US20080003087A1

US20080003087A1 - Clamping fixture for accommodating different component types

Info

Publication number: US20080003087A1
Application number: US11/755,593
Authority: US
Inventors: Karl-Heinz Geiss; Gerhard HILBERT
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2006-05-31
Filing date: 2007-05-30
Publication date: 2008-01-03
Also published as: CN101081479B; DE102006025311A1; EP1862252A2; EP1862252A3; CN101081479A

Abstract

The invention shows a clamping fixture to accommodate and accurately position different component types which comprises at least a rotary element mounted in a rotary manner around an axis of rotation and at least two component type-related accommodating elements attached to the rotary element to accommodate components, wherein the at least two accommodating elements are arranged offset to one another in the direction of rotation of the rotary element so that each accommodating element can be brought into a working position to accommodate and accurately position a component through rotating the rotary element around the axis of rotation.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This Utility Patent Application claims priority to German Application No. DE 10 2006 025 311.6, filed May 31, 2006.

TECHNICAL FIELD

The present invention lies in the area of production and assembly technology and relates to a clamping fixture for accommodating and accurately positioning different component types.

BACKGROUND

In the industrial mass production of motor vehicles the vehicle body, consisting of floor assembly, side and front parts and the vehicle roof, is gradually put together in different work stations wherein individual components can initially be pre-joined into larger component assemblies in separate work stations.
To join the components they are accommodated and accurately positioned (fixed) in type-related clamping fixtures in the respective work stations so that joining robots are able to join the components at defined joining points for example by means of welding. To this end, the clamping fixtures are mostly equipped with so-called geometrical grippers which are adapted to the specific outer (geometric) shape of the respective component type to be accommodated.
If different component types are to be accommodated in a same clamping fixture this means that the type-related geometrical grippers have to be changed which costs time and generally results in undesirable downtimes in the production and production losses.
To avoid time and cost-intensive conversion of clamping fixtures to other component types, clamping fixtures in work stations and production lines are usually always set and used for a same component type. In principle this procedure means that based on the variation of the component types, separate work stations and production lines have to be employed for each vehicle type and each vehicle model which, however, brings with it the need for large areas as well as major expenditure for investment and personnel.
In view of the cost pressure in vehicle manufacture which has been steadily growing in recent years efforts are made so that work stations and production lines can preferably be employed in as versatile and flexible a manner as possible in order to save investment and personnel expenditure on the one hand and enable flexibility in the vehicle manufacture on the other hand for instance when the demand for certain vehicle models diminishes and as a result capacity for the production of other vehicle models or types becomes available.
In practice, this endeavour however is opposed more preferably by the necessity of time and cost-intensive conversion of the type-related clamping fixtures to other component types as was explained.
In the European patent publication EP 1 100 715 B1 a flexible work station for the processing of different component types, more preferably in the body assembly, is described. The work station described comprises component-neutral and component-specific plant components, wherein transport robots are provided with exchangeable, type-related grippers as component-specific plant components. In the work station shown there the components are provided with receptacles for the grippers. In order to reduce the time required for changing grippers when changing the component type the gripper is placed on a component of the old type wherein this component upon renewed changing of the component type is processed first.
The disadvantage with this procedure is more preferably the fact that the change of the gripper as such, i.e. the putting down and picking up of the gripper by the transport robot, still takes up a relatively long time and that undesirable unproductive times therefore have to be expected.
In contrast with this, the object of the present invention consists in making available a clamping fixture for different component types through which a change from type-related accommodating elements to accommodate and accurately position different component types compared with conventional clamping fixtures can be performed quickly and easily so that undesirable downtimes and production losses in work stations and production lines can be largely avoided.

SUMMARY

This object according to the proposal of the invention is solved through a clamping fixture with the characteristics as subsequently described and claimed.
According to the invention, a clamping fixture to accommodate (to retain) and accurately position (three dimensional fixing) of different component types is shown. Here, the clamping fixture according to the invention comprises at least one rotary element mounted in a rotatable manner around an axis of rotation as well as at least two (component) type-related accommodating elements rigidly attached to the rotary element to accommodate and accurately position different component types.
According to the invention, the accommodating elements are arranged in the direction of rotation (circumferential direction) of the rotary element offset relative to one another so that each type-related accommodating element can be brought from a position of rest into a working position to accommodate and accurately position a component by turning the rotary element around its axis of rotation. In addition, the accommodating elements can be offset relative to one another in a direction parallel to the axis of rotation of the rotary element. Here, the accommodating elements can be rigidly attached to a carrier element, for example in form of a carrier plate, which, on the one hand, can be attached more preferably in a detachable manner to the rotary element. As a result, accommodating elements can be quickly replaced in a particularly easy manner.
In the clamping fixture according to the invention the accommodating elements are designed for example in the form of geometrical grippers for the gripping of a component adapted to an external shape of a component.
In an advantageous manner in the clamping fixture according to the invention the different accommodating elements which are arranged on the rotary element offset in the direction of rotation of the rotary element can be quickly and easily brought into their respective working position to accommodate and accurately position components by turning the rotary element around its axis of rotation. As a result, different component types can be accommodated and accurately positioned through the turning of the rotary element. In an advantageous manner no time-consuming removal and reapplying of respective accommodating elements is necessary in the clamping fixture for changing time-related accommodating elements but merely a turning of the rotary element is required.
With an advantageous development of the clamping fixture according to the invention at least two sets of accommodating elements (accommodating element sets) are provided. Here, each accommodating element set contains at least two type-related accommodating elements which can be offset relative to one another in a direction parallel to the axis of rotation and which are adapted to the same specific component type. The accommodating element sets proper are arranged offset relative to one another in the direction of rotation (circumferential direction) of the rotary element such that each accommodating element set can be brought into a rotary position by turning the rotary element around its axis of rotation in which all accommodating elements of a same accommodating element set are located in working position to accommodate a component.
With the above design of the clamping fixture according to the invention each accommodating element set is advantageously attached to the rotary element in modular form. Here it is possible for example that the accommodating elements of a same accommodating element set are attached to a same accommodating element carrier which for example is present in form of a carrier plate. The accommodating element carrier with the accommodating elements attached to it forms an accommodating element set module which can be attached to and removed from the rotary element in a simple manner. The accommodating element set module or the accommodating element carrier with the accommodating elements attached to it is advantageously attached to the rotary element in a detachable manner.
According to a further development of the clamping fixture according to the invention the rotary element has an elongated (oblong) shape along its axis of rotation. Here, the rotary element is advantageously designed vertically to the axis of rotation in form of a square or cylindrical tube with square or round cross sectional area. With a square-shaped rotary element the accommodating elements and accommodating element sets and accommodating set modules respectively can be attached offset to the (tube) surfaces of the square tube in circumferential direction in a particularly easy manner. For example the different accommodating elements and accommodating element sets and accommodating element set modules respectively can each be brought into working position through respective turning by 90°.
With a further particularly preferred development of the clamping fixture according to the invention a plurality (two, three, four or more) of rotary elements as described above is provided which is mechanically and control-technically coupled with one another such that they can be synchronously rotated relative to one another around their respective axes of rotation for example by means of a motor drive. As a result, type-related accommodating elements and type-related accommodating element sets respectively which are located on different rotary elements can be synchronously brought into their respective working position to accommodate and accurately position a same component in a particularly advantageous manner so that a component for example can be accommodated and accurately positioned from several sides in a particularly easy manner. Here, the rotary elements can be mechanically coupled (coupled in a rotary manner) for example by means of an angular drive (for example in form of a bevel gear drive). More preferably, the rotary elements coupled in a rotary manner in working position for the purpose of synchronous motion can only be rotated by merely one (sole) drive (for example drive motor) wherein merely one (sole) rotary element is directly rotated by the drive and the other rotary elements are co-rotated via the rotary coupling of the rotary elements. Thus, the accommodating elements and the accommodating element sets respectively of all rotary elements can be reliably and synchronously brought into their working position. As a result, all rotary elements can more preferably be rotated into their respective working position within the typical clocking times (i.e. for example within a time interval in which a component is passed on from a clamping fixture of a work station to a next clamping fixture of a further work station) of for example five seconds. In an advantageous manner costs can be saved if merely one drive is provided for rotating all rotary elements of a same clamping fixture.
With a further development of the clamping fixture according to the invention said fixture is provided with a motor drive which is mechanically and control-technically coupled with at least one rotary element so that the rotary element can be rotated around its axis of rotation.
In addition, a rotary element rotary position fixing device for fixing selectable rotary positions of a rotary element around its axis of rotation can be provided on the clamping fixture according to the invention. As a result, every one of the rotary elements can be brought into a definable rotary position particularly easily and safely in which respective accommodating elements or accommodating element sets are located in their working position to accommodate a component type. If the rotary elements are coupled in a rotary manner such that the other rotary elements co-rotate when a rotary element is rotated, it is sufficient in an advantageous manner if merely one rotary element rotary position fixing device is arranged on one rotary element.
In addition to this a sensor to sense rotary positions of a rotary element and/or function states of accommodating elements (such as opening or closing positions of geometrical grippers) can be provided on the clamping fixture according to the invention.
As a result, rotary positions of rotary elements and/or function states of accommodating elements attached to such fixture can be reliably sensed.
In addition, at least one processing element attached to at least one rotary element, more preferably for mechanical processing of the component, for example in form of a joining device, can be provided on the clamping fixture according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and

FIG. 1 shows an inclined top view in perspective of rotary elements coupled with one another in a rotary manner as part of an exemplary development of the clamping fixture according to the invention;

FIG. 2 shows an inclined top view in perspective of a clamping fixture according to the invention in which the part of the clamping fixture shown in FIG. 1 is contained.

In the Figures, same or identically acting components are designated with the same reference numbers.

DETAILED DESCRIPTION

The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description of the invention.
In the FIGS. 1 and 2 perspective views of an exemplary development of the clamping fixture according to the invention are shown wherein in FIG. 1 for improved understanding of the invention merely a part of the clamping fixture comprising the rotary elements coupled with one another in a rotary manner is shown.
Accordingly, the clamping fixture according to the invention which altogether is designated with the reference number 1 comprises three rotary elements 2 in form of square tubes which are mechanically and control-technically coupled with the help of two angular drives in form of bevel gear drives 3 so that they can be turned in synchronization with one another. To this end, the bevel gear drives 3 are each provided with two outputs. The rotary axes of the rotary elements 2 shaped as square tubes run parallel to the longitudinal direction of the square tubes.
In the exemplary embodiment shown the rotary elements 2 are arranged along the edges of a square and thus enable the accommodation and accurate positioning of a component from three different sides. In the process, one of the square tubes on its two faces is coupled in a rotary manner with the other square tubes with the help of the two bevel gear drives 3 while the other two square tubes each on one of its two faces are coupled in a rotary manner with the bevel gear drive 3 and at the other of their two faces are each supported in a rotary bearing 4. The rotary elements 2 can be synchronously rotated with the help of a sole electric motor 5 which is connected with a drive of one of the two bevel gear drives 3 such (for example with the help of a toothed connection) that it is able to rotate said drive. The other bevel gear drive 3 is co-rotated through the rotary element 2 coupled to both bevel gear drives 3 when this rotary element 2 is rotated through the rotary element coupled with the electric motor 5. The clamping fixture 1 is supplied electrically/hydraulically by way of a plurality of cable drags 7 which allows a rotary motion of the rotary elements 2.
With the help of an electronic logic device 6 which is coupled with the bevel gear drives 3 not connected with the electric motor 5, different rotary positions of the synchronously moved rotary elements 2 can be electronically sensed and transmitted to a higher plant control (not shown) by means of an output connection 1O. Based on the synchronous movement of the rotary elements 2 it is sufficient if the rotary position of merely a single rotary element 2 is sensed by the logic device 6.
A plug unit 14, through which a pin member can be inserted in respective plug openings of a rotary element 2 makes it possible that defined rotary positions of the rotary elements 2 moved in synchronization can be assumed accurately so that the accommodating elements can be brought into their respective working position to accommodate and accurately position components in a highly accurate and reliable manner. The rotary positions of the rotary elements 2 in the process are defined through the position of the plug openings. Based on the synchronous movement of the rotary elements 2 it is sufficient if plug openings are formed on merely a single one of the rotary elements 2.
The rotary elements 2 coupled with one another by way of the two bevel gear drives 3 are mounted on four support members 8 arranged in the corners of the square mentioned above wherein respective faces of the support members 8 carry the two bevel gear drives 3 and the two rotary bearings 4. The support members 8 are connected through cross members 9.
As can be seen from FIG. 2 a multiplicity of accommodating elements in form of type-related geometrical grippers to accommodate and accurately position different component types are provided in the clamping fixture 1 according to the invention explained as exemplary embodiment. The components are preferably body components in the production of motor vehicles.
Accommodating elements in form of type-related geometrical grippers are attached to each rotary element 2 in four module-type accommodating element sets (accommodating element set modules). Here, each accommodating element set module comprises a carrier plate and two type-related geometrical grippers attached to said carrier plate each of which is adapted to a certain (same) component type. In the exemplary embodiment shown, two geometrical grippers are arranged in each accommodating element set module which are offset relative to each other in a direction which is parallel to the axis of rotation of the relevant rotary element. However, it is also possible to provide a greater number of geometrical grippers in one accommodating element set module.
In the exemplary embodiment shown a first accommodating element set module comprising a carrier plate 111 and the first geometrical grippers 12 ₁attached to said plate, a second accommodating element set module comprising a carrier plate 11 ₂and the second geometrical grippers 12 ₂attached to said plate, a third accommodating element set module comprising a carrier plate 11 ₃and the third geometrical grippers 12 ₃attached to said plate and a fourth accommodating element set module comprising a carrier plate 11 ₄and the fourth geometrical grippers 12 ₄attached to said plate are attached to each rotary element 2. The carrier plates 11 ₁, 11 ₂, 11 ₃, 11 ₄of the accommodating element set modules are attached to each rotary element 2 formed as square tube at the four lateral surfaces so that the accommodating element set modules are arranged offset relative to one another in the direction of rotation (circumferential direction) of the rotary elements 2 formed as square tubes. Here, the carrier plates 11 ₁, 11 ₂, 11 ₃, 11 ₄of the accommodating element set modules are detachably attached to the respective square tube so that a simple and quick change of accommodating element set modules is made possible.
The four accommodating element set modules can be brought into their respective working positions through rotating the corresponding rotary element 2 around its axis of rotation in which the geometrical grippers are in a position suitable to accommodate and accurately position components. In the exemplary embodiment of FIG. 2 the accommodating element set modules are located in their working position when their carrier plate has a horizontal position which in FIG. 2 is the case for the first accommodating element set module with the carrier plate 11 ₁and the first geometrical grippers 12 ₁attached to said plate.
With regard to the three rotary elements 2 the four accommodating elements set modules are attached to lateral surfaces of the three square tubes corresponding to one another so that through a synchronous rotation of the rotary elements 2 simultaneously all first accommodating element set modules, simultaneously all second accommodating element set modules, simultaneously all third accommodating element set modules and simultaneously all fourth accommodating element set modules of the three rotary elements 2 can be brought into a working position for accommodating and accurately positioning components.
In the shown exemplary embodiment of FIG. 2 are located the first geometrical grippers 12 ₁of all first accommodating element set modules in their working position to accommodate and accurately position a component which for example is a body carcass of a left motor vehicle front door 13. The motor vehicle front door 13 is held through the first geometrical grippers 12 ₁of the first accommodating element set modules from three different sides. At the same time, the second, third and fourth geometrical grippers 12 ₂, 12 ₃, 12 ₄of the second, third and fourth accommodating element set modules respectively are in a position of rest in which they cannot accommodate any component. More precisely, the second and third geometrical grippers 12 ₂/12 ₃of the second and third accommodating element set modules each protrude sideways while the fourth geometrical grippers 12 ₄of the fourth accommodating element set modules protrude downwards. Through synchronous rotation of the rotary elements 2 all first geometrical grippers 12 ₁, all second geometrical grippers 12 ₂, all third geometrical grippers 12 ₃, and all fourth geometrical grippers 12 ₄respectively can be brought into their respective working positions. Each of the first, second, third and fourth geometrical grippers are adapted to different component types. As is shown in FIG. 2 the first geometrical grippers 12 ₁for example are adapted to the body carcass of a left motor vehicle front door, the second geometrical grippers 12 ₂for example to the body carcass of a left motor vehicle rear door, the third geometrical grippers 12 ₃, for example to the body carcass of a right motor vehicle rear door and the fourth geometrical grippers 12 ₄for example to the body carcass of a right motor vehicle front door.
In FIG. 1 and FIG. 2 merely one exemplary development of the clamping fixture according to the invention is shown which in no way is to restrict the invention. For example it is possible and intended according to the invention to arrange a lesser or greater number of rotary elements or a lesser or greater number of accommodating elements more preferably in form of geometrical grippers.
While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.

Claims

1. A clamping fixture to accommodate and accurately position different component types comprising at least one rotary element mounted in a rotating manner around an axis of rotation and at least two component type related accommodating elements to accommodate components attached to the rotary element, wherein the at least two accommodating elements are arranged offset to one another in the rotary direction of the rotary element such that each accommodating element can be brought into a working position to accommodate and accurately position a component by turning the rotary element around its axis of rotation.

2. The clamping fixture according to claim 1, characterized in that each accommodating element is detachably attached to the rotary element by means of a carrier element.

3. The clamping fixture according to claim 1, characterized through at least two accommodating element sets, of which each contains at least two accommodating elements offset in the direction along the axis of rotation, wherein the at least two accommodating element sets are arranged offset to one another in the direction of rotation of the rotary element such that each accommodating element set can be brought into a working position to accommodate a component through its accommodating elements by turning the rotary element around the axis of rotation.

4. The clamping fixture according to claim 3, characterized in that each accommodating element set is attached to the rotary element in modular form.

5. The clamping fixture according to claim 4, characterized in that each accommodating element set module by means of a carrier element is detachably attached to the rotary element.

6. The clamping fixture according to claim 1, characterized in that the rotary element has an elongated shape along its axis of rotation.

7. The clamping fixture according to claim 6, characterized in that the rotary element is designed in form of a square tube or cylindrical tube.

8. The clamping fixture according to claim 7, characterized through accommodating elements or accommodating element modules attached to the surfaces of the square tube.

9. The clamping fixture according to claim 1, characterized through a multiplicity of rotary elements which are coupled with one another in a rotary manner such that they are turned in synchronization with one another around their respective axes of rotation.

10. The clamping fixture according to claim 9, characterized in that the rotary elements are coupled in a rotary manner by means of an angular drive, for example a bevel gear drive.

11. The clamping fixture according to claim 9, characterized through a motor drive coupled in a rotary manner with only a single rotary element for rotating the rotary element around its axis of rotation.

12. The clamping fixture according to claim 1, characterized through a rotary element rotary position fixing device for fixing selectable rotary positions at least of one rotary element around is axis of rotation.

13. The clamping fixture according to claim 9, characterized through a single rotary element rotary position fixing device for fixing selectable rotary positions of a same rotary element around its axis of rotation.

14. The clamping fixture according to claim 1, characterized through a sensor element for sensing rotary positions of at least one rotary element.

15. The clamping fixture according to claim 9, characterized through a sole sensor element for sensing rotary positions of a same rotary element.

16. The clamping fixture according to claim 1, characterized in that the accommodating elements are designed in form of geometrical grippers.

17. The clamping fixture according to claim 1, characterized through at least one processing element for processing the component attached to at least one rotary element.