EP3746028B1 - Device for dosing a product - Google Patents

Description

State of the art

The present invention relates to a device for dosing a product according to the preamble of the independent claim.

From the DE 10001068 C1 A device for dosing and dispensing powder into hard gelatin capsules or the like is already known. This device includes a gradually rotated metering disk, in the base of which bores are formed which interact with up and down movable stuffing rams. The stuffing punches are arranged on a common stuffing punch carrier and press the powder into compacts when immersed in holes. In order to be able to detect breakages of springs and to make a statement about the mass of the compacts, means are provided which record the spring travel of the stuffing punches immediately upstream of the ejection punches.

WO 00/32474 A1 discloses a device with features of claim 1.

It is the object of the present invention to further improve the prior art, in particular to achieve faster and simpler adjustment of the device with high metering accuracy. This task is solved by the features of the independent claims.

Advantages of the invention

The device according to the invention with the features of the independent claim has the advantage that essential process parameters can be specifically and automatically changed, which have a significant effect on the accuracy of the desired weight to be dosed. This is achieved by both pressure means for generating a different pressure for a stuffing punch, with which the Tamping ram springs into the dosing opening, as well as adjusting means for adjusting the height at which the tamping rams dip into the dosing openings are provided. It turned out that the two process parameters pressure and height in this combination have a significant impact on the accuracy of the filled weight. Due to the targeted variability, the device according to the invention is now able to automatically set different process parameter combinations and determine the effects on the dosed weight in order to increase the accuracy of the dosing. The capsule weight can be specifically adjusted (for example the average weight) as well as the filling accuracy/deviations (for example in the form of the standard deviation), which depend on the process parameters.

Furthermore, at least one sensor is provided for detecting at least one product bed height of the product arranged on the metering disk and/or at least one product feed is provided for feeding the product to the metering disk in order to achieve a specific product bed height. The process parameter of the product bed height also has a significant effect on the quality of the weight, so that the provision of the sensor and/or the product feed further improves or accelerates the dosing quality of the device as well as automatic adjustment. This parameter can also be used to optimize the setting of the process parameters.

In an expedient further development, a control device specifies different process parameters, in particular different heights and/or different pressures and/or different product bed heights and/or different speeds of a drive of the metering disk. It is particularly useful for the control device to record the respective weight of the product dosed into the capsule for different settings of the process parameters. This allows the effects of the relevant process parameters on the desired weight to be determined in the form of a variety of measured values. It is particularly useful to provide an appropriate weighing device so that the data collection process can take place automatically.

In an expedient development, the control device is designed to create a model, depending on the different settings of the process parameters and the respective weight of the product dosed into the capsule, in which the connection between at least one process parameter and the weight and/or the standard deviation of the weight. This model is later used to achieve an optimal setting of the essential process parameters depending on a target weight specified by the user (or other specifications such as the permissible deviation of the weight, operating speed of the device, etc.). This setting process can now be automated, so that the user can do without tedious manual settings and time-consuming attempts.

In an expedient development, at least one sensor is provided for detecting at least one process parameter. This ensures precise recording of the essential process parameters, so that the accuracy in terms of generating the model and ultimately in terms of the quality of the dosing can be further improved.

In an expedient development, at least one pressure control element and/or at least one pressure chamber and/or at least one piston is provided as the pressure medium. Especially with this configuration, the variability of the device can be further increased using a pneumatic spring, since the pressure can be adjusted individually particularly easily.

In an expedient development it is provided that the control device at least controls the product feed in order to achieve a constant product bed height. This allows uniform filling of the dosing chambers to be achieved, which has a positive effect on the accuracy of the product to be dosed.

In an expedient development, at least one force sensor arranged on the transfer stamp is provided. By specifically monitoring the force required during the transfer, critical operating situations during dosing, such as those caused by deposits, adhesions, product residues or the like, can be identified in good time in order to initiate countermeasures at an early stage.

Further useful developments result from further dependent claims and from the description.

drawing

Exemplary embodiments of the device according to the invention are shown in the drawing and are described in more detail below.

• Figur 1 eine Stationsübersicht einer Vorrichtung zum Dosieren einer Kapsel,
• die Figur 2 eine Seitenansicht der Dosierscheibe mit zugehörigen Stopfstempeln bzw. Übergabestempel sowie Verstellantrieben zur Beeinflussung der Höhe,
• die Figur 3 eine Seitenansicht der Dosierscheibe insbesondere mit Fokus auf die Druckmittel zur Veränderung der Drücke, mit denen die Stopfstempel in die Dosieröffnungen eintauchen.

Show it:

• Figure 1 a station overview of a device for dosing a capsule,
• the Figure 2 a side view of the metering disk with associated tamping stamps or transfer stamps as well as adjustment drives to influence the height,
• the Figure 3 a side view of the metering disk, in particular with a focus on the pressure medium for changing the pressures with which the stuffing rams are immersed in the metering openings.

The exemplary embodiment according to Figure 1 shows an overview of various stations of a device 10 for filling and closing capsules 12, preferably hard capsules, in particular hard gelatin capsules. A capsule holder 11 includes various receptacles for capsules 12 in order to feed them to different work stations 21-32. The capsules 12, consisting of an upper capsule part 13 and a lower capsule part 15, are fed to the respective capsule holder 11 in at least one sorting station 21, 22, preferably two sorting stations. In a station 23 for scanning the upper part of the capsule, it is checked whether the capsules 12 supplied to the capsule holder 11 are present in full. This station 23 can also only be provided as an option. The capsules 12 tested in this way reach an optional filling station 24 by rotating a segment wheel 18 moving the capsule holders 11. In an adjoining filling station 25, the capsules 12 are supplied with filling material. These are usually powdered medications that are placed in the capsules 12. However, pellets or the like can also be filled into the capsules 12 as filling material or Zen product to be dosed. In conjunction, for example, with a metering disk 36 for filling powder or pellets, the capsule bases 15 are filled with the desired quantity of filling material. Different filling principles can be used here. This is optionally followed by another filling station 26. This is followed by an error capsule station 27. In this station 27, capsules 12 that are not separated, are incorrectly inserted or have a so-called double hat are ejected. This means that faulty capsules 12 are removed. This is optionally followed by a further filling station 28, for example for pellets or tablets. This is followed by a closing station 29, in which the filled capsule lower parts 15 are closed with the associated capsule upper parts 13. The next station is a capsule ejection 30. There they are filled and closed capsules 12 are ejected from the capsule holder 11 and fed to further processing steps. Defective capsules 16 can be removed as part of this ejection station. The next station also serves a capsule ejection 31 in order to increase the output quantity. The capsules 12 can be ejected individually in the ejection stations 30, 31 or remain in the capsule holder 11. A cleaning station 32 is used to clean the capsules 12 in the capsule holder 11, which are now empty or are still recognized as bad. The segment wheel 18 has now completed a complete rotation, so that the capsule holder 11 is again available for the sorting station 21 or 22.

The filling station 25 includes, for example, a metering disk 36, which is driven at a specific speed 40 by a schematically indicated drive 35. Several groups of metering openings 38 with associated filling stations 41-45 are provided in the metering disk 36. By way of example, five filling stations 41-45 and a transfer position 34 are implemented for transferring the product 17 dosed into the dosing openings 38 into the lower parts 15 of the capsules 12 provided by the capsule holder 11.

The filling station 25 is shown schematically in Figure 2 shown in more detail. For each of the exemplary five filling stations 41-45, at least one stuffing stamp 51-55 is provided. The number of stuffing rams 51-55 corresponds to the respective metering openings 38 of the respective filling station 41-45. In the exemplary embodiment, ten stuffing rams 51-55 are provided per filling station 41-45. As can be seen in the section, the metering disk 36 each has metering openings 38 with a height 39. The metering disk 36 could be designed so that the size of the metering openings 38 can be adjusted over a variable height 39.

The product 17 to be metered into the metering openings 38, such as powder, lies on the metering disk 36. Through a mechanism not shown in detail, it reaches the metering openings 38 and is compressed there by corresponding stuffing rams 51-55. More product 17 is dosed into each filling station 41-45. Corresponding to how the filling height of the product in the dosing opening 38 increases, the height h1 to h5 of the associated stuffing punches 51-55, with which the stuffing punches 51-55 dip into the dosing openings 38, decreases. The undersides of the dosing openings 38 are closed at the filling stations 41-45. To transfer the dosed product 17 into the capsules 12 in the transfer position 34, the underside of the dosing opening 38 is exposed so that the product 17 located in the dosing opening 38 slides down into the respective lower part 15 of the capsule 12 can be pushed over using at least one transfer stamp 47. A force sensor 50 is arranged on the transfer stamp 47, via which the force acting during the transfer process can be detected. The output signal of the force sensor 50 is fed to the control device 19 for further evaluation. The handover force should be within certain ranges if a proper handover process can be assumed.

The stuffing punches 51-55 each have associated adjustment drives 61-65, which can individually adjust the associated stuffing punches 51-55 in their height h1 to h5 or immersion depth. As a result, the stuffing stamps 51-55 each dip into the dosing openings 38 to different extents. Alternatively, in addition to electromotive adjustment drives, other mechanical adjustment means via gates or similar could be provided as adjustment means. It is important that at least two stuffing rams of different filling stations 41-45 can be adjusted independently of one another in height h1 to h5. However, at least one adjusting drive 61-65 is preferably provided for at least all of the stuffing punches 51-55 of a filling station 41-45, which can simultaneously adjust the height h1 to h5 of these stuffing punches 51-55 of a filling station 41-45.

In addition, each stuffing punch 51-55 has a pressure medium 71-75, which exerts a different force or pressure P1 to P5, for example in the form of a spring behavior, on the respective stuffing punch 51-55. This pressure medium 71-75 is individually adjustable. This could, for example, be a pneumatic spring, for which the pressure on the stuffing stamps 51-55 can be individually influenced, for example using pneumatic cylinders. The pressure medium 71-75 includes at least one displacement sensor 90 for detecting the heights h1 to h5 or immersion depths. A displacement sensor 90 is preferably arranged on each pressure medium 71-75. The output signals of the displacement sensors 90 are fed to the control device 19.

If the spring or the pressure medium 71-75 is an element in which the pressure p1 to p5 increases or decreases depending on the spring travel, then conclusions can be drawn about the immersion depth or the degree of filling according to the pressure p1 to p5 the metering opening 38 can be pulled. It is more expedient if the spring travel is measured directly via a displacement sensor 90.

How strong the tamping force is with which the individual tamping stamps 51-55 deflect into the corresponding metering openings 38, whether with a gentle or a strong reaction, can therefore be adjusted individually using the pressure means 71-75. A measure of this is the pressure p1 to p5 in the respective stuffing ram springs or pressure medium 71-75, which can be individually adjusted. As in Figure 3 As can be seen, the pressure means 71-75 each have a pressure chamber 59 in which the piston 58 is movably mounted. The piston 58 is connected to the respective stuffing ram 51-55. A pressure control element 57 is provided for each pressure chamber 59, which specifically influences the pressure p1 to p5 prevailing in the respective pressure chamber 59. The pressure p1 to p5 prevailing in the respective pressure chamber 59 is detected via corresponding transducers or sensors 74 and fed to the control device 19. The control device 19 in turn controls the pressure control elements 57 so that the desired pressure p1 to p5 is established. Furthermore, in Figure 3 shown how the pressure control elements 57, such as a pressure control valve, are connected to a pressure source, not shown, such as a compressed air source. Pressure control element 57, piston 58, pressure chamber 59 and transducers or sensors 74 can form the pressure medium 71-75; If necessary, individual components such as sensors 74 can be omitted or arranged elsewhere.

Preferably, at least one pressure medium 71-75 could be provided for the group of stuffing punches 51-55 of each filling station 41-45, via which the pressure p1 to p5 for the stuffing punches 51-55 of this filling station 41-45 can be adjusted at the same time. Thus, for example, only one pressure chamber 59 could be provided for all pistons 58 of the stuffing rams 51-55 of this filling station 41-45.

For example, it could also be springs as pressure medium 71-75 with a constant pressure independent of the spring travel. This has the advantage that the pressing force is always the same regardless of the filling level of the metering opening 38.

Alternatively, a change in the pressure p1 to p5 could also occur by changing the spring constants of mechanical springs.

The pressures p 1 to p5 can be adjusted individually at least for different filling stations 41-45. Alternatively, however, it is also possible to combine certain stuffing stamps 51-55 of certain filling stations into groups 41-45 and to apply identical pressures p1 to p5 to these groups. For example, the first filling stations 41-43 could have a constant form pressure (p1 to p3) are pressurized, while the last two filling stations 44-45 are pressurized with a main pressure (p4 to p5). The main pressure can be greater than the form pressure. This group formation can simplify the setting and control process.

The respective stuffing rams 51-55, adjusting drives 61-65 and pressure medium 71-75 are mounted on a movable holder 48, the height of which can be adjusted, in particular vertically, relative to the top of the metering disk 36 via an adjusting mechanism 49. The adjustment mechanism 49 can, for example, be a link through which the stamps 51-55; 47 can be done out of or into the dosing openings 38. However, how far the stuffing rams 51-55 dip into the metering openings 38 can be individually influenced via the adjusting drives 61-65, as described. The adjustment mechanism 49 is the main drive for the stuffing movement. For example, a ball bearing is positively guided by a cam and a linear stroke is generated from the rotary movement of a drive.

The above facts can be summarized as follows. The height h1 to h5 of the associated stuffing rams 51-55 is defined or set by the associated adjusting drives 61-65. The stroke or the immersed movement itself is controlled by the adjustment mechanism 49 as in Figure 2 shown generated. If there is now no product 17 in the dosing opening 38, the stuffing ram 51-55 moves without springing to the position that can be influenced by the adjusting means 61-65 (height h1 to h5), moved by the adjusting mechanism 49. If, however, product 17 is located in the dosing openings 38 and the counterforce of the product 17 located in the dosing openings 38 relative to the penetrating stuffing stamps 51-55 becomes so great that the pressure medium 71 deflects, the stuffing stamp 51-55 moves relative to the housing of the pressure medium 71- 75. This level of relative movement can be measured, as can the pressure increase when the pneumatic springs or pressure medium 71-75 deflect. The displacement sensors 90 can be used to determine how far the stuffing stamps 51-55 have actually penetrated into the metering opening 38. Due to the pressure medium 71, a smaller penetration depth can possibly be achieved than originally specified by the adjusting drives 61-65 in the form of the height h1 to h5.

When presented according to Figure 3 At least one sensor 78, preferably another sensor 80, is provided, which is arranged above the metering disk 36. The sensor(s) 78, 80 detect the distance to the surface of the metering disc 36 located product 17, preferably in different places. This can be done, for example, by evaluating, for example, the transit time of a corresponding reflection of an emitted wave on the surface of the product 17 or by other known technologies. For example, a laser sensor or an ultrasonic sensor is used. Alternatively, a capacitive sensor could be provided. However, the product bed height can be recorded more precisely and therefore adjusted more precisely using a laser sensor or ultrasonic sensor.

One sensor 78 detects a product bed height 82, the other sensor 80 detects a further product bed height 84 at different radii of the metering disk 36. Furthermore, a product feed 76 is provided, which supplies the metering disk 36 with additional product 17 to be metered. The product feed 76 can take place, for example, via a speed-adjustable metering screw, so that a specific product bed height 82, 84 can be achieved in conjunction with the product feed 76. The metering disk 36 rotates, for example, in a stop-and-go mode, so that the product 17 is distributed and a specific product bed height 82, 84 is established. A minimum height is required to ensure that the product 17 can be dosed.

The following have been found to be process parameters that have a significant influence on the weight or the standard deviation of the weight of the dosed product 17: the height h1-h5 (with which the stuffing punches 51-55 dip into the respective dosing openings 38), the Pressure p1-p5 (with which the stuffing stamps 51-55 spring into the dosing openings 38, so to speak, the pressure p1-p5, which is applied via the pressure means 71-75 or springs to the product 17, which is located in the dosing opening 38 ), the product bed height 82, 84, and the speed 40 at which the metering disk 36 is moved. The product feed 76 contributes to the desired setting of this process parameter through the desired adjustment of the product bed height 82, 84.

wobei Gewicht: y1, Geschwindigkeit bzw. Drehzahl 40: x1, Pulverbetthöhe 82, 84: x2, Stopfstempelhöhe h1-h5: x3, Federstärke bzw. Druck p1-p5: x4; sowie a0, a1, a2, a11, a22, e die entsprechenden zu bestimmenden Modellparameter des Modells 88.The concept of automated commissioning makes it possible, for example through a statistically optimized test plan, to describe the relationships between the process parameters and the target variable, i.e. in particular the weight and/or the standard deviation of the weight of the dosed product 17 in the form of a model 88. The tests are planned accordingly by the control device 19. The corresponding settings of the process parameters are made accordingly and the test room is then run through. On the one hand, this can For example, model 88 of the process implemented in the control device 19 can be formed. Different functions are available as a model basis for this (linear, interactions, quadratic, cubic, polynomial model...). For example, for a quadratic model, the relationship could be as follows: $$y1=a0+a1\ast x1+a2\ast x2+a11\ast x{1}^2+a22\ast x{2}^{\wedge }2+\cdots +e$$

where weight: y1, speed or rotational speed 40: x1, powder bed height 82, 84: x2, tamping ram height h1-h5: x3, spring strength or pressure p1-p5: x4; as well as a0, a1, a2, a11, a22, e the corresponding model parameters of model 88 to be determined.

This model 88 describes the relationships between the process parameters (preferably speed or rotational speed 40, powder bed height 82, 84, stuffing ram height h1-h5, spring strength or pressure p1-p5) and the weight y1 of the filled product 17 (capsule weight). This allows the process parameters to be set to be determined for a desired weight y1 or for a minimum required standard deviation.

After selecting a possible model 88, the model parameters a0, a1, a2, a11, a22, e are determined. Here, the control device 19 records the respective weight y1 for certain process parameters. The weight is particularly preferably picked up automatically. There is a special weighing device 23 for this, as exemplified in Figure 1 shown, which absorbs the weight, for example as part of the in-process control. Alternatively, the capsules 12 can also be bent by a separate unit or by taking samples. An automatic recording by the control device 19 with regard to the recorded weight values simplifies the automatic evaluation.

The process parameters are varied within certain limits and the corresponding measurements of the weight y1 are made. At least one adjusting drive 61-65 changes at least one of the heights h1 to h5 and/or at least one pressure p1 to p5 is changed, for example via corresponding changed pressure specifications of the control device 19 and/or at least the product bed height 82, 84 is changed and/or at least the speed 40 of the metering disk 16 is changed. The model parameters are determined using known model algorithms based on the various process parameter sets and associated measured values. For example, you can Between 5, 10 and 20 test series can be carried out. All process parameters can also be varied simultaneously in different test series.

When all process parameters of model 88 have been determined, the desired target weight is entered. The desired standard deviation or the spread and the target weight can also be set. Based on the created model 88, certain settings for the process parameters are now determined by the control device 19 for the specific target weight.

The regulation can be carried out from the statistical model 88. In addition to the control, a new way to regulate the process has been developed. In practice, the model 88 determined does not exactly correspond to reality. It is also necessary to react to external influencing variables or disturbance variables that are not present in the Model 88. This is done through a regulatory intervention in the process. The Model 88 can be used for automated commissioning. The Model 88 makes it possible to determine which process parameter has the greatest influence on this operating point and to what extent it must be changed to compensate for the deviation. Model 88 indicates which process parameter has which influence and how the parameters of a controller, for example, should be set in order to obtain the best possible process result. The origin of this Model 88 is the automated commissioning process. The prerequisite for the automated commissioning process is the appropriate design of the device in order to specifically influence the process parameters.

The process parameters can be influenced by a user interface, for example with regard to certain limits. The range of process parameters in which the device should vary these process parameters could also be specified.

The device carries out the tests automatically. For this purpose, a monitoring function is stored in the control device 19, which uses the measurement of the transfer force, determined by the force sensor 50. This function interrupts the currently set attempt, for example if the forces are too high, and tries to move the device freely (for example through reduced process parameters, lower pressure p1-p5, lower height h1-h5 of the tamping rams 51-55 or comparable measures. If this is not sufficient , the user is asked, for example, to intervene in the sense of cleaning or similar. The device or the control device 19 decides independently when samples are taken: at Investigation of the influence of the powder bed height 82, 84, otherwise dependent on the specified powder bed height 82, 84, otherwise after a certain time (possibly selectable by the user), or a certain stability of the target size (average weight, average standard deviation). The sample is taken automatically using the weighing station 23 or weighing device integrated into the process or using an external scale. The weight is automatically recorded and used to create the model 88. For example, the data from the experiments are fed to the polynomial model to create the corresponding parameters of model 88. This modeling (regression) takes place either automatically or with the support of the user. For example, the user could exclude certain experiments that would then not be used for modeling. In addition, the data obtained could be transformed.

Now that the model 88 has been created, the user can now display the influences of the process parameters and their interactions. If the user is satisfied with the Model 88, the Model 88 can determine the process parameters. The process parameters determined in this way can be used as the basis for another attempt for verification. Optionally, the control device 19, in which the data acquisition and the creation of the model 88 can be located, could be accessed by remote diagnosis.

The device for dosing a product is used in particular in packaging technology, particularly in capsule filling machines.

Claims (11)

1. A device for dosing a product into capsules (12) or the like, comprising at least one dosing disk (36) which has dosing openings (38), at least one product supply line (76) for supplying the product to the dosing disk (36) in order to achieve a specific product bed depth (82, 84), at least two filling stations (41-45) with which groups of dosing opening (38) are associated, the filling stations (41-45) each comprising at least one tamping pin (51-55), it being possible for the tamping pin (51-55) to dip into the dosing opening (38) in order to compact the product (17) to a certain depth (h1-h5), characterized in that at least one pressure means (71) is provided for generating a variable pressure (p1-p5), into which means the corresponding tamping pin (51-55) can spring, and at least one adjusting means, in particular an adjusting drive (61-65), is provided to adjust the depth (h1 to h5) for each tamping pin (51-55) independently of one another, at least one sensor (78, 80) being provided for detecting at least one product bed depth (82, 84) of the product arranged on the dosing disk (36).
2. The device according to claim 1, characterized in that at least one control apparatus (19) is provided for specifying different depths (h1 to h5) and/or different pressures (p1 to p5) and/or different product bed depths (82, 84) and/or different rotational speeds (40) of at least one drive (35) of the dosing disk (36) as possible process parameters to be influenced.
3. The device according to any of the preceding claims, characterized in that at least one weighing apparatus (23) is provided for determining the weight of the product dosed into the capsules (12).
4. The device according to claim 3, characterized in that the control apparatus (19) for the different settings of the process parameters detects each weight of the product dosed into the capsule (12).
5. The device according to claim 3 or claim 4, characterized in that the control apparatus (19) creates a model (88) in which the relationship between at least one process parameter and the weight and/or the standard deviation of the dosed product (17) is shown as a function of the different settings of the process parameters and each weight of the product dosed into the capsule (12).
6. The device according to claim 5, characterized in that the control apparatus (19) as a function of the model (88) selects at least one setting of at least one process parameter as a function of a desired weight and/or a desired standard deviation of a desired weight of the dosed product (17).
7. The device according to claim 5 or claim 6, characterized in that the control apparatus (19) changes at least the depth (h1 to h5) and the pressure (p1 to p5) as process parameters to create the model (88).
8. The device according to any of the preceding claims, characterized in that at least one sensor (60, 78, 80, 90) is provided for detecting at least one process parameter.
9. The device according to any of the preceding claims, characterized in that the pressure means (71) comprises at least one pressure control element (57) and/or at least one pressure chamber (59) and/or at least one piston (58).
10. The device according to any of the preceding claims, characterized in that the control apparatus (19) controls at least the product feed line (76) to achieve a constant product bed depth (82, 84).
11. The device according to any of the preceding claims, characterized in that at least one force sensor (50) is provided on the transfer pin (47), the transfer pin (40) being provided for transferring the product (17) located in a dosing opening (38) into at least a lower part (15) of the capsule (12).

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