Tool interface and robots with such a tool interface

Abstract

Tool interface (10) for coupling a tool (200) to a robot (100) with the following features: a. the tool interface (10) has a contact surface (12) for contacting a corresponding contact surface (212) of the tool (200), and b. the tool interface (10) has a coupling device (14) for mechanically coupling the tool (200) to the tool interface (10), and c. the tool interface (10) has a blow-off device (30) for generating a blow-off airflow in the area of ​​the contact surface (12), characterized by the following feature: d. the blow-off device (30) has a plurality of nozzle openings (32) for releasing the blow-off airflow, wherein the nozzle openings (32) are supplied with compressed air from a common compressed air connection (34) of the tool interface (10).

Description

The invention relates to a tool interface and to a robot having such a tool interface.A tool interface in the sense of the invention serves the purpose of detachably and exchangeably attaching a robot tool to a robot arm. A tool interface of the generic type has a contact surface for contact with a contact surface of a corresponding interface on the side of the tool. In addition, the tool interface has a coupling device, by means of which the tool interface on the robot arm side can be mechanically fastened to one another and in particular locked at a corresponding interface of the tool.It is known to provide at the interface of a blow-off device. Such a blow-off device usually has a nozzle opening through which compressed air is discharged in the form of an air blast during the coupling or decoupling process of the tool interface in order to eliminate contaminants in the region of the contact surface, since these make secure coupling and accurate operation of the robot more difficult.However, it has been found that the cleaning that can be achieved with known blow-off devices is sometimes not capable of achieving the desired blow-off effect, so that impurities remain. It is indeed possible to increase the cleaning quality by means of blow-off devices with a plurality of compressed air channels and nozzle openings. However, this is associated with a high outlay in the installation of the tool interface and increases the setup times to a considerable extent.OBJECT AND SOLUTIONThe object of the invention is to provide a tool interface of the type described at the beginning which achieves an improved blow-off effect.For this purpose, a tool interface according to the invention is primarily proposed. The invention also comprises, in addition, the set of this tool interface and a corresponding interface on the tool and the robot on whose robot arm the tool interface is provided.A tool interface according to the invention has a contact surface for bearing a corresponding contact surface of the tool. Although it is possible to design these contact surfaces to be non-planar in a corresponding manner to one another, a planar design of the contact surface is considered advantageous. Preferably, at least 80% of a contact surface lies in a common contact plane. The contact surface is preferably an at least predominantly metallic contact surface. In an edge region of the contact surface, a circumferential seal can be provided, which is provided for contact on the contact surface of the tool and makes it more difficult for dirt to penetrate during operation.The seal in particular preferably also surrounds the electrical contact surfaces for the transmission of data and / or electrical energy. In a coupled state of the tool interface, the contact surfaces are therefore protected from contamination from the outside by the seal.The tool interface has a coupling device for mechanically coupling the tool to the tool interface. This coupling device preferably has at least one conical or otherwise tapering alignment pin which, when coupled to the tool, engages into a corresponding receptacle provided thereon. In particular, two such alignment pins are preferably provided. Alternatively, the alignment pins can also be provided on the tool, so that the tool interface on the robot arm side instead has corresponding receptacles. In particular in addition thereto, the coupling device preferably has a locking mechanism for positively coupling the tool to the workpiece interface. This locking mechanism can in particular have locking bodies which, after the tool has been attached to the tool interface, are displaced transversely to the joining direction and thereby engage in a corresponding receptacle on the tool. The locking bodies can be in particular balls in a central locking connection piece which are pressed radially outwards and thus into at least one receptacle on the tool side by a control pin.The tool interface according to the invention has a blow-off device for generating a blow-off air flow in the region of the contact surface. The invention relates primarily to the particular configuration of this blow-off device.It is provided that the blow-off device has a plurality of nozzle openings for discharging the blow-off air flow. The compressed air is discharged by means of the at least two and preferably at least four nozzle openings in different regions of the contact surface and thereby ensures that the entire contact surface is freed of impurities. The various nozzle openings can emit the compressed air stream vertically to the contact surface or also angled with respect thereto. An angled and thus aligned delivery is particularly expedient when particular regions of the interface and in particular of the contact surface are in particular in need of cleaning. This can apply, for example, to electrical contact surfaces, by means of which control signals or electrical power are transmitted to the tool.The plurality of nozzle openings is supplied with through air from a common compressed air connection. The effort involved in producing the compressed air connection is therefore comparatively low. It is sufficient to connect a feed hose at one point to the tool interface, in particular a base body of the tool interface, in order to provide the plurality of nozzle openings as a result.It is preferably provided that the tool interface has the aforementioned base body. This base body is preferably metallic and forms at least a part of the contact surface of the tool interface. In principle, it is possible to provide the nozzle openings directly through separate bores in this base body.However, it is preferred if the tool interface has a nozzle body which is separate from the base body and through which preferably a plurality of and thus at least two nozzle openings pass. This nozzle body is attached to the base body and supplied with compressed air through at least one air channel in the base body. The nozzle body can also be metallic. However, a configuration is preferred in which the nozzle body is made of plastic, in particular of polyoxymethylene or of polyurethane. The nozzle body is preferably designed as a flat nozzle plate with a largely uniform wall thickness. In particular, the thickness of the nozzle plate can preferably be 15 mm or less, in particular 10 mm or less.It is preferably provided that the base body has at least one depression in the region of the contact surface. This contact surface is covered by the nozzle body. Compressed air which is supplied to the depression can thus pass within the depression to the plurality of nozzle openings and emerge here.The depression preferably performs a dual function. In addition to distributing the compressed air over the depression, at least one screw hole is preferably provided in the depression. This screw hole penetrates the base body, so that the fastening screws inserted here on the side of the base body opposite the contact surface serve for fastening to a flange of the robot arm.Preferably, a common depression is provided in which a plurality of screw holes are provided, in particular at least three screw holes. The screw holes can be arranged in particular on a circular shape and can be arranged together in a circular or circular-segment-shaped depression.The nozzle body can be fastened to the base body in various ways. It must be taken into account that the nozzle body is pressed away from the base body due to the compressed air and the fastening must be capable of preventing the separation.A preferred possibility provides that the nozzle body is connected to the base body via a screw connection. The screws are preferably screwed from the outside through the nozzle body into the base body. Preferably, at least three screws are provided, in particular preferably at least four.The nozzle body is preferably located at least partially in the described depression. It is particularly preferred that the nozzle body is adapted to the depression in such a way that an outer side of the nozzle body forms a uniform plane with surface sections of the contact surface surrounding the depression. The outer side of the nozzle body is a part of the contact surface in such a configuration.The arrangement of the nozzle body in the depression can likewise serve the purpose of securing the nozzle body to the base body. For this purpose, it can be provided that the nozzle body is held in the depression in a frictionally locking manner in that it has an excess compared to the depression at least in sections. A further possibility provides that the nozzle body is positively held in the depression. This can be achieved in particular by the depression having a geometry whose cross section narrows at least in sections in the direction of the contact surface, for example in the manner of a dovetail. The nozzle body is inserted therein and secured against separation by over-dimensioning with respect to the narrowest point of the depression. The dovetail shape or another shape of the depression tapering towards the contact surface is furthermore advantageous since it promotes an inclination of the nozzle body for automatically sealing the gaps between the nozzle body and the base body. If the nozzle body is pressed outward on its inside by compressed air, this closes the gaps and the air is largely discharged completely through the nozzle openings as intended.A configuration is particularly preferred in which the nozzle body is secured positively both in the manner described above by the shaping of the depression and additionally by means of screws.The depression preferably has at least one bearing surface for bearing the nozzle body. In particular, the depression can be configured such that such bearing surfaces and the above-described screw holes are provided alternately. A bearing surface is thus provided between each of two screw holes.In order that the air within the depression can reach the different nozzle openings, it can be provided that an air guide groove is introduced into the mentioned bearing surfaces, through which the compressed air spreads. Alternatively or additionally, it can be provided that the nozzle body has an air guide groove on an inner side, through which the air can flow to the nozzle openings.As already explained at the beginning, the invention also relates to a robot with a tool interface of the described type. This robot has a robot arm, at the distal end of which the tool interface is provided. The tool can thus be guided by means of the robot arm to a working position and moved there. The robot arm can furthermore be guided into the region of a changing station in which a tool is decoupled and a new tool is subsequently coupled.In particular, the use of the described tool interface is appropriate if the tool is provided as a tool for machining, in particular a drilling tool. During machining and in particular during drilling, a high load is produced by dust and chips, which can be countered well by the blow-off device according to the invention.The tool preferably has an interface corresponding to the tool interface, wherein the latter preferably likewise has a base body which offers the contact surface for the tool interface.BRIEF DESCRIPTION OF THE DRAWINGSFurther advantages and aspects of the invention are evident from the claims and from the following description of preferred exemplary embodiments of the invention, which are explained below with reference to the figures. FIG. 1 shows a robot according to the invention in an overall illustration. FIG. 2 shows a robot-side tool interface and a corresponding interface on the side of a tool. FIG. 3 shows the structure of a blow-off device on the robot-side tool interface together with nozzle openings for delivering compressed air. FIGS. 4 and 5 show in sectional representations the robot-side tool interface and the path of the compressed air to the nozzle openings.DETAILED DESCRIPTION OF THE EMBODIMENTSFIG. 1 shows a robot 100 which has a robot arm 110 by means of which a tool 200 can be moved flexibly and can in particular be moved into a working position and can be moved to a changing station for the purpose of changing the tool. The tool 200 is designed as a drilling tool in the present case and has a drill 202 by means of which bores can be made in surfaces. Supply lines 120, 122 run along the robot arm 110, wherein the supply line 122 is provided for transmitting electrical power and / or electrical signals. The supply line 120 is a compressed air line, by means of which compressed air is supplied to the robot-side tool interface 10 in order to free the interface from contamination and thus ensure reliable tool change and trouble-free operation.FIG. 2 shows the robot-side tool interface 10 and the corresponding counterpart of the tool-side interface 210 in an overall illustration, wherein the interfaces 10, 210 are not coupled to one another in the state of this illustration.On the side of the tool interface 10 which is provided on the robot arm 110, a metallic base body 16 is provided. The surface 12 of the base body 16 pointing upward in FIG. 2 forms a contact surface 12 for planar contact with a corresponding contact surface 212 of the tool-side interface 210. In the region of this contact surface, a coupling device 14 is provided which consists of a plurality of partial elements, namely of two conical alignment pins 14A which retract into corresponding recesses at the interface 210, and a central locking mechanism 14B at which radially extendable locking bodies in the form of balls 14C are provided which are pressed outwards after coupling of the tool 200 in order to achieve a positive coupling with the tool-side interface 210.In the region of the contact surface 12, two fields 23 with electrical contact surfaces 24 are provided. These are provided for transmitting electrical energy and for transmitting control signals to the tool 200 and are connected to the supply line 122 on the robot arm 110 in a manner not shown in more detail. In a manner not shown in more detail, corresponding contacts are provided opposite the tool-side interface 210.The contact surface 12 is provided on the edge side with a seal 13 which, after coupling the tool 200 to the tool interface 10, prevents dirt or chips from being able to pass into an intermediate space between the contact surfaces 12, 212 and into the region of the contact surfaces 24. In order to fulfil this task, however, it is necessary that chips or impurities are not already present on the contact surfaces 12, 212 during the coupling. To prevent this, a blow-off device 30 is provided.With reference to FIG. 3, it can be seen that a depression 20 is provided in the region of the contact surface 12 on the base body side. This depression 20, which has approximately the shape of a circular arc, which spans approximately 300°, consists of various partial regions, namely of six screw holes 22, in the region of which recessed screws are provided in order to fasten the base body 16 to a flange of the robot arm 110, and of intermediate regions beyond and between the screw holes 22, which provide bearing surfaces 21, which are, however, recessed with respect to the bearing surface 12.Inserted into the depression 20 formed in this way, in the manner which can also be seen in FIG. 2, is a nozzle body 18, the outer contour of which corresponds substantially to the contour of the depression 20. As can be seen from FIG. 2, this nozzle body 18 is inserted into the depression 20 in such a way that its outer side 18A ends essentially flush with the surrounding parts of the contact surface 12. In the inserted state, the nozzle body 18 protects the screws. If the tool interface 10 is to be separated from the robot arm 110, the nozzle body 18 is removed, so that access to the fastening screws is subsequently provided.However, the main task of the nozzle body 18 is to provide a total of six nozzle openings 32 belonging to the blow-off device 30, through which compressed air can be discharged from the depression 20 into a gap between the contact surfaces 12, 212. This compressed air is suitable for blowing away from here all chips and other impurities which are located in the region of the contact surfaces 12, 212 and in particular in the region of the contact surfaces 24.As can be seen with reference to the screws 40 and the corresponding screw openings 19 in the nozzle body 18, the nozzle body 18 is screwed firmly to the base body 16 as intended.In order to be able to hold the overpressure which arises in the depression 20 when compressed air is supplied, the nozzle body 18 can additionally have a cross section which tapers upwards in the direction of the contact surface 12 in the manner which can be seen in FIG. 5. Correspondingly, the depression 20 itself can also have a tapering shape in this region. This results in the dovetail geometry seen in FIG. 5. At high pressure in the depression 20, the nozzle body 18 is pressed upward on account of this geometry and in this case closes gaps between the nozzle body 18 and the base body 16.The compressed air is supplied via a single compressed air connection 34, which is provided on the outer side of the base body 16. This is evident in FIG. 4. From here, the compressed air flows through a compressed air channel 33 into the depression 20, and the mouth of the compressed air channel 33 into the depression 20 is shown in FIG. 3.In order that the compressed air can also continue to flow in the region of the bearing surfaces 21 within the depression 20 and thus can reach all the nozzle openings 32, grooves can be provided in the bearing surfaces 21. Alternatively or additionally, an air guide groove 18C may also be provided on an inner side of the nozzle body 18. This is apparent from FIG. 5.The nozzle openings 32 can all have a uniform geometry. In order to compensate for the respectively different geometrically induced resistance in the air supply to the air nozzles, it can however also be advantageous to equip the nozzle openings with different clear cross sections or geometries in order to compensate for the increased resistance in the air supply. In this way, it is possible to achieve a substantially uniform air flow at all nozzle openings despite this non-uniform air resistance.The nozzle openings can discharge the compressed air perpendicularly with respect to the contact surface. However, it can also be expedient to provide the nozzle openings with an inclined geometry in order to direct the air in a specific direction in a targeted manner. This is particularly useful in order to clean the electrical contact surfaces 24 for transmitting electrical power or electrical signals. If this is the case, some or all of the air nozzles are preferably oriented in such a way that they emit the compressed air in the direction of these contact surfaces.

Claims

Tool interface (10) for coupling a tool (200) to a robot (100), having the following features: a. the tool interface (10) has a contact surface (12) for contact with a corresponding contact surface (212) of the tool (200), and b. the tool interface (10) has a coupling device (14) for mechanically coupling the tool (200) to the tool interface (10), and c. the tool interface (10) has a blow-off device (30) for generating a blow-off air flow in the region of the contact surface (12), characterized bythe following feature: d. the blow-off device (30) has a plurality of nozzle openings (32) for discharging the blow-off air flow, wherein the nozzle openings (32) are fed with compressed air from a common compressed air connection (34) of the tool interface (10).Tool interface (10) according to Claim 1, having the following further features: a. the tool interface (10) has a base body (16), on which the common compressed air connection (34) is provided, and b. the tool interface (10) has a nozzle body (18), which is attached to the base body (16) and which is penetrated by a plurality of the nozzle openings (32).Tool interface (10) according to claim 2 with the following further features: a. the base body (16) has at least one depression (20) in the region of the contact surface (12), and b. in the depression (20) at least one leaf hole (22) is provided for attaching the tool interface (10) to a robot arm (110) by means of fastening screws, and c. the nozzle body (18) covers the depression (20).Tool interface (10) according to claim 3 having the following further feature: a. a plurality of screw holes (22) for attaching the tool interface (10) to a robot arm (110) by means of fastening screws is provided in the depression (20), wherein in particular preferably the screw holes (22) are arranged on a circular shape.Tool interface (10) according to claim 3 or 4, having the following further feature: a. the nozzle body (18) is connected to the base body (16) by means of a screw connection.Tool interface (10) according to one of the preceding claims, having the following further feature: a. the nozzle body (18) is located at least partially within the depression (20) in the base body (16).The tool interface (10) of claim 6 further comprising: a. the nozzle body (18) is frictionally retained within the recess (20).Tool interface (10) according to Claim 6 or 7, having the following further feature: a. the nozzle body (18) is held in the depression (20) in a positively locking manner, in particular by a shaping of the depression (20) which narrows in cross section in the direction of the contact surface (12).Tool interface (10) according to claim 6, 7 or 8, having the following further feature: a. the nozzle body (18) is adapted to the depression (20) in such a way that an outer side (18A) of the nozzle body (18) forms a uniform plane with surface sections of the contact surface (12) surrounding the depression.Tool interface (10) according to one of the preceding claims, having the following further feature: a. the nozzle body (18) is manufactured from plastic, preferably from polyoxymethylene or from polyurethane.Tool interface (10) according to one of the preceding claims, having the following further feature: a. the base body (16) is manufactured from metal.Tool interface (10) according to one of the preceding claims, having the following further feature: a. within the depression (20), at least one bearing surface (21) for bearing the nozzle body (18) is provided, wherein an air guide groove is provided in the bearing surface (21), through which the air can flow to the nozzle openings (32).Tool interface (10) according to one of the preceding claims, having the following further feature: a. the nozzle body (18) has an air guide groove (18C) on an inner side (18B), through which the air can flow to the nozzle openings (32).Tool interface (10) according to one of the preceding claims, having the following further features: a. the nozzle body (18) is designed as a flat nozzle body (18) with a largely uniform wall thickness, and b. the nozzle openings (32) have an extension direction inclined with respect to a normal vector of the nozzle body (18).Tool interface (10) according to one of the preceding claims, having the following further feature: a. the tool interface (10) has electrical contact surfaces (24) for transmitting data and / or electrical energy to the coupled tool (200).Tool interface (10) according to Claim 15, having the following further feature: a. the electrical contact surfaces (24) are provided in the region of the contact surface (12).Tool interface (10) according to claim 15 or 16, having the following further feature: a. at least one nozzle opening (32) is oriented in the direction of the electrical contact surfaces (24), wherein preferably the plurality of nozzle openings (32) are oriented in the direction of the electrical contact surfaces (24).Tool interface (10) according to any of the preceding claims, having the following further feature: a. the coupling device (14) comprises at least one conical alignment pin (14A), preferably two conical alignment pins (14A), or the coupling means comprises at least one receptacle for a conical alignment pin, preferably two receptacles for conical alignment pins.Tool interface (10) according to one of the preceding claims, having the following further feature: a. the coupling device (14) comprises a locking mechanism (14B) for positively coupling the tool (200) to the workpiece interface.Tool interface (10) according to one of the preceding claims, having the following additional feature: a. the contact surface (12) is surrounded on the outside by a seal (13).Tool interface (10) according to claim 20 having the following additional feature: a. the electrical contact surfaces (24) for transmitting data and / or electrical energy are provided on the contact surface (12) in such a way that they are surrounded on the outside by the seal (13) and, in a coupled state, are protected by the seal (13) against contamination from the outside.Tool interface (10) according to one of the preceding claims, having the following additional feature: a. at least two nozzle openings (32) have a mutually different geometry and / or a mutually different minimum clear cross section.Robot (100) having the following feature: a. the robot (100) has a movable robot arm (110), at the distal end of which a tool interface (10) is provided, characterized bythe following feature: b. the tool interface (10) is designed according to one of the preceding claims.Robot according to claim 23, having the following further features: a. a tool (200) for machining is attached to the tool interface (10), in particular a drilling tool (200), and b. the tool (200) has a tool interface (210) corresponding to the tool interface (10) on the robot arm (110).

Images