Magnetic gripper, system with magnetic grippers, method for gripping workpieces with height offset

Abstract

Magnetic gripper (10) for a handling device (12) for gripping an at least partially magnetizable and / or ferromagnetic workpiece (14, 14a, 14b), wherein the magnetic gripper (10) comprises: - a gripper base section (16) with an interior space (18), - a piston section (26) with a piston rod (28) extending along a longitudinal axis (27) and with a piston (40) arranged on the piston rod (28) and in the interior space (18), - a magnet section (62) with at least one holding magnet (76, 76a, 76b) for gripping the workpiece (14, 14a, 14b), wherein the magnet section (62) is arranged on the piston section (26), wherein the magnet section (62) is displaceable by means of the piston section (26) along the longitudinal axis (27) between an upper release position and a lower contact position, - a stripping section (42) with at least one stripper (46) arranged on the piston rod (28) and / or on the gripper base section (16) for releasing a gripping connection between the magnet section (62) and the workpiece (14, 14a, 14b) when the magnet section (62) is displaced in the direction of the release position, wherein the gripper base section (16) and / or the piston section (26) are designed such that the magnet section (62) protrudes in the contact position along the longitudinal axis (27) relative to the stripping section (42), and wherein the magnet section (62) has a magnet holder (68) for receiving the holding magnets (76, 76a, 76b) and an insulation element (66) arranged between the magnet holder (68) and the piston section (26).

Description

[0001] The invention relates to a magnetic gripper, a system with magnetic grippers and methods for simultaneously gripping workpieces with a height offset.

[0002] Electric vehicles with a battery storage system comprise a multitude of battery cells to provide the electrical energy needed to propel the electric vehicle. The numerous battery cells are often housed in a battery cell housing. The battery cells can have different shapes. For example, cylindrical battery cells, prismatic battery cells, or pouch battery cells are used for an electric vehicle's battery storage system. Even within the individual shapes, the battery cells can vary, for example, in size or height. The height offset varies depending on manufacturing tolerances.

[0003] Manually arranging the individual battery cells from the multitude of battery cells into the battery cell housing is time-consuming and not cost-effective. Furthermore, handling devices with a mechanical gripper can often only grip a specific battery cell shape and / or size, so changing the battery cell shape or size can require complex retooling of the handling device.

[0004] The invention is based on the object of providing a repeatable, secure gripping of workpieces with different heights, in particular a repeatable, secure and simultaneous gripping of a plurality of workpieces with different heights.

[0005] This object is achieved by a magnetic gripper having the features of claim 1. The magnetic gripper is intended for arrangement on a handling device and / or manipulator, such as a robot or gantry system. The magnetic gripper is designed to grip at least partially magnetizable and / or ferromagnetic workpieces. The magnetic gripper has a gripper base section with an interior space, wherein the interior is preferably cylindrical and / or is designed with an upper cylinder end and a lower cylinder end. Furthermore, the magnetic gripper provides a piston section with a piston rod extending along a longitudinal axis and with a piston arranged on the piston rod and in the interior space of the gripper base section.

[0006] In addition, the magnetic gripper provides a magnetic section with at least one holding magnet for magnetically gripping the workpiece, wherein the magnetic section is arranged on the piston rod and / or on the gripper base section.

[0007] The holding magnets can be permanent magnets, especially permanent neodymium magnets.

[0008] The piston rod and / or the magnetic section can be displaced by means of the piston along the longitudinal axis between an upper release position and a lower contact position. The maximum stroke of the piston section preferably corresponds essentially to the distance between the upper cylinder end and the lower cylinder end. The upper release position of the magnetic section preferably corresponds to the piston position at the upper cylinder end, and the lower contact position of the magnetic section corresponds to the piston position at the lower cylinder end.

[0009] The magnetic gripper further comprises a stripping section with at least one stripper for releasing a magnetic gripping connection between the magnetic section and the workpiece. The stripping section is arranged on the piston rod and / or on the gripper base section and is configured to strip the workpiece gripped by the magnetic section by means of the at least one stripper when the piston rod is displaced along the longitudinal axis of the piston rod. It is conceivable that, in addition to the stripping section, a pressing device is also provided for pressing the workpieces against the magnetic gripper. Alternatively, it is conceivable that the stripping section comprises a pressing device.

[0010] Furthermore, the gripper base section and / or the piston section and / or the magnet section and / or the stripping section are designed such that, in the contact position, the magnet section protrudes along the longitudinal axis relative to the stripping section. In the release position, the gripper base section and / or the stripping section preferably accommodate the magnet section, in particular completely.

[0011] Furthermore, it is advantageous if the magnet section has a magnet holder for accommodating the holding magnets. Furthermore, an insulating element is arranged between the magnet holder and the piston section, wherein the insulating element promotes an orientation of the magnetic field toward the workpiece. The insulating element can comprise at least one of the following elements: Al, Zn, Mg, Cu, and / or preferably be formed from an aluminum-zinc base.

[0012] Such a magnetic gripper has the advantage that a workpiece, in particular a battery cell, can be gripped easily, efficiently, quickly, and / or securely, regardless of its actual height. The magnetic gripper can be moved to a predetermined starting position by means of the handling device, whereby the workpiece to be gripped has not yet come into contact with the magnetic gripper, in particular with the gripper base section and / or the stripping section. To compensate for the height offset of the workpiece or the distance between the magnetic section and the workpiece, the magnetic section is moved to the lower contact position. This ensures secure gripping of workpieces of different heights without the handling device having to move the magnetic gripper to different starting positions.Furthermore, the magnetic gripper is designed in such a way that - if the magnetic gripper already comes into contact with the workpiece in the starting position - the workpiece is not pushed away or displaced when the magnetic section is moved.

[0013] Furthermore, such a magnetic gripper has the advantage that the gripped workpiece can be easily and safely released from the magnetic section by the stripping section when the magnetic section is moved toward the release position. The distance between the magnetic section and the workpiece is increased by the stripping section until the magnetic attraction force is no longer sufficient to maintain a magnetic gripping connection between the holding magnet and the workpiece.

[0014] It is conceivable that the magnetic section with the at least one holding magnet is arranged on the piston rod, and wherein the stripping section with the at least one stripper is arranged on the gripper base section. The distance between the magnetic section or the holding magnet of the magnetic section and the gripped workpiece can be increased by moving the magnetic section with the holding magnet away from the workpiece in the direction of the release position by displacing the piston rod along the longitudinal axis of the piston rod, wherein the stripper prevents the workpiece from moving along with the moving magnetic section or holding magnet.

[0015] It is also conceivable for the magnetic gripper to be designed as a non-magnetic gripper, with the magnetic section being designed as a gripping section and the holding magnet as an adhesion or cohesion element. Accordingly, even non-partially magnetizable and / or non-ferromagnetic workpieces could be gripped by the gripper.

[0016] The object underlying the invention is also achieved by a magnetic gripper according to claim 2. The magnetic gripper is intended for arrangement on a handling device and / or on a manipulator, such as a robot or gantry system. The magnetic gripper is designed to grip at least partially magnetizable and / or ferromagnetic workpieces. The magnetic gripper has a gripper base section with an interior space, wherein the interior is preferably cylindrical and / or is designed with an upper cylinder end and a lower cylinder end. Furthermore, the magnetic gripper provides a piston section with a piston rod extending along a longitudinal axis and with a piston arranged on the piston rod and in the interior space of the gripper base section.

[0017] The magnetic gripper also provides a magnetic section with holding magnets for magnetically gripping the workpiece. The holding magnets each have a magnetic north pole and a magnetic south pole. The magnetic section is arranged on the piston rod and / or on the gripper base section. The piston rod and / or the magnetic section can be displaced by means of the piston along the longitudinal axis between an upper release position and a lower contact position. The stroke of the piston section preferably corresponds essentially to the distance between the upper cylinder end and the lower cylinder end. The upper release position of the magnetic section preferably corresponds to the piston position at the upper cylinder end, and the lower contact position of the magnetic section corresponds to the piston position at the lower cylinder end.

[0018] The magnet section further comprises at least one first holding magnet with a north pole facing the workpiece and at least one holding magnet with a south pole facing the workpiece. Accordingly, the south pole of the first holding magnet and the north pole of the second holding magnet face the piston and / or the upper cylinder end.

[0019] Such a magnetic gripper offers the advantage that a workpiece, in particular a battery cell, can be gripped easily, efficiently, quickly and / or securely, regardless of its actual height. The magnetic gripper can be moved to a predetermined starting position by means of the handling device, whereby the workpiece to be gripped does not yet come into contact with the magnetic gripper, in particular with the gripper base section and / or the stripping section. The opposing orientation of the holding magnets creates a self-contained, axially directed magnetic field, whereby workpieces spaced apart from the magnetic section can also be gripped. Consequently, secure gripping of workpieces of different heights is ensured without the handling device having to move the magnetic gripper to different starting positions.

[0020] Advantageously, the magnetic gripper further comprises a stripping section with at least one stripper for releasing a magnetic gripping connection between the magnetic section and the workpiece, wherein the stripping section is arranged on the piston rod and / or on the gripper base section and is configured to strip the workpiece gripped by the magnetic section when the piston rod is displaced along the longitudinal axis of the piston rod by means of the at least one stripper. It is conceivable that, in addition to the stripping section, a presser is also provided for pressing the workpieces against the magnetic gripper. Alternatively, it is conceivable for the stripping section to comprise the presser. This has the advantage that the gripped workpiece can be easily and safely released from the magnetic section by the stripping section when the magnetic section is displaced towards the release position.The distance between the magnet section and the workpiece is increased by the stripping section until the magnetic attraction force is no longer sufficient to maintain a magnetic gripping connection between the holding magnet and the workpiece.

[0021] An advantageous development of the invention provides that the at least one first holding magnet is arranged along a first circular line arranged around the longitudinal axis with a first diameter, and / or the at least one second holding magnet is arranged along a second circular line arranged around the longitudinal axis with a second diameter. The annular arrangement of the individual first holding magnets and / or the individual second holding magnets results in a magnetic field with improved axial orientation.

[0022] It is advantageous for the first diameter to be larger than the second diameter. Alternatively, it is conceivable for the second diameter to be larger than the first diameter. Furthermore, it is advantageous for the ratio between the first diameter and the second diameter to be greater than 0.2:1, in particular greater than 0.5:1, preferably greater than 1:1, and more preferably greater than 1.2:1 and / or less than 5:1, in particular less than 3:1, preferably less than 2:1, and more preferably less than 1.5:1.

[0023] Advantageously, the magnet section has at least two first holding magnets, wherein, in particular, two first holding magnets adjacent along the circumference of the first circular line enclose a first angle α with the longitudinal axis. The first angle α is determined according to the following equation: α=360∘ / nNumber of first holding magnets

[0024] In the case of six first holding magnets, two adjacent first holding magnets have a first angle α of 60°.

[0025] Advantageously, the magnet section has at least two second holding magnets, wherein, in particular, two second holding magnets adjacent along the circumference of the second circular line enclose a second angle β with the longitudinal axis. The second angle β is determined according to the following equation: β=360∘ / nNumber of second holding magnets

[0026] In the case of six second holding magnets, two adjacent second holding magnets have a first angle α of 60°.

[0027] In the case of six first holding magnets and six second holding magnets, two adjacent holding magnets, i.e., a first holding magnet and a second holding magnet, have an angle γ of 30°. Accordingly, a uniformly distributed, axially directed magnetic field can be provided. To provide an axially directed magnetic field, it is advantageous to provide an even number (divisible by 2 without a remainder) of holding magnets.

[0028] Furthermore, it is advantageous if the gripper base section and / or the stripping section has a magnetic holder for receiving the holding magnets. It is also advantageous if an insulating element is arranged between the magnetic holder and the piston section, wherein the insulating element promotes an orientation of the magnetic field toward the workpiece. The insulating element can comprise at least one of the following elements: Al, Zn, Mg, Cu, and / or preferably be formed from an aluminum-zinc base.

[0029] In addition, the magnetic holder can have a holding leg that radially surrounds the at least one holding magnet, in particular completely, and / or is cylindrically shaped. The holding leg also serves to orient the magnetic field toward the workpiece and also ensures radial protection of the magnetic field. Accordingly, when using several magnetic grippers arranged radially next to one another, there is little or no mutual influence of the magnetic fields, in particular no magnetic field weakening. The magnetic holder, in particular the holding leg, preferably comprises a ferromagnetic and / or metallic material.

[0030] The magnetic holder advantageously has magnetic receptacles, which ensure precise positioning, in particular precise height positioning, of the holding magnets. The magnetic receptacles have at least partially the cross-section of the holding magnets and / or serve to guide and hold the holding magnets. The precise positioning of the holding magnets in the magnetic holder ensures optimal axial orientation of the magnetic field. It is advantageous if the empty space in the magnetic holder is filled with a material that does not influence the magnetic field, in particular epoxy resin, preferably by casting. The side of the magnetic holder facing the workpiece is then milled or turned flat so that each holding magnet and / or each magnetic gripper has a defined magnetic section end.

[0031] Thus, by positioning the magnetic gripper and / or the magnetic section, a defined air gap can be created between the holding magnets and the workpiece. Consequently, targeted gripping force and / or magnetic force adjustment is possible.

[0032] It is advantageous if the piston, with its interior space above the piston, defines an upper first pressure chamber and a lower second pressure chamber below the piston. To move the piston and / or the magnetic section from the release position to the contact position or to the workpiece, the first pressure chamber can preferably be subjected to a first operating pressure. To move the piston and / or the magnetic section from the contact position to the release position or away from the workpiece, the second pressure chamber can be subjected to a second operating pressure. Consequently, a precise displacement of the magnetic section can be achieved by a pneumatic or hydraulic drive.

[0033] A particularly preferred embodiment results from the fact that the magnetic gripper has at least one state sensor at least for detecting a gripping state of the magnetic gripper, in which the magnetic section is in the magnetic gripping connection with the workpiece or the magnetic gripping connection between the magnetic section and the workpiece is released or the magnetic gripping connection is stripped off at that moment. Furthermore, the magnetic gripper can additionally or alternatively have at least one position sensor for detecting the axial position of the magnetic section and / or the piston section. This ensures process reliability. The state sensor can, for example, be a magnetic switch. The state sensor can also be arranged on an outer circumferential surface of the gripper base section.In particular, the gripping state of the magnetic gripper can be detected by detecting the axial position of the piston in the interior of the gripper base section. It is also conceivable that at least one pressure sensor is provided. The pressure sensor and / or the position sensor can also be used to detect the height of the workpieces, in particular the battery cell, during gripping. It is conceivable that the state sensor is designed as an optical or inductive sensor. The state sensor and / or the position sensor and / or the pressure sensor can preferably be arranged in, on, or outside the gripper base section.

[0034] The pressure sensor can also be used to measure the holding force used to hold the workpiece in position. It is conceivable that the position signals from the position sensor and the pressure signals from the pressure sensor are processed together in a controller. Depending on the position signals and the pressure signals, a proportional force / displacement measurement can be performed, which serves as an indicator of a secure grip and the safe reaching of the contact position, the release position, or the gripping position. If low pressure is detected, the magnetic gripper cannot be moved to the contact position and the gripping position at the same time. A secure grip of all workpieces would then not be indicated. If the gripper is not in the defined gripping, holding, or release position, the safe operation of the respective individual magnetic gripper within the respective cluster cannot be guaranteed.

[0035] To determine the operating states of the at least one condition sensor, the magnetic gripper and / or the system and / or the handling device and / or the manipulator and / or the robot within which the magnetic gripper can be arranged provides a controller. This controller can be designed as a gripper control controller. By means of the controller, the operating states of the at least one condition sensor of each individual magnetic gripper, as well as the operating states of condition sensors of magnetic grippers that can be arranged in groups, can be determined. Furthermore, the respective operating states of the at least one condition sensor and / or the condition sensors can be changed by means of the controller. It can be provided that the operating states of the condition sensors, which can be determined and changed by means of the controller, are fed to a display unit, for example by means of a display or by means of illuminated displays.The display unit can be arranged on the magnetic gripper itself and / or the system and / or the handling device and / or the manipulator and / or the robot. If, based on interconnectable status sensors, such as the previously described fusion of the position and pressure signals, the controller, which can be designed as a higher-level gripper control system, detects in summary that only some of the magnetic grippers are engaging in the respective position or that only some of the magnetic grippers have disengaged, the higher-level control system can decide whether to repeat the gripping process or to end it before the gripping device is relocated. The summation by the controller can, for example, specify summary values ​​between 70% and 100%, in particular 80% and 100%, preferably between 90% and 100% as minimum values ​​for reliably gripping all workpieces present in the gripping device.

[0036] The invention also relates to a magnetic gripper with the features of claim 1 and with a plurality of holding magnets arranged on the magnetic section with opposite orientations (north pole - south pole). Such a magnetic gripper has the advantage that much larger distances between the magnetic gripper and the workpiece to be gripped can be compensated for by the displaceability of the magnetic section and the directed magnetic field. Furthermore, such a magnetic gripper with one or more features of claims 4 to 10 is conceivable.

[0037] The object underlying the invention is further achieved by a system having the features of claim 11. This system for a handling device serves for gripping at least partially magnetizable and / or magnetic workpieces, in particular for simultaneously gripping multiple workpieces, wherein the workpieces have a height offset from one another, e.g., due to manufacturing tolerances. The system comprises at least two previously described magnetic grippers and a receiving device for receiving the magnetic grippers.

[0038] The system has the advantage that when the handling device approaches workpieces that are vertically offset from one another, a distance can remain between the magnetic grippers and the workpieces. By displacing the magnetic section, in particular beyond the stripping section, and / or by the axially oriented magnetic field of the holding magnets, the workpieces can be magnetically gripped, preferably pressed against the stripping section, and then handled with the handling device. Due to the radially adjacent arrangement of the magnetic grippers, magnetic field losses can occur, which can be prevented either by lower magnetic fields by displacing the magnetic section or by directed magnetic fields. The system according to the invention is particularly advantageous for magnetic grippers arranged radially next to one another.

[0039] It is also advantageous if the system is set up in such a way that, in order to grip workpieces with a height offset simultaneously, a first magnetic section is moved into the contact position and a second magnetic section is moved into the gripping position. This can be made possible, for example, by a pneumatic or hydraulic drive for moving the magnetic sections. The magnetic sections are moved from the release position until they come into contact with the workpiece or the maximum stroke is reached. A third operating pressure when moving the magnetic sections is set so low that the magnetic sections are moved but no damage occurs to the magnetic gripper or the workpiece, should the workpiece be higher than the other workpieces. The "soft" air cushion enables gentle contact with the workpiece and at the same time prevents the workpiece from being pushed away.This eliminates height differences between the magnetic gripper and the workpiece to be gripped, which may not be accounted for or compensated for by the magnetic gripper during the gripping process. Furthermore, the holding force of the axially amplified magnetic field may be insufficient to attract the workpiece across the unintentionally created air gap. The air gap counteracts this disadvantage.

[0040] The receiving device can, in particular, be designed as a frame. Furthermore, the receiving device can be designed as one or more supporting structures, with each supporting structure comprising, for example, a number of 4, 8, or 15 magnetic grippers as a module. Accordingly, it is possible to assemble receiving devices of any size by assembling several supporting structures into one large receiving device. The individual supporting structures are designed so that they can be detachably connected to one another. Furthermore, mounting sections for arranging handles or tool holders can be provided on the receiving device.

[0041] The majority of magnetic grippers are each held in the holding device in a force-locking and / or positive-locking manner, and in particular are also releasably mounted. This makes it particularly easy to replace defective magnetic grippers.

[0042] It is particularly advantageous if the receiving device is designed such that the plurality of magnetic grippers are accommodated in the receiving device at least in a row next to one another. In other words, the magnetic grippers can be accommodated in a row next to one another in the receiving device. This makes it possible to accommodate a high packing density, as occurs, for example, in a battery storage system. It is also conceivable for the plurality of magnetic grippers to be accommodated in the receiving device both in a row and in a column. This makes it possible to grip or handle at least partially magnetizable and / or magnetic workpieces in a flat, two-dimensional manner. This makes it possible to handle multiple workpieces particularly quickly, easily, safely, and efficiently.

[0043] It is also particularly preferred that the receiving device has at least one pressure medium distribution channel for fluidically supplying the plurality of magnetic grippers with a pressure medium for displacing a respective piston of the magnetic grippers. Thus, the plurality of magnetic grippers can be fluidically supplied with a pressure medium directly via the pressure medium distribution channel. Furthermore, disruptive pressure medium hoses on an outer circumferential surface of the gripper base section of a magnetic gripper can be prevented, and the plurality of magnetic grippers can be received by a receiving device in a particularly space-saving manner. For this purpose, a gripper base section of a respective magnetic gripper can have at least one pressure medium inlet on a bottom side of the gripper base section facing away from the gripped workpiece.The receiving device and / or the pressure medium distribution channel of the receiving device can have a respective correspondingly designed pressure medium interface for fluidic connection to the at least one pressure medium inlet of a respective magnetic gripper of the plurality of magnetic grippers. The fluidic connection of a respective magnetic gripper to the pressure medium distribution channel is thus advantageously tubeless. It is also conceivable for the receiving device to have at least two pressure medium distribution channels for distributing a first pressure medium and a second pressure medium to the plurality of magnetic grippers. Thus, double-acting magnetic grippers or double-acting piston sections of the plurality of magnetic grippers can also be operated by means of the receiving device.

[0044] A particularly preferred embodiment results from the fact that the receiving device has a status section with a plurality of status sensors for detecting a gripping state of a respective magnetic gripper of the plurality of magnetic grippers, in which the magnetic section is in the magnetic gripping connection with the workpiece, or the magnetic gripping connection between the magnetic section and the workpiece is released, or the magnetic gripping connection between the magnetic section and the workpiece is stripped off at that moment. Thus, disruptive information lines for transmitting data and / or disruptive magnetic switches as status sensors on an outer surface of the gripper base section of a magnetic gripper can be avoided, and a plurality of magnetic grippers can be accommodated by a receiving device in a particularly space-saving manner.A controller can be provided as a gripping control controller which, depending on a fusion of status signals from various status sensors, evaluates a secure grip and / or the position of the magnetic gripper and / or the position of the magnetic section and then determines whether the grip should be repeated or terminated.

[0045] It is conceivable that a status sensor, a position sensor, and / or a pressure sensor is provided for each magnetic gripper, for each support structure, for each line of magnetic grippers, and / or for each column of magnetic grippers. Furthermore, it is conceivable that a pressure sensor and / or a volume flow sensor is provided for each pressure distribution channel.

[0046] The invention also relates to a handling device with at least one magnetic gripper designed according to the invention. Alternatively, the invention relates to the handling device with at least one system designed according to the invention. The handling device can be a robot, e.g., an industrial robot, or a linear axis system. Furthermore, the handling device, in particular a tool holder and / or a tool holder of the handling device, can have a counter-mounting section for arranging on a mounting section of a gripper base section of the magnetic gripper for operatively connecting the handling device to the magnetic gripper.Alternatively or additionally, the handling device, in particular a tool holder and / or a tool holder of the handling device, can have a counter-handling mounting section for arranging on a handling mounting section of a holder device of the system for operatively connecting the handling device to the system according to the invention.

[0047] The magnetic gripper according to claim 1 or 2, the system according to claim 11, the handling device according to the invention and / or the method according to claim 13 can further comprise a controller. The controller can be arranged in or on the magnetic gripper, in or on the system and / or in or on the handling device. By means of the controller, operating states, in particular secure grip of a workpiece and / or reaching the release position, contact position, gripping position, of the magnetic gripper or of each individual magnetic gripper in a system or in a handling device can be detected. It is also conceivable for several magnetic grippers to be grouped in a system or in a handling device, wherein the operating states of the group of magnetic grippers can be detected as a single state by means of the controller. The operating states can also be changed by means of the controller, e.g., by controlling a drive unit or valves.It can further be provided that the operating states that can be detected and / or changed by means of the controller can be displayed on a display unit, e.g., a display or illuminated indicators. The display can be shown on each magnetic gripper and / or on each group of magnetic grippers and / or on the system and / or on the handling device and / or the manipulator.

[0048] The object underlying the invention is further achieved by a method having the features of claim 13. The method serves for gripping at least partially magnetizable and / or magnetic workpieces with a height offset from one another, wherein first workpieces have a first height and second workpieces have a second height, and wherein the first height is greater than the second height. Gripping can be carried out by means of a magnetic gripper with magnetic sections displaceable along a longitudinal axis between an upper release position and a lower contact position and stripping sections for releasing the magnetic connection between the magnetic sections and the workpieces. Alternatively, gripping can be carried out by means of a previously described magnetic gripper or by means of a previously described system.

[0049] During gripping according to the invention, the magnetic gripper is moved, for example, by means of a handling device, into a starting position above the workpieces, wherein first magnetic grippers, in particular first stripping sections and / or first pressing elements, contact the first workpieces (step a). Accordingly, some magnetic grippers are already in contact with the workpieces with the greatest height in the initial position.

[0050] The magnetic sections are then applied to the workpieces by moving the magnetic sections (step b). On the workpieces that are already in contact with the magnetic gripper in the initial position, the magnetic sections are moved to a gripping position located between the release position and the contact position. On the remaining workpieces, the magnetic sections are moved to the contact position, whereby the magnetic sections come into contact with the workpieces. Accordingly, the first magnetic grippers rest on the first workpieces with the first stripping sections and / or with the first pressing devices and with the first magnetic sections, whereby the first workpieces have a greater height. Furthermore, the second magnetic grippers rest on the second workpieces with the second magnetic sections, whereby the second workpieces have a lower height.The maximum height offset between the first workpieces and the second workpieces essentially corresponds to the maximum stroke of the piston or the magnet section.

[0051] The second workpieces are then lifted into the gripping position by moving the second magnetic sections, whereby the second workpieces contact the second stripping sections and / or the second pressing devices (step c). By lifting the second magnetic sections, all magnetic sections are in the gripping position. Consequently, all workpieces are also brought into contact with the stripping sections and / or the pressing device. By attracting the workpieces, it is ensured that in a subsequent assembly, transport or handling process, the magnetic gripper comes into uniform and flat contact with as many workpieces as possible and that no workpiece can fall out of the workpiece assembly, in particular no battery can protrude from the cell assembly of the battery cluster.

[0052] Consequently, the workpieces can be handled safely together (step d).

[0053] Finally, the workpieces are stripped from the magnetic grippers by moving the magnetic sections into the release position, whereby the stripping sections release the magnetic connection between the magnetic sections and the workpieces (step e).

[0054] The advantage of this process is that the magnetic gripper can always be moved to the same starting position and all workpieces can be securely gripped and subsequently handled despite height offsets.

[0055] The object underlying the invention is further achieved by a method having the features of claim 14. The method serves for gripping at least partially magnetizable and / or magnetic workpieces with a height offset from one another, wherein first workpieces have a first height and second workpieces have a second height, and wherein the first height is greater than the second height. The gripping is carried out by means of a magnetic gripper with magnetic sections displaceable along a longitudinal axis between an upper release position and a lower contact position and stripping sections for releasing the magnetic connection between the magnetic sections and the workpieces. Alternatively, the gripping is carried out by means of a previously described magnetic gripper or by means of a previously described system.

[0056] During gripping according to the invention, all magnetic sections of the magnetic grippers are moved into the contact position protruding from the stripping section and / or the pressing section (step a).

[0057] The magnetic gripper is then moved toward the workpieces from above, e.g., using a handling device, until the first magnetic section contacts the first workpieces. The magnetic gripper's advancement continues until the first magnetic sections and the first stripping sections and / or first pressing elements contact the first workpieces. At this time, the second magnetic sections also contact the second workpieces (step b).

[0058] In order to now also apply the second workpieces to the second magnetic grippers for the purpose of a flat contact, the second magnetic sections are moved from the contact position to the gripping position (step c). Accordingly, all workpieces are applied to the stripping sections and / or the pressing device. Attracting the workpieces ensures that, in a subsequent assembly, transport, or handling process, the magnetic gripper contacts all workpieces evenly and evenly, and that no workpiece can fall out of the workpiece assembly, in particular no battery can protrude from the cell assembly of the battery cluster.

[0059] Consequently, the workpieces can be handled safely together (step d).

[0060] Finally, the workpieces are stripped from the magnetic grippers by moving the magnetic sections into the release position, whereby the stripping sections release the magnetic connection between the magnetic sections and the workpieces (step e).

[0061] The method has the advantage that the workpieces can initially be approached gently, i.e. with little force or pressure, by means of the protruding magnetic sections. It is advantageous if the magnetic sections are driven pneumatically or hydraulically so that the magnetic sections are flexible. This results in a slight spring effect that is particularly gentle on the workpieces to be gripped as well as on the gripper base section and / or the receiving device of the magnetic grippers. Alternatively, it is conceivable to arrange a compression spring in the first pressure chamber and / or a tension spring in the second pressure chamber on the piston. As the magnetic grippers approach the workpieces further, the first magnetic grippers are pushed back by the workpieces from the contact position into the gripping position. In addition, the method ensures secure gripping of workpieces with a height offset.

[0062] It is advantageous if, according to step a), in the starting position between the second magnet sections and the second workpieces, there is a first distance between 0 mm and 30 mm, in particular between 0 mm and 20 mm, preferably between 0 mm and 10 mm, further preferably between 0 mm and 5 mm and preferably between 0 mm and 2 mm.

[0063] Further details and advantageous embodiments of the invention can be found in the following description, on the basis of which embodiments of the invention are further described and explained.

[0064] They show: Fig. 1 a schematic side view of a magnetic gripper according to the invention in an initial situation above the workpiece, wherein the magnetic section is in the release position, Fig. 2 a schematic side view of the magnetic gripper according to Fig. 1, wherein the magnet section is shifted to the contact position, Fig. 3 a schematic side view of the magnetic gripper according to Fig. 1, wherein the magnet section is moved to the gripping position and the workpiece is slightly lifted, Fig. 4 a schematic side view of the magnetic gripper according to Fig. 1, whereby the magnetic gripper is moved together with the workpiece, Fig. 5 a schematic side view of a magnetic gripper according to the invention in a starting position above the workpiece, wherein the magnet section is displaced in the contact position, Fig. 6 a schematic side view of the magnetic gripper according to Fig. 5, whereby the magnetic gripper is moved towards the workpiece until the magnetic section comes into contact with the workpiece, Fig. 7 a schematic side view of the magnetic gripper according to Fig. 5, whereby the magnetic gripper is moved further towards the workpiece until the magnetic section is moved by the workpiece from the contact position to the gripping position, Fig. 8 a schematic side view of the magnetic gripper according to Fig. 5, whereby the magnetic gripper is moved together with the workpiece, Fig. 9 a schematic side view of a system according to the invention with three magnetic grippers according to the invention, wherein two workpieces with a first height and one workpiece with a second height are to be gripped, Fig. 10 a schematic side view of a system according to Fig. 9, wherein two magnetic grippers each bear against two workpieces with a stripping section and wherein one magnetic gripper bears against the third workpiece with a protruding magnetic section, Fig. 11 a schematic partial section of a magnetic gripper according to the invention, Fig. 12 a perspective view of a system according to the invention as a magnetic gripper cluster with 15 magnetic grippers according to the invention, Fig. 13 a perspective view of a magnet section and a stripping section of a magnetic gripper according to the invention, Fig. 14 a sectional view of the magnetic gripper according to Fig. 13, Fig. 15 a schematic front view of a magnetic gripper according to the invention with eight holding magnets, Fig. 16 a schematic front view of a magnetic gripper according to the invention with 12 holding magnets, Fig. 17 a schematic front view of a magnetic holder, Fig. 18 a schematic sectional view of the magnet holder according to Fig. 17, Fig. 19 a perspective view of the magnetic holder according to Fig. 17 with 7 of 14 mounted holding magnets, Fig. 20 a perspective view of the magnetic holder according to Fig. 17 with 14 mounted holding magnets, and Fig. 21 a schematic side view of the magnetic holder according to Fig. 17 with a void filled with epoxy resin.

[0065] In the Fig. 11 shows a partial section of a magnetic gripper 10 according to the invention. Fig. 1 to 8 also show the magnetic gripper 10 according to the invention according to Fig. 11 in an abstract representation. The magnetic gripper 10 is used for arrangement on a Fig. 9 and for gripping an at least partially magnetizable and / or ferromagnetic workpiece 14. The magnetic gripper 10 has a pot-shaped gripper base section 16 with a cylindrical interior 18. The interior 18 is delimited by a cylinder base 20 and a sleeve-shaped cylinder shell 22. The interior 18 of the gripper base section 16 is accessible from the cylinder base 20 through a cylinder opening 24.

[0066] The magnetic gripper 10 further comprises a piston section 26 with a piston rod 28 arranged along a longitudinal axis 27, wherein the piston rod 28 has a first rod end 30 facing the cylinder base 20 and a second rod end 32 opposite the first rod end 30. The piston rod 28 has a guide receptacle 34 at its first rod end 30 for receiving a guide element 36. Furthermore, a base recess 38 for receiving the guide element 36 is provided in the cylinder base 20. In addition, the piston section 26 has a piston 40, wherein the piston 40 is arranged at the first rod end 30. The piston 40 is arranged displaceably along the longitudinal axis 27 in the interior 18 of the gripper base section 16. A position tappet 37 is also provided on the guide element 36, which is formed as an extension of the piston rod 28 and serves to query the position of the piston 40.

[0067] The magnetic gripper 10 has a substantially cylindrical stripping section 42 with a stripping head 44 facing the gripper base section 16 and a stripper 46 opposite the stripping head 44. The stripping head 44 comprises on its outer side an outer first threaded section 48, which is screwed into an inner second threaded section 49 arranged on the gripper base section 16. In the screwed-in state, the stripping head 44, opposite the cylinder base 20, closes the interior 18 of the gripper base section 16. Accordingly, the gripper base section 16 and the stripping head 44, together with the piston 40, form a cylinder-piston unit.

[0068] The piston 40, together with the cylinder base 20 and the cylinder jacket 22, defines a first pressure chamber 50. The piston 40 further defines a second pressure chamber 52 with the stripping head 44 and the interior space 18. Accordingly, the piston section 26 is displaceably guided in the cylinder base 20 and, via the piston 40, on the cylinder jacket 22. The first pressure chamber 50 is fluidically connected to a first pressure medium distribution channel 54. The second pressure chamber 52 is fluidically connected to a second pressure medium distribution channel 56. The piston 40 is displaceable along the longitudinal axis 27 between an upper first cylinder end 58 assigned to the cylinder base 20 and a lower second cylinder end 60 assigned to the stripping head 44, wherein the first pressure chamber 50 can be pressurized with a first operating pressure p1 by means of the first pressure medium distribution channel 54 and / or the second pressure chamber 52 can be pressurized with a second operating pressure p2 by means of the second pressure medium distribution channel 56.The distance between the first cylinder end 58 and the second cylinder end 60 corresponds to the maximum stroke of the piston 40.

[0069] The magnetic gripper 10 further comprises a magnet section 62, wherein the magnet section 62 is arranged on the second rod end 32 of the piston rod 28, in particular by means of at least one first fastening means 64, such as a screw, extending along the longitudinal axis 27. The magnet section 62 is guided displaceably on the inside of the stripping section 42 along the longitudinal axis 27. The magnet section 62 has an insulating element 66 and a magnet holder 68, wherein the first fastening means 64 fastens the insulating element 66 to the piston rod 28 and a second fastening means 70 extending parallel to the longitudinal axis 27 fastens the magnet holder 68 to the insulating element 66.

[0070] The magnetic holder 68 has a holder base 72 facing the insulation element 66, wherein the holder base 72 has magnet receptacles 74 for receiving holding magnets 76 (not shown). The holding magnets 76 form a magnetic field 73, which is used for magnetically gripping the workpieces 14. The magnet receptacle 74 can be introduced in the holder base 72 in the form of a groove. Alternatively, the magnet receptacle 74 can be formed as shown in Fig. 17 and Fig. 19, be formed as a plurality of circular recesses 75, which are arranged adjacent to one another along a circumference with a radial offset from one another. Due to the overlap of the circular recesses 75, the magnet receptacle 74 is formed, which extends continuously along the circumference and into which the holding magnets 76 can be securely positioned. This ensures that the holding magnets 76 generate a defined magnetic field 73.

[0071] The magnet holder 68, in particular the holder base 72, has an opening 77, whereby the magnet section 62 can be detached from the piston rod 28 via the fastening screw 64 even when the magnet holder 68 is mounted on the insulation element 66.

[0072] At the base of the support 72, according to Fig. 17 to 21, a holding leg 78 is also arranged, protruding from the holding base 72. The holding leg 78 is circular and radially surrounds the holding magnets 76. Due to the insulation element 66, the holding base 72, and the holding leg 78, it can be ensured that the magnetic field 73 generated by the holding magnets 76 is axially oriented and preferably acts in the direction of the workpiece 14 to be gripped. Furthermore, the magnetic field 73 can be radially secured by the holding leg 78, so that there is no mutual influence of the magnetic fields 73 in adjacent magnetic grippers 10.

[0073] The cavity 80 formed by the support base 72, the holding magnets 76, and the support leg 78 can preferably be filled with a filler 82, in particular epoxy resin, that does not influence the magnetic field. The active surface 84 of the magnetic section 62 facing the workpiece is subsequently turned or milled flat, creating a defined underside of the magnetic section 62. Due to the magnet receptacle 74, a defined distance or air gap can be provided between the magnetic gripper 62 and the workpiece 14.

[0074] For targeted axial orientation of the magnetic field, it is advantageous if the magnet section 62 is arranged according to Fig. 13 to 21 comprises at least one first holding magnet 76a with a magnetic north pole 86 facing the workpiece 14 and at least one second holding magnet 76b with a magnetic south pole 88 facing the workpiece. Accordingly, the first holding magnet 76a has a magnetic south pole 88 facing the holder base 72 and the second holding magnet 76b has a magnetic north pole 86 facing the holder base 72. In the magnet sections 62 of the Fig. 13, 17 to 21, seven first holding magnets 76a and seven second holding magnets 76b are provided. In the magnet sections 62 of the Fig. 15, four first holding magnets 76a and four second holding magnets 76b are provided. In the magnet sections 62 of the Fig. 16, six first holding magnets 76a and six second holding magnets 76b are provided.

[0075] The first holding magnets 76a, in particular their centers, are arranged along a first circular line 90 with a first diameter 92 arranged around the longitudinal axis 27. The first holding magnets 76a are evenly spaced along the circular line 90. Two adjacent first holding magnets 76a, in particular their centers, enclose a first angle α with the longitudinal axis 27, wherein the first angle α corresponds to the formula 360° / n Anzahl der ersten Haltemagnete Accordingly, for example, two adjacent first holding magnets 76a, when six first holding magnets 76a are provided, have a first angle α of 60°.

[0076] The second holding magnets 76b, in particular their centers, are arranged along a second circular line 94 with a second diameter 96 arranged around the longitudinal axis 27. The second holding magnets 76b are evenly spaced along the circular line 94. Two adjacent second holding magnets 76b, in particular their centers, enclose a second angle β with the longitudinal axis 27, wherein the angle β corresponds to the formula 360° / n Anzahl der zweiten Haltemagnete Accordingly, two adjacent second holding magnets 76b, when six second holding magnets 76b are provided, have a second angle β of 60°.

[0077] The holding magnets 76 are arranged alternately, so that a first holding magnet 76a and a second holding magnet 76b alternate along the circular lines 90, 94. With a total of twelve holding magnets 76, two adjacent holding magnets 76, i.e., a first holding magnet 76a and a second holding magnet 76b, have a third angle γ of 30°.

[0078] Furthermore, the holding magnets 76 are arranged such that the first diameter 92 is larger than the second diameter 96. The first diameter 92 and the second diameter 96 have a ratio between 0.2:1 and 5:1, in particular between 0.5:1 and 3:1, preferably between 1:1 and 2:1, and more preferably between 1.2:1 and 1.5:1. Consequently, the first holding magnets 76a are offset radially outwards and the second holding magnets 76b are offset radially inwards. Due to the offset arrangement of the holding magnets 76, an axially oriented magnetic field 73 is produced, so that a secure gripping of workpieces 14 is possible, even with an air gap between the magnet section 62 and the workpiece 14.

[0079] The Fig. 1 to 4 and the Fig. 5 to 8 show two different methods for gripping workpieces 14 by means of a magnetic gripper 10 according to the invention. The magnetic gripper 10 is arranged on a handling device 12 (not shown) and can be moved by it along the axes X, Y and Z.

[0080] In Fig. 1, the magnetic gripper 10 is in a starting position above the workpiece 14 to be gripped, with the arrow indicating that the entire magnetic gripper 10 has been moved. The distance 98 between the magnetic gripper 10, in particular the stripping section 46, and the workpiece 14 is approximately 2 mm, whereby the distance 98 in the illustration shows a greater distance 98 than 2 mm in relation to the magnetic gripper 10 and the workpiece 14 for better illustration. The distance 98 enables the magnetic gripper 10 to move quickly to the workpiece without an unwanted collision occurring. The magnetic section 62 is in an upper release position, in which no relevant magnetic effect emanates from the magnetic section 62 on the workpiece 14. The release position of the magnetic section 62 corresponds to the position of the piston 40 in the region of the upper first cylinder end 58.

[0081] In Fig. 2, the magnetic section 62 is in a lower contact position, wherein the magnetic section 62 contacts the workpiece 14 and thus a magnetic connection exists between the magnetic section 62 and the workpiece 14. The contact position of the magnetic section 62 corresponds to the position of the piston 40 in the region of the lower second cylinder end 60. To displace the magnetic section 62 from the release position to the contact position, i.e. in the Z direction, the first pressure chamber 50 is pressurized with a third operating pressure p3 by means of the first pressure medium distribution channel 54. The stripping section 42, in particular the stripping head 44, forms the end stop of the piston 40 opposite to the Z direction.

[0082] In Fig. 3, the magnetic section 62 is displaced counter to the Z direction along the longitudinal axis 27 such that the magnetic section 62 is flush with the stripper 46. In this position, the magnetic section 62 is in a gripping position arranged between the release position and the contact position. To displace the magnetic section 62 from the contact position to the gripping position, the second pressure chamber 52 is pressurized with a fourth operating pressure p4. In this process, the workpiece 14 is attracted against the stripper section 42 and / or a pressure element (not shown) to ensure uniform contact of the workpiece 14.

[0083] The magnetic holder 68 or the stripping section 42 can further provide a sleeve-shaped guide section (not shown) for more securely holding the workpieces 14 during gripping. In this case, the guide section has an inner cross-section that corresponds to the outer cross-section of the workpiece 14 to be gripped.

[0084] Afterwards, according to Fig. 4 the workpiece 14 is handled, wherein the magnet section 62 remains in the gripping position and the entire magnetic gripper 10 is displaced by the handling device 12.

[0085] The first operating pressure p1 preferably serves to displace the magnetic section 62 from the release position to the contact position. The second operating pressure p2 preferably serves to displace the magnetic section 62 from the contact position and / or gripping position to the release position. The third operating pressure p3 serves as a cushion and / or spring when approaching the workpiece when the magnetic section 62 is in the contact position. The fourth operating pressure p4 serves to displace the magnetic section 62 from the contact position to the gripping position when the magnetic section 62 contacts a workpiece 14 in the contact position and attracts it to the stripping section 42.

[0086] Preferably, the first operating pressure p1 corresponds to the second operating pressure p2. Furthermore, it is conceivable that the third operating pressure p3 is smaller than the first operating pressure p1 and / or the second operating pressure p2. Furthermore, it is conceivable that the fourth operating pressure p4 is smaller than the first operating pressure p1 and / or the second operating pressure p2. The first operating pressure p1 and / or the second operating pressure p2 is preferably 6 bar. The third operating pressure p3 is preferably determined from the ratio between the maximum permissible force F zul which is applied from the outside to the gripping surface A Kolben of the workpiece 14 to be gripped: p3=F zulA piston

[0087] Furthermore, the fourth operating pressure p4 is greater than the ratio between A Kolben the weight force F Gew Wst of the workpiece 14 and the gripping surface and / or smaller than the ratio between the magnetic force and the gripping surface: F weight of the workpiece A piston <p4<F magnetA kolben

[0088] In Fig. 5, the magnetic gripper 10 is in a starting position above the workpiece 14 to be gripped. Before the magnetic gripper 10 approaches the workpiece 14, the magnetic section 62 is moved into the contact position. The first pressure chamber 50 is pressurized with a third operating pressure p3 such that the magnetic section 62 can be moved against the workpiece 14 under spring pressure, in particular with damping. This allows the workpieces 14 to be gripped particularly gently.

[0089] As soon as the third operating pressure p3 is established in the first pressure chamber 50, the magnetic gripper 10 can be moved to the workpiece 14 with the magnetic section 62 projecting opposite the stripping section 42 in the opposite direction to the Z-axis. In the contact position, the magnetic section 62 contacts Fig. 6 the workpiece 14, wherein the axially directed magnetic field 73 has an attractive effect on the workpiece 14. The stripping section 42 preferably has a distance 98 from the workpiece 14.

[0090] According to Fig. 7, the magnetic section 62 is displaced counter to the Z direction along the longitudinal axis 27 such that the magnetic section 62 is flush with the stripper 46. In this position, the magnetic section 62 is in the gripping position. The workpiece 14 is thereby attracted against the stripper section 42 and / or a pressing device (not shown).

[0091] Afterwards, according to Fig. 8 the workpiece 14 can be handled, wherein the magnet section 62 remains in the gripping position and the entire magnetic gripper 10 is displaced by the handling device 12.

[0092] Another method is a combination of the Fig. 1 to 4 and the method shown in the Fig. 5 to 8. First, the magnetic gripper 10 with the protruding magnetic section 62 is moved to the workpiece 14 until the magnetic section 62 is in accordance with Fig. 6 contacts the workpiece 14 and the stripping section 42 has a distance 98 to the workpiece 14. Subsequently, the workpiece is Fig. 3 is pulled towards the stripping section 42, whereby the magnetic gripper 10 remains in its position. Then the workpiece 14 is Fig. 4 by moving the entire magnetic gripper 10.

[0093] According to Fig. 9 and Fig. 10, a plurality of magnetic grippers 10 can be combined in a system 100 according to the invention as a magnetic gripper cluster. The system 100 serves to simultaneously grip a plurality of workpieces 14, wherein a magnetic gripper can be provided for each workpiece 14 to be gripped. In this case, the system 100 has a receiving device 102 for receiving three magnetic grippers 10, each of which is intended to grip a workpiece 14. The workpieces 14 comprise two first workpieces 14a and a second workpiece 14b, wherein the first workpieces 14a have a first height 104 and the second workpiece 14b have a second height 106. For example, the first height 104 is 2 mm greater than the second height 106.

[0094] Fig. 9 shows the first step in using the system 100 according to the invention. However, this also represents the current state of the art. When a system 100 with multiple magnetic grippers 10 approaches the workpieces 14, the left and right magnetic grippers 10 come into contact with the associated first workpieces 14a, since these have a first height 104. Neither the system 100 nor the middle magnetic gripper 10 can be moved further downward to grip the second workpiece 14b with the lower second height 106. In the prior art, the middle second workpiece 14b would therefore not be gripped.

[0095] According to Fig. 10, the system 100 according to the invention with the magnetic gripper 10 according to the invention can grip the middle second workpiece 14b despite the height offset. To do so, the magnetic section 62 is displaced counter to the Z direction beyond the stripping section 42 into the contact position. In the contact position, the magnetic section 62 contacts the second workpiece 14b and can attract it to the stripping section 42. Accordingly, all workpieces 14 are gripped, with all magnetic sections 62 being arranged in the gripping position.

[0096] The Fig.Figure 12 shows a system 100 configured as a magnetic gripper cluster with 15 magnetic grippers 10, wherein the magnetic grippers 10 are arranged in a 5x3 matrix. To achieve a particularly high packing density, the columns and rows of the matrix are offset from one another. Accordingly, adjacent lines of three magnetic grippers 10 are each offset from one another by the radius of a magnetic gripper 10. It is conceivable for the systems 100 to be modular, so that a plurality of systems 100 can be combined to handle more than 15 workpieces 14 simultaneously.

[0097] Furthermore, a control and / or regulating device 108 with a processor and a memory can be provided on the system 100 and / or for each magnetic gripper 10, wherein the control and / or regulating device 108 serves to control and / or regulate the pressure medium supply, in particular the pressurization of the pressure chambers 50, 52. Furthermore, at least one sensor 110 can be provided on the magnetic gripper 10 for detecting the position, the pressure, and / or the volume flow. The control and / or regulating device 108 can initiate the pressure medium supply depending on the sensor signals of the at least one sensor 110. Furthermore, the control and / or regulating device 108 can detect the functionality of a magnetic gripper 10.

[0098] In a system 100 with magnetic grippers 10 arranged in a matrix, it is advantageous if one sensor 110 is provided per cluster of, for example, 15 magnetic grippers 10 and / or per row and / or per column. In the event of a failure of a cluster, a column, and / or a row of magnetic grippers 10, maintenance can be directed accordingly.

[0099] It is further conceivable that, in a system 100 with a plurality of magnetic grippers 10, a pressure medium inlet is provided for each magnetic gripper 10, each cluster, each column, and / or each row. If a first pressure medium inlet 112 is provided for the first pressure chamber 50 and a second pressure medium inlet 114 is provided for the second pressure chamber 52 for a cluster, then a first pressure medium distribution channel 54 leads from the first pressure medium inlet 112 to the first pressure chamber 50 of a magnetic gripper 10, and a second pressure medium distribution channel 56 leads from the second pressure medium inlet 114 to the second pressure chamber 52 of a magnetic gripper 10. List of reference symbols α first angle β second angle γ third angle p0 ambient pressure p1 first operating pressure p2 second operating pressure p3 third operating pressure p4 fourth operating pressure n Number of first / second holding magnets X X-axis Y Y-axis Z Z-axis 10 magnetic grippers 12 Handling device 14, 14a, 14b Workpiece 16 Gripper base section 18 Interior 20 cylinder base 22 Cylinder barrel 24 cylinder opening 26 Piston section 27 Longitudinal axis 28 Piston rod 30 first rod end 32 second rod end 34 Lead recording 36 Guide element 37 Position tappet 38 floor recess 40 pistons 42 Stripping section 44 Stripping head 46 scrapers 48 first thread section 49 second thread section 50 first pressure chamber 52 second pressure chamber 54 first pressure medium distribution channel 56 second pressure medium distribution channel 58 first cylinder end 60 second cylinder end 62 Magnet section 64 first fastener 66 Insulation element 68 magnetic holder 70 second fastener 72 support base 73 Magnetic field 74 Magnetic holder 75 recesses in the base of the holder 76, 76a, 76b Holding magnets 77 Breakthrough in support base 78 bracket legs 80 cavity in magnetic holder 82 Filler in cavity 84 Effective area of ​​the magnet section 86 magnetic north pole of holding magnet 88 magnetic south pole of holding magnet 90 first circle line 92 first diameter 94 second circle line 96 second diameter 98 Distance between magnetic gripper and workpiece 100 systems 102 Holding device 104 first height 106 second height 108 Control and / or regulating device 110 Sensor 112 first pressure medium inlet 114 second pressure medium inlet

Claims

[1] Magnetic gripper (10) for a handling device (12) for gripping an at least partially magnetizable and / or ferromagnetic workpiece (14, 14a, 14b), the magnetic gripper (10) comprising: - a gripper base section (16) with an interior space (18), - a piston section (26) with a piston rod (28) extending along a longitudinal axis (27) and with a piston (40) arranged on the piston rod (28) and in the interior space (18), - a magnet section (62) with at least one holding magnet (76, 76a, 76b) for gripping the workpiece (14, 14a, 14b), wherein the magnet section (62) is arranged on the piston section (26), wherein the magnet section (62) is displaceable by means of the piston section (26) along the longitudinal axis (27) between an upper release position and a lower contact position, - a stripping section (42) with at least one stripper (46) arranged on the piston rod (28) and / or on the gripper base section (16) for releasing a gripping connection between the magnet section (62) and the workpiece (14, 14a, 14b) when the magnet section (62) is displaced in the direction of the release position, wherein the gripper base section (16) and / or the piston section (26) are designed such that the magnet section (62) protrudes in the contact position along the longitudinal axis (27) relative to the stripping section (42), and wherein the magnet section (62) has a magnet holder (68) for receiving the holding magnets (76, 76a, 76b) and an insulation element (66) arranged between the magnet holder (68) and the piston section (26). [2] Magnetic gripper (10) for a handling device (12) for gripping an at least partially magnetizable and / or ferromagnetic workpiece (14, 14a, 14b), the magnetic gripper (10) comprising: - a gripper base section (16) with an interior space (18), - a piston section (26) with a piston rod (28) extending along a longitudinal axis (27) and with a piston (40) arranged on the piston rod (28) and in the interior space (18), - a magnet section (62) with holding magnets (76, 76a, 76b) each having a north pole (86) and a south pole (88) for magnetically gripping the workpiece (14, 14a, 14b), wherein the magnet section (62) is arranged on the piston section (26), wherein the magnet section (62) is displaceable by means of the piston section (26) along the longitudinal axis (27) between an upper release position and a lower contact position, and wherein the magnet section (62) has at least one first holding magnet (76, 76a) with a north pole (86) facing the workpiece (14, 14a, 14b) and at least one second holding magnet (76, 76b) with a south pole (88) facing the workpiece (14, 14a, 14b). [3] Magnetic gripper (10) according to claim 2, wherein the magnetic gripper (10) comprises: - a stripping section (42) with at least one stripper (46) arranged on the piston rod (28) and / or on the gripper base section (16) for releasing a gripping connection between the magnet section (62) and the workpiece (14, 14a, 14b) when the magnet section (62) is displaced in the direction of the release position. [4] Magnetic gripper (10) according to claim 2 or 3, wherein the at least one first holding magnet (76, 76a) is arranged along a first circular line (90) arranged around the longitudinal axis (27) with a first diameter (92) and / or wherein the at least one second holding magnet (76, 76b) is arranged along a second circular line (94) arranged around the longitudinal axis (27) with a second diameter (96). [5] Magnetic gripper (10) according to one of claims 2 to 4, wherein the first diameter (92) is larger than the second diameter (96). [6] Magnetic gripper (10) according to one of claims 2 to 5, wherein two adjacent first holding magnets (76, 76a) enclose a first angle (α) with the longitudinal axis (27), wherein the first angle (α) is 360° / n Anzahl der ersten Haltemagnete corresponds, and / or wherein two adjacent second holding magnets (76, 76b) enclose a second angle (β) with the longitudinal axis (27), wherein the second angle (β) is 360° / n Anzahl derzweiten Haltemagnete corresponds. [7] Magnetic gripper (10) according to one of the preceding claims, wherein the magnet holder (68) has a holding leg (78) radially surrounding the at least one holding magnet (76, 76a, 76b) for orienting a magnetic field (73) generated by the holding magnets (76, 76a, 76b) and / or for radially shielding the at least one holding magnet (76, 76a, 76b), wherein preferably the magnet holder (68), in particular the holding leg (78), is ferromagnetic and / or metallic. [8] Magnetic gripper (10) according to one of the preceding claims, wherein the piston (40) with the interior space (18) delimits an upper first pressure chamber (50) and a lower second pressure chamber (52), wherein in order to displace the magnet section (62) from the release position into the contact position, the first pressure chamber (50) can be subjected to a first operating pressure (p1) and / or wherein in order to displace the magnet section (62) from the contact position into the release position, the second pressure chamber (52) can be subjected to a second operating pressure (p2). [9] Magnetic gripper (10) according to one of the preceding claims, wherein the magnetic gripper (10) has at least one state sensor (110) for detecting a gripping state and / or release state and / or stripping state of the magnetic gripper (10) and / or a position sensor (110) for detecting the position of the magnet section (62) and / or the piston section (26). [10] System (100) for a handling device (12) for gripping at least partially magnetizable and / or magnetic workpieces (14, 14a, 14b) with at least two magnetic grippers (10) according to one of the preceding claims and a receiving device (102) for receiving the magnetic grippers (10). [11] System (100) according to claim 10, wherein the system (100) is configured such that, in order to grip the workpieces (14, 14a, 14b), a first magnet section (62) is moved into the contact position and, at the same time, a second magnet section (62) is moved into the gripping position. [12] Method for gripping at least partially magnetizable and / or magnetic workpieces (14, 14a, 14b) with a height offset from one another, by means of magnetic grippers (10) with magnetic sections (62) that can be displaced along a longitudinal axis (27) between an upper release position and a lower contact position, and stripping sections (42) for releasing the magnetic connection between the magnetic sections (62) and the workpieces (14, 14a, 14b), or by means of a magnetic gripper (10) according to one of claims 1 or 3 to 6, or by means of a system (100) according to claim 10 or 11, comprising the following steps: a) moving the magnetic grippers (10) into a starting position above the workpieces (14, 14a, 14b), wherein first stripping sections (42) contact first workpieces (14, 14a), b) applying the magnetic sections (62) to the workpieces (14, 14a, 14b) by moving the magnetic sections (62), wherein first magnet sections (62) are displaced above first workpieces (14, 14a) into a gripping position arranged between the contact position and the release position, and wherein second magnet sections (62) are displaced into the contact position above second workpieces (14, 14b), c) lifting the second workpieces (14, 14b) by moving the second magnet sections (62) into the gripping position, whereby the second workpieces (14, 14b) contact the second stripping sections (42), d) handling the workpieces (14, 14a, 14b), and e) releasing the workpieces (14, 14a, 14b) from the magnetic grippers (10) by moving the magnetic sections (62) into the release position, wherein the stripping sections (42) releases the magnetic connection between the magnetic sections (62) and the workpieces (14, 14a, 14b). [13] Method for gripping at least partially magnetizable and / or magnetic workpieces (14, 14a, 14b) with a height offset from one another, by means of magnetic grippers (10) with magnetic sections (62) that can be displaced along a longitudinal axis (27) between an upper release position and a lower contact position, and stripping sections (42) for releasing the magnetic connection between the magnetic sections (62) and the workpieces (14, 14a, 14b), or by means of a magnetic gripper (10) according to one of claims 1 or 3 to 6, or by means of a system (100) according to claim 10 or 11, comprising the following steps: a) moving the magnet sections (62) into the contact position, b) moving the magnetic grippers (62) to a starting position above the workpieces (14, 14a, 14b), wherein first stripping sections (42) and first magnet sections (62) contact first workpieces (14, 14a), and wherein second magnet sections (62) contact second workpieces (14, 14b), c) lifting the second workpieces (14, 14b) by displacing the second magnet sections (62) into a gripping position arranged between the contact position and the release position, wherein the second workpieces (14, 14b) contact the second stripping sections (42), d) handling the workpieces (14, 14a, 14b), and e) releasing the workpieces (14, 14a, 14b) from the magnetic grippers (10) by moving the magnetic sections (62) into the release position, wherein the stripping sections (42) releases the magnetic connection between the magnetic sections (62) and the workpieces (14, 14a, 14b). [14] Method according to one of claims 12 or 13, wherein for displacing the magnet sections (62) the first pressure chamber (50) can be subjected to a first operating pressure (p1) and for contacting the magnet sections on the workpiece (14) the first pressure chamber (50) can be subjected to a third operating pressure (p3), wherein a ratio between the first operating pressure (p1) and the third operating pressure (p3) is in a range of 1:1.01 and 1:5, in particular in a range of 1:1.1 and 1:2, preferably in a range of 1:1.2 and 1:1.5.

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