The invention relates to a gripping arrangement for gripping, holding and placing down workpieces, in particular sheet metal workpieces, and a manipulator having a gripping arrangement.
Usually, according to the prior art, manipulators having vacuum gripping devices, i.e. having suction grippers, are used to grip workpieces such as sheet metal workpieces from a workpiece stack. However, since vacuum gripping device are often not very advantageous or even unsuitable to carry out processing steps on a bending machine or the like after gripping and/lifting, the workpieces to be manipulated are often passed on to a second manipulator, which is designed having a pincer gripper. Such an approach can be useful in particular for smaller or already bent workpieces. However, two manipulators are expensive and require a lot of space. Moreover, there is a risk of collisions and the freedom of movement of the manipulators can be limited.
To overcome these disadvantages, experts know combined manipulator arrangements, in which an individual manipulator is formed both for gripping by means of suction grippers and for gripping by means of a pincer gripper. However, the known formations are limited in their gripping and suction functionality and thus do not represent adequate and satisfying solutions.
For example, JP2019014027 A presents a bending robot having a combined pincer and suction gripper head. A suction gripper is arranged on a displaceable frame, wherein a plane of adhesive action of the suction gripper is aligned parallel to a clamping plane of the pincer gripper.
CN108927822 A also discloses a combined gripping device, wherein a pincer gripper is designed with suction pads at its front end. By moving the pincer arms, the suction grippers, which are rigidly mounted on the front ends of the pincer arms of the pincer gripper, are moved in a positively coupled manner. In this regard, a plane of adhesive action of the suction gripper is aligned orthogonal to the clamping plane of the pincer gripper.
It was the object of the present invention to overcome the shortcomings of the prior art and to provide means by means of which workpieces for a processing machine, in particular for a bending machine, can be manipulated in a quick and efficient manner.
This object is achieved by means of a gripping arrangement and a manipulator according to the claims.
The invention relates to a gripping arrangement for gripping, holding and placing down workpieces, in particular sheet metal workpieces, comprising a connection interface for attachment to a manipulator and a pincer gripper having a first pincer arm and a second pincer arm. The pincer arms are movable relative to one another by means of a pincer drive and in their closed position define a clamping plane extending between the pincer arms. The pincer arms in their closed position define a longitudinal pincer axis extending parallel to the pincer arms and in the clamping plane. The gripping arrangement further comprises an adhesion gripper having at least one vacuum gripping element or having at least one magnetic gripper element. The adhesion gripper has a plane of adhesive action for holding a workpiece and is displaceable along an adjustment axis in the direction of the longitudinal pincer axis relative to the pincer gripper between a working zone and a stand-by zone by means of an adjustment drive. In this regard, it is provided that the clamping plane and the plane of adhesive action are aligned at a right angle to one another and that the plane of adhesive action extends at a right angle to the longitudinal pincer axis.
By the formation of a gripping arrangement according to the invention, two full grippers, i.e. two grippers each fully functional on their own, are realized in one single, structurally integrated and/or combined gripping arrangement. In this context, the term “full grippers” is understood as a pincer or adhesion gripper arrangement, the functionality, stability and freedom of movement of which is at least largely equivalent to a single, structurally individual pincer or adhesion gripper arrangement. Thus, the functional range of the pincer gripper of the gripping arrangement according to the invention is not or just to a slight extent affected by the joint formation with the adhesion gripper. The same applies to the adhesion gripper.
Neither the pincer gripper nor the adhesion gripper—as compared to two separate and/or independently formed gripping arrangements, which are each attached to a separate manipulator—are limited in their functionality. Hence, mutual blocking of the grippers is largely avoided.
By the arrangement of the two grippers according to the invention, a risk of mutual obstructions or even collisions is at least largely avoided or even completely reduced. The formation according to the invention impresses with a high degree of freedom of movement of both grippers.
In particular when the adhesion gripper is displaced into its stand-by zone, the pincer gripper can work without any limitations of movement. In this regard, the pincer grippers are impeded neither by the vacuum gripping elements nor by the magnetic gripper element itself, nor by potential pneumatic lines. Moreover, re-gripping, i.e. a direct workpiece transfer from the adhesion gripper to the pincer gripper and vice versa, is possible because the adhesion gripper can be displaced along its adjustment axis in the direction of the longitudinal pincer axis and because the clamping plane and the plane of adhesive action are aligned at a right angle to each other. Thus, the grippers can also be used simultaneously where required. Loss of time due to an intermediate work step, such as placing down the workpiece, is thus reduced.
Due to the possibility for both grippers to be used as full grippers, the number of required re-gripping or re-positioning operations is reduced and thus the entire manipulation and processing operation becomes more efficient. By the clamping plane and the plane of adhesive action being arranged at a right angle to one another and the plane of adhesive action extending at a right angle to the longitudinal pincer axis, less manipulator movements are required, meaning that less re-positioning of the manipulator is required to carry out the necessary working steps. Moreover, the adjustment paths to be carried out by a manipulator for the entire gripping arrangement can also be kept as short as possible. This particularly applies after a carried-out processing and/or bending step, after which the workpiece and/or the sheet metal bending part has limbs that are angled towards each other. This reduces the cycle times of the workpiece processing and thus increases the efficiency of the process.
Moreover, the two grippers are loadable to at least approximately the same extent and can thus manipulate the same workpiece weights. Hence, damage to the manipulator as a result of overloading and also accidents and hazards for an operator can at least largely be prevented.
In this regard, a displacement of the adhesion gripper along the adjustment axis can be carried out in a stepless manner and thus an optimal and/or desired position can be set. In this regard, the stand-by zone and/or the working zone can preferably be regions along the adjustment axis. Preferably, the adhesion gripper cannot be actuated while a position in the stand-by zone is being taken. Preferably, the adhesion gripper can take a plurality of advantageous positions in the working zone and can be displaced between an axially outermost and an axially innermost working zone.
Experts know a plurality of formations of adhesion grippers and pincer grippers, which are not elucidated in detail in this document. In this regard, it can be possible for both a vacuum gripping element as well as a magnetic gripper element to be activated pneumatically. While vacuum gripping elements can be formed as suction grippers having a usually cup-shaped suction element, magnetic gripper elements can comprise a permanent magnet, wherein said permanent magnet can be displaceable by means of a pressure-activated piston or cylinder.
Moreover, it can be useful if the longitudinal pincer axis and the adjustment axis are positioned coaxially. Hence, a load capacity of the gripping arrangement or the manipulator can be increased and optionally heavy or large workpieces can also be manipulated. Moreover, the gripping arrangement can be designed more compact when the axes are arranged coaxially, which can further reduce the risk of collisions or motion blockages. In particular, a coaxial arrangement can also allow for and/or facilitate a rotation of workpieces, whereby the application possibilities of the gripping arrangement can be additionally extended.
It can further be provided that the longitudinal pincer axis and the adjustment axis are positioned in different orientations. Such a further embodiment can be advantageous to extend the application possibilities of the pincer gripper. In this regard, for example, larger opening widths of the pincer arm can be realized.
Moreover, it can be provided that at least three vacuum gripping elements or at least three magnetic gripper elements are formed, which are arranged annularly around the pincer gripper axis. In this context, it can also be advantageous if the vacuum gripping element or the magnetic gripper element are arranged around the pincer gripper when the adhesion gripper is in the working zone. Such a further embodiment can represent a very loadable arrangement. By multiple gripper elements being positioned annularly and centered around the pincer gripper, a high number of gripping elements can be realized. Hence, a full adhesion gripper can be realized which is also suitable for manipulating large, flat or bulky workpieces. Moreover, by means of this further embodiment, re-gripping from the pincer gripper to the adhesion gripper and vice versa can be facilitated. Advantageously, the vacuum gripping element and/or the magnetic gripper elements can be arranged at an equal distance to the adjustment axis. This can especially be the case where the longitudinal pincer axis and the adjustment axis are positioned coaxially.
A design, according to which it can be provided that the second pincer arm is arranged rigidly in relation to the pincer drive and that the first pincer arm is mounted so as to be movable relative to the second pincer arm, is also advantageous.
By means of thus formed pincer arms, a risk of collisions between the pincer gripper and the adhesion gripper can be reduced or even prevented. This is mainly due to the fact that such an arrangement can be easily controlled mechanically if the adhesive gripper is located directly below and/or in the vicinity of the rigid, i.e. non-movable, pincer arm. In this regard, the pincer gripper and the adhesion gripper can optionally also be positioned very close and/or narrow to one another. Thus, a compact construction of the gripping arrangement can be realized.
According to a further embodiment, it is possible that the longitudinal pincer axis and a central axis of the connection interface are positioned coaxially to a manipulator. Hence, a highly loadable position for the gripping arrangement can be realized by it being formed centrally on the outermost manipulator arm.
It can further be useful if a pivot axis of the first pincer arm is formed at a right angle to the longitudinal pincer axis and parallel to the clamping plane or in the clamping plane, wherein the first pincer arm is formed so as to be pivotable about the pivot axis. This can in particular be useful where one of the pincer arms is formed to be rigid and the other one is formed to be movable.
Moreover, it can be provided that the first pincer arm and the second pincer arm are linearly movable with respect to one another. Hence, workpieces having different workpiece thicknesses and/or sheet thicknesses can be gripped reliably and, in this regard, a constant contact pressure can be ensured.
Moreover, it can be provided that the plane of adhesive action, when the axially outermost working zone of the adhesion gripper is taken, projects beyond an end face of the pincer gripper in the axial direction of the adjustment axis. By the possibility of the adhesion gripper being moved out so far and thus projecting beyond a tip of the pincer gripper and/or its end face, a workpiece can possible be gripped more easily. Possible obstructions and/or limitations of movement can thus be prevented by the pincer gripper.
According to a particular embodiment, it is possible that the pincer arms, by means of at least one stop or locking element or controlled by a controller, cannot be transferred to a partially or fully open position when the adhesion gripper is moved into the working zone. Hence, an efficient safety feature for the prevention or avoidance of collisions can be realized.
According to an advantageous embodiment, it can be provided that the pincer drive and the adjustment drive can be activated independently of one another and simultaneously. Hence, re-gripping and/or passing on of a workpiece from the pincer gripper to the adhesion gripper and vice versa can be facilitated. Hence, by means of this further embodiment, an additional flexibilization of the application possibilities of the gripping arrangement can be achieved.
It can in particular be advantageous if the pincer drive and/or the adjustment drive comprises a pressure-driven cylinder, preferably a pneumatic cylinder.
It can further be provided that the pressure-driven cylinders can be acted upon by pressure by means of a joint pressure line, wherein at least one valve is formed in the pressure line, said valve being controllable by means of the controller. In particular, by the formation of joint pressure lines and the pressure supply, a structurally simple setup and thus compact design can be realized. This can further have a positive effect on the freedom of movement of the adhesion gripper and the pincer gripper. Preferably, the valve is formed as a switching valve, which can enable selective pressurization of the adjustment drive and the pincer drive. It might also be of advantage if the gripper elements can also be supplied and/or acted upon with pressure by the valve or switching valve.
Moreover, it can be provided that the valve is configured for simultaneously supplying the pressure-driven cylinders and the at least one vacuum gripping element or the at least one magnetic gripper element.
An embodiment, according to which it can be provided that the pressure-driven cylinder of the adjustment drive comprises an annular cylinder space, said annular cylinder space being arranged around the pressure-driven cylinder of the pincer drive, wherein a cylinder axis of the pressure-driven cylinder is positioned coaxially to the adjustment axis, is also advantageous. Hence, the construction can be even more compact and the risk of collisions or limitations of movement can be reduced.
The invention also relates to a manipulator having a gripping arrangement for gripping, holding and placing down workpieces, in particular sheet metal workpieces, wherein the gripping arrangement is designed according to one of claims. The advantages offered thereby can be gathered from the description above.
For the purpose of better understanding of the invention, it will be elucidated in more detail by means of the figures below.
These show in a respectively very simplified schematic representation:
First of all, it is to be noted that in the different embodiments described, equal parts are provided with equal reference numbers and/or equal component designations, where the disclosures contained in the entire description may be analogously transferred to equal parts with equal reference numbers and/or equal component designations. Moreover, the specifications of location, such as at the top, at the bottom, at the side, chosen in the description refer to the directly described and depicted figure and in case of a change of position, these specifications of location are to be analogously transferred to the new position.
The gripping arrangement 1 comprises a connection interface 3 for attachment to the shown manipulator 4. Moreover, the gripping arrangement 1 is formed having a pincer gripper 5, which comprises a first pincer arm 6 and a second pincer arm 7. The pincer arms 6,7 are movable relative to one another by means of a pincer drive 8 and in their closed position 9 define a clamping plane 10 extending between the pincer arms 6, 7. The closed position 9 of the pincer arms 6, 7 is illustrated in
The gripping arrangement 1 further comprises an adhesion gripper 12 having at least one vacuum gripping element 13 or having at least one magnetic gripper element 14, wherein the adhesion gripper 12 is formed having a vacuum gripping element 13 in
The longitudinal pincer axis 11 and the adjustment axis 17 can be positioned in different orientations. However, alternatively, it is also conceivable that the longitudinal pincer axis 11 and the adjustment axis 17 are positioned coaxially. The longitudinal pincer axis 11 and a central axis 20 of the connection interface 3 to the manipulator 4 can be positioned coaxially.
The first pincer arm 6 and the second pincer arm 7 can be formed to be linearly movable with respect to one another. In this regard, the pincer arms can be movable synchronously, but also independently of each other or individually. It can be useful if the plane of adhesive action 15, when the axially outermost working zone 18 of the adhesion gripper 12 is taken, projects beyond an end face 22 of the pincer gripper 5 in the axial direction of the adjustment axis 17, as is illustrated in
In this regard, the gripping arrangements 1 in
It is shown in both gripping arrangements 1 in
While in the gripping arrangement 1 in
It is shown in particular in
Advantageously, the pincer drive 8 and the adjustment drive 16 can each comprise a pressure-driven cylinder 26, wherein the pressure-driven cylinder 26 preferably is a pneumatic cylinder. It is useful if the pressure-driven cylinders 26 can be acted upon by pressure by means of a joint pressure line. In this regard, at least one valve can be formed in the pressure line, said valve being controllable by means of a controller 24. Optionally, it is also possible that the valve is designed for simultaneous supply of the pressure-driven cylinders 26 and the at least one vacuum gripping element 13, and/or the at least one magnetic gripper element 14. However, it can also be useful if the at least one vacuum gripping element 13 and/or the at least one magnetic gripper element 14 are operated with a vacuum. For reasons of clarity,
The magnetic gripper elements 14—that are shown highly schematic and merely as an exemplary sketch—are formed having a hollow-cylindrical body 31 in
In
In
The exemplary embodiments show possible embodiment variants, and it should be noted in this respect that the invention is not restricted to these particular illustrated embodiment variants of it, but that rather also various combinations of the individual embodiment variants are possible and that this possibility of variation owing to the technical teaching provided by the present invention lies within the ability of the person skilled in the art in this technical field.
The scope of protection is determined by the claims. Nevertheless, the description and drawings are to be used for construing the claims. Individual features or feature combinations from the different exemplary embodiments shown and described may represent independent inventive solutions. The object underlying the independent inventive solutions may be gathered from the description.
All indications regarding ranges of values in the present description are to be understood such that these also comprise random and all partial ranges from it, for example, the indication 1 to 10 is to be understood such that it comprises all partial ranges based on the lower limit 1 and the upper limit 10, i.e. all partial ranges start with a lower limit of 1 or larger and end with an upper limit of 10 or less, for example 1 through 1.7, or 3.2 through 8.1, or 5.5 through 10.
Finally, as a matter of form, it should be noted that for ease of understanding of the structure, elements are partially not depicted to scale and/or are enlarged and/or are reduced in size.
Number | Date | Country | Kind |
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A51006/2020 | Nov 2020 | AT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/AT2021/060435 | 11/17/2021 | WO |