Hose lifter with control valve

Abstract

Tube lifter (10), comprising - a lifting hose (12) which has a hose interior (14) and can be shortened by applying negative pressure to the hose interior (14); - a suction gripping device (18) which is arranged at one end of the lifting hose (12) and can be supplied with negative pressure through the hose interior (14) of the lifting hose (12), wherein the suction gripping device (18) has at least one suction point (20) for sucking up an object; - a control valve (24) for adjusting a flow resistance for flows from the suction gripping device (18) to the hose interior (14), wherein the control valve (24) comprises a valve housing (26) which extends along a main flow direction (32) from a suction connection (30) for flow connection with the suction gripping device (18) to a lifting hose connection (28) for flow connection with the lifting hose (12), wherein the valve housing (26) delimits a valve interior (34) which, on the one hand, is fluidly connected to the hose interior (14) via the lifting hose connection (28) and, on the other hand, is fluidly connected to the suction gripping device (18) via the suction connection (30), wherein the control valve (24) comprises a valve body (36) which is arranged in the valve interior (34) and is displaceable between a first switching position and a second switching position,wherein a total flow cross-section for flows from the suction connection (30) to the lifting hose connection (28) in the first switching position of the valve body (36) is smaller than in the second switching position of the valve body (36), but greater than zero, wherein the valve body (36) is acted upon in the direction of the second switching position, wherein the valve body (36) has a throttle passage (48) such that a first flow cross-section of the total flow cross-section is provided by the throttle passage (48), wherein the throttle passage (48) is open in the first and in the second switching position of the valve body (36), wherein a flow resistance for flows through the throttle passage (48) is defined such that the valve body (36), starting from the second switching position,in the case of free suction with at least one unoccupied suction point (20) is transferred into the first switching position against the application of pressure and in the case of suction with at least one occupied suction point (20) is transferred from the first switching position to the second switching position by the application of pressure.

Description

[0001] The invention relates to a tube lifter with a lifting hose, a suction gripping device and a control valve for adjusting a flow resistance for flows from the suction gripping device to the lifting hose.

[0002] Hose lifters are vacuum handling devices that can be used to lift, relocate, and then set down loads using negative pressure. The lifting force is exerted by a lifting hose, which can be shortened by applying negative pressure to its interior and lengthened again by releasing the negative pressure. A hose lifter is known, for example, from DE 10 2021 102 572 A1.

[0003] At one end of the lifting hose, a suction gripper device with at least one suction point for sucking up an object is typically arranged. The suction gripper device can preferably be supplied with negative pressure through the interior of the hose of the tube lifter. When the suction point is applied to an object to be transported, this creates a seal extending into the interior of the lifting hose, so that a negative pressure acting in the lifting hose shortens the lifting hose and thus lifts the object.

[0004] To prevent the lifting hose from shortening or to lengthen it again, e.g., to deposit the object, a vent valve is usually provided through which ambient air can be supplied to the lifting hose – superimposed on the negative pressure inside the hose. After the workpiece has been deposited at a target location, the separation of the object from the suction gripper can be assisted by opening the vent valve even further.

[0005] When the suction point is unoccupied, i.e., when no object is resting against the suction point of the suction gripper, leaking air flows through the suction point into the lifting hose, dissipating the negative pressure inside the hose and lengthening the lifting hose. However, this is not always desirable. For example, it can be advantageous if the hose lifter does not move to an end position, but remains at a preset hovering height even when the suction point is unoccupied, e.g., to be able to grasp the suction gripper from this working height in preparation for the next transport operation of an object.

[0006] For this purpose, it is known to provide a throttle valve flap, which represents a throttle cross-section for the air flowing through the suction gripper device. Depending on the throttle cross-section, a dynamic pressure can then be adjusted in the hose interior, thus keeping the lifting hose in a predefined floating position.

[0007] For example, DE 10 2020 128 380 A1 discloses a hose lifter for sucking up and transporting loads by means of suction force. The hose lifter comprises a suction foot assembly, which can be subjected to a vacuum created in a vacuum chamber via an operating unit operatively connected to a geodetically lower end of a lifting hose. The operating unit for varying the vacuum comprises a manually operable valve unit accommodated in a housing body with a duct arrangement formed in a valve body and in flow communication with the vacuum chamber for supplying external air. The external air volume flow can be regulated via a closing element that can be manually actuated by means of an actuating mechanism against the force of an energy accumulator and can be moved between a closed position and an open position to change the flow cross-section of the duct arrangement.wherein the closing element is held in the open position for external air supply by means of the force effect of the energy accumulator in the manually unactuated rest state, whereby the suction foot arrangement assumes its lower position in the rest state. In order to restore full suction power for picking up an object, automatic opening of the throttle valve flap is desirable. For this purpose, it is known, for example from DE 693 01 992 T2 and DE 196 14 478 C1, to provide a plunger on the suction gripping device. This plunger interacts with the throttle valve flap and is automatically actuated, e.g., pressed in, when the suction gripping device is placed on the object to be gripped. In some application situations, however, such a plunger can create an undesirable interference contour during gripping.

[0008] The invention is concerned with the task of simplifying the operation of a hose lifter, in particular of being able to adjust a floating position of a lifting hose in a structurally simple, robust and compact manner.

[0009] This object is achieved according to the invention by a tube lifter having the features of claim 1. The tube lifter is designed for gripping and handling, in particular lifting and setting down again, objects.

[0010] The tube lifter comprises a lifting hose. The lifting hose has a hose interior. The lifting hose can be shortened by applying negative pressure to the hose interior and lengthened again by ventilating the hose interior (i.e., by allowing air, particularly ambient air, to flow into the hose interior).

[0011] The tube lifter also comprises a suction gripping device for gripping an object. The suction gripping device is arranged at one end of the lifting hose and can be supplied with negative pressure through the interior of the lifting hose. The suction gripping device comprises at least one suction point for sucking up an object. In this respect, the suction gripping device comprises one or more suction points for sucking up an object. The suction gripping device can, for example, be an elastomer suction cup. In this case, a suction point can be provided by a suction opening of the elastomer suction cup. The suction gripping device can, for example, also be designed as a surface suction gripper with a plurality of suction points. For example, it is conceivable for the suction gripping device to be designed as a surface suction gripper with a plurality of suction bodies. In this case, each suction body can provide a suction point for sucking up an object.

[0012] The tube lifter also comprises a control valve for adjusting a flow resistance for flows from the suction gripping device, in particular from the at least one suction point, to the interior of the lifting hose. In this respect, the control valve is arranged in particular in a flow path from the suction gripping device, in particular from the at least one suction point of the suction gripping device, to the interior of the lifting hose.

[0013] The control valve comprises a valve housing. The valve housing has a suction port for fluid connection to the suction gripping device and a lifting hose port for fluid connection to the lifting hose. The valve housing extends along a main flow direction from the suction port to the lifting hose port.

[0014] The valve housing defines a valve interior. The valve interior is fluidically connected to the interior of the lifting hose via the lifting hose connection, on the one hand, and to the suction gripper device via the suction connection, on the other. The valve housing can, for example, have a cylindrical basic shape. In this case, it is conceivable, for example, for the lifting hose connection to be arranged on a first end face of the valve housing and the suction connection to be arranged on the opposite end face of the valve housing.

[0015] The control valve also comprises a valve body arranged in the valve interior, in particular between the suction connection and the lifting hose connection. In particular, the valve body is arranged in the valve interior such that the lifting hose connection is located on one side of the valve body and the suction connection is located on the other side of the valve body. The valve body is accommodated in the valve interior such that it can be displaced between a first switching position and a second switching position, in particular along the main flow direction.

[0016] The valve body is designed and provided in the valve interior such that a total flow cross-section for flows from the suction connection to the lifting hose connection is smaller in the first switching position of the valve body than in the second switching position of the valve body, but the total flow cross-section in the first switching position of the valve body is greater than zero. In this respect, the valve body is in particular designed and provided in the valve interior such that a flow cross-section for flows from the suction connection to the lifting hose connection is provided in both switching positions. In other words, the control valve is at least partially open in both switching positions of the valve body. As explained below, the total flow cross-section can be formed from a plurality of flow cross-sections or flow channels.

[0017] The valve body is loaded in the direction of the second switching position, in particular spring-loaded.

[0018] The valve body has a throttle passage, in particular a flow channel, such that a first flow cross-section of the total flow cross-section is provided by the throttle passage. The throttle passage thus provides a flow channel for flows from the suction port to the lifting hose connection. In other words, the valve body is particularly designed such that a flow path from the suction port to the lifting hose connection runs through the valve body or through the throttle passage of the valve body.

[0019] The valve body is designed and arranged in the valve interior such that the throttle passage is at least partially open in both the first and second switching positions. In this respect, the valve body is designed in particular such that a flow path for flows from the suction connection to the lifting hose connection is provided through the throttle passage, wherein this flow path is open in the first and second switching positions. In other words, the control valve is designed in particular such that a flow path from the suction connection to the lifting hose connection is opened through the throttle passage in both the first and second switching positions of the valve body.

[0020] The throttle passage is designed, in particular dimensioned, and preferably matched to the pressure, in such a way that a flow resistance for flows through the throttle passage is defined in such a way that the valve body, starting from the second switching position, is transferred into the first switching position against the pressure (in particular by the air flow from the suction connection to the lifting hose connection) in the case of free suction with at least one suction point unoccupied (i.e. when in particular no object is sucked into the at least one suction point), and in the case of suction with at least one occupied suction point (i.e. when, in the case of a single suction point, this is occupied, or when, in the case of several suction points, at least one of these suction points or several of these suction points, preferably all of these suction points, are occupied; for example, when an object is arranged or positioned at the at least one suction point).is sucked in) is transferred from the first switching position to the second switching position by the application.

[0021] Such a design makes it possible to automatically change the flow resistance for flows from the suction gripper device to the lifting hose, depending on whether or not an object is being suctioned onto the suction gripper device, in particular to switch between a comparatively large flow cross-section (second switching position) and a comparatively small flow cross-section (first switching position). In this way, a comparatively large flow cross-section and thus a high suction power can be provided when an object is being suctioned (i.e. when the suction point is occupied), and a reduced flow cross-section can be provided when there is free suction without an object (i.e. when the suction point is unoccupied). When there is free suction, the inflow of leakage air through the suction gripper device into the interior of the lifting hose is throttled.The total flow cross-section in the second switching position is selected in particular such that the lifting hose is held in an intermediate length between a minimum and a maximum length when subjected to negative pressure (floating position).

[0022] In particular, the valve body and the actuation of the valve body in the direction of the second switching position are designed and coordinated with one another in such a way that the valve body, starting from the second switching position, is displaced into the first switching position in the case of free suction with at least one suction point unoccupied and is displaced from the first switching position into the second switching position by the actuation when suction is effected with at least one occupied suction point (i.e. when a single suction point is present and this is occupied, or when at least one of these suction points or several of these suction points, preferably all of these suction points, are occupied) in the case of suction with at least one occupied suction point (i.e. when several suction points are present and at least one of these suction points or several of these suction points, preferably all of these suction points, are occupied).

[0023] The valve body can be acted upon by gravity. In this respect, the valve body can be provided such that it is acted upon by gravity in the direction of the second switching position, in particular in a state without the influence of negative pressure, it is in the second switching position. Alternatively or additionally, the control valve can be provided with a spring device designed to act upon the valve body in the direction of the second switching position. In this respect, the valve body can be spring-loaded into the second switching position. The spring device can in particular comprise one or more compression springs.

[0024] The valve body can in principle be shaped as desired. Advantageously, the valve body can be designed as a valve disc. In this respect, the valve body can be disc-shaped. The valve disc can preferably be arranged such that a disc plane is oriented orthogonal to a main flow direction from the suction connection to the lifting hose connection. In this respect, the valve disc can be designed such that it extends flatly in a plane orthogonal to the main flow direction. Configuring the valve body as a valve disc has the advantage that a comparatively large contact surface is provided for flows from the suction connection to the lifting hose connection, which promotes reliable switching of the control valve.

[0025] Preferably, the throttle passage is formed as a channel, for example, a bore, through the valve body. It is also conceivable for the throttle passage to be formed by a plurality of channels, for example, in the form of a sieve, which extend through the valve body. If the valve body is configured as a valve disc, the channel(s) preferably extend orthogonally to the disc plane, in particular concentrically.

[0026] The valve body, in particular the valve disc, is preferably provided in the valve housing, in particular mounted, in such a way that an air gap is provided at least in sections along a circumference around the valve body between the valve body and the valve housing, in particular between the valve body and an inner wall of the valve housing. The valve body is therefore particularly provided in the valve housing in such a way that at least in some positions along a circumference around the valve body a distance or gap is formed between the valve body and the valve housing. The air gap can, in particular, provide a further flow path from the suction connection to the lifting hose connection. In this respect, the air gap can, in particular, provide a second flow cross-section of the total flow cross-section.The total flow cross-section can therefore be the sum of the first flow cross-section (throttle passage) and the second flow cross-section (air gap).

[0027] As mentioned above, the control valve is designed such that a total flow cross-section for flows from the suction connection to the lifting hose connection is smaller in the first switching position of the valve body than in the second switching position of the valve body. One possible implementation can be that the valve body is provided in the valve housing such that the air gap between the valve body and the valve housing (and thus the second flow cross-section) is smaller in the first switching position of the valve body than in the second switching position. It is possible for the air gap to be closed in the first switching position and thus for the total flow cross-section in the first switching position to be provided exclusively by the first flow cross-section (throttle passage).

[0028] The first and second switching positions are in particular end positions of the valve body along the main flow direction from the suction connection to the lifting hose connection.

[0029] In particular, the first switching position can be defined by a first stop for the valve body, which limits a movement path of the valve body in the main flow direction from the suction connection to the lifting hose connection. The second switching position can be defined by a second stop, which limits a movement path of the valve body counter to the main flow direction. A control valve designed in this way is robustly constructed and thus reliable in its function. Furthermore, such a configuration allows the control valve to be flexibly adapted to different operating situations by changing the position of the stops, for example, depending on the design of the lifting hose and / or the suction gripper device.

[0030] It may be particularly advantageous if a position of the first stop along the main flow direction is, in particular, repeatable, variable, and in particular adjustable. In particular, the control valve can be designed such that the total flow cross-section provided in the first switching position can be changed by changing the position of the first stop.

[0031] Such a design makes it possible to variably change a throttle resistance during free suction with an unoccupied suction point and thus to adjust a floating position of the lifting hose during free suction as required.

[0032] A change in the total flow cross-section by changing the first stop can be achieved, for example, by changing the position of the first stop along the main flow direction, thereby changing the distance between the valve body and the valve housing. In particular, by changing the position of the first stop, the width of the air gap between the valve body and the valve housing (and thus the second flow cross-section) in the first switching position can be changed.

[0033] It may be particularly advantageous if the control valve comprises an adjustment device by means of which a position of the first stop along the main flow axis can be changed, in particular adjusted. This makes it possible to easily change a flow resistance in the first switching position and thus a floating position of the lifting hose, especially during operation.

[0034] The adjustment device can, in particular, comprise an actuator, for example in the form of a slide element or adjusting screw, which is mounted on the valve housing so as to be displaceable along an adjustment axis. The actuator is preferably coupled to the first stop via a gear mechanism or lifting mechanism, in particular such that a displacement movement of the actuator along the adjustment axis can be transferred into a displacement movement of the first stop along the main flow direction.

[0035] The adjusting axis can run parallel to the main flow direction. In a particularly advantageous embodiment, the adjusting axis can run orthogonal to the main flow axis. The adjusting element can, in particular, have a wedge-shaped stop section with a wedge surface, which forms the first stop for the valve body. The wedge surface is, in particular, oriented at an angle to the main flow direction. By displacing the adjusting element along the adjusting axis, the position of a section of the wedge surface that interacts with the valve body can be changed along the main flow direction. In other words, a horizontal movement can be redirected into a vertical movement via the wedge-shaped mechanism. Such a configuration makes it possible to change the position of the first stop in a simple and ergonomic manner without having to open the valve housing.In particular, the actuator can be arranged on the side of the tube lifter.

[0036] In an advantageous further development, the valve body can be motion-coupled to a wedge-shaped counter-stop section. A wedge surface of the counter-stop section is then preferably oriented at an angle to the main flow direction, in particular at the same angle as the wedge surface of the stop section of the actuator. In the first switching position of the valve body, the wedge surface of the counter-stop section can then abut the wedge surface of the stop section. In this way, a particularly stable configuration is formed.

[0037] Within the scope of an advantageous development, the tube lifter can have an operating device for operating the tube lifter. The operating device is preferably arranged between the lifting hose and the suction gripper device. In particular, the operating device can have a lifting hose connecting section for connecting to the lifting hose and a suction gripper connecting section for connecting to the suction gripper device. The operating device can have an operating handle for moving the lifting hose.

[0038] In a design with an operating device, the control valve can be integrated into the operating device. It is also conceivable for the control valve to be provided as a separate module from the operating device, arranged between the operating device and the lifting hose or between the suction gripper device and the operating device.

[0039] The above-mentioned object is also achieved by a hose lifter having the features of claim 13. The advantages and optional features of the hose lifter described above can also be used to design the hose lifter according to claim 13, so that in order to avoid repetition, reference is made to the above disclosure in this regard.

[0040] The above object is also achieved by a control valve for use in one of the hose lifters described above.

[0041] The invention is explained in more detail below with reference to the figures. They show: Fig. 1 a simplified schematic representation of a hose lifter with control valve; Fig. 2 a sketched representation of an embodiment of the control valve in a perspective view; Fig. 3 a sketched representation of the control valve according to Fig. 2 in a plan view; Fig. 4 a sketched representation of the control valve according to Fig. 2 in a sectional view along the Fig. 3 section plane IV-IV with valve body in second switching position; and Fig. 5 a sketched representation of the control valve according to Fig. 2 in a sectional view along the Fig. 3 shown section plane IV-IV with valve body in first switching position.

[0042] In the following description and in the figures, the same reference symbols are used for identical or corresponding features.

[0043] The Fig. 1 shows a simplified schematic representation of an embodiment of a tube lifter, which is designated overall by the reference numeral 10.

[0044] The tube lifter 10 comprises a lifting hose 12, which encloses a hose interior 14. The lifting hose 12 can be shortened by applying negative pressure to the hose interior 14 (e.g., through an external vacuum supply) and can be lengthened again by ventilating the hose interior 14. In other words, the lifting hose 12 is reversibly shortened or lengthened depending on the pressure level in the hose interior 14, e.g., under the effect of weight.

[0045] The lifting hose 12 can, for example, be connected to a support or scaffold at its upper end. It is also conceivable for the lifting hose 12 to be attached to a manipulator, e.g., in the form of a column-mounted jib crane, at the upper end, and thus be movable by the manipulator.

[0046] The tube lifter 10 also comprises a suction gripping device 18 for sucking and thus gripping an object (not shown). By way of example and preferably, the suction gripping device 18 is designed as a surface suction gripper with a plurality of suction points 20. In the specific example, the suction gripping device 18 comprises a plurality of suction bodies 22, e.g., elastomer suction cups, each of which provides a suction point 20 for sucking an object. In embodiments not shown, however, the suction gripping device 18 can also have any other configurations.

[0047] The suction gripping device 18 is mounted on the lifting hose 12, so that by shortening the lifting hose 12, the suction gripping device 18 and thus an object sucked up by the suction gripping device 18 can be lifted. The suction gripping device 18 can be supplied with negative pressure through the hose interior 14 of the lifting hose 12.

[0048] The tube lifter 10 also comprises a control valve 24 for adjusting a flow resistance for flows from the suction gripping device 18 to the hose interior 14 of the lifting hose 12. As in Fig. 1, the control valve 24 is arranged between the suction gripping device 18 and the lifting hose 12, so that the suction gripping device 18 can be supplied with negative pressure through the control valve 24.

[0049] The control valve 24 comprises a valve housing 26, which comprises a lifting hose connection 28 for flow connection with the hose interior 14 of the lifting hose 12 and a suction connection 30 for flow connection with the suction gripping device 18.

[0050] The lifting hose connection 28 may, in particular, comprise a connecting device (not shown) for mechanically connecting the valve housing 26 to the lifting hose 12. The suction connection 30 may, in particular, comprise a connecting device (not shown) for mechanically connecting the valve housing 26 to the suction gripping device 18. The connecting devices may, for example, be designed in the form of quick-release couplings.

[0051] In the example shown, the lifting hose connection 28 and the suction connection 30 are arranged on opposite sides of the valve housing 26. The valve housing 26 extends, in particular, along a main flow direction 32 from the suction connection 30 to the lifting hose connection 28.

[0052] The valve housing 26 encloses a valve interior 34, which on the one hand is fluidly connected to the hose interior 14 of the lifting hose 12 via the lifting hose connection 28 and on the other hand is fluidly connected to the suction gripping device 18 via the suction connection 30.

[0053] As in Fig. 1 only schematically shown, the control valve 24 also comprises a valve body 36, which is arranged in the valve interior 34 between the suction connection 30 and the lifting hose connection 28.

[0054] The valve body 36 is, for example, preferably designed as a valve disc 38, which extends flat in a plane orthogonal to the main flow direction 34 (see also Fig. 2)

[0055] The valve body 36 (valve disc 38) is movable along the main flow direction 32 between a first switching position (cf. Fig. 5) and a second switching position (cf. Fig. 4 and Fig. 1). The first switching position is defined by a first stop 40, which limits the movement path of the valve body 36 in the main flow direction 32. The second switching position is defined by a second stop 42, which limits the movement path of the valve body 36 opposite to the main flow direction 32.

[0056] As explained in more detail below, the first stop 40 is preferably adjustable so that a position of the first stop 40 along the main flow direction 32 can be adjusted.

[0057] The valve body 36 is biased toward the second switching position. In the example shown, the control valve 24 comprises a spring device 44, which is designed to bias the valve body 36 toward the second switching position (see also Fig. 4). The spring device 44 may comprise one or more compression springs 46. It is also conceivable that the valve body 36 is biased toward the second switching position solely as a result of gravity.

[0058] As explained in more detail below, the valve body 36 is provided in the valve housing 26 such that a total flow cross-section for flows from the suction connection 30 to the lifting hose connection 28 is smaller in the first switching position of the valve body 36 than in the second switching position of the valve body 36, but is greater than zero. By changing a position of the valve body 36 along the main flow direction 32, a flow resistance for flows from the suction connection 30 to the lifting hose connection 28 and thus a flow resistance for flows from the suction gripping device 18 or the suction points 20 to the hose interior 14 of the lifting hose 12 can be changed.

[0059] As can be seen in particular from the Fig. 2 and Fig. 3, the valve body 36 has a throttle passage 48, for example in the form of a channel 50. The throttle passage 48 provides a first flow cross-section of the total flow cross-section. The throttle passage 48 is open in both the first and second switching positions of the valve body 36 (see FIG. Fig. 4 and Fig. 5).

[0060] A second flow cross-section of the total flow cross-section is provided by an air gap 52, which is formed between the valve body 36 and the valve housing 26 or an inner wall 54 of the valve housing 26 (cf. Fig. 4). Specifically, the valve body 36 is provided in the valve interior 34 such that, at least in sections along its circumference around the main flow direction, a distance is formed between the valve body 36 and the valve housing 26. For example, it is conceivable that a diameter of the valve body 36 or the valve disc 38 is smaller than a diameter of the valve interior 34.

[0061] The valve housing 26 is designed such that the air gap 52 in the first switching position (cf. Fig. 5) is smaller than in the second switching position (cf. Fig. 4). For example, it is conceivable that the valve body 36 bears sealingly against the valve housing 26 in the first switching position, so that the air gap 52 is closed. It is also conceivable that in the first switching position, a flow cross-section of the air gap 52, in particular a distance between the valve body and the inner wall 54 of the valve housing 26, is smaller than in the intermediate switching position.

[0062] In the example shown, a change in the total flow cross-section is brought about by a change in the air gap 52 between the valve body 36 and the valve housing 26 when the valve body 36 is transferred between the first and second switching positions.

[0063] The operation of the control valve 24 is described below with reference to the Fig. 4 and Fig. 5 using an example application situation of the tube lifter 10.

[0064] In an exemplary initial position of the tube lifter 10, the suction points 20 of the suction gripping device 18 are initially unoccupied (i.e. no object is placed at the suction points 20) and a vacuum supply to the lifting hose 12 is switched off.

[0065] In this initial position, the control valve 24 is in the Fig. 4, in which the valve body 36 rests against the second stop 42 as a result of the action by the spring device 44, i.e. is in the second switching position.

[0066] If the vacuum supply is now activated, the valve body 36 is entrained as a result of the resulting air flow from the suction connection 30 to the lifting hose connection 28 (or from the suction points 20 to the hose interior 14) and is thus transferred from the second switching position to the first switching position, contrary to the action of the spring device 44, in which the valve body 36 then rests against the first stop 40.

[0067] In the first switching position, an inflow of ambient air from the suction points 20 to the hose interior 14 is throttled by the throttle passage 48, so that a dynamic pressure is established in the lifting hose 12 and this is thus held in a predetermined floating position.

[0068] If the suction gripping device 18 is now placed on an object so that the suction points 20 are sealed (occupied), the air flow from the suction connection 30 to the lifting hose connection 28 decreases, so that it is no longer sufficient to hold the valve body 36 in the first switching position against the action of the spring device 44. As a result, the valve body 36 is automatically moved into the second switching position (see Fig. 4) transferred.

[0069] As mentioned above, in this second switching position the air gap 52 between the valve body 36 and the valve housing 26 is larger, so that the effective total flow cross-section for flows from the suction connection 30 to the lifting hose connection 28 is now increased and thus an increased suction power for sucking in the object is provided.

[0070] If the object is now removed from the suction points 20, the valve body 36 is transferred back into the first switching position with a smaller total flow cross-section by the air flow during free suction, as described above.

[0071] In the illustrated example, an adjustment device 56 is provided, by means of which a position of the first stop 40 can be changed. In the specific example, the adjustment device 56 comprises an actuator 58, which is mounted on the valve housing 26 so as to be displaceable along an adjustment axis 60 orthogonal to the main flow direction 32 (see FIG. Fig. 4). The actuator 58 has two wedge-shaped stop sections 62 (cf. Fig. 3), wherein a respective wedge surface 64 of the stop sections 62 forms the first stop 40. As in Fig. 4, the wedge surfaces 64 are oriented inclined to the main flow direction 32.

[0072] The valve body 36 is motion-coupled to two wedge-shaped counter-stop sections 66. The counter-stop sections 66 each have a wedge surface 68, by means of which the valve body 36 rests against the wedge surfaces 64 (first stop 40) of the actuator 58 in the first switching position. The wedge surfaces 68 of the counter-stop sections 66 are preferably oriented at the same angle as the wedge surfaces 64 of the stop sections 62, inclined to the main flow direction 32. Due to the wedge-shaped mechanism, a position of the valve body 36 in the first switching position can be changed by displacing the actuator 58 along the actuating axis 60, and thus a width of the air gap 52 between the valve body 36 and the valve housing 26 can be changed.

[0073] In embodiments not shown, it is also possible for the actuator 58 to have only one stop section 62 and for the valve body 36 to be coupled in motion to only one counter-stop section 66.

Claims

[1] Tube lifter (10), comprising - a lifting hose (12) which has a hose interior (14) and can be shortened by applying negative pressure to the hose interior (14); - a suction gripping device (18) which is arranged at one end of the lifting hose (12) and can be supplied with negative pressure through the hose interior (14) of the lifting hose (12), wherein the suction gripping device (18) has at least one suction point (20) for sucking up an object; - a control valve (24) for adjusting a flow resistance for flows from the suction gripping device (18) to the hose interior (14), wherein the control valve (24) comprises a valve housing (26) which extends along a main flow direction (32) from a suction connection (30) for flow connection with the suction gripping device (18) to a lifting hose connection (28) for flow connection with the lifting hose (12), wherein the valve housing (26) delimits a valve interior (34) which, on the one hand, is fluidly connected to the hose interior (14) via the lifting hose connection (28) and, on the other hand, is fluidly connected to the suction gripping device (18) via the suction connection (30), wherein the control valve (24) comprises a valve body (36) which is arranged in the valve interior (34) and is displaceable between a first switching position and a second switching position,wherein a total flow cross-section for flows from the suction connection (30) to the lifting hose connection (28) in the first switching position of the valve body (36) is smaller than in the second switching position of the valve body (36), but greater than zero, wherein the valve body (36) is acted upon in the direction of the second switching position, wherein the valve body (36) has a throttle passage (48) such that a first flow cross-section of the total flow cross-section is provided by the throttle passage (48), wherein the throttle passage (48) is open in the first and in the second switching position of the valve body (36), wherein a flow resistance for flows through the throttle passage (48) is defined such that the valve body (36), starting from the second switching position,in the case of free suction with at least one unoccupied suction point (20) is transferred into the first switching position against the application of pressure and in the case of suction with at least one occupied suction point (20) is transferred from the first switching position to the second switching position by the application of pressure. [2] Hose lifter (10) according to claim 1, wherein the valve body (36) is designed as a valve disc (38), in particular wherein the valve disc (38) is arranged such that a disc plane is oriented orthogonal to the main flow direction (32) from the suction connection (30) to the lifting hose connection (28). [3] Hose lifter (10) according to one of the preceding claims, wherein the throttle passage (48) is formed as a channel (50) or a plurality of channels through the valve body (36). [4] Hose lifter (10) according to one of the preceding claims, wherein the valve body (36) is provided in the valve housing (26) in such a way that an air gap (52) is provided between the valve body (36) and the valve housing (26) at least in sections along a circumference around the valve body (36), wherein the air gap (52) provides a second flow cross-section of the total flow cross-section, wherein the air gap (52) is smaller in the first switching position than in the second switching position. [5] Hose lifter (10) according to one of the preceding claims, wherein the first and second switching positions are end positions of the valve body (36) along the main flow direction (32). [6] Hose lifter (10) according to one of the preceding claims, wherein the first switching position is defined by a first stop (40) for the valve body (36), which limits a movement path of the valve body (36) in the main flow direction (32), and wherein the second switching position is defined by a second stop (42) which limits a movement path of the valve body (36) counter to the main flow direction (32). [7] Hose lifter (10) according to the preceding claim, wherein a position of the first stop (40) along the main flow direction (32) is variable, wherein by changing the position of the first stop (40) the total flow cross-section provided in the first switching position, in particular a flow cross-section of the air gap (52), is variable. [8] Hose lifter (10) according to the preceding claim, wherein the control valve (24) comprises an adjusting device (56) for adjusting the position of the first stop (40) along the main flow direction (32). [9] Hose lifter according to the preceding claim, wherein the adjusting device (56) has an actuator (58) which is mounted on the valve housing (26) so as to be displaceable along an adjusting axis (60) and cooperates with the first stop (40) via a gear device, in particular such that a displacement movement of the actuator along the adjusting axis (60) can be transferred into a displacement movement of the first stop (40) along the main flow direction (32). [10] Hose lifter (10) according to claim 8, wherein the adjusting device (56) has an actuator (58) which is mounted on the valve housing (26) so as to be displaceable along an adjusting axis (60) orthogonal to the main flow direction (32), wherein the actuator (58) has a wedge-shaped stop section (62), wherein a wedge surface (64) of the stop section (62) forms the first stop (40), wherein the wedge surface (64) of the stop section (62) is oriented at an incline to the main flow direction (32). [11] Hose lifter (10) according to the preceding claim, wherein the valve body (36) is movement-coupled to a wedge-shaped counter-stop section (66), wherein a wedge surface (68) of the counter-stop section (66) is oriented inclined to the main flow direction (32), wherein in the first switching position of the valve body (36) the wedge surface (68) of the counter-stop section (66) bears against the wedge surface (64) of the stop section (62). [12] Hose lifter (10) according to one of the preceding claims, wherein the hose lifter (10) has an operating device for operating the hose lifter (10), wherein the operating device is arranged between the lifting hose (12) and the suction gripping device (18), wherein the control valve (24) is integrated into the operating device. [13] Tube lifter (10), comprising - a lifting hose (12) which has a hose interior (14) and can be shortened by applying negative pressure to the hose interior (14); - a suction gripping device (18) which is arranged at one end of the lifting hose (12) and can be supplied with negative pressure through the hose interior (14) of the lifting hose (12), wherein the suction gripping device (18) has at least one suction point (20) for sucking up an object; - a control valve (24) for adjusting a flow resistance for flows from the suction gripping device (18) to the hose interior (14), wherein the control valve (24) comprises a valve housing (26) which extends from a suction connection (30) for flow connection with the suction gripping device (18) to a lifting hose connection (28) for flow connection with the lifting hose (12), wherein the valve housing (26) delimits a valve interior (34) which, on the one hand, is fluidly connected to the hose interior (14) via the lifting hose connection (28) and, on the other hand, is fluidly connected to the suction gripping device (18) via the suction connection (30), wherein the control valve (24) comprises a valve body (36) which is arranged in the valve interior (34) and is displaceable between a first switching position and a second switching position,wherein a total flow cross-section for flows from the suction connection (30) to the lifting hose connection (28) in the first switching position of the valve body (36) is smaller than in the second switching position of the valve body (36), but greater than zero, wherein the valve body is acted upon in the direction of the second switching position, wherein the valve body (36) and the actuation of the valve body (36) in the direction of the second switching position are designed and coordinated with one another such that the valve body (36), starting from the second switching position, is displaced into the first switching position in the case of free suction with at least one unoccupied suction point (20) and is displaced from the first switching position into the second switching position by the actuation in the case of suction with at least one occupied suction point (20).

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