FIELD

The invention relates to a system for exchanging a workpiece holding device for a robot processing station.

BACKGROUND

Workpiece holding devices, such as jigs and fixtures, are used to hold a workpiece during various automated processing operations on the workpiece, such as mounting, welding, riveting, gluing or the like. Active workpiece holding devices may be provided with sensors and actuators, such as clamps or other manipulation actuators, for actively interacting with the workpiece, for example to clamp and move the workpiece relative to the holding device during or between processing operations.

Such sensors and actuators are typically controlled by a central control unit, to which the actuators are to be connected. As workpiece holding devices are tailored to the workpiece they hold, the processing of various different workpieces at a single robot station may require regular exchange of the custom workpiece holding devices, including their associated sensors and actuators. The exchange of workpiece holding devices in conventional systems involves cumbersome and time-consuming disconnecting from and reconnecting sensors and actuators to the central control unit.

SUMMARY

It is an aim to facilitate the exchange of workpiece holding devices at a robot processing station. It is particularly an aim to provide a system for efficiently exchanging workpiece holding devices.

According to an aspect, a workpiece holding device exchange system for a robot processing station is provided, comprising a base structure having a plurality of mounting sites. Each of the mounting sites is arranged for releasably mounting a workpiece holding device to the base structure. Each mounting site is provided with a communication port connected to a communication bus, which communication bus extends between the communication port and a central control unit. The system further comprises a workpiece holding device arranged for being releasably mounted to the base structure at any selected one of the mounting sites. The workpiece holding device may include a fixture and/or a jig. The workpiece holding device is provided with one or more sensors and/or actuators for handling a workpiece. The workpiece holding device is provided with a processing module connected to the one or more sensors and/or actuators, wherein the processing module comprises a communication connector arranged for being releasably connected to the communication port of the selected mounting site.

Hence, the processing module of the workpiece holding device can be connected and disconnected via the communication bus to the central control unit, wherein the communication port is arranged at the mounting site. The processing module may receive control signals from the central control unit, and may be configured to process the received control signals and control the one or more actuators accordingly. The processing module may also be configured to communicate to the central control unit what sensors and/or actuators are associated with the processing module.

The processing module may also receive sensor signals from one or more sensors of the workpiece holding device. The processing module may be configured to process the received sensor signals, and/or send the (processed) received sensor signals to the central control unit.

The workpiece holding device can be releasably mounted to the base structure at any selected one of the mounting sites. It will be appreciated that the workpiece holding device can be dismounted from one mounting site and mounted at another mounting site if desired. It is also possible to mount the workpiece holding device to a different base structure. Especially if there are a plurality of base structures and a plurality of workpiece holding devices, each workpiece holding device can be mounted to any mounting site of any base structure. It is also possible to reuse an existing base structure e.g. by dismounting the existing workpiece holding device(s) and mounting one or more new workpiece holding devices. Hence, the workpiece holding device may be an exchangeable workpiece holding device. Hence, the exchangeable workpiece holding device may be configured to be exchangeably mountable to the base structure at any one of the mounting sites.

Optionally, each mounting site of the base structure is provided with a power supply port connected to a power supply line and the processing module optionally includes a power connector arranged for being releasably connected to the power supply port of the selected mounting site.

Optionally, the power supply port is integrated with the communication port. The power supply port and the communication port may for example be integrated in a single connector, such as single socket. The power connector may correspondingly be integrated with the communication connecter, for example into a single connector, e.g. a single plug, that is commentary to the connector having the power supply port and communication port.

Optionally, each mounting site of the base structure is provided with a gas supply port connected to a gas supply line and the processing module optionally includes a gas connector arranged for being releasably connected to the gas supply port of the selected mounting site. Hence, pneumatic actuators, which may be provided on the workpiece holding device, may be driven by the gas supply. The system may for example include a central gas source, from which the gas can be supplied through the gas supply line. Each mounting site may have a separate gas supply line. Alternatively, the mounting sites may share a common gas supply line, wherein each gas supply port connects to the common gas supply hne.

Optionally, each mounting site of the base structure is provided with a first gas supply port to a first gas supply line and a second gas supply port to a second gas supply line separate from the first gas supply hne, wherein the processing module optionally includes a first gas connector arranged for being releasably connected to the first gas supply port and a second gas connector arranged for being releasably connected to the second gas supply port of the selected mounting site. The first gas supply hne may supply a first gas and the second gas supply line may supply a second, different, gas. The first gas may for example be air of a controlled quality, and the second gas may be air of an uncontrolled quality. The processing module may be arranged to control a supply of gas to an actuator, and may accordingly be arranged to select the appropriate gas supply hne. The processing module may be for instance be arranged to switch a gas supply to an actuator from the first gas supply line to the second gas supply line, or vice versa.

Optionally, the workpiece holding device comprises a support surface for supporting a workpiece, or workpiece holder, thereon. The workpiece holding device can include a support, e.g. having the support surface as a top surface. Optionally, the workpiece holding device comprises a spacer for engaging the base structure so as to provide a spacing between the workpiece holding device and the base structure. The spacer can e.g. project from a bottom surface of the support opposite the support surface. A spacing between the workpiece holding device and the base structure provides room for mounting the workpiece holding device to the base structure, and for connecting and disconnecting the processing module to at least the communication port.

Optionally, the system comprises a frame for holding the base structure, wherein the base structure is movably coupled to the frame. Hence the base structure, including any workpiece holding device mounted thereon, can be moved relative to a processing robot .

Optionally, the workpiece holding device is movably, e.g. pivotally, mounted to the base structure.

Optionally, the base structure is rotatable relative to the frame about a rotation axis. The workpiece may hence be oriented at different angles relative to a processing robot.

Optionally, the rotation axis is offset from the workpiece holding device. The rotation axis may particularly extend through a robot processing zone in which the workpiece is generally positioned by the holding device and where a processing robot generally performs processing operations on the workpiece. The base structure can thus be swiveled about the rotation axis, wherein a position of the robot processing zone is substantially maintained and only rotated about the rotation axis.

Optionally, the workpiece holding device comprises a support surface for supporting a workpiece, or workpiece holder, thereon, and wherein the rotation axis extends parallel to the support surface.

Optionally, the system comprises a further workpiece holding device, separate from the workpiece holding device, arranged for being releasably mounted to the base structure at any other selected one of the mounting sites.

Optionally, the workpiece holding device and the further workpiece holding device form a compound workpiece holding device for handling the workpiece. Hence, the compound workpiece holding device, being formed by at least two workpiece holding devices, can be used to handle the same, e.g. a single, workpiece, wherein each individual workpiece handling devices can be conveniently interchanged, for instance between processing steps. The compound workpiece holding device may be for example be formed by two, three, four or five, or more, workpiece holding devices. The workpiece holding devices that form the compound holding device may be similar to each other. Features described herein in relation to the workpiece holding device can also apply to the further workpiece holding device. For example, the further workpiece holding device may be provided with one or more further sensors and/or actuators for handling the workpiece, wherein the further workpiece holding device is provided with a further processing module connected to the one or more further sensors and/or actuators, and wherein the further processing module comprises a further communication connector arranged for being releasably connected to the communication port of the selected mounting site at which the further workpiece holding device is mounted.

Optionally, each work piece holding device of the compound workpiece holding device has a support surface for supporting the workpiece, or workpiece holder, thereon, wherein a size of the support is standardized. The size of the support surfaces may for example be equal to each other. Also, a spacer of the workpiece holding devices may be standardized, such that the support surfaces of the workpiece holding device are, in use, level. Standardized workpiece holding devices facilitates interchanging the workpiece holding devices. One or more sensors and/or actuators may be mounted to the support surface. The workpiece holding devices may also include a processing module, e.g. mounted to a bottom surface opposite the support surface.

Another aspect provides a base structure of a workpiece holding device exchange system as described herein.

Another aspect provides a workpiece holding device of a workpiece holding device exchange system as described herein.

Another aspect provides a set comprising a plurality of workpiece holding devices as described herein. The workpiece holding devices of the set may be configured for being exchangeably mountable to a base structure. Another aspect provides a compound workpiece holding device comprising a plurahty of workpiece holding devices as described herein. An aspect relates to a robot processing station, such as welding station, comprising a robot processing device, such as a welding robot, arranged for processing a workpiece, and a workpiece holding device exchange system as described herein.

Optionally, the robot processing device is arranged for mounting, welding, riveting, gluing, painting, or the like.

According to a further aspect, a method is provided for connecting a workpiece holding device for a robot processing station to a base structure. The method includes the steps of providing a base structure having a plurality of mounting sites, each arranged for releasably mounting a workpiece holding device to the base structure, wherein each of the mounting sites is provided with a communication port connected to a communication bus that extends between the communication port and a central control unit; mounting a workpiece holding device to the base structure at a selected one of mounting sites, the workpiece holding device being provided with one or more sensors and/or actuators for handling a workpiece, a processing module connected to the one or more sensors and/or actuators, and a communication connector connected to the communication port; and connecting the communication connector of the workpiece holding device to the communication port of the selected mounting site of the base structure.

Optionally, each mounting site of the base structure is provided with a power supply port connected to a power supply line and the processing module includes a power connector arranged for being releasably connected to the power supply port, the method including connecting the power connector to the power supply port of the selected mounting site of the base structure. Optionally, each mounting site of the base structure is provided with a gas supply port connected to a gas supply line and the processing module includes a gas connector arranged for being releasably connected to the gas supply port, the method including connecting the gas connector to the gas supply port of the selected mounting site of the base structure.

It will be appreciated that any of the aspects, features and options described herein can be combined.

BRIEF DISCRIPTION OF THE DRAWING

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings in which:

Figure 1 shows a perspective view of an exemplary workpiece holding device exchange system;

Figure 2 shows a frontal view of an exemplary workpiece holding device exchange system;

Figure 3 shows a top view of an exemplary workpiece holding device exchange system;

Figure 4 shows a bottom view of an exemplary workpiece holding device exchange system.

DETAILED DESCRIPTION

Figures 1-4 show respective views of an exemplary workpiece holding device exchange system 1000. The system 1000 comprises a base structure 100, here having a hollow beam body 101 that extends between two outer ends 102, 103. The base structure 100 has a plurality of mounting sites for releasably mounting a workpiece holding device 210, 220, 230, 240 to the base structure 100. For example, the hollow beam body 101 may be provided with coupling means, e.g. screw holes, at various locations for coupling a workpiece holding device, such as a jig or a fixture, thereto.

In the example of figures 1-4, the base structure 100 includes four mounting sites, namely a first 110, a second 120, a third 130, and a fourth 140 mounting site. The base structure 100 forms a backbone of the system to which workpiece holding devices 210, 220, 230, 240 can be connected and disconnected, both structurally and communicatively.

Each of the mounting sites 110, 120, 130, 140 is provided with a port module 111, 121, 131, 141 for connecting a connector thereto. Here, four port modules are provided; at least one port module for each mounting site. The base structure includes multiple port mounting locations 115 where port modules can be provided. In this example nine port mounting locations are provided, allowing nine mounting possible mounting sites to be created. The base structure 100 enables selection of various locations of the mounting sites relative to the base structure and various sizes of mounting sites. This way, the mounting sites can be adapted to the workpiece holding devices and ultimately to the particular workpiece to be processed.

Each port module 111, 121, 131, 141 includes at least a communication port that connects to a communication bus that extends along, e.g. through, the base structure 100, here through an internal cavity of the beam body, between the communication ports and a central control unit. The port modules, here, also include a power supply port connected to a power supply line that extends along, e.g. through, the beam body 101. In this example, the power supply ports and the communication ports are integrated into a single port 112, 122, 132, 142.

The system 1000 further comprises a workpiece holding device, in this example showing four workpiece holding devices, namely a first 210, second 220, third 230, and fourth 240 workpiece holding device. Each workpiece holding device is arranged for being releasably mounted to the base structure 200 at any selected one of the respective mounting sites 110, 120, 130, 140. The workpiece holding devices 210, 220, 230, 240 are hence exchangeable workpiece holding devices, that are exchangeably mountable to base structure 100 at any mounting site 110, 120, 130, 140. In this particular example, the first workpiece holding device 210 is mounted to the base structure 100 at the first mounting site 110, the second holding device 220 at the second mounting site 120, the third workpiece holding device 230 at the third mounting site 130 and the fourth workpiece holding device 240 at the fourth mounting site 140, but it will be appreciated that each holding devices can be mounted at any other mounting site as well.

Each workpiece holding device 210, 220, 230, 240 includes a coupling means 211, 221, 231, 241 for enabling coupling of one or more sensors and/or actuators to a support surface 212, 222, 232, 242 of the holding devices, e.g. of a support, such as a support plate of the workpiece holding device. Each workpiece holding device 210, 220, 230, 240 is provided with a processing module 213, 223, 233, 243 for being connected to the one or more sensors and/or actuators. In this example, the processing modules 213, 223, 233, 243 are coupled to the respective workpiece holding devices 210, 220, 230, 240 at a bottom facing side of the workpiece holding devices, opposite a support surface 212, 222, 232, 242.

The processing modules 213, 223, 233, 243 associated with respective holding devices 210, 220, 230, 240 include a communication connector that is complementary to the communication ports 111, 121, 131, 141, and arranged for being releasably connected to any one of the communication ports 111, 121, 131, 141 of the mounting sites 110, 120, 130, 140. In this example, the processing module also includes a power connector, that is, here, integrated with the communication connector.

The port modules 111, 121, 131, 141 each further include a gas supply port connected to a gas supply line. The processing module includes a complementary gas connector arranged for being releasably connected to the gas supply port of the selected mounting site. More specifically, the port modules 111, 121, 131, 141 at each mounting site are each provided with a first gas supply port 113, 123, 233, 143 connected to a first gas supply line and a second gas supply port 114, 124, 134, 144 connected to a second gas supply line. The first and second gas lines extend from the respective gas supply ports along, e.g. through, the beam body 101 of the base structure 100 to two respective gas sources. The gas source can be a source of compressed air, or a gas required during processing, such as nitrogen or carbondioxide. In this example the first gas source is a source of compressed air, and the second gas source is a source of compressed air switchable by an emergency switch. The processing modules 213, 223, 233, 243 include complementary first gas connectors arranged for being releasably connected to the first gas supply ports 113, 123, 233, 143 and second gas connectors arranged for being releasably connected to the second gas supply ports 114, 124, 134, 144.

In this example, each of the workpiece holding devices 210, 220, 230, 240 comprises spacers 216, 226, 236, 246 that project from a bottom surface, substantially transverse to the support surface 212, 222, 232, 242. The spacers 216, 226, 236, 246 engage, with outer ends thereof, the base structure 100 so as to provide a spacing between the support surface 212, 222, 232, 242 and the base structure 100, in which the processing modules are 213, 223, 233, 243 provided. The spacers 216, 226, 236, 246 are in this example equal to each other, such that the support surfaces 212, 222, 232, 242 of the workpiece holding devices 210, 220, 230, 240 are, in use, aligned.

The base structure 100 may be rotatable about a rotation axis A which rotation axis A here extends above the workpiece holding devices 210, 220, 230, 240, parallel to the support surfaces, through a robot processing zone in which the workpiece is generally positioned by the holding devices 210, 220, 230, 240 and where a processing robot generally performs processing operations on the workpiece. The base structure can thus be swiveled about the rotation axis A, wherein a position of the robot processing zone is substantially maintained and only rotated about the rotation axis.

Here, the four workpiece holding devices 210, 220, 230, 240 form a compound workpiece holding device. The holding devices of the compound workpiece holding device can for example together hold one and the same workpiece. The individual holding devices 210, 220, 230, 240 may accordingly form modules of the compound workpiece holding device, that can easily be exchanged individually without having to disconnect the other workpiece holding devices. The support surfaces 212, 222, 232, 242 of the workpiece holding devices 210, 220, 230, 240 together form a compound support surface for holding a single workpiece. The support surfaces 212, 222, 232, 242 are in this example identically sized. The support surfaces 212, 222, 232, 242 may also differ in size. A set of standardized workpiece handling devices may be provided compatible with the base structure 100, to allow for efficient exchange of workpiece holding devices.

Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein, without departing from the essence of the invention. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged.

However, other modifications, variations, and alternatives are also possible. The specifications, drawings and examples are, accordingly, to be regarded in an illustrative sense rather than in a restrictive sense.

For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word ‘comprising’ does not exclude the presence of other features or steps than those listed in a claim. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of these measures cannot be used to an advantage.