Patent Application
20120139559
The present invention relates to a positioning system for a traveling transfer system which is used, in particular, in packaging machine technology.
Traveling transfer systems are used, for example, in the field of packaging machines in order to load the latter with goods to be packaged, for example bars of chocolate, bags, bottles, etc. In this case, such traveling transfer systems have a traveling transport section as well as a multiplicity of travelers which travel around the transport section and carry out the transport tasks in the process. When more than one traveler is used in particular, it would be advantageous to determine the exact position of the travelers in order to control the latter. This is advantageous, in particular, when the travelers can be driven independently of one another at different speeds and relative positions between the individual travelers can therefore change.
DE 43 35 004 C2 discloses a measuring system having a sensor, in which a defined electrical resistance section and a contact electrode which follows the course of the path of the resistance section are arranged at an insulating distance, a position of the contact being able to be determined when making contact between the contact electrode and the resistance section. However, such a sensor is not undoubtedly suitable for a traveling transfer system since it does not operate without wear and, in particular, has high production costs.
In contrast, the positioning system according to the invention has the advantage that it operates without wear and provides a very cost-effective absolute displacement measuring system. A modular design is also possible in this case, with the result that any desired transport sections can be equipped with the positioning system according to the invention. Another great advantage of the positioning system according to the invention can be seen in the fact that there is no need for an active sensor on the travelers, with the result that it is possible to avoid supplying electrical energy and transmitting measurement signals to and from the traveler. This is achieved, according to the invention, by virtue of the fact that the positioning system has a positioning device having a multiplicity of position sensors which are arranged on the transport section. In this case, the position sensors are provided in two rows which are arranged parallel to one another. In this case, the position sensors have free ends which form overlapping regions perpendicular to the direction of travel. This makes it possible to reliably determine a position of any traveler arranged on the transport section according to the invention.
A length of each position sensor in the direction of travel is particularly preferably the same as or greater than a length of a detector region of the traveler in the direction of travel. This ensures that individual position sensors can only be covered by one respective traveler at the same time.
The detector region of the traveler is also preferably arranged laterally beside the position sensors in the two rows which are parallel to one another, with the result that the position sensors and travelers overlap.
The two parallel rows of position sensors are also preferably arranged beside one another. Alternatively, the two parallel rows of position sensors are arranged above one another, a partition which shields magnetic fields then preferably being arranged between the two rows arranged above one another. This partition is preferably a thin sheet, in particular with a thickness in the μ range, and particularly preferably a metal foil.
In order to be able to be produced in a particularly cost-effective manner, the individual position sensors are preferably in the form of resistive or inductive sensors. Both types of sensor can be produced in a particularly cost-effective manner using screen printing in thick-film technology. In this case, conductor tracks for connecting a supply voltage and measurement signal lines are also preferably arranged on an underside of the sensors.
The design of the positioning system according to the invention can be simplified further if at least one permanent magnet is arranged on each traveler. As a result, each traveler has a defined magnetic field as a detector region, which can be used to detect the position of the traveler. Alternatively, a coil is provided for the inductive displacement measurement.
The positioning device particularly preferably comprises a sensor printed circuit board on which a plurality of position sensors are arranged. In this case, the sensor printed circuit board is arranged on the traveling transport section. This makes it possible to provide a common line for electrical supply and for measurement signal transmission for a plurality of position sensors on a sensor printed circuit board. Such lines are particularly preferably arranged on the underside of the sensor printed circuit board. A plurality of position sensors can therefore be arranged on a common sensor printed circuit board, which simplifies mounting on the traveling transfer system, in particular. The positioning system particularly preferably comprises a multiplicity of sensor printed circuit boards each having defined supporting points. As a result, any desired traveling transport sections can be equipped using individual, prefabricated sensor printed circuit board structural units, thus enabling rapid and simple adaptation to a wide variety of transport sections with standardized sensor printed circuit boards. As a result of the standardized interfaces, differently shaped sensor printed circuit boards can be combined with one another as desired in this case. Straight sections, 90° curves, 180° curves or curves with any other desired arc lengths, for example 45° or 120°, can be provided as individual sensor printed circuit board components, for example. In this case, the individual sensor printed circuit boards preferably have a common electrical supply and/or common measuring lines which is/are preferably arranged on the underside of the sensor printed circuit boards, whereas the position sensors are arranged on a top side of the sensor printed circuit boards.
A preferred exemplary embodiment of the invention is described in detail below with reference to the accompanying drawing, in which:
A positioning system 1 according to a preferred exemplary embodiment of the invention is described in detail below with reference to
As is clear from
A positioning device 4 in the form of a sensor printed circuit board is also arranged on the transport section 2. The positioning device 4 simulates the same route as the transport section 2 and is used to exactly position the traveler 3. The positioning device 4 comprises a multiplicity of position sensors 5 which are arranged in a first row 6 and in a second row 7 in this exemplary embodiment. In each row, the position sensors 5 are arranged at a distance from one another in this case, the position sensors in the second row 7 being respectively arranged at the corresponding gaps in the first row 6. In this case, the position sensors 5 are arranged in such a manner that they respectively have a short overlapping region 16 at their start in the direction of travel A and at their end in the direction of travel A. In this case, the position sensors 5 have a length 17 which is longer than a position-relevant length 18 of a detector region 3a of the traveler 3 in the direction of travel of the traveler. As is clear from
In this exemplary embodiment, the position sensors 5 are each in the form of a potentiometer. In accordance with a change in a relative position of the permanent magnet 8 as a result of a movement of the traveler 3, the electrical resistance at the respective position sensor 5 changes, which connects the respective position sensor 5 as a voltage divider, as a result of which an electrical voltage which changes relative to the position of the permanent magnet 8 is obtained at the potentiometer. This makes it possible to define an exact position of the traveler 3.
The position sensors 5 in this exemplary embodiment are in the form of potentiometers which are simple to produce, a plurality of position sensors 5 respectively being arranged on a separate printed circuit board part. In this case, the multiplicity of position sensors for each printed circuit board part have a common electrical supply and measuring line which is respectively denoted using the reference symbol 10 in the figures. As is clear from
According to the invention, it is thus possible to always exactly determine a position of the traveler 3 since the permanent magnet 8 on the traveler 3 is operatively connected either to a position sensor 5 in the first row 6 or to a position sensor 5 in the second row 7. The overlapping areas 16 between the position sensors in the first and second rows thus ensure that there is no position on the transport section 2 at which no position sensor is arranged. The position signals obtained are supplied, via the lines 10, to a control unit (not shown) which can then pass acceleration or delay commands to the respective travelers 3 in a corresponding manner in order to maintain defined spacings or defined conveying speeds, for example. Since there is no contact between the traveler 3 and the positioning device 4, the positioning system according to the invention is completely free of wear and can be produced in a very cost-effective manner in this case. The modular design enables any desired transport sections in this case without requiring special production for the individual printed circuit board parts of the sensor printed circuit board here. Furthermore, existing transport systems can easily be extended if necessary. In addition, there are no active sensors on the traveler 3, with the result that it is possible to dispense with complicated supply of electrical energy and transmission of measurement signals from or to the traveler 3. In this case, the design of the positioning system according to the invention remains very simple and cost-effective.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102009003080.8 | May 2009 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2010/054427 | 4/1/2010 | WO | 00 | 10/21/2011 |
