Transport device

Abstract

The invention relates to a device (10a, 10b, 10c) for transporting electrically conductive connecting elements (12a, 12b) such as rivets or screws from a transmitting station to a receiving station, comprising a line (20, 20c) enclosing a transport channel (22, 22c) for the connecting elements (12a, 12b) and leading from the transmitting station to the receiving station, and comprising a first coil arrangement (24, 24c) with at least one first magnetic coil (26, 26c) for generating a first electromagnetic field in the transport channel (22, 22c), the windings of which coil circulate around a first section (28, 28c) of the transport channel (22, 22c), the first electromagnetic field inducing eddy currents in the connecting elements (12a, 12b) which accelerate the connecting elements (12a, 12b) in the direction of the receiving station.According to the invention, a second coil arrangement (30, 30c) with at least one second magnetic coil (32, 32c) is provided for generating a second electromagnetic field in the transport channel (22, 22c), the windings of which run around a second section (34, 34c) of the transport channel (22, 22c), which is arranged closer to the receiving station than the first section (28, 28c), wherein the second electromagnetic field induces eddy currents in the connecting elements (12a, 12b) which accelerate the connecting elements (12a, 12b) in the direction away from the receiving station.

Description

The invention relates to a transport device for transporting electrically conductive connecting elements such as rivets or screws from a transmitting station to a receiving station according to the preamble of claim 1.A device of the type mentioned at the beginning is known from U.S. Pat. No. 1,441,250 and serves for feeding rivets to a riveting gun. The rivets are transported by being accelerated by magnetic fields from solenoids disposed around a transporting line for the rivets. In the known device, however, the rivets impact uncontrolled and in extreme cases at high speed against a stop at the receiving station or onto rivets already waiting there.It is therefore an object of the invention to further develop an apparatus of the type mentioned at the beginning in such a way that the arrival of the connection elements at the receiving station can be controlled better.This object is achieved according to the invention by a device having the features of claim 1. Advantageous further developments of the invention are the subject of the dependent claims.The invention is based on the idea of braking the connecting elements moving at high speed through the transport channel of the line to the receiving station in a defined manner before arriving at the receiving station.In this way, it can be avoided, on the one hand, that the connecting elements arrive at the end of the line at high speed and cause wear there over time. On the other hand, it is also possible to brake the connecting elements in an end region of the line and to keep them in readiness there, so that the final feeding to the receiving station only has to take place over a short path. The windings of the at least one first and the at least one second magnet coil do not have to circulate around the entire first or second section of the transport channel. As a rule, they only surround a part of the section in question.According to an advantageous development, the line between the first section and the second section has a switch which connects the second section selectively to the first section or to a third section of the transport channel which follows the second section in the direction away from the receiving station. The optional connection to further sections is also possible. In this way, it is possible to transport unnecessary connecting elements away from the receiving station back without hindering the feeding of further connecting elements from the transmitting station. For example, the connecting elements can be transported into a container into which the third section expediently opens. In another operating mode, different connecting elements can be supplied to the switch and thus to the second section via the first, third and optionally further sections. Furthermore, a detector for determining parameters defining the connecting elements can advantageously be arranged between the second section and the switch. The detector can be used, for example, to detect when the relevant connection elements are faulty connection elements or connection elements of the wrong type. This detection can be carried out, for example, by the detector being configured to measure an eddy current induced by a connecting element. Furthermore, a control device can be provided which serves to control the switch in dependence on data received from the detector. If the data determined by the detector indicate that the connection elements do not meet the requirements, because, for example, a parameter of the connection element determined by the detector lies outside a predefined tolerance range, the switch can be set for connecting the second section to the third section, and the connection elements can be transported back into the third section. The recognition of the connecting elements, just like their removal from the second section, can be effected manually by an operator, for example by returning via the switch or emptying the second section, who also sets the switch. Automatic emptying of the second section is also possible when a fault is detected.The at least one first magnet coil and the at least one second magnet coil can be arranged on the line or connected to it in different ways. In particular, it is possible for the at least one magnet coil and / or the at least one second magnet coil to be embedded in the line. It is further possible for the at least one magnet coil and / or the at least one second magnet coil to be arranged so as to circulate around an outer side of the line.Advantageously, the transport channel has a cross section which corresponds in its shape to a longitudinal section of the connecting elements. The connecting elements can then be transported through the line in a defined orientation. For example, rivets having a T-shaped longitudinal section can all be transported in the same way, for example with the head upward, so that they do not have to be rotated into the correct position at the receiving station.According to an advantageous development, a fiber-optic sensor is provided, which has at least one sensor fiber guided with the line, a light detector connected to the at least one sensor fiber for detecting light guided through the at least one sensor fiber, and a light source for introducing light into the at least one sensor fiber. If the line is bent to such an extent that a passage of the connecting elements through the transport channel is significantly restricted, the sensor fiber guided by the line is also bent, so that the intensity of the light detected by the light detector is reduced. This advantageous further development of the device according to claim 1 can also form an independent invention independently of the teaching of claim 1. Expediently, a control unit for controlling the transport of the connection elements is provided, which contains information from the light detector about the intensity of the received light. If this intensity is too low, the control unit concludes that the bend in the sensor fiber and thus also in the line is too strong, so that the transport of the connecting elements can be stopped and the bend in the line can be eliminated.The invention is explained in more detail below with reference to two exemplary embodiments schematically shown in the drawing. They show FIGS. 1 a, 1 b show a device for transporting connecting elements according to a first exemplary embodiment in a schematic perspective illustration and in a detailed illustration; FIGS. 2 a, 2 b show a device for transporting connecting elements according to a second exemplary embodiment in a schematic perspective illustration and in a detailed illustration; FIG. 3 shows a device for transporting connecting elements according to a third exemplary embodiment in a schematic perspective illustration, and FIGS. 4 a, 4 b show a line in a perspective illustration and in cross section.The device 10 a, which is only schematically shown, according to FIGS. 1 a, 1 b, serves for transporting rivets 12 afrom a transmitting station, which is not shown, to a receiving station, which is likewise not shown, for example from a rivet stock to a processing station equipped with a rivet gun. It has a line 20 which encloses a transport channel 22 which is T-shaped in cross section. The cross section of the transport channel 22 is thus adapted to a longitudinal section of the rivet 12 a, so that the rivet shank is accommodated in the vertical line of the T, while the rivet head is accommodated in the transverse line. In this way, the rivets 12 acan be transported in a defined position. For transporting the rivet 12 a, the device 10 aincludes a first coil arrangement 24, which includes a first magnetic coil 26, the windings of which run around a part of a first section 28 of the transport channel 22. The first coil arrangement 24 generates a first electromagnetic field in the transport channel 22, which generates eddy currents in the rivets 12 a, which accelerate the rivets 12 atoward the receiving station. The apparatus 10 afurther includes a second coil arrangement 30, which includes a second magnetic coil 32, the windings of which rotate around a part of a second section 34 of the transport channel 22. The second coil arrangement 30 generates a second electromagnetic field in the transport channel 22, which induces eddy currents in the rivets 12a, which accelerate them away from the receiving station. This electromagnetic field allows rivets 12a, which move towards the receiving station, accelerated by the first coil arrangement 24, to be braked before reaching the receiving station.The device 10 bin accordance with the second exemplary embodiment (FIGS. 2 a, 2 b) differs from the device 10 ain accordance with the first exemplary embodiment only in the form of the line 20. The schematic structure of the device 10 bin accordance with the second exemplary embodiment is identical to the schematic structure of the device 10 ain accordance with the first exemplary embodiment. However, the device 10 bis configured for transporting screws 12 b, elongated rivets, preferably having a length of at least 10 mm, set or self-piercing rivet bolts or pins, and the transport channel 22 has a circular cross section or a cross section in the form of a regular polygon. As indicated in FIG. 2 b, the screws 12 bare transported in the axial direction through the line 20. The further mode of operation of the device 10 bis identical to the mode of operation of the device 10 aaccording to the first exemplary embodiment.The device 10 caccording to the third exemplary embodiment (FIG. 3 ) also resorts to the same principle. Here too, connecting elements such as the rivets 12a or the screws 12b are transported from a transmitting station, not shown, to a receiving station, not shown. For this purpose, a first coil arrangement 24 cis provided, which has two magnet coils 26 carranged at a distance from one another, the windings of which each circulate around parts of a first section 28 cof the transport channel 22 cprovided for the transport of the connecting elements. Furthermore, a second coil arrangement 30 cis provided, which has two second magnet coils 32 c, the windings of which in each case circulate around parts of a second section 34 cof the transport channel 22 c. The transport channel 22 cis again surrounded in a ring by a line 20 c. Between the first section 28 cand the second section 34 cis arranged a switch 40 from which a third section 42 of the transport channel 22 cextends in a direction away from the receiving station from the switch 40 as far as a container, not shown. A third coil arrangement 44 has two third magnet coils 46, the windings of which each circulate around parts of the third section 42. The third coil arrangement 44 serves to induce eddy currents in the connecting elements, which accelerate the latter towards the container. Connectors coming from the transmitting station are initially transported through the first section 28c and the switch 40 into the second section 34c. A detector arranged there, not shown in detail, determines parameters defining the connection elements by measuring eddy currents inducing the connection elements due to their movement. If the detector recognizes that the connecting elements do not meet the specifications, for example, in that parameters determined by it do not fall within a standard range, a control device, likewise not shown in detail, controls the switch 40 so that it connects the second section 34 cto the first section 28 cbut to the third section 42. The second coil arrangement 30c brakes the connecting elements in the second section 34c and accelerates them back to the switch 40 and into the third section 42, from where they are transported to the container by means of the third coil arrangement 44.For the device 10c according to the third embodiment, a further operating mode is conceivable. Thus, connecting elements of different types of transmitting stations can be transported to the receiving station. Connecting elements of a first type can be transported from a first transmitting station, not shown, via the first section 28 cto the switch 40 while connecting elements of a second type can be transported from a second transmitting station, not shown, via the third section 42 to the switch 40, depending on the type of connecting elements required. The transport to the receiving station takes place from the switch 40 via the second section 34c. These may be, for example, screws having two different lengths. It is also possible to connect more than two sections at the switch 40 in order to transport more than two types of connecting means to the switch 40. As a rule, the required connecting elements are kept ready near the receiving station. If another connector is needed, the connectors held near the receiving station may be transported back to the transmitting station from which they came. Then the switch 40 switches over and the other connection elements are transported to the receiving station. In this embodiment too, it is possible for a detector to be provided which detects which connecting elements are transported or kept available.FIGS. 4 a, 4 b show a line 20 which can be used in the devices 10 a, 10 b, 10 cin accordance with FIGS. 1 a, 1 b, 2 a, 2 b, 3 and replaces the line 20, 20 cshown there completely or in sections. The line 20 encloses a transport channel 22, which in turn is T-shaped in cross section and serves for transporting rivets 12 a. The T-shaped cross section can however be seen here merely as an example. Embedded in the line 20 are four sensor fibers 50, which are part of a fiber-optic sensor. The sensor fibers 50 extend parallel and spaced apart along the entire length of the conduit 20 In addition to the sensor fibers 50, the fiber optic sensor includes a light source having light input into the sensor fibers 50 at one end and a light detector disposed at the other end of the sensor fibers 50 for receiving light from the light source. The light source and the light detector are not shown in detail in the drawing. If the line 20 is bent too much, this is due to a reduced intensity of the light received by the light detector. A reduction in the intensity of the received light below a predetermined minimum value is detected by a control unit, likewise not shown in detail, which then stops the transport of connecting elements through the kinked line 20. It goes without saying that it is not absolutely necessary for four sensor fibers 50 to be embedded in the line 20. The principle underlying this aspect of the invention is also possible when using only one sensor fiber 50 or when using a different number of sensor fibers 50.In summary, the following is to be stated: The invention relates to a device 10 a, 10 b, 10 cfor transporting electrically conductive connecting elements 12 a, 12 b, such as rivets or screws, from a transmitting station to a receiving station, having a line 20, 20 csurrounding a transport channel 22, 22 cfor the connecting elements 12 a, 12 band leading from the transmitting station to the receiving station, and having a first coil arrangement 24, 24 cwith at least one first magnetic coil 26, 26 cto generate a first electromagnetic field in the transport channel 22, 22 c, the windings of which first electromagnetic field circulate around a first section 28, 28 cof the transport channel 22, 22 c, wherein the first electromagnetic field induces eddy currents accelerating the connecting elements 12 a, 12 bin the direction of the receiving station in the connecting elements 12 a, 12 b. According to the invention, a second coil arrangement 30, 30 cis provided with at least one second magnetic coil 32, 32 cto generate a second electromagnetic field in the transport channel 22, 22 c, the windings of which coil arrangement circulate around a second section 34, 34 cof the transport channel 22, 22 c, which is arranged closer to the receiving station than the first section 28, 28 c, wherein the second electromagnetic field induces eddy currents accelerating the connecting elements 12 a, 12 bin the direction away from the receiving station in the connecting elements 12 a, 12 b.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedU.S. Pat. No. 1,441,250

[0002]

Claims

Device for transporting electrically conductive connecting elements (12a, 12b) such as rivets or screws from a transmitting station to a receiving station, having a line (20, 20c) which envelopes a transport channel (22, 22c) for the connecting elements (12a, 12b) and leads from the transmitting station to the receiving station, and having a first coil arrangement (24, 24c) having at least one first magnetic coil (26, 26c) for generating a first electromagnetic field in the transport channel (22, 22c), the windings of which circle around a first section (28, 28c) of the transport channel (22, 22c), the first electromagnetic field inducing eddy currents accelerating the connecting elements (12a, 12b) in the direction of the receiving station in the connecting elements (12a, 12b), characterized bya second coil arrangement (30, 30c) having at least one second magnetic coil (32, 32c) for generating a second electromagnetic field in the transport channel (22, 22c), the windings of which coil around a second section (34, 34c) of the transport channel (22, 22c) which is arranged closer to the receiving station than the first section (28, 28c), wherein the second electromagnetic field induces eddy currents accelerating the connecting elements (12a, 12b) in the direction away from the receiving station in the connecting elements (12a, 12b).Device according to claim 1, characterised in that the line (20c) has, between the first section (28c) and the second section (34c), a switch (40) which connects the second section (34c) selectively to the first section (28c) or at least to a third section (42) of the transport channel (22c) following the second section (34c) in the direction away from the receiving station.Device according to claim 2, characterised in that the third portion (42) opens into a container for the connecting elements (12a, 12b).Device according to claim 2 or 3, characterised bya detector arranged between the second section (34c) and the switch (42) for determining parameters defining the connecting elements (12a, 12b).Apparatus according to claim 4, characterised bya control device for controlling the switch (42) in dependence on data obtained from the detector.Device according to claim 4 or 5, characterised in that the detector is configured to measure an eddy current induced by a connecting element (12a, 12b).Device according to one of the preceding claims, characterized in that the at least one first magnet coil (26, 26c) and / or the at least one second magnet coil (32, 32c) is embedded in the line (20, 20c).Device according to one of the preceding claims, characterized in that the at least one first magnet coil (26, 26c) and / or the at least one second magnet coil (32, 32c) is arranged so as to circulate around an outer side of the line (20, 20c).Device according to one of the preceding claims, characterized in that the transport channel (22, 22c) has a cross section which corresponds in its shape to a longitudinal section of the connecting elements (12a, 12b).Device according to one of the preceding claims, characterized bya fibre-optic sensor which has at least one sensor fibre (50) guided with the line (20, 20c), a light detector connected to the at least one sensor fibre (50) for detecting light guided through the at least one sensor fibre (50) and a light source for introducing light into the at least one sensor fibre (50).Method for transporting electrically conductive connecting elements (12a, 12b) from a transmitting station to a receiving station using a device (10a, 10b, 10c) according to one of the preceding claims, wherein the connecting elements (12a, 12b) are accelerated by means of the first coil arrangement (24, 24c) in the direction from the transmitting station to the receiving station and are decelerated by means of the second coil arrangement (30, 30c) before reaching the receiving station.Method according to Claim 11 using a device according to Claim 5 or 6, characterized in that the control device actuates the switch (40) for connecting the second section (34c) to the first section (28c) and the second coil arrangement (30c) for accelerating a connecting element (12a, 12b) from the second section (34c) into the third section (42) if a parameter of the connecting element (12a, 12b) determined by the detector is outside a predefined tolerance range.Device for transporting connecting elements (12a, 12b) such as rivets or screws from a transmitting station to a receiving station, having a line (20, 20c) which envelopes a transport channel (22, 22c) for the connecting elements (12a, 12b) and leads from the transmitting station to the receiving station, and having a device (24, 24c) for accelerating the connecting elements in the direction from the transmitting station to the receiving station, characterized bya fibre-optic sensor which has at least one sensor fibre (50) guided with the line (20, 20c), a light detector which is connected to the at least one sensor fibre (50) for detecting light guided through the at least one sensor fibre (50) and a light source for introducing light into the at least one sensor fibre (50).Device according to claim 10 or 13, characterised bya control unit for controlling the transport of the connection elements (12a, 12b) which receives information from the light detector about the intensity of the received light.Method for transporting connecting elements (12a, 12b) such as rivets or screws from a transmitting station to a receiving station using a device according to Claim 14, characterized in that the control unit stops the transport of the connecting elements (12a, 12b) if the intensity of the received light falls below a predefined minimum value.

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