Assembly trolley for assembling a motor vehicle

Abstract

Assembly trolley for assembling a motor vehicle, comprising a chassis (12), a receiving device (14) for receiving a workpiece or an assembly tool, wherein the receiving device (14) is fastened to the chassis (12) via a lifting device (20), wherein the lifting device (20) is designed such that the receiving device (14) is adjustable between different heights.

Description

[0001] The invention relates to an assembly trolley for assembling a motor vehicle, comprising a chassis, a receiving device for receiving a workpiece or an assembly tool.

[0002] Such assembly trolleys are generally known for the assembly of motor vehicles and serve to simplify assembly for the worker. For example, a workpiece does not have to be permanently held at the assembly height by the worker while it is being fastened to another component. Instead, it is already arranged on the assembly trolley at an assembly height required for fastening, and the worker only has to push the assembly trolley towards the other component and insert the fastening elements. In a similar way, an assembly tool can be mounted on the assembly trolley. Here, too, the assembly tool is arranged at a height required for assembling two components together thanks to the mounting by the assembly trolley, and the assembly trolley only has to be moved into a position required for assembly.

[0003] The disadvantage is that a specially designed assembly trolley must be available for each assembly station or for each workpiece or for each assembly tool, since almost all assembly stations differ from one another with regard to the position of the workpiece or the assembly tool.

[0004] US Pat. No. 7,581,713 B1 discloses an assembly carriage for assembling a motor vehicle, which carriage comprises a chassis and a receiving device for receiving a component. The receiving device is attached to the chassis via a lifting device. The lifting device is designed such that the receiving device can be adjusted between different heights. For this purpose, the lifting device comprises a lifting support unit and a guide unit. The lifting support unit drives the guide carriage in the vertical direction during a height adjustment of the receiving device, the lifting support unit comprising a lifting cylinder.

[0005] Furthermore, an assembly workstation is known from WO 2020 / 016 633 A1, wherein a workbench is designed to be adjustable.

[0006] The task is to provide an assembly trolley for the assembly of a motor vehicle, which is designed uniformly and can be used flexibly, i.e. for different assembly stations.

[0007] The problem is solved by the features of claim 1.

[0008] Because the holding device is attached to the chassis via a lifting device, the lifting device being designed such that the holding device can be adjusted between different heights, different heights of the holding device can be set, allowing a workpiece or an assembly tool to be positioned at different heights for assembly. This allows the identical assembly trolley to be used at different assembly stations where the workpieces to be assembled or the assembly tools required for the assembly of the workpieces must be positioned at different heights, allowing the assembly trolley to be used flexibly. This can reduce the costs of an assembly facility for assembling a motor vehicle.

[0009] The lifting device has a lifting support unit and a guide unit, wherein the guide unit has a guide rail fastened to the chassis and a guide carriage fastened to the receiving device or has a guide rail fastened to the receiving device and a guide carriage fastened to the chassis, and wherein the lifting support unit drives the guide carriage when the receiving device is adjusted in the vertical direction. The lifting support unit is in particular fastened to the chassis. Due to the guide unit, the worker only has to load the receiving device in the vertical direction when adjusting the height, wherein a displacement of the receiving device in other spatial directions is prevented by the guide device, thus simplifying the height adjustment for the worker.The lifting support unit ensures that the worker does not have to exert as much force to adjust the height of the holding device, i.e., to lift the holding device with any workpiece or assembly tool mounted on it, since the lifting support unit applies a vertical load to the holding device. The lifting support unit is preferably designed such that the vertical load caused by the lifting support unit corresponds to the weight of the holding device and the workpiece or assembly tool, so that the worker only needs to exert a small amount of force to lift the holding device. This can significantly simplify assembly for the worker.

[0010] The lifting support unit includes a balancer. A balancer has a circumferentially spring-loaded cable pulley and a cable wound around the cable pulley, with the cable connected to the guide carriage. Due to the spring preload, the cable continuously pulls on the guide carriage in the vertical direction, assisting the worker when lifting the support device to adjust the assembly height. If the resulting force from the spring force and the force applied by the worker exceeds the weight of the support device and the workpiece or assembly tool, the height is adjusted. The crucial point is that the worker does not have to apply the entire force required for lifting, but only the difference between the weight force and the spring force. The balancer therefore assists the worker in adjusting the height.

[0011] Alternatively, the lifting support unit can have a gas spring aligned in the vertical direction. The gas spring is basically a pneumatic adjustment element and consists of the pressure tube and a piston as well as suitable connections. The pressure tube is filled with a compressed gas, the quantity of which determines the preset internal pressure. The extension force acting on the piston can be precisely defined within physical limits by selecting the appropriate filling pressure and the diameter of the pressure tube and piston. The pressure acting on the piston and the resulting force on the piston in the vertical direction are supported by the gas spring when the worker lifts the holding device and the workpiece or assembly tool. The worker only has to apply the force for lifting, which is the difference between the spring force of the gas spring and the weight of the holding device and the workpiece or assembly tool.of the assembly tool. This means that a reduced force is required by the worker to lift the holding fixture and the workpiece or assembly tool.

[0012] The gas spring can be locked at different heights. The gas spring can be locked, for example, by a locking device. Two locking elements are arranged on the pressure tube and can move towards or away from each other, with a section of the piston arranged between the two locking elements. In a first position of the locking elements, the distance between the two locking elements is shortened such that the piston is clamped between the two locking elements. This connects the piston to the locking elements in a force-locking manner. In a second position, the locking elements are moved apart such that the locking elements are spaced from the piston, allowing the piston to move. The locking elements can be operated manually by a worker using a lever. The lever is connected to the locking device via Bowden cables or a hydraulic line.

[0013] Preferably, a user support device is provided, which forms the interface between the assembly trolley and the worker. The user support device has two handles.

[0014] Two embodiments of the invention are explained in more detail with reference to the drawings. Fig. 1 shows a first embodiment of an assembly trolley in perspective view, and Fig. 2 shows a second embodiment of an assembly trolley in perspective view.

[0015] Fig. 1 shows an assembly carriage 10 used for assembling a motor vehicle to simplify the assembly of a workpiece, in particular a motor vehicle component, to another motor vehicle component for a worker. For example, a not yet assembled body element can be mounted on a body shell. The body element is held at a location on the body shell to be mounted by means of the assembly carriage 10, and the worker only has to insert the fastening elements, for example, screws, without having to simultaneously hold the body element.

[0016] The assembly carriage 10 has a chassis 12, which has a double-T-shaped base element 122 and a coupling element 121 extending vertically from the base element 122. The base element 122 has a longitudinal web 1221 and two transverse webs 1222, 1223, each fastened to one end of the longitudinal web 1221 and extending transversely to the main extension direction of the longitudinal web 1221. Two rollers 131, 132, 133, 134 are arranged on each of the transverse webs 1222, 1223, each of which is rotatably mounted on the transverse webs about a rotational axis D1 extending vertically and, on the other hand, about a rotational axis D2 to enable the rollers 131, 132, 133, 134 to roll. This allows the assembly carriage 10 to be moved to move a workpiece into a position predefined for assembly.In addition, the assembly trolley 10 has a parking brake 151, 152, 153, 154 arranged on the rollers 131, 132, 133, 134 in order to block the rollers 131, 132, 133, 134 and thereby prevent undesired movement of the assembly trolley 10.

[0017] To hold the workpiece on the assembly carriage 10, the assembly carriage 10 has a holding device 14. The holding device 14 has a longitudinal web 141 and a transverse web 142 firmly connected to the ends of the longitudinal web 141. A further transverse web 145 is fastened to the transverse web 142 via two webs 143, 144, which form an L-shape. Two holding means 161, 162 are provided on the transverse web 145 for holding the workpiece. Furthermore, a U-shaped user holding device 18, formed by a plurality of webs, is fastened to the web 144. The user holding device has two handles 181, 182.

[0018] For adjusting the height of the workpiece or the holding device 14, the assembly carriage 10 has a lifting device 20. The lifting device 20 has a guide unit 22 and a lifting support unit 26.

[0019] The guide unit 22 has a guide rail 23 and two guide carriages 241, 242 which interact with the guide rail 23, wherein the guide rail 23 is formed on the coupling element 121 and the guide carriages 241, 242 are fastened to the crosspiece 141.

[0020] The lifting support unit 26 has a gas spring 28, which essentially has a piston 282 and a cylinder 281, wherein the cylinder 281 is attached to the chassis 12 and the piston 282 is attached to the receiving device 14.

[0021] During assembly of a workpiece, the workpiece is picked up on the assembly carriage 10, i.e., on the holding device 14, via the holding means 161, 162, and the assembly carriage 10, including the workpiece, is pushed to a predefined position. In addition, the holding device 14 and the workpiece are manually adjusted by the worker to a height required for assembly by lifting them using the handles 181, 182. The guide carriages 241, 242 slide along the guide rail 23. During the vertical displacement of the workpiece, the piston 262 is pushed out by the air pressure prevailing in the cylinder 261, whereby the holding device 14 is loaded in the vertical direction.The gas spring 28 thus supports the worker in lifting the workpiece. If the resulting force from the spring force of the gas spring 28 and the force applied by the worker exceeds the weight of the workpiece and the holding device 14, the holding device 14 shifts vertically. The gas spring 28 can be locked at different heights by a clamping device (not shown).

[0022] Fig. 2 shows a second embodiment of an assembly trolley 10, the essential differences from the first embodiment being Fig. 1 are that instead of a workpiece, an assembly tool, ie an assembly tool, is received by the receiving device 14 and the lifting support unit 26 has a so-called balancer 30 instead of a gas pressure spring 28. Accordingly, the receiving device 14 and the lifting support unit 26 for the first embodiment are Fig. 1 executed differently.

[0023] The receiving device 14 has an assembly tool clamping unit 17, which has a first clamping element 171 fastened to the longitudinal web 141 and a clamping element 172 fastened, for example screwed, to the first clamping element 171. The assembly tool is positioned between the two clamping elements 171, 172 when the second clamping element 172 is at least partially released from the first clamping element 171, and the second clamping element 172 is then finally fastened to the first clamping element 171, whereby the assembly tool is pressed between the two clamping elements 171, 172 and thus connected in a force-fitting manner.

[0024] The balancer 30 has a circumferentially spring-loaded cable pulley 32 and a cable 34 wound on the cable pulley 32 and connected to the longitudinal web 141 or to the guide carriages 241, 242. To load the longitudinal web 141 upward in the vertical direction, the cable 32 is deflected via a deflection pulley 36 rotatably mounted on the coupling element 121. When lifting the support device 14 or the assembly tool, the worker is assisted by the spring force transmitted to the support device 14 via the side 34, so that the force required by the worker to lift the tool is reduced by the spring force.

[0025] Both designs create an assembly trolley 10 which can be used at different assembly stations, whereby the height adjustment of the holding device 14 or the workpiece or assembly tool can be simplified by the worker.

Claims

[1] Assembly trolley for assembling a motor vehicle, with a chassis (12), a receiving device (14) for receiving a workpiece or an assembly tool, wherein the receiving device (14) is fastened to the chassis (12) via a lifting device (20), wherein the lifting device (20) is designed such that the receiving device (14) can be adjusted between different heights, wherein the lifting device (20) has a lifting support unit (26) and a guide unit (22), wherein the guide unit (22) has a guide rail (23) fastened to the chassis (12) and a guide carriage (241, 242) fastened to the receiving device (14) or has a guide rail fastened to the receiving device (14) and a guide carriage fastened to the chassis (12), and wherein the lifting support unit (26) drives the guide carriage (241, 242) in the height direction when the height of the receiving device (14) is adjusted. characterized by , that the lifting support unit (26) has a balancer (30). [2] Assembly trolley according to claim 1, characterized by that a user holding device (18) is provided.

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