit (23), and the analysis and processing unit obtains the quality criterion (40, 47).

Description

Device and method for testing closures

technical field

The present invention relates to devices and methods for inspecting closures.

Background technique

The invention proceeds from a device and a method for checking closures of the type according to the independent claims. In pharmaceutical manufacturing it is common to place closures on containers such as bottles. In a further step, the closure and the container are connected by means of a cap. A gap may form between the closure and the container. The height of this gap is critical for pharmaceutical production, since the product can be contaminated in the worst case due to an excessively large gap. Accurate verification of said gaps is important since containers with small gaps can still be accepted to avoid unnecessary rejects.

A device of this type is already known from WO 2012/061441 A1. In this case, the closure area to be detected enters the path formed by the laser and the corresponding receiver. The laser beam passes through the closure region from the side with respect to the longitudinal axis of the container. However, it must be ensured at a precise triggering time that the measurement only starts when the object to be detected is located in the laser line. Fluctuations in the trigger signal can cause problems, so that this must be taken into account when setting the trigger time point and the measurement does not start until a little further inside the closure. As a result, the gap between container and closure cannot be reliably dimensioned at the outermost edge of the closure. The identification of an overturned closure in a container is also problematic.

Contents of the invention

The object of the invention is to sense the size of the gap between container and closure with high precision. This task is solved by the features of the independent claims.

In contrast, the device according to the invention for checking the region of a closure has the advantage that a tipping of the closure can be detected reliably. The tipping of the closure or the corresponding height profile then enters the calculation of quality criteria such as the size of the gap between container and closure. According to the invention, this can be achieved in that at least one sensor is provided for ascertaining the height profile, in particular the height profile of the closure. The device having the features of independent claim 1 makes it possible, in addition to the orientation of the closure, to determine the gap between the upper edge of the container and the lower edge of the closure at defined support points. The maximum encircling gap size can then be ascertained from this result.

Particularly advantageously, the output signal of the sensor is combined with the output signal of a sensor unit which preferably detects the closure region optically.

Because closures are usually made of soft material. That is to say, it cannot be assumed from this that the lower container plate has a flat surface. Just in case the closure is tipped over or bent, the lower closure plate may be deformed. In the prior art, along the optical axis, in the case of a camera system, along the light line, the plug slit is passed as a secant, unlike the prior art, in the event of a bending or tipping of the closure plate Down, the height of the gap is underestimated. Since the gap in the shadow image is reduced due to the orientation of the closure tipped over in the container, the responsibility lies in the two-dimensional projection of the three-dimensionally oriented closure. According to the invention, the orientation of the closure and the size of the gap (preferably between the upper edge of the container and the lower edge of the closure plate) can now be determined at defined support points. From this, it is possible to ascertain the largest circumferential gap size as a quality criterion. In this way a better accuracy can be achieved compared to the prior art.

The rotation of the container can also be canceled during the inspection. This turning can be mechanically complex. Furthermore, there is the risk that the closure is lost due to the rotation or that most of the liquid product comes into contact with the closure. Since such a rotation is no longer required in the device according to the features of claim 1 , such a device can also be easily integrated into existing installations.

Furthermore, the use of sensors for ascertaining the height profile can also be used for other inspection possibilities and for defining other quality criteria. For example, packaging material-specific markings on the surface of the closure can be checked. This ensures that the correct packaging material is used for the corresponding load. Furthermore, the surface of the closure plate can be checked for damage or deformation by means of the ascertained measurement data. In addition, product reliability, which is of great importance especially in the pharmaceutical industry, can thus be increased.

In one expedient refinement, it is provided that a triangulation-based system is used as sensor for ascertaining the height profile. Thus, the surface of the closure to be detected is guided step-by-step along the sensing region of the eg linear triangulation laser, so that the entire surface or height profile can be easily sensed.

In a particularly expedient development, the sensing of the height profile of the closure is combined with the determination of the gap size at a defined support point of the optical sensor unit. Through an intelligent combination of the measurement results, the size of the gap between the upper edge of the container and the lower edge of the closure plate can be determined at any point on the circumference of the closure. As a result, the maximum gap can be ascertained much more accurately than in previous systems, especially when the plug or closure is tilted or deformed. In addition, the false reject rate can thus be significantly reduced.

For this purpose, an algorithm is particularly preferably used in the evaluation software which performs a circumferential interpolation of the gap size from the three-dimensional height information on the basis of the gap size measured at a defined point or support point. In this case, the sensor unit and the sensor for ascertaining the height profile are coupled to each other, for example on a central image processing computer which can evaluate the information of both measurements in combination. The mechanical positioning of the two systems is also matched to each other, so that the positioning of the support points can be determined with respect to the three-dimensional height profile. The setup of the system can take place, for example, by means of setup models (Einstell dummies).

Further expedient refinements emerge from the other subclaims as well as from the description.

Description of drawings

An exemplary embodiment of a device according to the invention for testing closures is shown in the drawings and explained in more detail below. The accompanying drawings show:

Figure 1 shows a schematic diagram of the structure of the overall system in top view,

FIG. 2 shows a schematic diagram of a sensor for ascertaining a height profile in side view,

3 and 4 show a schematic view of a sensor unit for determining the size of the gap between the upper edge of the container and the lower edge of the closure plate at four support points in plan view and associated side view,

5 and 6 show schematic views of the closure area with support points in side view and associated top view,

Figure 7. Schematic representation of combined measurements.

detailed description

The containers 12 are conveyed to the conveying device 20 via the inlet 28 . The container 12 has already been filled with a product, for example a liquid medicine, at a preceding, not shown, workstation and closed by a closure 14 . The device shown in FIG. 1 is used for checking the area of the closure or for checking the size of the gap formed between the container 12 and the closure 14 . The conveying means 20 is designed, for example, as a conveying star. The transfer means 20 has on the outside a receptacle 22 in which the container 12 can be fixed. The transfer means 20 rotates clockwise. Thus, the container 12 first arrives in the sensing range of the sensor 18 for ascertaining the height profile. The sensor 18 for ascertaining the height profile is arranged above the transport path of the containers 12 . By way of example, the sensor is configured in the form of a line and at least partially covers the surface of the closure 14 which closes the container 12 . The sensor 18 for ascertaining the height profile is oriented with its longitudinal axis toward the center point of the conveying device 20 or perpendicularly to the conveying direction of the containers 12 . The sensor 18 for ascertaining the height profile senses the entire height profile of the surface of the closure 14 through the further transport of the container 12 by performing multiple or continuous scans. The output signal of sensor 18 for ascertaining the height profile is supplied to evaluation unit 23 . The evaluation unit 23 also receives the signals of the sensor unit 24 . The evaluation unit 23 thus ascertains a quality criterion. Preferably, the gap size 40, 47 between the closure 14 and the container 12 serves as a quality criterion. Information about the height profile of the closing element 14 is also conceivable as a quality criterion. Evaluation unit 23 ascertains quality criterion 40 , 47 at least from the output signal of sensor 18 or from the height profile.

The sensor unit 24 is likewise arranged in the transport path of the containers 12 . The closed containers 12 are each brought into the sensing region of a sensor unit 24 by means of a transport device 20 . The sensor unit 24 is oriented relative to the container 12 and the closure 14 located therein in such a way that the region of the closure is transmitted from the side with respect to the longitudinal axis of the container 12 . The containers 12 are then conveyed further by the conveying device 20 and via the discharge 30 into further processing stations not shown.

The sensor 18 for determining the height profile is shown in detail in a side view in FIG. 2 . The sensor 18 shown in FIG. 2 determines the height profile of the closure surface by means of a triangulation method. An effective triangulation method utilizes a light source, mostly a laser, which illuminates the object (here the closure 14) at an angle, the surface of which is to be measured. Electronic image converters, mostly CCD or CMOS cameras or PSDs, record diffuse light. The emitted and reflected laser beams are shown schematically with reference numerals 15 , 16 . The sensor 18 therefore comprises at least means for generating a directed optical beam, in particular the laser beam 15 , 16 , and an optical sensor for sensing the beam reflected from the surface of the closure 14 . The distance of the object from the camera can thus be determined with knowledge of the beam direction and knowledge of the distance between the camera and the light source. The line connecting the camera to the light source and the two beams 15 , 16 originating from and reaching the surface of the enclosure form a triangle (triangulation). If the method is carried out in grid or continuous motion, the surface topography or the height profile can be determined with high accuracy (up to 0.01 mm in the case of commercially available sensors).

The conveying device 20 moves the container 12 with the closure 14 applied into the sensing range of the sensor 18 and the emitted laser beam 15 , 16 . Correspondingly inclined surfaces of the closure part 14 reflect the laser beams 15 , 16 according to the inclination or curvature of the closure part 14 . As a result, the entire surface of the closure 14 is scanned and sensed in terms of height profile or orientation or inclination in the context of the further transport of the containers 12 along the transport direction 21 . It is thus clear when and in what form the closure 14 is inclined relative to the generally horizontally arranged container 12 . A corresponding inclination or curvature affects the gap size 40 between the container 12 and the closure 14 .

FIG. 3 shows a top view and FIG. 4 a side view of the sensor unit 24 for lateral transmission of the closure region. The sensor unit 24 consists, for example, of at least one emitter 34 and at least one receiver 32 , which receives emitted radiation, as indicated by arrows (for example in the optical region). In the exemplary embodiment, two emitters 34 are provided, which are each arranged offset by 90° relative to one another. A receiver 32 , which is designed, for example, as a video camera, is arranged on the respectively opposite side. The container 12 with the closure 14 put on is located in the center of the two radiation areas. In the side view it is clear that, based on the 2D projection of the emitted radiation in the camera or receiver 32, only a reduced gap size 36 is detected, which results from the close emission of the closure area. One side of device 34. On the side facing the receiver 32, however, the gap dimension 40 is significantly larger. As is clear from FIG. 5 , this maximum gap size 40 may not be detectable if only a single measurement is performed by the sensor unit 24 . The output signal of sensor unit 24 is therefore combined with the output signal of sensor 18 for ascertaining the height profile, as explained in more detail below.

In the exemplary embodiment according to FIGS. 3 and 4 , the gap size 40 between the upper edge 39 of the container 12 and the lower edge 38 of the closure plate can now be sensed at four support points 43 (see also FIG. 5 ). In particular, a non-contact, preferably optical system is used as sensor unit 24 . This can be, for example, a camera system or a laser-based system in which a laser band is projected into the closure area. However, other systems suitable for sensing the gap size 36 are also contemplated.

FIG. 5 shows a schematic illustration of the support point 43 on which the measurement of the gap size 40 or the measured quality criterion between the upper edge 39 of the container 12 and the lower edge 38 of the closure plate takes place. In FIG. 5 is shown in relation to the container 12 or the container flange Closure 14 in inclined position. The two arrows indicate at which point of the closure part 14 or at which support point the gap dimension 40 is determined. It is particularly advantageous on the outermost point, namely on the lower edge 38 of the closure 14 oriented towards the container 12 (see arrow and dotted line in FIG. 5 ) and on the upper edge 39 of the container 12 or container flange. Determination of gap size 40. This ensures that the support points 43 are ideally distributed equidistantly along the circumference even when the closure is tilted. This results in four support points 43 each offset by 90° in the case of the two transmitter-receiver systems as clearly shown in FIG. 3 . Each camera or each receiver 32 thus detects in each case two support points 43 with an associated gap size 40 which is determined at the outermost position to the left or right of the camera axis.

The four support points 43 are shown with corresponding symbols in FIG. 6 . The sensor unit 24 measures the associated gap size 40 (measured gap size) at the four support points 43 . The tipping 41 of the closure 14 relative to the container 12 is indicated by an arrow. The transmitter 34 is not shown in FIG. 6 . The edges 38 , 39 can be ascertained precisely by providing a sensor unit 24 comprising at least one camera. Corresponding image analysis algorithms are used for this purpose, which can accurately determine the outermost points (lower edge 38 , upper edge 39 ) on the basis of light-dark transitions from left to right or from top to bottom. It is for this support point 43 that the sensor unit 24 measures the gap size 40 . The gap dimension 40 is therefore formed by the distance between the support point 43 on the lower edge 38 and the associated (for example vertically below the support point on the lower edge) support point 43 on the upper edge 39 . This already results in a higher accuracy when detecting the reduced gap 36 with only one projection, as in FIG. 4 .

The four support points 43 from FIG. 6 are now also shown in FIG. 7 . In the four support points 43 , as already described, the associated gap dimensions 40 are measured by means of the sensor unit 24 or determined by image processing. FIG. 7 shows the height information of sensor 18 for ascertaining the height profile. The associated height profile has already been ascertained for each point of the surface of the closure part 14 . The height profile is visible in FIG. 7 by the height-dependent color scale. The relatively brighter sections have a high height, ie, are more spaced apart from the upper edge of the container 12 , while the darker areas are located closer to the upper edge of the container 12 .

The outer edge 49 of the closure element 14 is ascertained in the following steps. This takes place, for example, if the general geometry of the closure part 14 is known, by placing this general geometry, for example a circle or an ellipse, in the support point 43 . This shape geometrically defines the outer edge 49 of the closure 14 . Alternatively, it is possible to ascertain the course of the entire outer edge 49 of the closure part 14 via the height profile of the surface of the closure part 14 . In this case, it is assumed that the outer edge 49 is present at the point at which a very large change in the height profile occurs.

The course of the outer edge 49 of the closure element 14 is now used to evaluate the quality criterion to be ascertained by the evaluation unit 23 (for example the gap size 40 at the corresponding location of the outer edge 49 ) on the basis of the height profile at the associated location of the outer edge 49 . Interpolation. The gap size 40 measured at the corresponding support point 43 in the outer edge 49 is associated with the associated height profile. The quality criterion to be ascertained or the gap size 40 also increases as the outer edge 49 moves away from the support point 43 in a rising height profile (the distance to the upper edge 39 of the container 12 increases). The increase in slot size 40 is proportional to the increase in height profile. The reduction in the height profile is associated with a reduction in the gap size 40 . Accordingly, starting from each support point 43 with the measured gap size 40 , the associated gap size 40 is calculated for the entire outer edge 49 .

The maximum gap size 47 is then ascertained from the previously determined maximum value of the gap size 40 . This maximum gap size 47 is compared with a limit value to determine whether the closed container 12 is still within the permissible range. Alternatively, it is possible to determine the maximum gap size 47 for the locations on the outer edge 49 at which the height profile also has a maximum value. This may simplify calculations.

In addition to determining the maximum gap size 47 , the sensor 18 for determining the height profile can also be used for checking the surface of the closure 14 . To this end, the sensed height profile is compared with an expected target height profile. In the case of a uniform height profile, it follows that the desired closure 14 is also actually used. The height profile is used as a further or alternative quality criterion. This facilitates quality control, which is of particular interest in the pharmaceutical industry.

The device described can advantageously be a component, in particular, of a pharmaceutical filling system in which a so-called fit control or closure fit control is required. However, the application is not set here.

Claims (12)

1. A device for checking a closure (14), wherein said closure (14) closes a container (12), wherein an analysis unit (23) is provided for determining quality criteria (40, 47) , especially the size of the gap between the closure (14) and the container (12), is characterized in that at least one sensor (18) for determining the height profile of the closure (14) is provided, wherein the At least one output signal of a sensor (18) is supplied to the evaluation unit (23), which determines the quality criterion (40, 47) from the output signal of the sensor (18) . 2. The device according to claim 1, characterized in that at least one sensor unit (24) is provided for at least one support point (43), preferably at the outer edge ( 49) on at least one support point, the quality criterion (40) is measured. 3. The device as claimed in one of the preceding claims, characterized in that at least one output signal of the sensor unit (24) is fed to the evaluation unit (23), which evaluates according to the sensor The output signal of the unit (24) ascertains the quality criterion (40), in particular at the outer edge (49) of the closure (14), preferably remote from the support point (43 ) quality criterion. 4. The device according to one of the preceding claims, characterized in that a quality criterion (40) is determined for at least one location on the outer edge (49) of the closure (14), when using the sensor The output signal of (18) or in the case of a height profile at the at least one location. 5. The device according to one of the preceding claims, characterized in that the outer edge (49) of the closure (14) is determined in such a way that the general surface of the closure (14) A contour, in particular a circle or an ellipse, is placed in at least one support point (43). 6. The device according to one of the preceding claims, characterized in that the analyzing The processing unit (23) ascertains the quality criterion (40, 47) by interpolation from the corresponding height profile at the at least one location and/or from the quality criterion measured in the at least one support location (43). According to (40), the quality criterion (47) for this part is obtained. 7. The device as claimed in claim 1, characterized in that at least one extreme value is determined from a plurality of quality criteria (40) for comparison with the limit value. 8. The device as claimed in claim 1, characterized in that the sensor (18) for ascertaining the height profile is based on laser triangulation. 9. A method for checking a closure (14), wherein the closure (14) closes a container (12), wherein the analysis unit (23) determines a quality criterion, in particular a closure (14) and a container Gap size (40,47) between (12), is characterized in that, comprises the following steps: - at least one sensor (18) determines the height profile of said closure (14), - the evaluation unit (23) ascertains the quality criterion (40, 47) from the output signal of the sensor (18). 10. The method according to the preceding method claim, comprising the further steps of: - determining the outer edge (49) of said closure (14) and/or - determine the height profile on the outer edge (49) of said closure (14), - determining said quality criterion (40, 47) on said outer edge (49) from said height profile. 11. The method according to one of the preceding method claims, comprising the further step of: - at least one sensor unit (24) measures at least one quality criterion (40) on at least one support point (43), - the evaluation unit (23) determines a quality criterion on the outer edge (49) of the closure (14) from the quality criterion (40) measured on the support point (43) According to (47). 12. The method according to one of the preceding method claims, characterized in that, for at least one location on the closure (14), especially on the outer edge (49) of the closure (14), according to The corresponding height profile at the at least one location is determined by interpolation and/or from the quality criterion (40) measured in the at least one support location (43) for the quality criterion (47) for the at least one location ).