EP3795530A1 - Closure device and method for closing screw caps - Google Patents

Abstract

The invention relates to a closing device for closing screw caps, comprising a motor and a drive train in order to transmit power from the motor to the screw caps by means of the drive train. The locking device comprises a control device which is designed to dynamically adapt the engine operation using a measured actual value of an operating parameter of the engine, a target locking torque and an actual locking torque model.

Description

The invention lies in the technical field of devices that automatically close screw closures of containers, for example motor-driven. In particular, it relates to a closing device for closing screw caps, comprising a motor and a drive train and designed to transmit power from the motor to the screw caps by means of the drive train.

It is known to close screw caps by means of a motor in that the motor force is suitably translated so that the screw cap is turned onto a thread, for example a thread on a container opening. For example, a maximum motor torque is specified. This variable can be recorded well with existing systems and the motor can be controlled in such a way that the maximum motor torque is not exceeded. The torque that is output by the motor is referred to here as the motor torque. When it is transmitted to the closure, this motor torque is at least divided between the inherent torque of the drive train and the torque acting on the screw closure. How tightly a screw cap is closed after it has been closed can be quantified, for example, by the actual closing torque. The actual closing torque depends on the torque acting on the screw cap during the closing process. In addition, the properties of the screw cap and the counterpart, in particular of the respective thread, also play a role in the closing. In order to determine their influence on the actual locking torque, this can be quantified in the form of a counter torque. For example, the coefficient of friction of the closure and counterpart, the geometry of the thread or the material elasticity can influence the size of the counter torque. The actual closing torque depends not only on the torque acting on the screw cap but also on this counter-torque.

In principle, it is desirable that the actual actual locking torque deviates as little as possible from a predetermined target locking torque. With the known systems, however, there is a relatively wide spread of the actual locking torques.

One object of the invention is therefore to provide a closing device and a method for closing screw caps, in which the deviation of the actual closing torque from the target closing torque is reduced on average.

The object is achieved by the subject matter of the independent claims. Preferred embodiments are described in the dependent claims.

According to the invention, the locking device mentioned at the outset comprises a control device which is designed to dynamically adapt the engine operation using a measured actual value of an operating parameter of the engine, for example an actual speed of the engine, a target locking torque and an actual locking torque model .

Measuring the actual locking torque during operation is technically difficult. The inventors have also found that a significant contribution to the deviations results from the mass inertia and friction that occur in the drive train, which, among other things, can lead to a certain lag. Even if the actual locking torque were measured during operation and the motor was stopped when the target locking torque was reached, the locking torque would increase due to the overrun of the drive train by an amount that depends on various system parameters and / or operating parameters. A correction with a simple offset therefore does not lead to the desired improvement in all cases. In addition, deviations in the properties of the closure and / or the counterpart of the closure, for example material-related, also play a role, since the timing of the counter-torque caused by them varies from closure process to closure process due to such deviations, in particular the respective course towards the end of a closure process.

The claimed dynamic adaptation, on the other hand, enables a reliable reduction in the deviation of the actual locking torque from the target locking torque.

The target locking torque is understood to mean a predetermined value which the actual or actual locking torque should have after the closure process has been completed. The target locking torque can be stored at any point, for example on a storage medium of the locking device and a separate storage medium. It can have been saved by a user. How high the target locking torque is and in what form or what units it is specified depends on the actual application and can be suitably selected by a person skilled in the art.

In addition to the motor and the drive train, the closing device can furthermore comprise an element which interacts directly with the closure, for example a screw head, whichever is designed to hold the closure and / or the direct power transmission during the closing process. The motor can be an electric motor, for example. The drive train can include, for example, a transmission.

The screw closures can include closures, for example lids, for containers, the closures having a thread, in particular an internal thread.

Dynamic adaptation is understood here to mean that during the entire locking process, for example by means of a control process that receives the actual values of the operating parameters of the motor and tracks the set values of the operating parameters of the motor, in order to regulate to a predetermined target locking torque. The locking device can in particular be designed in such a way that measurement and adaptation of the motor operation, in particular a calculation of the actual locking torque by means of the actual locking torque model, take place continuously.

In particular, the inherent torque of the drive train can be continuously calculated and the actual locking torque derived therefrom, and the values of the operating parameters can be tracked based on this calculation. In the simplest case, the actual locking torque model can generate a value for the actual locking torque by calculating the difference between the engine torque (torque output by the engine) and the internal torque of the drive train.

The actual locking torque model can be designed in such a way that, based on a modeled torque acting on the locking device, it provides a modeled actual locking torque resulting from this modeled torque.

The torque acting on the closure can result from the motor torque, the inherent torque of the drive train and possibly also other system parameters, for example friction, and is the torque that is transmitted to the closure. The locking torque depends on the torque acting on the lock and the counter torque. The counter torque can, for example, depend on the properties of the closure and / or its counterpart, in particular its thread, as explained above. These properties and parameters can therefore be incorporated into the modeled torque acting on the closure and the modeled closure torque.

The actual closure torque model can be designed in such a way that it provides the torque acting on the closure using a drive train model, the Drive train model includes in particular a modeled internal torque of the drive train.

The drive train model can be designed in such a way that it provides a value of the inherent torque of the drive train based on mass inertia and / or friction in the drive train.

The control device can be designed to dynamically adapt the engine operation based on a control loop.

The control loop can be designed to output a value and / or a value range and / or an upper and / or lower limit for the value as input variables based on the measured actual value of the operating parameter and a predetermined target locking torque as input variables for at least one operating parameter to be set .

The control loop can be designed to use the actual locking torque model to determine a current value of the actual locking torque and, based on the current value of the actual locking torque and the target locking torque, the value and / or the value range and / or to determine the upper and / or lower limit for the value of the at least one operating parameter to be set, in particular based on a comparison of the value of the actual locking torque with the setpoint locking torque.

The control loop can be designed to determine the value and / or the value range and / or the upper and / or lower limit for the value of the operating parameter to be set in such a way that, according to the actual locking torque model, when the value of the operating parameter to be set is set accordingly an approximation of the value of the actual locking torque to the target locking torque is to be expected.

The control device can be designed to set a value for an operating parameter on the engine that corresponds to the output value and / or is in the output range of values and / or is below the output upper limit and / or is above the output lower limit.

The operating parameter to be set can include an engine speed and / or an engine torque.

The locking device can be designed so that by means of the actual locking torque model using a or the set value of the operating parameter, an expected actual value of the operating parameter and the measured value of the operating parameter, a value of a counter-torque, in particular the counter-torque described above, that is caused, for example, by the screw cap.

The invention also relates to a closer comprising at least one of the above-described closing devices. The closer can in particular be designed for continuous operation. The capper, in particular the capper designed for continuous operation, can be designed in the form of a machine comprising a plurality of the capping devices described above. The machine can in particular be designed in the form of a rotary machine and comprise a large number of closure devices according to the invention. In this case, the closing devices can in particular be arranged on the outer circumference of a carousel of the rotary machine, which is designed to transport the containers to be closed. In particular, the closing devices can be arranged at regular intervals on the outer circumference of the carousel.

The provision of several closing devices is advantageous for increased throughput. Particularly in the case of arrangements with a large number of closing devices, especially in rotary machines, it is particularly advantageous, due to this high throughput, to carry out the closing motorized, as quickly as possible, but nevertheless precisely, so that the use of the closing device described above, especially in such machines, results in a high throughput high quality.

The invention also relates to a filling system, in particular for filling foodstuffs, which comprises one or more of the sealing devices described above, in particular at least one of the sealing devices described above, in particular at least one of the rotary machines described above.

The invention also relates to a method for closing screw caps, wherein for closing by means of a drive train, force is transmitted from a motor to the screw caps. The engine operation is dynamically adapted using a measured actual value of an operating parameter of the engine, for example an actual speed, a target locking torque, and an actual locking torque model.

The method steps can be carried out as a control method, that is, the steps can be carried out repeatedly and the values of the operating parameters can be adjusted dynamically. The measurement of the actual value of the operating parameter and adaptation of the engine operation can in particular take place continuously.

The engine operation can in particular be adapted dynamically based on a control loop. The control loop can in particular be designed to use a value and / or a value range and / or an upper and / or lower limit as input variables based on the measured actual value of the operating parameter and a predetermined target locking torque as input variables for at least one operating parameter of the motor to be set for the value to be output.

The control loop can be designed to use the actual locking torque model to determine a current value of the actual locking torque and, based on the current value of the actual locking torque and the target locking torque, the value and / or the value range and / or to determine the upper and / or lower limit for the value of the at least one operating parameter to be set, in particular based on a comparison of the value of the actual locking torque with the setpoint locking torque.

The control loop can in particular be designed to determine the value and / or the range of values and / or the upper and / or lower limit for the value of the operating parameter to be set in such a way that, according to the actual locking torque model, with the corresponding setting of the value of the operating parameter to be set Operating parameters an approximation of the value of the actual locking torque to the target locking torque is to be expected.

The method can include setting a value for the operating parameter on the engine by means of a control device which corresponds to the output value and / or is in the output value range and / or is below the output upper limit and / or is above the output lower limit.

The features and advantages described in connection with the device can also be used analogously for the method.

• Figur 1 eine schematische, nicht-maßstabsgetreue Darstellung einer Verschließvorrichtung gemäß einer Ausführungsform und
• Figur 2 einen Regelkreis gemäß einer Ausführungsform.

Further features and advantages are explained below with reference to the exemplary figures. Show:

• Figure 1 a schematic, not to scale representation of a closing device according to an embodiment and
• Figure 2 a control loop according to an embodiment.

In Figure 1 a closing device 1 of an embodiment of the invention is shown schematically and not true to scale. The closing device comprises a motor 2, a drive train 3 and a screw head 4.

Furthermore, the figure shows a holder 5, which can be part of the closing device, but does not have to, and is designed to hold a container 6, in particular to hold the container in the working area of the screw head.

A screw cap 7 held by the screw head is also shown. The screw cap has a thread 7a, here an internal thread. To clarify the thread, a cross section through the screw cap is shown here. The container has a thread 6a at the end to be closed, here an external thread as an example, which fits the thread of the screw cap. It goes without saying that the closing device is not limited to the closing of precisely this type of container and closures.

In the figure, a sensor 8 is also shown, which can be attached to the engine or formed integrally with the engine. The sensor is designed to measure actual values of at least one operating parameter of the engine, for example designed to detect the engine speed and / or the engine torque.

Furthermore, a control device 9 is shown, which is connected to the sensor via a data connection 10, the sensor and the control device being designed in such a way that data recorded by the sensor are transmitted to the control device. Alternatively, the control device and the sensor can be formed integrally.

The control device is designed to set the respective value of one or more operating parameters of the engine. For this purpose, the control device can have a data connection 11 to the motor. Alternatively, the control device can be formed integrally with the motor.

In the following, a method for closing screw closures is described, which can in particular be carried out with the closure device described above.

In particular, to close a screw cap, the screw cap can be screwed onto the container thread of a container. For example, the container can be held by a holder and the screw cap by a screw head. Of the The motor can be operated, for example controlled by a control device, and the motor power can be transmitted to the screw cap by a drive train, in particular via the screw head. The transmission of the motor power can include a translation and / or redirection of the motor power.

The engine operation is dynamically adapted using a measured actual value of an operating parameter of the engine, for example an actual speed, a target locking torque, and an actual locking torque model. A control loop can be used for this, for example the one below in connection with Figure 2 control loop described in detail.

For example, based on the measured actual value of the operating parameter and a predetermined target locking torque as input variables, a value and / or a value range and / or an upper and / or lower limit can be set by means of the actual locking torque model for at least one operating parameter of the engine to be set. or lower limit for the value can be determined and output.

For example, a motor speed to be set and / or a motor torque to be set and / or a maximum value for the motor torque to which the motor torque is limited, i.e. an upper limit for the motor torque, can be determined and output.

The method can include that, using the actual locking torque model, a current actual locking torque is determined, and based on the current actual locking torque and the target locking torque, the value and / or the value range and / or the upper and / or or the lower limit is determined for the at least one operating parameter to be set. For this purpose, for example, the actual locking torque can be compared with the setpoint locking torque, in particular subtracted.

The value and / or value range and / or the upper and / or lower limit for the value of the operating parameter to be set can be determined in such a way that, according to the actual locking torque model, with a corresponding setting of the value of the operating parameter to be set, an approximation of the value of the actual Closing torque to the target closing torque is to be expected.

A value is then set on the engine for the operating parameter which corresponds to the output value and / or is in the output value range and / or is below the output upper limit and / or is above the output lower limit.

The method steps described above are carried out as a control method, that is, the steps are carried out repeatedly and the values of the operating parameter are dynamically adapted. The measurement, determination and output can in particular take place continuously.

An exemplary control loop 12 that can be used for the method described above and / or in the closure device described above for dynamically adapting the engine operation is shown in FIG Figure 2 shown. The control loop includes, in particular, a locking torque controller 13. The locking torque is regulated here, the input variables for the locking torque controller being the target locking torque and the actual locking torque.

In addition to the locking torque controller, the control loop includes a section 14 which determines the actual locking torque from the actual speed of the motor and the (limited) motor torque using an actual locking torque model and outputs it to the locking torque controller. The section here also models the inherent torque of the drive train as an example.

It goes without saying that, in general, the features mentioned in the exemplary embodiments described above are not restricted to these special combinations and are also possible in any other combinations.

Claims (15)

Closing device (1) for closing screw caps (7) comprising a motor (2) and a drive train (3) and designed in such a way that power is transmitted from the motor (2) to the screw caps (7) by means of the drive train (3),
marked by
a control device (9) which dynamically adapts the engine operation using a measured actual value of an operating parameter of the engine (2), a target locking torque and an actual locking torque model. Closing device (1) according to claim 1, wherein the actual closing torque model provides the modeled actual closing torque resulting from this modeled torque based on a modeled torque acting on the closure. Closing device (1) according to claim 2, wherein the actual closing torque model provides the torque acting on the closure using a drive train model, the drive train model in particular comprising a modeled intrinsic torque of the drive train (3). Closing device (1) according to claim 3, wherein the drive train model provides a value for the inherent torque of the drive train (3) as a function of mass inertia and / or friction in the drive train (3). Closing device (1) according to one of Claims 1 to 4, the control device (9) being designed to dynamically adapt the engine operation based on a control loop (12). Closing device (1) according to claim 5, wherein the control loop (12) is designed, based on the measured actual value of the operating parameter and a predetermined target closing torque as input variables for at least one operating parameter to be set, a value and / or a value range and / or to represent an upper and / or lower limit for the value. Closing device (1) according to claim 6, wherein the control loop (12) is designed to determine a current value of the actual closing torque using the actual closing torque model, and based on the current value of the actual closing torque and to determine the value and / or the value range and / or the upper and / or lower limit for the at least one operating parameter to be set for the target locking torque, in particular based on a comparison of the value of the actual locking torque with the value of the target locking torque. Closing device (1) according to claim 7, wherein the control loop (12) is designed to determine the value and / or the value range and / or the upper and / or lower limit for the operating parameter to be set in such a way that according to the actual closing torque Model with a corresponding setting of the value of the operating parameter to be set, an approximation of the value of the actual locking torque to the value of the target locking torque is to be expected. Closing device (1) according to one of claims 6 to 8, wherein the control device (9) is designed to set a value on the motor (2) which corresponds to the output value and / or is in the output value range and / or below the output value Upper limit is and / or is above the lower limit issued. Closing device (1) according to one of claims 6 to 9, wherein the operating parameter to be set comprises a motor speed and / or a motor torque. Closing device (1) according to one of the preceding claims, wherein the device is designed to generate a counter torque by means of the actual closing torque model using a or the set value of the operating parameter, an expected actual value of the operating parameter and the measured value of the operating parameter caused by the screw cap (7). Method for closing screw caps (7), wherein for closing by means of a drive train (3) force is transmitted from a motor (2) to the screw caps (7),
characterized in that
the engine operation is dynamically adapted using a measured actual value of an operating parameter of the engine (2), a target locking torque and an actual locking torque model. The method according to claim 12, wherein the engine operation is dynamically adapted based on a control loop (12), the control loop (12) being designed in particular to be based on the measured actual value of the operating parameter and a predetermined target locking torque as input variables at least for to output an operating parameter of the motor (2) to be set, a value and / or a value range and / or an upper and / or lower limit for the value. Method according to claim 13,
wherein the control loop (12) is designed to use the actual locking torque model to determine a current value of the actual locking torque, and based on the current value of the actual locking torque and the target locking torque, the value and / or the range of values and / or to determine the upper and / or lower limit for the at least one operating parameter to be set, in particular based on a comparison of the value of the actual locking torque with the target locking torque,
in particular, the control loop (12) being designed to determine the value and / or the value range and / or the upper and / or lower limit for the operating parameter to be set in such a way that, according to the actual locking torque model, when the value is set accordingly of the operating parameter to be set, an approximation of the value of the actual locking torque to the target locking torque is to be expected. A method according to claim 14, wherein a control device (9) is used to set a value on the motor (2) which corresponds to the output value and / or is in the output value range and / or is below the output upper limit and / or above the output lower limit lies.

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