WO2007012360A1

WO2007012360A1 - Transport system and method for simultaneously transporting workpieces and assemblers on a production line

Info

Publication number: WO2007012360A1
Application number: PCT/EP2006/004793
Authority: WO
Inventors: Jürgen Röckle; Werner Swoboda
Original assignee: Eisenmann Anlagenbau Gmbh & Co. Kg
Priority date: 2005-07-25
Filing date: 2006-05-20
Publication date: 2007-02-01
Also published as: CN101228064A; DE102005034582B4; EP1907268A1; US20080276827A1; DE102005034582A1

Abstract

The invention relates to a transport system (10) for simultaneously transporting workpieces (28) and assemblers on a production line (12) comprising at least one rectilinear production section (18, 20) for several guided motor vehicles (22), each of which is provided with a mounting platform (24) which extends along the entire vehicle length and on which the assemblers can move, wherein said vehicles can form a train (30) during the displacement thereof along the production line (12). Each mounting platform is provided with its own drive (42). Said drives are controllable in such a way that the vehicles are driven in the form of a train (30) during the displacement thereof along the production section (18, 20). A method for simultaneously transporting workpieces (28) and assemblers along the production line (12) provided with at least one rectilinear production section (18, 20). The inventive method consists in driving the vehicles (22) in the form of a train by means of the drives (42) mounted on the vehicles (22) during the displacement thereof along the production section (18, 20).

Description

Conveyor system and method for the simultaneous transport of workpieces and fitters in a production line

The invention relates to a conveyor system and a method for the simultaneous transport of workpieces and fitters in a production line with at least one rectilinear manufacturing section, wherein the conveyor system comprises a plurality of track-bound vehicles, the

a) each have an over the entire length of the vehicle extending and accessible to fitters mounting platform;

b) when driving along the production line can form a bandage in which the mounting platforms of adjacent vehicles are adjacent to one another virtually without any gaps; and

c) each have their own drive.

Such conveyor systems are known from DE 40 20 286 C2 and are used for example in the final assembly of motor vehicles. In contrast to conveyor systems, which are designed only for the transport of workpieces, the conveyor systems described there allow fitters to be carried along with the workpieces over a longer period of time. In this way, the fitters can make assembly or other work on the workpieces without having to run alongside the workpieces. For this purpose, the vehicles along a straight-line production section of the production line form a push bandage. The last vehicle in each case pushes the vehicles in front through the rectilinear production section, where it is driven by stationary external drive means. These drive means may, for example, be friction wheels which act from the outside on the longitudinal sides of the mounting platforms and in this way apply the thrust force required for the forward movement. By pushing from behind it is achieved that the pushing platforms within the push band always adjoin one another virtually gap-free, so that the fitters can move as unhindered and safely as possible on the mounting platforms and in particular can go from one mounting platform to the next.

At the end of a rectilinear production section, the pusher assembly is broken up again by vertically or horizontally transferring the individual vehicles in a transfer station or by driving on a curve to another rectilinear production section. In the conveyor system known from DE 40 20 286 C2, the vehicles have their own drives, so that the vehicles can move independently between the straight-line production sections. As soon as a vehicle is taken into the pusher unit, its own drive is switched off.

The assembly platforms not only have to carry the fitters and the workpiece, but also absorb and divert high longitudinal and often also transverse forces. In the longitudinal direction, in particular, those thrust forces that act on the individual vehicles by driving in the push association. These longitudinal forces are greatest at the respectively driven and rearmost in the direction of travel Vehicle, as this affects the resistance to movement of the entire push bandage. Transverse forces can be caused mainly by the external drive means, such as friction wheels.

Due to these forces applied to them, the assembly platforms are subject to high stresses, which is why they have to be manufactured with rigidity and stability which go beyond the requirements arising from the weight of the workpiece to be carried and the installer.

The object of the invention is to provide a conveyor system of the type mentioned, in which the forces exerted on a mounting platform are reduced.

This object is achieved in a conveyor system of the type mentioned above in that the drives of the vehicles are controllable such that they drive the vehicles while driving along the rectilinear production section in the association. - ^■

In this way it is possible to dispense with external drive means, such as friction wheels, which exert transverse forces. Each vehicle is always driven by its own drive, so acting on the rearmost in the push assembly vehicle in the direction of travel also lower longitudinal forces, since this now no longer experiences the entire resistance to movement of the push association.

It is advantageous if the drives of the vehicles are controllable such that the torques generated by the drives of the vehicles are the greater the further back a vehicle is in the association. This will ensure that the entire bandage Always driven evenly and the mounting platforms of adjacent vehicles always adjoin each other practically gap-free. At the same torques, there is the danger that adjacent vehicles will separate as a result of different friction resistances.

Under virtually gapless is understood here that between the mounting plates of two adjacent vehicles still a distance of not more than 5 cm, preferably less than 1 cm, may remain, which is bridged for example by a rubber bead.

In order not to let the shear forces acting on the assembly platforms become too large, it is favorable if the drives of the vehicles are controllable in such a way that no thrust forces above a threshold value act between adjacent vehicles in their direction of travel. Overall, the threshold value depends on the requirements of the production line or the conveyor system, which are influenced in particular by the workpiece to be assembled and / or machined.

Furthermore, it is favorable if the vehicles can be connected to one another in the association by means of clutches during driving. This is the bandage and therefore a safe

Moving a mechanic between two adjacent vehicles is also ensured if the control of a single vehicle or its drive should fail or the controller due to their interpretation, a separation of vehicles in the association can not prevent in principle.

It proves to be particularly favorable when the clutches automatically latch together when starting up. To ensure that the vehicles do not disconnect when driving in the composite, it is advantageous if a device, for. B. a pressure sensor, is provided for determining the thrust forces generated by the drives of the vehicles.

The drives of the moving vehicles in the association are then controlled so that the determined thrust forces are within a predetermined interval.

In order to ensure safe passage from the mounting platform of a vehicle to the mounting platform of an adjacent vehicle for a mechanic, it is advantageous if the mounting platforms of adjacent vehicles when driving in the association less than 5 cm, preferably less than 1 cm, are spaced apart , The distance is then to be bridged by a rubber bead o. Ä.

So that the workpiece to be assembled and / or machined is to be arranged so as to be easily accessible to a fitter on a mounting platform, it is favorable if a functional unit is arranged on the vehicles. This can be a technically simple manner to a lifting table, with which a workpiece arranged thereon can be moved to different heights.

Moreover, it is an object of the invention to provide a method of the type mentioned, by which the forces exerted on a mounting platform forces are reduced.

This object is achieved by a method of the type mentioned, in which the vehicles by means of arranged on the vehicles drives during driving be driven along the rectilinear manufacturing section in the dressing.

Advantageous developments of the method can be found in claims 14 to 22, the advantages of which emerge mutatis mutandis from the above.

An embodiment of the invention will be explained in more detail with reference to the drawing. In this show:

Figure 1 is a highly simplified plan view of an embodiment of a conveyor system;

Figure 2 is an enlarged plan view of a single vehicle of the conveyor system shown in Figure 1;

Figure 3 is an enlarged side view of a vehicle of the conveyor system shown in Figure 1 without workpiece thereon;

Figure 4 is an enlarged rear view of a vehicle of the conveyor system shown in Figure 1 without workpiece thereon;

Figure 5 is a further enlarged simplified side view of a coupling for connecting the vehicles during the latching operation; and

Figure 6: the coupling shown in Figure 5 in the locked state.

FIG. 1 shows, in a simplified simplified plan view, an exemplary embodiment of a conveyor system 10 that is used for the simultaneous transport of workpieces and fitters in a production line partially shown in FIG 12 is provided. The conveyor system 10 includes a track formed by rails 14, 16. In the illustrated simplified embodiment, two manufacturing sections 18, 20 are provided, along which the rails 14, 16 extend in a straight line. The rails 14, 16 are laid as level as possible in an assembly hall, wherein the production line 12 may include a total of more such rectilinear manufacturing sections 18, 20. Between the production sections 18, 20, the rails 14, 16 are arcuately curved in sections 17, whereby a closed track is formed.

On the rails 14, 16 run identically constructed vehicles 22, one of which is shown enlarged in Figure 2 in a plan view. The vehicles 22 each have an assembly platform 24 and carry centrally each a lifting table 26 on which a workpiece to be mounted 28 is mounted movable in height. In the exemplary embodiment shown here, the workpiece 28 is intended to be a vehicle bodywork prepared for final assembly, which is only indicated in a highly schematic manner in FIGS. 1 and 2.

Along the production sections 18, 20, the vehicles 22 form a bandage 30 in which the mounting platforms 24 adjoin one another virtually without any gaps. In this way, for the fitters a continuously accessible area, on which they can move during assembly of the workpieces 28.

In the figures 3 and 4, in which the workpiece 28 is not shown for the sake of clarity, the lifting table 26 can be seen better. This is adjustable by means of a shear drive 34 in height, as is known per se in the prior art. To prevent, that the fitters can get into the shearer 34, the lifting table 26 is completed round with bellows 36 to the mounting platform 24, in Figure 4, the bellows 36 are omitted transversely to the rails 14, 16 so that the shearer 34 is visible.

As can be seen in FIGS. 3 and 4, the vehicle 22 runs on the rails 14, 16 by means of running wheels 38. A pair of wheels 40 can be driven by means of a drive, for example an electric motor. The electric way of an electric motor 42, drivable. The electric motor 42 is connected via a line 44 to a vehicle control 46, which controls the electric motor 42. The vehicle controller 44 may be a processor unit known per se, for example.

The vehicle controller 46 includes a receiving unit 48 and a transmitting unit 50, by means of which it communicates wirelessly with a central controller 52, which can be seen in Figure 1, which will be explained in more detail below. Of course, the communication between the vehicle controller 46 and the central controller 52 via busbars by means of Schleifkon .... or even done without contact.

Provided on the vehicle 22 is a position sensor 54 with a reading head 56, which reads out a position code 58, for example, attached to the inside of a rail 14, 16. The position sensor 54 transmits the thus determined position data of the vehicle 22 via a line 60 to the vehicle controller 46, which in turn transmits this data to the central controller 52 in conjunction with a signal 22 that can be assigned to the specific vehicle 22. Figures 5 and 6 show a coupling 62 with which the mounting platforms 24 of adjacent vehicles 22 can be coupled. The coupling 62 includes a hook 64 attached to a mounting platform 24 and a fastener 24 attached to the adjacent mounting platform

Pivot pawl 66. Both hook 64 and pawl 66 are substantially L-shaped and have ramped ramp surfaces 68. Pivot pawl 66 is pivotally mounted at its long end, the pivot axis being transverse to the direction of travel of vehicles 22 shown in FIGS 5 and 6 as in Figure 1, indicated by arrows 70.

On the front side of the mounting platform 24 of a vehicle 22 pointing in the direction of travel, a pressure sensor 72 is mounted to determine the direction of travel 70 thrust forces generated by the electric motors 42 of the vehicles 22, the output signal via a line 74 to the vehicle control 46th of the respective vehicle 22 and from this in combination with a vehicle 22 assignable signal to the central controller 52 is transmitted.

At the mounting platforms 24, a rubber bead 76 is provided above the pressure sensor.

The above-described conveyor system 10 functions as follows:

At transitions 78, 80, 82, 84 (Figure 1) between an arcuately curved portion 17 of the rails 14, 16 and a rectilinear manufacturing section 18, 20 each have a position code 58 is provided. In the embodiment shown here, the position codes at the transitions 78, 80 correspond to the direction of travel 70 of the vehicles 22 for the transition between an arcuately curved portion 17 and a rectilinear manufacturing section 18, 20. The two remaining position codes 58 are at the transitions 82, 84 respectively for the transition between a rectilinear manufacturing section 18, 20 and an arcuate curved portion 17th ,

If a vehicle 22A located at the tip of the dressing 30 passes over a position code 58, for example at the transition 82, the central controller 52 recognizes from the transmitted position signal that the relevant vehicle 22A is now leaving the rectilinear production section 18 and into an arcuately curved section 17 of the rails 14 16 retracts.

In the latter case, the central controller 52 transmits to the vehicle controller 46 of the vehicle 22A a control signal which causes the torque of the electric motor 42 to be increased. The vehicle controller 46 of the vehicle 22A accordingly controls the drive 42 accordingly, so that the speed of the vehicle 22A increases in relation to its speed in the dressing 30.

The vehicle 22A now travels at an increased speed through the arcuately curved section 17 of the rails 14, 16 until it reaches the point 78, that is, corresponds to the vehicle 22B in FIG. The speed increased relative to the speed of the vehicle 22A in the dressing 30 is, in terms of throughput, the

Production line 12 desirable so that the vehicles 22 get as fast as possible from one production section 18, 20 to the next.

In the vehicle 22B, the central controller 52 recognizes Based on the transmitted position signal at the transition 78 that the vehicle in question 22B now leaves the arcuate section 17 of the rails 14, 16 and enters the rectilinear manufacturing section 20.

The central controller 52 now transmits to the vehicle controller 46 of the vehicle 22B a control signal which causes the torque of the electric motor 42 to be reduced.

However, in order to ensure that the vehicle 22B ascends to the preceding vehicle 22C, the torque of the electric motor 42 of the vehicle 22B is higher than that of the electric motor 42 of the vehicle 22C, which is already in the association 30.

Until the vehicle 22B now reaches the vehicle 22C and the mounting plate 24 of the vehicle 22A runs onto the mounting plate 24 of the vehicle 22C, the pressure sensor 72 of the vehicle 22B generates a zero signal since it can not detect a back pressure.

If the pressure sensor 72 of the vehicle 22B comes into contact with its facing end face of the mounting plate 24 of the vehicle 22C, as shown in FIG. 6, then the pressure sensor 72 transmits a signal via the vehicle control 46 of the vehicle 22B to the central controller 52, which reproduces how large the thrust forces exerted by vehicle 22B on vehicle 22C are.

The central controller 52 controls the individual vehicles 22 in the association 30 such that the torques or thrust forces generated by the electric motors 42 of the vehicles 22 are within a predetermined interval. This ensures that a vehicle 22, such as vehicle 22B, always applies light thrust forces to a preceding vehicle 22, such as 22C, thereby preventing the gap between the mounting platforms from opening.

For mounting platforms 24, which are separated from rubber beads 76, a detection of the thrust forces can also be performed by means of distance sensors. Since the rubber beads 76 yield resiliently, the larger the thrust forces, the smaller the distance between adjacent mounting platforms 24.

As an alternative to controlling the vehicles 22 via the shear forces exerted in the pushing association between the individual assembly platforms 24, it is also possible to control the drives 42 of the vehicles 22 via a combined speed-torque control. The target speed is set slightly higher than the actually achieved speed. Torque limiting ensures that the thrust forces between the mounting platforms 24 do not become unnecessarily large. The current through the electric motors 42 can be used as a measure of the torque generated by the electric motors 42.

To further increase safety, the clutches 62 are provided on the vehicles.

Reduces the distance between the two mounting platforms 24, for example, the vehicles 22B and 22C, when the vehicle 22B is retracted into the rectilinear manufacturing section 20, the two ramp surfaces 68 of the coupling 62 run on each other, whereby the pivoting pawl 66 is raised, as shown in FIG FIG. 5 is recognizable. As the distance between the mounting platforms 24 further decreases, the pivot pawl 66 locks as shown in FIG.

The attached to the mounting platform 24 of the vehicle 22B rubber bead 76 thereby closes the remaining narrow gap between the adjacent mounting platforms 24th

As can be seen in Figure 6, remains in vehicles 22 in the association 30 between the locking lugs of the pawls 64, 66, a gap 86. The pivot pawl 66 is thus at the usually desired distance between the mounting platforms .zweier two adjacent vehicles 22 - the at - At least less than 5 cm, preferably less than 1 cm - is exposed to no tensile load.

By additionally provided coupling 62 is prevented in any case that two adjacent vehicles 22 can move away from each other, as long as they drive within the rectilinear manufacturing section 18, 20 in the association 30.

At or just before the transitions 82 and 84 between each of the rectilinear manufacturing sections 18, 20 and the arcuately curved portions 17 of the rails 14, 16, a means for releasing the clutch 62 is provided in each case provided clutch. This may, for example, be a plunger pushing against the pivoting pawl 66 of the coupling 62 from below.

Optionally, the clutches 62 alone can ensure the dressing 30. In this case, the vehicles 22 would not have to be controlled in such a way that those generated by the electric motors 42 of the vehicles 22 Shear forces are within a predetermined interval.

As an alternative to mechanically detachable couplings and electromagnets can be used, which are attached to the end faces of the vehicles 22 and electrically switchable.

Claims

claims

A conveyor system for simultaneously transporting workpieces (28) and fitters in a production line (12) having at least one rectilinear manufacturing section (18, 20), the conveyor system (10) including a plurality of track-bound vehicles (22)

a) each have an over the entire length of the vehicle extending and accessible to fitters mounting platform (24);

b) when driving along the production line (12) a

Association (30) can form, in which the mounting platforms (24) of adjacent vehicles (22) adjacent to each other virtually gap-free; and

c) each have their own drive (42),

characterized in that

the drives (42) of the vehicles (22) are controllable to drive the vehicles (22) during travel along the rectilinear manufacturing section (18, 20) in the dressing (30).

2. Conveying system according to claim 1, characterized in that the drives (42) of the vehicles (22) are controllable such that the of the drives (42) of the vehicles (22) generated torques are greater, the further behind a vehicle (22) is located in the bandage (30).

3. A conveyor system according to claim 1 or 2, characterized in that the drives (42) of the vehicles (22) are controllable such that act between adjacent vehicles (22) in the direction of travel (70) no thrust forces above a threshold.

4. conveyor system according to one of the preceding claims, characterized in that the vehicles (22) during driving in the association (30) via couplings (62) are connectable to each other.

5. Conveying system according to claim 4, characterized in that the couplings (62) automatically latch together when starting up.

6. conveyor system according to claim 4, characterized in that the couplings comprise electromagnets.

7. conveying system according to one of the preceding claims, characterized in that on the vehicles (22) a

Device (72) is provided for determining the thrust forces generated by the drives (42) of the vehicles (22).

8. conveying system according to claim 7, characterized in that the means (72) for determining the of the

Drives (42) of the vehicles (22) generated thrust forces is a pressure sensor (72).

9. A conveyor system according to any one of the preceding claims, characterized in that on the vehicles (22) a distance sensor for determining the distance between adjacent mounting platforms (24) is arranged.

10. Conveying system according to one of the preceding claims, characterized in that the mounting platforms (24) of adjacent vehicles (22) when traveling in the dressing (30) less than 5 cm, preferably less than 1 cm apart.

11. Conveying system according to one of the preceding claims, characterized in that on the vehicles (22) a functional unit (26) is arranged.

12. A conveyor system according to claim 11, characterized in that the functional unit (26) is a lifting table (26), with which a workpiece (28) arranged thereon can be moved to different heights.

13. A method for the simultaneous transport of workpieces (28) and fitters along a production line (12) with at least one rectilinear manufacturing section (18, 20) in which a plurality of track-bound vehicles (22), each extending over the entire vehicle length and Fitters accessible to fitters (24), when driving along the production line (12) can form a bandage (30) in which the mounting platforms (24) adjacent vehicles (22) adjacent to each other virtually gap-free,

characterized in that

the vehicles (22) are driven by means of drives (42) arranged on the vehicles (22) during driving along the rectilinear production section (18, 20) in the dressing (30).

14. The method according to claim 13, characterized in that the vehicles (22) by means of the drives (42) are driven such that the thrust forces generated by the drives (42) are greater, the farther at the rear there is a vehicle (22) in the bandage (30).

15. The method according to claim 13 or 14, characterized in that the vehicles (22) by means of the drives (42) are driven in such a way that between adjacent vehicles (22) in their direction of travel (70) no thrust forces above a threshold value.

16. The method according to any one of claims 13 to 15, characterized in that the vehicles (22) during the

Driving in association (30) via couplings (62) are interconnected.

17. The method according to claim 16, characterized in that the couplings (62) engage automatically when driving together.

18. The method according to any one of claims 13 to 17, characterized in that the thrust forces generated by the drives (42) of the vehicles (22) are determined by means provided on the vehicles (22) means (72).

19. Method according to claim 18, characterized in that the thrust forces generated by the drives (42) of the vehicles (22) are determined by means of a pressure sensor (72).

20. The method according to any one of claims 13 to 19, characterized in that the mounting platforms (24) of adjacent vehicles (22) while driving in the dressing (30) are less than 5 cm, preferably less than 1 cm apart.