Capping device and method for closing screw caps

Abstract

The present invention relates to a capping device for closing screw caps, comprising a motor and a power train so as to transmit force from the motor to the screw caps by means of the power train. The capping device comprises a control unit configured for dynamically adapting the operation of the motor, making use of a measured actual value of an operating parameter of the motor, a target closing torque and an actual closing torque model.

Claims

1. A capping device for closing a screw cap, comprising a motor, a control unit, and a power train and configured for transmitting force from the motor to the screw cap by means of the power train for a purpose of closing the screw cap, wherein the control unit dynamically adapts operation of the motor to close the screw cap, making use of a measured actual value of an operating parameter of the motor, a target closing torque and an actual closing torque model, wherein the actual closing torque model provides, based on a modelled torque acting on the screw cap, a modelled actual closing torque resulting from this modelled torque while closing the screw cap, wherein the control unit is configured for dynamically adapting the motor operation, based on a control loop, wherein the control loop is configured for outputting for the operating parameter to be set a value and/or a range of values and/or an upper and/or lower limit for the value, based on the measured actual value of the operating parameter and a predetermined target closing torque as input variables, and wherein the control loop is configured to determine a current value of the actual closing torque making use of the actual closing torque model, and to determine, based on a comparison between the current value of the actual closing torque and the value of the target closing torque, the value and/or the range of values and/or the upper and/or lower limit for the operating parameter to be set.

2. The capping device according to claim 1, wherein the actual closing torque model provides the torque acting on the screw cap, making use of a power train model, the power train model comprising in particular a modelled intrinsic torque of the power train.

3. The capping device according to claim 2, wherein the power train model provides a value for the intrinsic torque of the power train, depending on inertia and/or friction in the power train.

4. The capping device according to claim 1, wherein the control loop is configured to determine the value and/or the range of values 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, an approach of the value of the actual closing torque to the value of the target closing torque can be expected, when setting the value of the operating parameter to be set.

5. The capping device according to claim 1, wherein the control unit is configured to set at the motor a value, which corresponds to an outputted value and/or lies within an outputted range of values and/or is below an outputted upper limit and/or is above an outputted lower limit.

6. The capping device according to claim 1, wherein the operating parameter to be set comprises a motor speed and/or a motor torque.

7. The capping device according to claim 1, wherein the device is configured for determining a counter-torque, which is caused by the screw cap, by means of the actual closing torque model and by making use of a, or of a set value of the operating parameter, of an expected actual value of the operating parameter and of a measured value of the operating parameter.

8. A method for closing a screw cap, the method comprising: transmitting a force from a motor to the screw cap by means of a power train for a purpose of closing the screw cap, dynamically adapting operation of the motor to close the screw cap making use of a measured actual value of an operating parameter of the motor, a target closing torque as well as an actual closing torque model, wherein the actual closing torque model provides, based on a modelled torque acting on the screw cap, a modelled actual closing torque resulting from this modelled torque while closing the screw cap, dynamically adapting the operation of the motor on a basis of a control loop, the control loop outputting, based on the measured actual value of the operating parameter and on a predetermined target closing torque as input variables, at least for one motor operating parameter to be set, a value and/or a range of values and/or an upper and/or lower limit for the value, and the control loop determining a current value of the actual closing torque making use of the actual closing torque model, and for determining, based on a comparison between the current value of the actual closing torque and the target closing torque, the value and/or the range of values and/or the upper and/or lower limit for the at least one operating parameter to be set.

9. The method according to claim 8, further comprising: the control loop determining the value and/or the range of values 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, an approach of the value of the actual closing torque to the target closing torque can be expected, when setting the value of the operating parameter to be set.

10. The method according to claim 9, further comprising: using a control unit to set a value at the motor, which corresponds to the outputted value and/or lies within the outputted range of values and/or is below the outputted upper limit and/or is above the outputted lower limit.

11. A capping device for closing a screw cap, comprising a motor, a control unit, and a power train and configured for transmitting force from the motor to the screw cap by means of the power train for a purpose of closing the screw cap, wherein the control unit dynamically and continuously adapts operation of the motor to close the screw cap, making use of a measured actual value of an operating parameter of the motor, a target closing torque and an actual closing torque model, wherein the actual closing torque model continuously provides, based on a modelled torque acting on the screw cap, a modelled actual closing torque resulting from this modelled torque, wherein the control unit is configured for dynamically and continuously adapting the motor operation, based on a control loop, wherein the control loop is configured for outputting for the operating parameter to be set a value and/or a range of values and/or an upper and/or lower limit for the value, based on the measured actual value of the operating parameter and a predetermined target closing torque as input variables, and wherein the control loop is configured to determine a current value of the actual closing torque making use of the actual closing torque model, and to determine, based on a comparison between the current value of the actual closing torque and the value of the target closing torque, the value and/or the range of values and/or the upper and/or lower limit for the operating parameter to be set.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows a schematic representation of a capping device according to an embodiment, which is not true to scale, and

(2) FIG. 2 shows a control loop according to an embodiment.

DETAILED DESCRIPTION

(3) In FIG. 1 a capping device 1 of an embodiment of the present invention is shown schematically and not true to scale. The capping device comprises a motor 2, a power train 3 and a screwing head 4.

(4) In addition, the figure shows a support 5, which may or may not be part of the capping device and which is configured for supporting a container 6, in particular for supporting the container in the operating area of the screwing head.

(5) Furthermore, a screw cap 7 held by the screwing head is shown. The screw cap has a thread 7a, which is here an internal thread. In order to illustrate the thread, a cross-section through the screw cap is shown here. The container has at the end to be closed a thread 6a, which is here exemplarily an external thread that matches the thread of the screw cap. It goes without saying that the capping device is not limited to closing exactly this type of containers and caps.

(6) The figure also shows a sensor 8, which may be attached to the motor or formed integrally with the motor. The sensor is configured for measuring actual values of at least one operating parameter of the motor, e.g. for detecting the motor speed and/or the motor torque.

(7) Furthermore, a control unit 9 is shown, which is connected to the sensor via a data link 10, the sensor and the control unit being configured in such a way that data detected by the sensor are transmitted to the control unit. Alternatively, the control unit and the sensor may be formed integrally with each other.

(8) The control unit is configured for setting the respective value of one or of a plurality of operating parameters of the motor. To this end, the control unit may have a data link 11 to the motor. Alternatively, the control unit may be formed integrally with the motor.

(9) In the following, a method for closing screw caps will be described, which can be carried out in particular with the above-described capping device.

(10) In particular, for closing a screw cap, the screw cap may be screwed onto the container thread of a container. In so doing, the container may e.g. be supported by a support and the screw cap may be held by a screwing head. The motor may be operated e.g. controlled by a control unit, and the motor force may be transmitted to the screw cap through a power train, in particular via the screwing head. The transfer of the motor force may include a transmission and/or a deflection of the motor force.

(11) The operation of the motor is dynamically adapted making use of a measured actual value of an operating parameter of the motor, e.g. an actual speed, a target closing torque, and an actual closing torque model. A control loop may be used for this purpose, e.g. the control loop described hereinafter in detail in connection with FIG. 2.

(12) For example, based on the measured actual value of the operating parameter and a predetermined target closing torque as input variables, the actual closing torque model can be used for determining and outputting, for at least one motor operating parameter to be set, a value and/or a range of values and/or an upper and/or lower limit for the value.

(13) 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 outputted.

(14) The method may comprise determining, making use of the actual closing torque model, a current actual closing torque and, based on the current actual closing torque and the target closing torque, determining the value and/or the range of values and/or the upper and/or lower limit for the at least one operating parameter to be set. To this end, the actual closing torque may e.g. be compared with, in particular subtracted from, the target closing torque.

(15) 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 can be determined in such a way that, according to the actual closing torque model, an approach of the value of the actual closing torque to the target closing torque can be expected, when setting the value of the operating parameter to be set.

(16) The value set for the operating parameter at the motor will then be a value, which corresponds to the outputted value and/or lies within the outputted range of values and/or is below the outputted upper limit and/or is above the outputted lower limit.

(17) The above-described method steps are carried out as a closed-loop control process, i.e. the steps are repeatedly carried out and the values of the operating parameter are dynamically adapted. Measurement, determination and output may, in particular, be performed continuously.

(18) An exemplary control loop 12, which can be used for the above-described method and/or in the above-described capping device for dynamically adapting the operation of the motor, is shown in FIG. 2. The control loop includes in particular a closing torque controller 13. The controlled variable is here the closing torque, the input variables for the closing torque controller being the target closing torque and the actual closing torque.

(19) The control loop comprises, in addition to the closing torque controller, a section 14, which, making use of an actual closing torque model, determines the actual closing torque from the actual speed of the motor and the (limited) motor torque and outputs it to the closing torque controller. The section executes here, exemplarily, also a modelling of the intrinsic torque of the power train.

(20) It goes without saying that, generally, the features mentioned in the above-described embodiments are not limited to these special combinations and may also be used in any other combination.