EP3148755A1

EP3148755A1 - Gripping jaw safety device

Info

Publication number: EP3148755A1
Application number: EP15726946.5A
Authority: EP
Inventors: Julian STOCKSCHLÄDER; Eugen Schukow; Otmar Honsberg
Original assignee: KUKA Systems GmbH
Current assignee: KUKA Systems GmbH
Priority date: 2014-06-02
Filing date: 2015-06-01
Publication date: 2017-04-05
Also published as: DE102014210330B4; CN106414000A; CN106414000B; DE102014210330A1; WO2015185493A1

Abstract

The present invention relates to a gripping device (1), in particular as effector for an industrial robot, comprising two clamping jaws (10, 20) which are movable relative to each other to engage a workpiece. At least one of the clamping jaws (10, 20) comprises a safety element (30, 40) which is movably mounted on the clamping jaw and can be moved between a safety position and a release position in order to prevent objects or body parts from being accidentally inserted in the occupied space.

Description

Gripper jaw lock l. FIELD OF THE INVENTION The invention relates to a gripping device, in particular as

Effector is provided for an industrial robot, and which is equipped with a mechanical backup, and a robot system comprising such a gripping device. 2. Background

Industrial robots are programmable machines which are designed for the automatic handling or processing of objects or workpieces. A typical representative are so-called

Articulated robots having a plurality of links connected by joints. In the simplest form, such an industrial robot on a frame on which a rotatable so-called carousel is set up. At the carousel is connected via another rotary joint, a first arm of the robot, which is also referred to as a rocker. At this rocker another arm is arranged on another pivot, which is provided at its free end with a receptacle for a tool. The tool is also called an effector. Depending on the intended use of the industrial robot, different tools can be provided, so that the industrial robots can have a variety of applications, such as the handling and transport of objects and workpieces, the machining of workpieces, measurement tasks, etc. For handling objects or workpieces a variety of gripping tools for robots previously known.

For example, from EP 1 943 064 Bi a robot gripper is previously known, which is provided as an effector of a robot arm or can be attached to end portions of linear or rotary drives. The previously known gripper comprises at least one frame and an actuator element disposed thereon, the at least two

Has gripper jaws or jaws, which can be operated via a hinge unit. The actuator element is formed bellows-like and can be filled with a medium, whereby it expands and acts on a suitable force transmission element on the jaws in order to move them relative to each other to access objects can. The gripper itself has no security devices that could prevent, for example, that a person working with the corresponding robot is injured, in particular crushed, by the gripper. In the open state of the jaws of the prior art gripper, it is namely possible that inadvertent objects or body parts of a person are introduced into the space between the two jaws. If the actuator is actuated at this time, the jaws may be seriously injured as they move

cause.

It is therefore the object of the present invention

To provide gripping device, which can be used in particular as an effector for an industrial robot, and which is designed safer and in particular prevents the injury of persons by the gripping operation as safe as possible. This object is achieved with a gripping device according to claim l. It is also an object of the invention to provide a robot system that with a

Gripping device is provided and a particularly safe operation allowed. This object is achieved with a robot system according to claim 13. 3. Detailed description of the invention

The gripping device according to the invention, which can be used in particular as a tool or effector for a robot, has at least two clamping jaws, which are arranged so as to be movable relative to one another in order to grip a workpiece. To move the jaws, an actuator or drive means may be provided, such as in particular electrically, hydraulically or pneumatically operated drive means. According to the invention, at least one of the clamping jaws

Securing element, which is movably mounted on the jaw and is movable between a securing position and a release position. The securing element is designed so that it occupies at least partially in the securing position, the space between the two jaws to prevent inadvertent insertion of objects or body parts in the occupied space. Preferably, the fuse element works without it requires an external power supply, for example by adjusting means. In this context, it is advantageous if the securing element is biased by a spring element in the securing position. In this way, the gripping device is designed for safe side and the fuse element without an error-prone control device always in the correct position for the protection of people.

The securing device according to the invention is particularly advantageous when clamping jaws are used which have two or more associated pairs of functional surfaces. such

Jaws allow the functionally correct gripping of two differently shaped workpieces. For example, the first pair of functional surfaces may be formed to be round

Object, whereas the second pair of

Functional surfaces is designed to grip an object with a cuboid structure. In such gripping devices naturally only one of the pairs of functional surfaces is used in the application, for example, the pair with the contour for receiving a round component. Because both pairs of

However, functional surfaces are arranged on the same jaws, move during the operation of the jaws always with the functional surfaces that are designed to handle the other object, such as the mentioned cuboid component. It comes, so to speak, to an "empty movement" of the jaws in the area of unused functional surfaces, which is associated in practice with a special risk, since the space between these unused functional areas is not occupied and here

unintentionally about a body part can be introduced. The present invention thus allows safe operation of such jaws with at least two associated pairs of

Functional surfaces. Preferably, the securing element is configured such that it can be moved by the insertion of a workpiece to be gripped in a predetermined direction between the two jaws from the securing position. If, however, a workpiece or a body part is guided from a direction other than the predetermined direction between the two jaws, blocked

Securing element and prevents insertion into the from

Fuse element occupied space. In an advantageous embodiment, the securing element is arranged, for example, on the jaw pivotally about a pivot axis and the pivot axis is perpendicular to the relative direction of movement of the jaws. A movement of the securing element from the securing position into the release position is possible in such a case only when the securing element is rotated about this predetermined pivot axis. For this purpose, it is necessary that a force acting on the securing element, which is substantially perpendicular to the pivot axis. In other words, only when an object, or a body part, in a direction perpendicular to the pivot axis acts on the securing element, this can be moved to the release position and the object or the body part in the of the securing element occupied space. Unintentional insertion of objects or body parts parallel or obliquely to the pivot axis is thus not possible.

Preferably, the securing element is set up such that it can only be moved out of the securing position if a force perpendicular to the pivot axis and perpendicular to the relative

Direction of movement of the jaws acts on the securing element. It will be understood by those skilled in the art that the phrase "perpendicular to the pivot axis and perpendicular to the relative axis of rotation

Movement direction "is not strictly mathematical to understand, but also deviations from the vertical direction are allowed, as long as a sufficiently large force component is used vertically.

Preferably, the gripping device according to the invention has exactly two clamping jaws and preferably each of the two clamping jaws has a corresponding securing element. The two jaws are thus preferably designed symmetrically to each other, at least in connection with the securing element.

In a further preferred embodiment, the jaws are provided with cutting or pressing tools, so that the jaws not only grip a workpiece, but can also cut or press. In this context, gripping operations in the broadest sense also mean cutting or pressing operations, since a cutting or pressing process also always involves gripping the machined workpiece.

The present invention further relates to a robot system comprising at least one robot arm provided with a gripping device as described above or as will be described below in connection with the figures. The robot or the robot system preferably comprises at least one Actuator to actuate the gripping device, in particular an electrically, hydraulically or pneumatically operated actuator.

4. Description of preferred embodiments

In the following, the present invention will be explained in more detail with reference to the attached figures. Hereby shows:

Fig. 1 is a gripping device according to the invention in one

three-dimensional schematic view;

FIG. 2 shows the gripping device of FIG. 1 in a side view; FIG.

Fig. 3 is a sectional view of the gripper shown in Fig. 2;

Fig. 4 is an exploded view of the gripper of Fig. 1; and

5 shows the gripping device of FIG. 1 in a three-dimensional,

partially cut view attached to an actuator of a robot arm.

FIG. 1 shows a gripping device 1 according to the invention in a schematic, three-dimensional view. The gripping device 1 comprises two clamping jaws 10 and 20, which are arranged movable relative to one another in order to grip a workpiece. The two

Jaws have a substantially symmetrical structure and both have a corresponding securing element 30 and 40, respectively. The securing elements are rotatably mounted on the jaws via bolts 13 and 23. As the skilled person will appreciate from the figures, the pivot axis corresponds to the longitudinal orientation of the bolts 13 and 23 and is thus perpendicular to the relative

Direction of movement of the jaws 10 and 20, this is preferably a substantially rectilinear displacement movement of the jaws 10 and 20 relative to each other. The illustrated gripping device 1 has two associated pairs of functional surfaces to allow the functional gripping of two differently shaped workpieces. The first pair of functional surfaces is defined by the concave contours of the

Functional surfaces 14 and 24 formed. The functional surfaces 14 and 24 form an associated pair, which is designed in particular for gripping workpieces with a round outer contour, such as pipes or hoses. The second pair is from the

Functional surfaces 15 and 25 formed. The two functional surfaces 15 and 25 are flat and parallel to each other and designed to grip an object or body, the plane and parallel

Exterior walls has or has. As can be clearly seen in particular in FIG. 2, between the two clamping jaws 10 and 20 there is a free space 2, which is partially occupied by the two securing elements 30, 40, so that unintentional introduction of objects or body parts into the occupied space Space is prevented. In particular, it is not possible to insert an object or a body part between the two functional surfaces 14 and 24. The securing elements 30, 40 are shown in their securing position. Without the two securing elements, it would be possible, for example, when gripping an object with the second pair of functional surfaces 15, 25, another object or a body part into the space between the first pair of

Functional surfaces 14, 24 passes and there damaged by the closer together functional surfaces 14, 24 or injured.

Of course, the invention is not on

Embodiments with two pairs of functional surfaces limited, but can also develop their beneficial effects, for example, if the second pair of functional surfaces 15, 25 is not provided and the jaws 10, 20 so to speak at the height of the bolts 13 and 23 end. Furthermore, it can be seen in FIG. 2 that the

Fuse elements 30, 40 do not contact. This is based on this, since this a simpler movement of

Securing elements 30, 40 from the securing position in the

Release position, preferably by the workpiece to be gripped / pressed, is / is possible. However, one is as well

Embodiment conceivable in which the securing elements 30, 40 at least partially touch, so that (in the securing position), a gap between the securing elements 30, 40 can be kept as low as possible or avoided.

In FIGS. 1 to 3, the two securing elements 30, 40 are shown in their securing position, in which they partially occupy the space between the two clamping jaws, namely to the extent that unintentional introduction of objects or body parts into the occupied space is prevented. In the embodiment shown, the fuse elements fill the occupied space in all three

Dimensions off. However, it is also conceivable that the

Securing elements consist only of, for example, thin lock washers, of which could then be provided on each jaw two, inadvertent insertion of objects from the front or rear into the free space 2 (front here refers to the arrangement, as shown in Figure 1 1, with the side to be visible in FIG. 1 being "front." Ultimately, the spatial configuration of the securing element depends on the size and design of the clamping jaws and can be performed by a person skilled in the art

be selected accordingly.

The fuse elements 30 and 40 are at their respective

Jaws movably mounted, so they are shown off the

Be further securing position out in a release position in which it is possible for the gripping device 1, an object by means of the first pair of functional surfaces 14, 24 to grip. Referring now to the sectional view of Figure 3 recognizes the skilled artisan, as the Secured element 40 is biased by a spring 27 in the securing position. The fuse element 30 is biased analogously with a spring 17. A stop 41 or 31 on the securing elements prevents the securing elements from being rotated further towards one another by their springs. It can also be seen in Figure 3 that the jaw 20 is provided with a pin 26 which is guided in a corresponding receptacle 16 of the jaw 10 in order to guide the relative movement of the two jaws to each other. The relative movement is indicated in Figure 2 by a double arrow. To the fuse elements from their backup position in their

To move or rotate release position, a force perpendicular to the axis of rotation of the bolts 13, 23 must act on the fuse elements. The securing element 40 can then, as indicated by the arrow in Figure 3, move clockwise from the securing position into a release position. For this purpose, the jaw 20 has a correspondingly shaped cavity 28 for receiving the

Fuse element on. The fuse element is in the

Release position substantially completely absorbed in this cavity. The securing element 30 is rotated counterclockwise around the axis of rotation of the bolt 23 into a corresponding cavity 18 in the clamping jaw 10. The corresponding force component perpendicular to the axis of rotation - as the skilled artisan recognizes - can be advantageously generated in that a workpiece to be gripped is inserted in a predetermined direction between the two jaws. If the gripping device 1, for example, to grab a pipe, this must be substantially parallel to the axis of rotation of the

Be oriented security elements. The surface of the tube, when the tube is so guided between the two jaws, come into contact with the two securing elements and rotate them against the force of the springs 17, 27 in the corresponding release position. The fuse elements must therefore not be moved separately by appropriate adjusting means, but the energy or force to move the fuse elements can be removed from the already existing kinetic energy of the gripper. As can be clearly seen in the figures, the pivot or rotation axis of the securing elements is perpendicular to the relative direction of movement of the jaws. In order to move the securing elements into the release position, it is therefore necessary in the preferred embodiment shown that the workpiece is introduced perpendicular to the pivot axis as well as perpendicular to the relative direction of movement of the clamping jaws. For example, if an article or a body part is "from above" in the illustration of FIGS

Securing elements 30, 40 hits, they are not in the

Release position moves, but reliably block the

The person skilled in the art will recognize on the basis of the constructive embodiment of the embodiments that it is not absolutely necessary here for a workpiece to be perpendicular to the workpiece

Swivel axis and perpendicular to the relative direction of movement in the strict mathematical sense is introduced, but that it is sufficient if the workpiece is inserted so close to the mathematical perpendicular that a sufficiently large vertical force component acts on the security elements.

FIG. 4 shows a schematic exploded view of the gripping device 1. The jaws 10, 20 are due to the design of several elements that can be screwed together by means of screws 19. From the exploded view also shows how the gripping device 1 is mounted.

FIG. 5 is a three-dimensional, partially sectioned view showing the gripping device 1 attached to an actuator 60, which in turn is mounted on the end of a robot arm 70. Of the

Robot arm 70 is only indicated by the dashed lines and may for example be part of a joint robot. The actuator 60 has a housing 61 in which a motor 62 is located to the

Relative movement of the two jaws in the in Figure 2 by the Double arrow indicated direction. With reference to FIG. 63, a motor control box of the engine 62 is designated.

LIST OF REFERENCE NUMBERS

1 gripping device

2 free spaces

10, 20 jaws

13, 23 bolts

14, 24 pairs of functional surfaces

15, 25 second pair of functional surfaces

16 receptacle for pins

26 cones

17, 27 springs

18, 28 cavity

19 screws

30, 40 security elements

3i, 4i stroke

60 actuator

61 housing

62 engine

63 engine control box

70 robot arm

Claims

Claims 1 - 13

1. gripping device (1), in particular as an effector for a

Industrial robot comprising gripping device:

at least two jaws (10, 20) adapted to be movable relative to one another for gripping a workpiece, characterized in that at least one of the jaws (10, 20) has a securing element (30, 40) movably mounted on the jaw is and between a backup position and a

Release position is movable and the at least partially occupied in the securing position, the space (2) between the two jaws (10, 20) to prevent inadvertent insertion of objects or body parts in the occupied space.

2. gripping device (1) according to claim 1, characterized

characterized in that the securing element (30, 40) by means of a spring element (17, 27) is biased in the securing position.

3. gripping device (1) according to one of the preceding claims, characterized in that at least one jaw (10) has a pin (26) and at least one other jaw (20) has a corresponding receptacle (16) for the pin (26), in the pin (26) during the relative movement of the two jaws (10, 20) is guided.

4. gripping device (1) according to any one of the preceding claims, characterized in that the clamping jaws (10, 20) at least two associated pairs of functional surfaces (14, 24, 15, 25) to the functionally correct gripping of at least two differently shaped workpieces to allow.

5. Gripping device (1) according to one of the preceding claims, characterized in that the securing element (30, 40) is arranged such that it can be moved by the insertion of a workpiece to be gripped in a predetermined direction between the two jaws (10, 20) from the securing position.

6. gripping device (1) according to one of the preceding claims, characterized in that the securing element (30, 40) on the clamping jaw (10, 20) is arranged pivotably about a pivot axis, and the pivot axis perpendicular to the relative

Movement direction of the jaws is arranged.

7. gripping device (1) according to the preceding claim, characterized in that the securing element (30, 40) is arranged such that it by inserting a workpiece to be gripped between the two jaws (10, 20) of the

Fuse position is movable and only if the

Insertion of the workpiece perpendicular to the pivot axis and perpendicular to the relative direction of movement of the jaws (10, 20).

8. gripping device (1) according to any one of the preceding claims, characterized in that the securing element (30, 40) having jaw (10, 20) has a cavity (18, 28) for

Receiving the securing element (30, 40), in which the

Secured element (30, 40) is at least partially received in the release position.

9. gripping device (1) according to one of the preceding claims, characterized in that the securing element (30, 40) by means of a bolt (13, 23) on the clamping jaw (10, 20) is pivotally mounted about a pivot axis, wherein the Schenkachse perpendicular to the relative direction of movement of the clamping jaws (10, 20) is arranged, and wherein the securing element (30, 40) by means of a spring (17, 27) is biased into the securing position and from this

Be pivoted securing position out in the release position can and wherein the securing element (30, 40) is arranged such that it is movable by the insertion of an object to be gripped between the two jaws (10, 20) from the securing position and only if the insertion of the workpiece perpendicular to the pivot axis and perpendicular to the relative

Movement direction of the jaws is.

10. gripping device (1) according to any one of the preceding claims, characterized in that the gripping device (1) comprises exactly two clamping jaws (10, 20), wherein preferably each clamping jaw has a securing element (30, 40).

11. Gripping device (1) according to any one of the preceding claims, characterized in that the clamping jaws (30, 40) are provided with cutting or pressing tools to cut or press a workpiece.

12. Gripping device (1) according to one of the preceding claims, characterized in that for movement of the clamping jaws (10, 20) an actuator (60) is provided, in particular an electrically, hydraulically or pneumatically operated actuator (60).

A robotic system comprising a robotic arm (70), characterized in that the robot arm (70) is provided with a gripping device (1) according to any one of the preceding claims, and at least one actuator (60) for gripping the gripping device (1) actuate.