AT513564A1 - Transport system and method for the transport of parts by means of parts carrier of a production plant - Google Patents

Abstract

The invention relates to a transport system (2) for conveying parts (3) by means of a subcarrier (4), which has a base frame, deflection wheels (17, 18) rotatably mounted thereon, a guide rail (17, 18) guided around the deflection wheels (17, 18) ) comprehensive transport chain (19) having an upper strand (20) and a lower strand (21), a feed drive (23) coupled to one of the deflection wheels (17, 18) for advancing the transport chain (19), extending between the outer sprockets (17, 18) extending guide means (22) for the upper strand (20) of the transport chain (19). A first deflection wheel (17) is coupled to an electronically controllable drive motor as a feed drive (23) and a second diverter wheel (26) to a brake drive (24). The invention further relates to a method for cycled transport of parts (3), wherein in the braking phase, the first deflecting wheel (1 driven by the electronically controllable drive motor and a second deflecting wheel (18) of a brake drive (24) is braked such that the leading, upper StrangIenkrädern (17, 18) is stretched.

Description

1

The invention relates to a transport system and a method for the transport of parts by means of parts carrier within a manufacturing plant with in the transport direction successively arranged workstations and / or parts supply stations.

WO 89/06177 A1 and WO 89/08002 A1 disclose a generic transport system for transporting parts by means of parts carrier, which a base frame, at this rotatably mounted deflecting wheels, guided around the guide wheels transport chain with a leading, upper strand and a returning, lower Strand, a extending between the pulleys guide device for the leading, upper strand, and one coupled to one of the deflection wheels electric feed drive for locomotion of the transport chain in the transport direction comprises. The chain links of the transport chain form the part carriers. The transport chain is endless and is set manually in it via a mechanical tensioning device a bias. The prestressing of the transport chain must be checked by trained specialist personnel at regular maintenance intervals.

In addition, the transport system has to be highly dynamic in order to meet the high line requirement to the production plant, therefore switching between acceleration phases and deceleration phases is made within the shortest possible time intervals. Associated with this are vibrations in the transport chain which can lead to insufficient longitudinal positioning of the parts carriers relative to the workstations and / or parts supply stations. 2/40 N2012 / 13200 2

The invention has for its object a transport system and a method for the transport of parts by means of parts carrier to create within a manufacturing plant, with which (m) can achieve improved positioning of the parts carrier in the transport direction relative to workstations and / or parts delivery stations.

The object of the invention is achieved in that a first deflection wheel is coupled with an electronically controllable drive motor as a feed drive and a second deflection wheel with a brake drive.

The workstations and / or parts delivery stations are arranged on one or both sides of the transport system in a preferably constant grid spacing. Thus, it is common for workstations to include assembly devices, joining devices and / or processing devices and the like, and the parts supply stations singulation devices, alignment devices and / or conveyors and the like. The workstations each define a spatially limited work area in which a parts carrier is moved in order to assemble, add and / or process parts there.

The drive motor is a dynamic electric motor, in particular servomotor, which is intermittently operated in each case by a grid spacing of the workstations and / or parts supply stations. The feed path per further cycle of the transport chain corresponds to the grid spacing.

The part carriers are accelerated by the feed drive in an acceleration phase in the work areas and after completion of the operations from the work areas out. Before reaching the working positions in the work areas, the part carriers are braked by the feed drive and the brake drive in a braking phase again to a standstill. During the stoppage phase of the parts carrier work processes can be performed simultaneously at several workstations. The stoppage phase results from the duration of the longest working process in the series of workstations. 3/40 N2012 / 13200 3

The drive motor (electric motor) is connected to an electronic control device, which in turn comprises a controller, in particular servo-controller (servo-stronger). By regulation (torque, speed or position control) of the drive motor, a high positioning accuracy of the parts carrier is already achieved in the transport direction.

The "regulated" driving force is transmitted from the first deflection wheel via positive engagement on the transport chain and thus allows even with the high acceleration forces a slip-free "timed" drive the transport chain. This applies both to the acceleration phase and to the braking phase of the feed drive.

The positioning accuracy of the parts carrier can also be significantly improved in the transport direction, if at least in the braking phase of the feed drive or the transport chain on the second guide wheel, a braking force acts such that the leading, upper chain strand is stretched between the guide wheels. Chain vibrations occurring in the braking phase are considerably reduced or avoided, so that the parts carriers reach the working positions in the working areas in a shorter time and with higher positioning accuracy compared to the known transport systems. The braking force is transmitted from the second deflection wheel via positive engagement on the transport chain and thus enables a slip-free braking of the transport chain even with the high (negative) acceleration forces.

Against this background, it is now possible to use the transport system also on production equipment in which parts of the smallest dimensions and tightest tolerances are processed.

It is also advantageous if the feed drive is formed by a direct drive, the drive motor is coupled directly to the first deflection. For example, so-called "torque motors" are used, which allow large accelerations with very accurate longitudinal positioning of the parts carrier relative to the workstations. A gear is not required and thus 4/40 N2012 / 13200 4 is a low-noise and low-maintenance and dynamic operation of the transport system possible. Furthermore, the scheme is simple.

The brake drive may comprise an electrically controllable or electric drive motor, for example a synchronous motor, which is coupled to the second deflection wheel. The use of an electric drive motor allows the design of different control tasks. The drive motor or electric motor can be used exclusively for braking the transport chain in a braking phase or both for driving the transport chain in an acceleration phase and for braking the transport chain in a braking phase. Preferably, the drive motor is a stepper motor whose voltage terminals with an electronic switch, such as a relay, can be short-circuited for a short time to initiate a braking force to the second deflection. The braking of the transport chain from maximum acceleration can be done very quickly by a control device (automatically) and an unwanted movement of the transport chain in the transport direction is avoided even in the standstill phase. The use of an electric drive motor also has the advantage that in the acceleration phase of the feed drive, this drive motor for driving the transport chain can be switched by this briefly applied to the second guide wheel with a driving force.

If the brake drive comprises an electronically controllable drive motor (servomotor), the braking force can be regulated depending on the drive force of the feed drive or speed-dependent.

An exact height and side guidance of the parts carrier in the upper chain strand can be achieved if the guide device on the base frame with parallel parallel guides and the transport chain on the guides with guide members abstützbare chain links, on the one hand a first guide and this associated first guide members each have a height guide surface and side guide surface and on the other hand, a second guide and this associated second guide members each exclusively a Hö- 5/40 N2012 / 13200 5 henführungsfläche form. Combined with the above-described effect of the improved positioning accuracy of the parts carriers in the transport direction (longitudinal positioning), parts with narrowest tolerance limits can now be processed.

An advantageous embodiment of the invention is also provided if the base frame in a plane parallel to the transport plane extending boundary and in the longitudinal direction of the guides extending stop strips and that the transport chain are provided on some of their hinged chain links on one of the transport plane opposite bottom with stop projections, which are arranged and designed such that the stop projections engage behind the stop bars on the advancing movement of the transport chain along the guide device. As a result, a lifting of the guide members of the chain links or part carrier is limited by the guides or even avoided and ensured even in case of malfunction of the feed and / or brake drive, the leadership function for the chain links or parts carrier.

According to an advantageous embodiment, the guides each form an extending in the longitudinal direction of the stop bar. As a result, a very compact construction is achieved and in addition a rigid construction for the guides is provided.

It is also of advantage if the chain links which form the parts carriers or on which the parts carriers are fastened are produced by metal injection-molded parts in the metal injection molding process. Such parts can be made particularly cost-effective within close tolerances with low weight, reduced wall thickness and possibly without reworking.

But it is also advantageous if the chain links, which form the parts carrier or on which the parts carrier are attached, are made by stamping and forming parts. Such parts can be made of sheet metal without forming formed parts and manufactured at low cost, especially in mass production. The consumption of material for the production is low. The sheet material allows almost unlimited designs. It can spanless 6/40 N2012 / 13200 6

Forming process, in particular methods for cold forming of sheets, such as bending, pressing, embossing and the like., Can be used. The deformation of the sheet takes place in an accuracy that can be realized within narrow position and shape tolerances. Machining can usually be omitted.

According to a possible embodiment of the invention, the transport system has a connected to a control device optical detection device, in particular a camera system, by means of which a relative position (Istposi-tion) of at least one parts carrier in the transport direction and / or transversely to the transport direction can be detected, wherein the control device an evaluation unit, from which in a target-actual comparison, a manipulated variable is calculated, and an actuator, of which a working module of at least one workstation is acted upon by the manipulated variable, is connected. Thus, it is now possible that wear-related changes in length of the transport chain and / or positioning inaccuracies of the parts carrier possibly occurring after a long production use are compensated for by a self-acting, automatic readjustment of an work module to a corrected working coordinate parallel and / or transversely to the transport direction and have no effect has the production process.

It also proves to be advantageous for dynamic reasons if the brake drive also acts as a feed drive in the acceleration phase of the transport chain. Thus, the brake drive can act alternately with a driving force and a braking force on the second deflection.

It is also advantageous if in the braking phase of the transport chain of the feed drive reduces a drive torque and the brake drive changes a braking torque depending on the drive torque of the feed drive. In other words, a bias in the upper run of the transport chain is set by a torque difference between the drive torque and the braking torque. The braking torque is lower than the drive torque and may vary depending on the speed of the feed drive. 7/40 N2012 / 13200 7

A torque difference between the drive torque and the braking torque for setting a bias in the upper run of the transport chain can also be achieved if in the braking phase of the transport chain of the feed drive reduces a drive torque and the brake drive generates a braking torque by shorting voltage terminals of an electric drive motor.

For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

Each shows in a highly schematically simplified representation:

1 shows a manufacturing plant with a first embodiment for a transport system for the transport of parts by means of parts carrier and in the transport direction successively arranged workstations and parts supply stations in a perspective view.

Fig. 2 shows the transport system of Figure 1 in side view.

Fig. 3 shows the transport system of Figure 1 in plan view.

Fig. 4 part carrier of a transport chain for the transport system of FIG. 2;

FIG. 5 shows the conveyor chain cut along the lines V - V in FIG. 3; FIG.

6 shows the time courses for a working process, the driving force on the transport chain and the braking force on the transport chain over two feed strokes;

Fig. 7 shows a second embodiment of a transport system for the transport of parts by means of parts carrier for a manufacturing plant according to Fig. 1;

FIG. 8 part carrier of a transport chain for the transport system according to FIG. 7.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals and the same component names, wherein the disclosures contained in the entire description are transmitted mutatis mutandis to the same parts with the same reference numerals or identical component designations 8/40 N2012 / 13200 can. Also, the location information chosen in the description, such as top, bottom, side, etc. related to the immediately described and illustrated figure and are to be transferred to the new situation mutatis mutandis when a change in position.

Fig. 1 shows a manufacturing plant 1, which comprises at least one transport system 2 for the transport of parts 3 by means of parts carriers 4 and along a transport section in the transport direction 5 successively arranged work stations 6 and part delivery stations 7.

The transport system 2 comprises a base frame 8 and can be constructed on this on a support housing 9. For this purpose, the support housing 9 forms on its upper side facing away from the bottom 10 a mounting plane 11 or connecting plane on which the transport system 2 can be supported with the base frame 8 and detachably fastened to the support housing 9 via connecting elements, not shown, for example screws.

On the other hand, the transport system 2 can also be set up directly on the ground 10 by means of the base frame 8.

The number of workstations 6 and / or parts delivery stations 7 may vary depending on the complexity of the product being manufactured. Thus, the manufacturing plant 1 may also comprise only a workstation 6 or a workstation 6 and a parts supply station 7. The workstations 6 and parts delivery stations 7 are preferably operated automatically.

For reasons of better clarity, only two workstations 6 and only two parts delivery stations 7 are shown in FIG. Typically, such manufacturing facilities 1 comprise up to twenty workstations 6 per transport installation 2.

The workstations 6 and parts delivery stations 7 are arranged on a specially designed frame structure 12, whereby independent Lagerrah-menmodule 13 can also be constructed on the support housing 9. The bearing frame modules 13 are supported on the mounting plane 11 and 9/40 N2012 / 13200 9 via fasteners, not shown, for example, screws, releasably secured to the support housing 9.

In addition, the bearing frame modules 13 can be connected to one another via parallel to the transport direction 5 and guided through receiving openings 14 longitudinal bars 15, as indicated in dash-dotted lines. The longitudinal bars 15 are preferably held against rotation in the receiving openings 14.

Thereby, the bearing frame modules 13 can be connected to a self-supporting frame structure 12, which is characterized by its modular structure. Each storage frame module 13 forms a receiving module.

As entered in FIG. 1, two of the three illustrated bearing frame modules 13 are each equipped with a work station 6 and / or a parts supply station 7. The third storage frame module 13, however, for the sake of clarity, not equipped with a workstation 6 and / or part delivery station 7.

The workstations 6 comprise, according to the embodiment shown, a handling device 16 with a gripper with which a part 3 provided at the parts supply station 7 can be taken over and transferred to a part carrier 4.

On the other hand, a workstation 6 may comprise a process module, for example a press device. In this case, a part 3 may already have been transferred to the parts carrier 4 at a workstation 6 preceding in the transport direction 5 and transported to the workstations 6 following in the transport direction 5, where the parts 3 are joined together. A separate parts delivery station 7 can be omitted at this workstation 6.

The parts supply station 7 comprises a feeding device for conveying and / or separating, with which the parts 3 are removed from a bulk goods container or parts store (not shown), singulated and / or aligned and conveyed to a staging area, from where the parts 3 at 10 / 40 N2012 / 13200 10 are removed by way of the handling device 16. The parts 3 are formed for example by grafting, discs, pins, contacts, etc. Such parts delivery stations 7 have become known, for example, in EP 0 637 559 A1, EP 1 460 006 A1 or DE 44 34 146 A1.

In FIGS. 2 to 5, the transport system 2 and parts carrier 4 are shown in different views.

The transport system 2 comprises the base frame 8, at this rotatably mounted deflecting wheels 17, 18, a guided around the guide wheels 17, 18 via positive transport chain 19 with a leading, upper strand 20 and a returning, lower strand 21, a between the guide wheels 17th , 18 extending guide device 22 for the leading, upper strand 20, one coupled to the first guide wheel 17 feed drive 23 for advancing the transport chain 19 in the transport direction 5 and coupled to the second guide wheel 18 brake drive 24th

The base frame 8 comprises deflection station 25, 26 for the transport chain 19 and between these a plurality of housing parts 27. These housing parts 27 have mutually facing end plates 28 which can be connected to each other via (not shown) guiding and / or coupling devices to the self-supporting support structure. The base frame 8 of the transport system 2 formed by the deflection stations 25, 26 and housing parts 27 is supported on the mounting plane 11 by support devices 29. The housing parts 27 are preferably made in one piece. The support devices 29 are fastened via not shown connecting elements, such as screws, detachably on opposite side walls of the housing parts 27.

The deflecting stations 25, 26 each comprise a housing part, a deflecting wheel 17, 18 rotatably mounted thereon, and guide rail parts (not shown), the latter being described in detail in WO 89/06177 A1. As a result, the different chain speeds caused by the polygon effect in the deflection region of the transport chain 19 are also compensated. This allows a dynamic operation of the transport system 2. The transport chain 19 can be driven with 11/40 N2012 / 13200 11 very high feed speeds, which is also possible by the special structure of the transport system 2.

The guide wheels 17, 18 each comprise guide pulleys 30 rigidly connected to each other and diametrically opposed engagement grooves recessed in the outer periphery 31. As will be described below, the parts carriers 4 comprise guide rollers on their longitudinal sides extending in the transport direction 5, which engage in the engagement grooves 31 the deflection plates 30 engage positively, when the transport chain 19 in the steering range to the pulleys 17, 18 is guided.

The transport chain 19 comprises articulated axles 32 hingedly interconnected chain links, which form the part carrier 4 according to the embodiment shown. In the following, reference is made to a first type of part carrier 4.1 and a second type of part carrier 4.2. The hinge axis 32 connects two successive parts carrier 4.1, 4.2 and extends parallel to the axis of rotation of the guide wheels 17, 18th

As can be seen in FIG. 4, the chain links or the respective successive parts carriers 4.1, 4.2 are designed differently and preferably with optimized weight. For example, the parts carrier 4.1, 4.2 metal injection molded parts, which can be produced in high quantities cost and with high manufacturing accuracy.

Both a first type part carrier 4.1 and a second type part carrier 4.2 comprise a receiving plate 33 and on its underside tabs 34, 35. The receiving plate 33 may comprise on its upper side a holding receptacle, not shown, by means of which to be mounted parts 3 on the transport between the workstations 6 can be kept. Further, the receiving plate 33 for reasons of weight saving and / or the accessibility of tools of a workstation 6 with a recess 36 are designed.

According to the embodiment shown, the transport chain 19 in the upper strand 20 forms a transport plane 37 (FIG. 5), which is defined by the upper side of the receiving plates 12/40 N2012 / 13200 12 33. The transport plane 37 can also define a work plane at the same time.

As can be seen, extend in the first type part carrier 4.1, the inner (lamellar) tabs 34.1 in the longitudinal direction of the parts carrier 4.1 and protrude with their ends to the opposite direction in the transport direction 5 end edges 38 and each comprise in their opposite end portions bearing bores 39. Die Bearing holes 39 form cylindrical bores through which a bearing pin 40 (FIG. 5) is passed. A longitudinal axis of the bearing pin 40 extends parallel to the axis of rotation of the guide wheels 17, 18. The outer (lamellar) tabs 35.1 extend in the longitudinal direction of the parts carrier 4.1 and with their ends approximately to the opposite direction in the transport direction 5 end edges 38. In addition, the parts carrier 4.1 are provided on the bottom with stop projections 41, which are arranged and designed such that they engage behind on the advancing movement of the transport chain 19 along the guide device 22 stop strips 42, as shown in Fig. 5. The stop strips 42 are fixedly arranged on the base frame 8 and extend at a mutual distance in the transport direction 5 between the guide wheels 17, 18th

As can be seen, extend in the second type part carrier 4.2, the inner (lamellar) tabs 34.2 in the longitudinal direction of the parts support 4.2 and project with their ends to the opposite direction in the transport direction 5 end edges 38 and each form a bearing receptacle 43 in their end regions forms a cylindrical bore, in which a bearing 44 (Fig. 5) arranged, in particular is pressed. A longitudinal axis of the bore extends parallel to the axis of rotation of the guide wheels 17, 18. The outer (lamellar) tabs 35.2 extend in the longitudinal direction of the parts carrier 4.2 and with their ends approximately up to the opposite in the transport direction 5 end edges 38th

As can be seen in the synopsis of FIGS. 4 and 5, the parts carriers 4 are supported by guide elements, in particular guide rollers 45, 46 on guide tracks 49, 50, the latter being formed on guides 47, 48. The guide device 22 comprises the guides 47, 48. The guides 47, 48 are fixedly arranged on the base frame 8 and extend at a mutual distance in the transport direction 5 between the guide wheels 17, 18th

The first guide 47 forms a vertical and lateral guide track 49, which is formed according to the embodiment shown by inclined to each other tapered guide surfaces.

The second guide 48 forms exclusively a height guide track 50, which is formed by the embodiment shown by a parallel to the transport plane 37 extending (horizontal) guide surface.

As can be seen in FIG. 5, the guides 47, 48 can also be produced with the stop strips 42. The stop strips 42 can be integrally formed with the guides 47, 48, or are made separately and secured by fasteners, such as screws on the guides 47, 48.

The guide rollers 45, 46 are each mounted on the bearing pin 40, the latter defining the bearing axis 32.

The first guide roller 45 forms a coaxial with the bearing axis 32 extending engagement portion 51 and a coaxial with the bearing axis 32 extending guide portion 52. The engagement portion 51 is formed with a cylindrical engagement surface. The guide section 52 comprises a circumferential guide groove with a height and side guide surface 53, which is designed to be complementary to the height and side guide track 49 of the first guide 47. The height and side guide surface 53 is formed by shown embodiment by inclined to each other guide surfaces. The first guide roller 45 lies with its guide portion 52 unrolled on the height and side guide track 49 of the first guide 47.

The second guide roller 46 forms a coaxial with the bearing axis 32 extending guide portion 54 with a cylindrical height guide surface 55 and is preferably a rolling bearing. The second guide roller 45 rests with its Höhenfüh- 14/40 N2012 / 13200 14 rungsfläche 55 unrolled on the height guide track 50 of the second guide 48.

If the transport chain 19 with the part carriers 4.1, 4.2 is guided around the deflection wheels 17, 18, then the first guide rollers 45 each engage with their engagement section 51 and the second guide rollers 46 each with their guide section 54 into the engagement grooves 31 of the deflection pulleys 30 arranged on a rotation axis a positive fit.

The described guide arrangement between the parts carriers 4.1, 4.2 and the guides 47, 48 an exact height and side guidance of the upper strand 20 of the transport chain 19 is achieved. Thus, a work process can also be performed directly on the parts carrier 4.1, 4.2, without having to lift a part 3 of the parts carrier 4.1.4.2.

As can also be seen in Fig. 5, the bearing pin 40 of the articulated connection of the parts carrier 4.1, 4.2, for which purpose this is passed through the bearing holes 39 of the inner (lamellar) tabs 34.1 of the parts carrier 4.1 and on the other hand by the bearing 44 of the parts carrier 4.2. Between the bearings 44, a spacer sleeve 55 is disposed on the bearing pin 40.

The outer (lamellar) tabs 35.1, 35.2 of the part carriers 4.1, 4.2 are provided at their ends facing away from each other, each with a semicircular recess 56 (Fig. 4). Disc-shaped covers 77 (FIG. 5) are fastened to the front ends of the bearing journal 40, which rests within two recesses 56.

The guide rollers 45, 46 are each arranged in a receiving channel between an inner (lamellar) tabs 34.1 of the parts carrier 4.1 and an outer (lamellar) tab 34.2 of the parts carrier 4.2. As a result, an optimal protection for the guide rollers 45, 46 against external influences, such as spray, spatter, dirt deposits created during a work process. 15/40 N2012 / 13200 15

If a distance measure 57 between the outer tabs 35.1, 35.2 of the parts carrier 4.1.4.2 dimensioned larger than a Führungsbreitenmaß 58 between the guides 47, 48, during a work process, an optimal protection for the guides 47, 48 against external influences, such as splashing water, Spatters, dirt deposits, chips and the like created.

As not further shown, the lower strand 21 of the transport chain 19 between the guide wheels 17, 18 are performed, the accuracy of this guide device does not have to meet the accuracy requirements of the guide device 22, but can.

As can be seen from FIGS. 4 and 5, the part carrier 4.1, 4.2 is provided along its end edges 38 with recesses 59 which serve to receive a strip-like sealing lip 60. The sealing lip 60 is attached to one of the parts carriers 4.1, 4.2 at the bottom of the recess 59 and protrudes at the front edge 38 into the recess 59 of the other (in the transport direction 5 subsequent) parts carrier 4.1.4.2, so that at least one distance gap 61 facing each other End edges 38 successive parts carrier 4.1, 4.2 is covered. The sealing lip 60 is preferably made of elastic plastic material. If the parts carriers 4.1, 2.4.2 are guided around the deflecting wheels 17, 18, then the sealing lip section projecting into the recess 59 of the other (downstream in the transporting direction 5), 4.1, 4.2, is swung out of the recess 59. It proves to be advantageous if the sealing lip 60 is fastened to the bottom of that recess 59 which is adjacent to the rear end edge 38 viewed in the transporting direction 5. As a result, even before the arrival of a parts carrier 4.1, 4.2 in the direction of transport 5 considered first workstation 6 between the led out of the deflection 26 part carriers 4.1.4.2 of viewed at the front edge 38 of the transport direction 5, front part support 4.1, 4.2 projecting sealing lip portion pivoted into the recess 59 of the viewed in the transport direction, rear part support 4.1.4.2 and achieved the "sealing effect".

As described above, the feed drive 23 are coupled to the first guide wheel 17 and the brake drive 24 to the second guide wheel 18. After a preferred embodiment, both drives are formed by an electric motor, wherein at least the feed drive 23 comprises an electronically controlled electric motor.

The electric motor (servo motor) of the feed drive 23 is arranged coaxially with the first guide wheel 17 and is preferably a so-called "torque motor". This is a high-voltage, direct electrical drive from the group of low-speed machines and is characterized by very high torques at relatively low speeds. The power supply is possible with DC or AC voltage. The large drive torque of "torque motors" allows large accelerations with very accurate longitudinal positioning of the parts carrier 2 relative to the workstations. 6

As entered in FIG. 3, the electric motor of the feed drive is connected to an electronic control device 62. The control device 62 is connected to an electronic drive circuit (not shown), which is impressed by a controller (not shown) on a target trajectory for a desired speed or target drive force.

The electric motor of the brake drive 24 is arranged coaxially with the second deflection wheel 18 and is preferably a so-called "stepping motor".

As indicated in FIGS. 3 and 3a, the electric motor of the brake drive 24 is operated by an electronic control device 62. The control device 62 is connected to a schematically represented electronic control circuit 63, which in turn comprises an electronic switch 64, for example a relay, which can short-circuit the voltage connections 65 (motor terminals) of the electric motor for a braking phase of the transport chain 19. The electronic switch 64 is for this purpose connected via an indicated control line to the control device 62, which in turn acts on the switch 64 in the braking phase with a brake signal. The switch 64 is thus automatically operated. The voltage terminals 65 are connected to an inverter or frequency converter (not shown), the latter supplying the electric motor with DC voltage or AC voltage. 17/40 N2012 / 13200 17

According to another embodiment, the electric motor of the brake drive 24 may include an electronically controlled electric motor (servo motor), which is connected to the electronic control device 62. The control device 62 is connected to an electronic control circuit (not shown), which is impressed by a controller (not shown) on a target trajectory for a setpoint speed or desired braking force.

In addition, it is possible, but not shown, that the feed drive 23 comprises two electronically controlled electric motors, which are each arranged coaxially with the first guide wheel 17 and coupled thereto. Both electric motors are electronically controlled electric motors, which are controlled synchronously by the control device 62. The electric motors are preferably so-called "torque motors".

Likewise, the brake drive 24 may include two electric motors, as is not shown. The electric motors are each arranged coaxially with the second deflection wheel 18 and coupled thereto. The electric motors are preferably so-called "stepper motors". Also, both electric motors can be electronically controlled.

As schematically illustrated in FIGS. 1 and 3, the transport system 2 can also have an optical detection device 66, in particular a camera system. This is connected to the electronic control device 62, which in turn comprises an evaluation unit 67. The evaluation unit 67 can perform a desired-actual comparison for a position of the parts carrier 4. In this way, a relative position or actual position of at least one chain link or part carrier 4 in the transport direction 5 and / or transversely to the transport direction 5 can be detected. The detection of the actual position in the transport direction 5 and / or transversely to the transport direction 5 is preferably carried out at a standstill of the transport chain 19 and on a parts carrier 4 in the upper strand 20. The evaluation unit 67 can perform a target-actual comparison for a position of the parts carrier 4 and a Calculate the manipulated variable for an actuator 68. The workstation 6 comprises the actuator 68, in particular at least one electronically controlled actuator, such as line drive, by means of which a repositioning of a working module, in particular a peripheral device, for example a gripper, into a corrected working coordinate parallel to the transport direction 5 and / or transversely to the transport direction 5 can be performed. For this purpose, when the deviation of Istpositi-on from the desired position, the actuator 68, an electrical correction signal or a corrected manipulated variable is switched and accordingly moves the working module (peripheral device) by the actuator 68 in the corrected working coordinate.

If the production plant 1 comprises a plurality of workstations 6, each with one actuator 68, the workstations 6 can be repositioned at all of the workstations 6, in particular peripherals, for example grippers, joining apparatuses and the like, in each case a corrected working coordinate parallel to the transport direction 5 and / or be performed transversely to the transport direction 5.

The evaluation of the setpoint-actual position of at least one parts carrier 4 can be carried out at defined time intervals or after each power stroke when the transport chain 19 is at a standstill.

6a to 6c show the course of a working process, the course of the driving force (drive torque) for the feed drive and the course of the braking force (braking torque) for the brake drive over two feed cycles of the transport chain.

The working process (FIG. 6 a) is, for example, a welding process in which parts 3 are positioned and joined to one another. During the duration of the work process, the transport chain 19 is stationary. If several workstations 6 are present, the standstill phase results from the duration of the longest working process in the row of workstations 6.

The feed stroke for the transport chain 19 is composed of an acceleration phase h, l2,... In and a braking phase Ih, ll2j... Iln together. Between the braking phase Il-ι, ll2l ... Iln of a preceding feed cycle and the acceleration phase h, l2, - - - In a subsequent feed cycle is a standstill phase llli, ... lll ", like in FIGS. 6b, 6c. During the standstill phase, no driving force (drive torque) and braking force (braking torque) act. Basically, it is conceivable, as registered in dashed lines, that in the stoppage phase of the transport chain 19 from the electric motor of the feed drive 23, a driving force on the first guide wheel 17 and the electric motor of the brake drive 24, a braking force on the second guide wheel 18 act such that on the throughout the duration of the standstill phase constant bias conditions in the upper run 20 of the transport chain 19 prevail. The driving force and braking force are - depending on the friction conditions - in terms of magnitude approximately equal. However, such an operation is only required if positioning of the parts carrier 4 relative to the workstations 6 in the range of a few hundredths of a millimeter is required. Usually, however, it is sufficient for the positioning of the parts carrier 4 relative to the workstations 6 in the range of a few tenths of a millimeter, when the bias in the upper run 20 of the conveyor chain 19 is adjusted solely by the friction conditions in the system.

As is apparent from Fig. 6b, within a feed cycle of the electric motor of the feed drive 23 between the acceleration phase h, l2l ... In and the braking phase Ih, II2, ... Iln. During the acceleration phase h, l2l ...

In, a drive force (drive torque) is specified by the controller as desired value or setpoint trajectory "Fsoii" (MSOii) in such a way that a steep (positive) acceleration increase takes place within a short time span t0. H, which makes a relatively longer time span h... T2 more constant Acceleration follows. This is followed by a transition from the acceleration phase h, l2) ... to the braking phase Ih, ll2) ... Iln, which results from a steep acceleration drop within a short time span t2 .. t3.

After the time t3, the driving force (driving torque) reverses the sign and initiates the braking phase Ih, ll2l ... Iln. 20/40 N2012 / 13200 20 During the braking phase Il-ι, ll2l ... Iln, a drive force (drive torque) is specified by the controller as setpoint or desired trajectory such that the steep acceleration drop continues within a short period t3 .. t4 , which follows a relatively longer period t4 .. t5 constant (negative) acceleration. Thereafter, a steep (negative) acceleration increase within a short period ts .. t6 follows.

According to the illustrated embodiment, the time period t0 .. U and time t2 .. t3 are approximately equal in length. This is possible because in the braking phase Il-ι, ll2) ... Iln also a negative driving force or braking force (braking torque) from the brake drive 24 acts. On the other hand, the time span t2 .. t4 can also amount to a multiple of the time span to .. t2, in order to achieve the smoothest possible braking operation for the transport chain 19.

As can be seen from FIG. 6c, within a feed cycle the electric motor of the brake drive 24 is switched between the acceleration phase I-1, 12>... In and the braking phase Mi, II2l... Iln.

On the other hand, it is also possible that the brake drive 24 is operated exclusively with a braking phase II-II, II2l ... Iln, which at the latest with the end of the acceleration phase U, l2l ... In the feed drive 23, therefore at the end of the period t2 .. t3 starts. However, it is also possible for the braking phase II-1, II2l ... Iln of the brake drive 24 to be started already at the end of the time interval ti .. t2. Accordingly, in the acceleration phase I-ι, l2l ... In only the feed drive 23 generates a driving force.

However, it proves to be advantageous if, during the acceleration phase l-i, l2> ... In of the feed drive 23, the brake drive 24 also acts as an "active" drive, as shown in FIG. 6c. During the acceleration phase I-1, l2l ... In, a drive force (drive torque) as desired value or setpoint trajectory "FSoii" (MSOii) is predetermined by the controller in such a way that a steep (positive) acceleration increase takes place within a short time span t0 .. ti , which follows a relatively longer period ti 21/40 N2012 / 13200 21 .. t2 constant acceleration. This is followed by a transition from the acceleration phase l2l ... to the braking phase Ih, W2, ··· Mn, which results from a steep drop in acceleration within a short period t2 .. t3.

After the time t3, the driving force (driving torque) reverses the sign and initiates the braking phase Ih, ll2l ... Iln. During the braking phase Ih, Ih ···· lln, a drive force (drive torque) is specified by the controller as setpoint or desired trajectory in such a way that the steep acceleration drop continues within a short period of time t3..t4, which is a relatively longer time span t4. t5 constant (negative) acceleration follows. Thereafter, a steep (negative) acceleration increase within a short period t5 .. t6 follows.

As illustrated in FIGS. 6 b, 6 c, the setpoint value for the drive force (drive torque) at the brake drive 24 may be lower than the setpoint value for the drive force (drive torque) at the feed drive 24.

In Figs. 7 and 8, a second embodiment for the transport system 2 'and the parts carrier 4' is shown.

The transport system 2 'comprises the base frame 8', at this rotatably mounted (not visible) deflecting wheels 17, 18, a guided around the guide wheels 17, 18 via positive transport chain 19 'with a leading, upper strand 20 and a returning, lower strand 21st , a between the guide wheels 17, 18 extending guide device 22 'for the leading, upper strand 20, coupled to the first guide wheel 17 feed drive 23 for locomotion of the transport chain 19' in the transport direction 5 and coupled to the second guide wheel 18 brake drive 24th The base frame 8 'comprises deflection stations 25, 26 for the transport chain 19' and between these a plurality of housing parts 27 '.

As can be seen from these figures, the chain links or part carriers 4 'are formed by stamped and formed parts. Likewise, the housing parts of the 22/40 N2012 / 13200 22

Stations 25, 26 and / or housing parts 27 'of the base frame 8' are produced as stamped and formed parts.

FIG. 8 shows a longitudinal section of the transport chain 19 ', which comprises articulated links connected by joint axes 32'. On the chain links (not shown) supporting plates can be attached, the latter form the part carrier 4 '. The transport chain 19 forms in the upper strand 20 a transport plane 37 ', which is defined in this case by the top of the support plates and is above the strand 20. The transport plane 37 'can also define a work plane at the same time.

The chain links comprise a receiving plate 69 and on its underside parallel to the transport direction 5 extending tabs 70. The receiving plate 69 may have on its upper side the support plate with a holding receptacle, not shown, which can hold parts to be mounted 3 on the transport between the workstations 6.

The tabs 70 protrude with their ends to the opposite direction in the transport direction 5 end edges of the receiving plate 69 and each comprise in their opposite end portions bearing bores 71. The bearing bores 71 form cylindrical holes, through which each one the bearing axis 32 'forming bearing pin passed become. A longitudinal axis of the bearing pin extends parallel to the axis of rotation of the guide wheels 17, 18th

At the ends of the bearing pins guide members, in particular guide rollers 72 are arranged. In addition, the parts carrier 4 'with guide members, in particular guide rollers 73 are provided which are rotatable about perpendicular to the plate plane aligned axes of rotation.

The parts carrier 4 'are based on the guide members, in particular guide rollers 72, 73 on guideways 74, 75, the latter are formed on guides 76. The guide device 22 'comprises the two guides 76 which are fixedly arranged on the base frame 8' and extend at a mutual distance in the transport direction 5 between the guide wheels 17, 18. 23/40 N2012 / 13200 23

The guides 76 each form separately arranged height and side guideway 74, 75, which is formed by the embodiment shown by at right angles to each other and in the transport direction 5 extending guide surfaces. The guide roller 72 forms a coaxial with the bearing axis 32 'extending guide portion with a cylindrical height guide surface and is preferably a rolling bearing. If the transport chain 19 'with the parts carriers 4' guided around the guide wheels 17, 18, the guide rollers 72 engage in the above-described engagement grooves 31 of the arranged on a rotation axis order pulleys 30 a form-fitting.

The described guide arrangement between the parts carriers 4 'and the guides 76 an exact height and lateral guidance of the upper strand 20 of the transport chain 19' is achieved. Thus, a work process can also be performed directly on the parts carrier 4 'without having to lift a part 3 from the part carrier 4'.

Even if an electric motor is used as the brake drive according to the preferred embodiment, it would also be conceivable that the brake drive comprises a so-called "rotation brake", as has become known for example from DE 20 2006 010 648 U1.

On the other hand, it would also be conceivable that the brake drive 24 comprises a braking device with brake elements engageable with each other, in particular a so-called "magnetic brake", as has become known for example from DE 197 52 543 A1. In this case, a brake disk (first brake element) is non-rotatably mounted on the (m) to be braked or fixed deflecting pulley 30 or deflecting wheel 18. On the other hand, the brake drive 24 comprises an armature disk displaceable axially between a braking position and a release position via an actuator with a brake pad (second brake element) fixedly mounted thereon. The actuator is connected to the control device 62, which in turn controls the armature disk in the braking phase Il-ι, ll2l ... Iln from the release position to the braking position. In the braking position, the armature disk is pressed with its brake pad against the brake disc, so that 24/40 N2012 / 13200 24, the transport chain 19; 19 'can be braked and / or determined on its advancing movement by the frictional engagement between the brake pad on the armature disk and the brake disk.

Also, an electromagnetic brake with a permanent magnet as a brake drive 24 is possible, as it has become known for example from DE 10 2005 006 699 A1.

Thus, the invention is not limited to consider that the brake drive 24 includes an electrically controllable, optionally controllable electric motor, but may also include a braking device which acts permanently in both the acceleration phase and braking phase of the feed drive 23, therefore, the second guide wheel 18 continuously with a braking force (braking torque) acted upon. In this case, although a more powerful drive motor on the feed drive 23 is necessary, however, a control of the brake drive 24 can be omitted.

The embodiments show possible embodiments of the transport system, which should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but also various combinations of the individual embodiments are mutually possible and this possibility of variation due to the teaching of technical action by representational Invention in the skill of those skilled in this technical field. So are all conceivable embodiments, which are possible by combinations of individual details of the illustrated and described embodiment variant, includes the scope of protection.

For the sake of order, it should finally be pointed out that for a better understanding of the structure of the transport system, these or their components have been shown partially unevenly and / or enlarged and / or reduced in size. 25/40 N2012 / 13200

REFERENCE NUMBERS

Production plant 36 Recess Transport system 37 Transport level Part 38 Front edge Part carrier 39 Bearing hole Transport direction 40 Bearing workstation 41 Stop projection Part supply station 42 Stop bar Base frame 43 Bearing support Carrier 44 Bearing Bottom 45 Guide roller Assembly level 46 Guide roller Frame construction 47 Guide Bearing frame module 48 Guidance Admission opening 49 Height and side guideway Crossbeam 50 Height guideway Handling device Guide wheel 51 Engagement section Guide wheel 52 Guide section Transport chain 53 Height and side guide upper strand surface 54 Guide section lower strand 55 Distance sleeve Guide device Feed drive 56 Recess Brake drive 57 Distance deflection station 58 Guide width dimension 59 Recess deflection station 60 Sealing lip Housing part End plate 61 Distance gap Support device 62 Control device Deflection plate 63 A Control circuit 64 Switches engagement groove 65 Voltage connection Joint axis Mounting plate 66 Detection device Tab 67 Evaluation unit Tab 68 Actuator 69 Mounting plate 70 Tab N2012 / 13200 71 Bearing bore 72 Guide roller 73 Guide roller 74 Guide track 75 Guide track 76 Guide 77 Cover 27/40 N2012 / 13200

Claims (15)

1. Transport system (2, 2 ') for conveying parts (3) by means of Teileträ ger (4, 4') within a manufacturing plant (1) in the transport direction (5) successively arranged workstations (6) and / or parts delivery stations ( 7), which has a base frame (8, 8 '), deflection wheels (17, 18) rotatably mounted thereon, and a transport chain (19, 19') guided over the deflection wheels (17, 18) with a leading, upper strand (FIG. 20), which faces a transport plane (37, 37 '), and a returning lower strand (21), a feed drive (23) coupled to one of the deflection wheels (17, 18) for advancing the transport chain (19, 19') in the transport direction (5), a guide device (22; 22 ') extending between the guide wheels (17, 18) for the leading upper strand (20) of the transport chain (19; 19'), the transport chain (19; ) comprises the part carriers (4, 4 '), characterized g ekennzeichnet that a first deflecting wheel (17) with at least one electronically controllable drive motor as a feed drive (23) and a second deflecting wheel (26) with a brake drive (24) is coupled. 28/40 N2012 / 13200 2 2. Transport system according to claim 1, characterized in that the feed drive (23) is formed by a direct drive, whose drive motor is directly coupled to the first deflection wheel (17). 3. Transport system according to claim 1, characterized in that the brake drive (24) comprises at least one electric drive motor, in particular a stepping motor, which is coupled to the second deflection wheel (18). 4. Transport system according to claim 3, characterized in that the electric drive motor of the brake drive (24) has voltage terminals (65) which are connected to an electronic switch (64) for shorting the voltage terminals (65). 5. Transport system according to claim 1 or 3, characterized in that the brake drive (24) comprises at least one electronically controllable drive motor. 6. Transport system according to claim 1, characterized in that the guide device (22) on the base frame (8) at a distance parallel guides (47, 48) and the transport chain (19) on the guides (47, 48) with guide members (45, 46) comprises supportable chain links, wherein on the one hand a first guide (47) and associated first guide members (45) each have a height guide surface (49, 53) and side guide surface (49, 53) and on the other hand a second guide (48) and associated second guide members (46) each form exclusively a height guide surface (50, 55). 7. Transport system according to claim 1 or 6, characterized in that the base frame (8) in a parallel to the transport plane (37) extending boundary plane and in the longitudinal direction of the guides (47, 48) extending stop strips (42) and that the transport chain ( 19) are provided on some of their articulated chain links on one of the transport plane 29/40 N2012 / 13200 3 (37) facing away from bottom with stop projections (41) which are arranged and designed such that the stop projections (41) on the advancing movement of Transport chain (19) along the guide device (22) engage behind the stop strips (42). 8. Transport system according to claim 7, characterized in that the guides (22) each form an extending in the longitudinal direction of the stop bar (42). 9. Transport system according to claim 1, characterized in that the transport chain (19) made of metal injection molded parts chain links comprises. 10. Transport system according to claim 1, characterized in that the transport chain (19 ') made of stamped and formed parts chain links comprises. 11. Transport system according to claim 1, characterized in that the transport system (2; 2 ') has an optical detection device (66) connected to a control device (62), in particular a camera system, by means of which a relative position (actual position) of at least one parts carrier ( 4, 4 ') in the transport direction (5) and / or transversely to the transport direction (5) can be detected, and that the control device (62) with an evaluation unit (67), of which in a target-actual comparison, a manipulated variable is calculated, and an actuator (68) from which a working module of at least one workstation (6) is acted upon by the manipulated variable is connected. 12. A method for conveying parts (3) by means of a transport system (2, 2 ') between in the transport direction (5) successively arranged workstations (6) and / or parts delivery stations (7), which transport system (2, 2') one to the Deflection wheels (17, 18) via a form-fitting guided transport chain (19, 19 ') with a leading, upper strand (20), which a transport plane 30/40 N2012 / 13200 4 (37, 37') faces, and a returning, lower Strand (19) and part carrier (4; 4 '), in which the part carriers (4; 4') are moved stepwise by way of a common, intermittent feed drive (23) in the transport direction (5) to the workstations (6) and / or parts supply stations (5). 7) are moved and thereby accelerated in an acceleration phase and decelerated in a braking phase, wherein in the acceleration phase, a first deflection wheel (17) from the feed drive (23) is driven, characterized in that in the Bremsph Ase the first guide wheel (17) driven by an electronically controllable drive motor so and a second guide wheel (18) by a brake drive (24) is braked such that the leading, upper strand (20) between the guide wheels (17, 18) is stretched , 13. The method according to claim 12, characterized in that in the acceleration phase of the transport chain (19, 19 ') and the brake drive (24) acts as a feed drive. 14. The method according to claim 12, characterized in that in the braking phase of the transport chain (19, 19 ') of the feed drive (23) reduces a drive torque and the brake drive (24) changes a braking torque depending on the drive torque of the feed drive (23). 15. The method according to claim 12, characterized in that in the braking phase of the transport chain (19, 19 ') of the feed drive (23) reduces a drive torque and the brake drive (24) by shorting voltage connections (65) of an electric drive motor generates a braking torque. 31/40 N2012 / 13200