Automatic Gripping Module

Abstract

A gripping module grips and moves objects and can be used on robots or automatic handling machines. The gripping module has a module carrier and at least two active elements, which can be displaced relative to one another and have gripping surfaces for gripping an object. At least one of the active elements is displaceable relative to the module carrier by a drive system. The drive system has an electric motor and an actuator element displaceable by an electromagnet. The electric motor and the actuator element are each kinematically coupled to the active element.

Claims

1. A gripping module for gripping and moving objects, the gripping module comprising: a module carrier; two active elements that are displaceable relative to one another, wherein each of the two active elements has a gripping surface for gripping an object; and a drive system that is configured to displace at least one of the two active elements relative to the module carrier, wherein the drive system includes an electric motor, an electromagnet, and an actuator element displaceable by means of the electromagnet, wherein the electric motor and the actuator element are kinematically coupled to the at least one of the two active elements.

2. The gripping module of claim 1, wherein the drive system is configured to displace the two active elements toward and away from each other relative to the module carrier.

3. The gripping module of claim 1, further comprising: a drive spindle that is rotatably movable relative to the module carrier and that is axially movable; and a translationally displaceable spindle nut that is guided on the drive spindle and is kinematically coupled to the at least one of the two active elements.

4. The gripping module of claim 3, wherein the drive spindle is rotationally coupled to the electric motor and axially displaceable by means of the actuator element.

5. The gripping module of claim 3, wherein the electric motor is fixedly attached to the module carrier, and wherein an output shaft of the electric motor and the drive spindle are connected to each other in a rotationally fixed and axially displaceable manner.

6. The gripping module of claim 5, wherein at least one portion of the output shaft has a non-circular cross section, and wherein the drive spindle has a non-circular centric recess configured to receive the at least one portion of the output shaft.

7. The gripping module of claim 3, wherein the electric motor and the actuator element are provided opposite each other on both sides of the drive spindle.

8. The gripping module of claim 3, wherein the spindle nut is connected to the at least one of the two active elements via an intermediate lever, and wherein the intermediate lever is pivotally movable about an axis stationary relative to the at least one of the two active elements and about an axis stationary relative to the spindle nut.

9. The gripping module of claim 8, further comprising at least two swivel joint bores or swivel joint axes that are provided on at least one of the spindle nut or the at least one of the two active elements so that the intermediate lever can be pivotably attached to the spindle nut or the at least one of the two active elements in two different positions.

10. The gripping module of claim 1, further comprising a drive spindle that is rotatably movable relative to the module carrier, wherein the drive spindle is connected in a rotationally fixed manner to a pressure plate, and wherein the actuator element has a receiving space for receiving the pressure plate.

11. The gripping module of claim 1, further comprising a spring device that is configured to be tensioned by activation of the electromagnet.

12. The gripping module of claim 10, wherein the spring device has a spring end that rests on the actuator element.

13. The gripping module of claim 10, wherein the spring device acts on the actuator element in such a way that the active element is force-loaded in a gripping direction.

14. The gripping module of claim 10, wherein the spring device comprises a compression spring.

15. The gripping module of claim 1, wherein the electric motor is arranged between the two active elements.

16. The gripping module of claim 1, wherein the at least one of the two active elements is guided by a linear guide so as to be movable relative to the module carrier.

17. The gripping module of claim 1, comprising at least one sensor configured to detect a position or an end position of the at least one of the two active elements.

18. The gripping module of claim 1, wherein the gripping module is a robot gripper, and wherein the module carrier comprises a coupling device that is configured to attach the gripper module to a robot arm of a robot.

19. The gripping module of claim 1, wherein the electric motor has a maximum power that results in a maximum force between the two active elements of less than 50 Newton.

20. A robot comprising a robot arm and the gripping module of claim 1, wherein the gripping module is attached to the robot arm.

21. A handling machine comprising a carriage and the gripping module of claim 1, wherein the carriage is translationally movable and the gripping module is attached to the carriage.

22. A method of gripping an object, the method comprising: a. positioning two active elements of a gripping module in an initial position in which the two active elements are positioned at a distance from surfaces of the object; b. displacing at least one of the two active elements by an electric motor until the active elements are in contact with the surfaces of the object; and c. activating or deactivating an electromagnet, whereby the at least one of the two active elements is force-loaded and exerts a gripping force on the object.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Further advantages and aspects of the disclosure are apparent from the claims and from the following description of embodiments of the disclosure, which are explained below with reference to the figures.

[0048] FIG. 1 shows a sectional view of a gripping module according to the present disclosure.

[0049] FIG. 2 shows a drive spindle of the gripping module and its kinematic coupling with the active elements of the gripping module.

[0050] FIG. 3 shows a spindle component and its rotational coupling with an output shaft of an electric motor of the gripping module.

[0051] FIGS. 4A to 4C show the operation of the gripping module when it is used as an external gripper.

[0052] FIGS. 5A to 5C show the operation of the gripping module when it is used as an internal gripper.

[0053] FIG. 6 shows an industrial robot according to the present disclosure with a gripping module according to the disclosure.

[0054] FIG. 7 shows a handling machine according to the present disclosure with a gripping module according to the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0055] FIG. 1 shows a sectional view of a gripping module 10 according to the present disclosure. FIG. 2 shows a partial section of FIG. 1 enlarged and partially cut in a different way.

[0056] The gripping module 10 has a module housing acting as a module carrier 12, which is provided with a coupling device 18, not described in more detail, in order to be coupled, for example, to a robot arm 104 or an automatic handling machine 200.

[0057] The gripping module 10 has two active elements 20, which are displaceable guided by a shaft guide 70. The two active elements 20 have gripping jaws 22 projecting outwardly from the module housing, which have internally located gripping surfaces 22B facing toward each other and externally located gripping surfaces 22A facing away from each other. By means of these gripping jaws 22 or gripping fingers attached thereto, the gripping module 10 can grip gripping objects as intended. For this purpose, the gripping jaws 22 are moved from the outside or inside to the gripping object concerned and a gripping force sufficient for handling is applied between them.

[0058] For displacement and application of force to the active elements 20, the gripping module 10 has a drive system whose components are described below.

[0059] The drive system has as its main component a drive spindle 42, which is part of a spindle component 40. A spindle nut 30 is screwed onto the drive spindle 42, which has two outwardly facing wings. These wings of the spindle nut 30 are connected to extensions 24 of the active elements 20 via intermediate levers 26. These intermediate levers 26 are, as can be seen in particular in the enlarged illustration of FIG. 2, in each case hinged to the spindle nut 30 so as to be pivotable about an axis A and to the extension 24 so as to be pivotable about an axis B2. They are thus able to convert a movement of the spindle nut 30 that takes place vertically with respect to the figures into a horizontal movement of the active elements 20.

[0060] An electric motor 50 and an electromagnet 60 are provided for moving the drive spindle 42 and the entire spindle component 40.

[0061] The electric motor 50 is a gearless and brushless DC motor whose output shaft 52 coincides with its rotor shaft, i.e. is arranged coaxially with the rotor and rotates at the speed of the motor. The output shaft 52 is inserted from above into a recess 46 of the drive spindle 42 in the manner clearly shown in FIGS. 2 and 3, whereby rotational stability is achieved between the output shaft 52 and the drive spindle 42 due to the non-circular shape of both the output shaft 52 and the recess 46. However, axial mobility remains since there is no axial coupling between the output shaft 52 and the drive spindle 42.

[0062] The electromagnet 60 also acts on the spindle component 40 via an actuator 64, which is pressed by a spring device 62 in the form of a helical compression spring in the direction of an upper end position. The electromagnet 60 makes it possible to attract this actuator element 64 against the force of the spring device 62, so that the actuator element 64 rests against the electromagnet 60 in its lower end position in the manner illustrated in FIG. 1. When the electromagnet 60 is deactivated, the spring device 62 expands and pushes the actuator element 64 upward with respect to the figures. The actuator element 64 has a receiving space in which a pressure plate 44 of the spindle component 40 is rotatably mounted.

[0063] Due to this design, it is possible to raise and lower the drive spindle 42 and with it the spindle nut 30 to a limited extent via activation and deactivation of the electric motor 60.

[0064] For controlling the electric motor 50 and the electromagnet 60, the gripping module 10 has a control board 90, which is connected to the electric motor 50 and the electromagnet 60 and, if necessary, to supplementary sensors such as end position sensors in a manner not shown in greater detail. For connection of an external control line, the control board has a connection socket 92, which is placed in an opening of the module housing.

[0065] FIGS. 4A to 4C illustrate the use of the gripping module 10 as an external gripper.

[0066] FIG. 4A shows an initial state in which the electromagnet 60 is energized and thus pulls the actuator element 64 and the drive spindle 42 into a lower end position against the force of the spring device 62. By means of the electric motor, the active elements 20 are spaced apart from each other to such an extent that the gripper jaws 22 are at a distance from a gripping object 120.

[0067] Starting from this initial position, the electric motor 50 is first supplied with power by means of the control board 90 and is rotated in a direction, which leads to an upward movement of the spindle nut 30. Through this movement, the active elements 20 are moved towards each other by means of the intermediate levers 26 until they are in contact with the outside of the gripping object 120 in the manner illustrated in FIG. 4B. However, a relevant gripping force is not yet applied, since the electric motor 50 does not have sufficient power.

[0068] Starting from the state of FIG. 4B, the current supply to the electromagnet 60 is then cancelled. The effect of this is that the spring device 62 presses the actuator element 64 upwards and displaces it together with the spindle nut 30. This displacement has the effect that the force of the spring device 62, which is designed as a compression spring, is transmitted to the gripping jaws 22 and causes a gripping force that is sufficient for handling the gripping object 120.

[0069] If a power failure occurs in the state of FIG. 4C, this is irrelevant for the gripping state, since this is maintained by the spring device 62.

[0070] FIGS. 5A to 5C show the same gripping module, but in a different configuration, namely in the configuration of an internal gripper.

[0071] In this configuration, the intermediate levers 26 are not pivotable about the axis B2, but about the axis B1 shown in FIG. 2. Furthermore, in the initial state of FIG. 5A, the spindle nut 30 is in a significantly lowered position relative to the drive spindle 42.

[0072] The gripper jaws 22 are thus moved away from each other in this internal gripper for the purpose of gripping. This is done in a similar manner as already explained for FIGS. 4A to 4C.

[0073] Starting from the state of FIG. 5A, the drive spindle 42 is first rotated by means of the electric motor 50 so that the spindle nut 30 is raised and, due to the geometric conditions now prevailing, the active elements 20 are pushed away from each other via the intermediate levers 26 until they reach the end position of FIG. 5B, in which they lie opposite each other on the inside of the gripping object 120.

[0074] Once this state is reached, the current supply to the electromagnet 60 is again lifted, causing the spring device 62 to push the actuator element 64 upwards. The corresponding force continues via the intermediate levers 26 to the active elements 20 and now causes a gripping force with which the gripping jaws 22 are pressed away from each other and with which they hold the gripping object 120.

[0075] FIGS. 6 and 7 show typical applications of a gripping module corresponding to that of FIGS. 1 to 5C.

[0076] FIG. 6 shows a robot 100 that has a multi-link robot arm 104 that is movable relative to a base 102. A coupling device is provided at the distal end of this robot arm 104, to which the gripping module 10 is attached by means of its coupling device 18. The gripping module 10 is connected to the robot 100 via a control line 106. In this configuration, the robot can be used to grasp, transport and deposit gripping objects 120.

[0077] FIG. 7 shows a handling robot 200, which has a carriage 202 that can be moved in all three spatial axes. On the underside, the carriage 202 has a coupling interface to which a gripping module 10 corresponding to that of FIGS. 1 to 5C is coupled by means of its coupling device 18. The gripping module 10 can thus be moved freely in space with constant orientation, in particular with downward orientation, grasp gripping objects 120, transport them and deposit them again at a different location.