Driverless transport vehicle

Abstract

An unmanned transport vehicle, especially for transporting a goods carrier, has a load-bearing frame, a chassis and a load-receiving platform for receiving the goods carrier, the load-receiving platform being arranged on the load-bearing frame and the load-bearing frame and the chassis being arranged vertically below the load-receiving platform. The chassis has an intermediate axle with two non-steering wheels, a front axle with at least one steering wheel unit and a rear axle with at least one steering wheel unit. According to the invention, the intermediate axle and the front axle of the chassis are arranged on a first cantilever, the first cantilever being articulated to the load-bearing frame by means of a first articulation axis which has a horizontal swivel axis extending in the vehicle transverse direction, the rear axle of the chassis being arranged on a second cantilever, the second cantilever being articulated to the intermediate axle or the first cantilever by means of a second articulation axis which has a horizontal swivel axis extending in the vehicle transverse direction, the second cantilever being connected to the load-bearing frame by means of a coupling element which is articulated to the second cantilever and to the load-bearing frame.

Description

Technical Field

[0001] The present invention relates to an autonomous transport vehicle, especially for transporting a goods carrier, which has a load-bearing frame, a chassis and a load receiving platform for receiving the goods carrier, wherein the load receiving platform is arranged on the load-bearing frame, and the load-bearing frame and the chassis are arranged vertically below the load receiving platform, and wherein the chassis has an intermediate axle with two non-steering wheels, a front axle with at least one steering wheel unit and a rear axle with at least one steering wheel unit. Background Art

[0002] Such autonomous transport vehicles are known from DE 20 2013 004 209 U1.

[0003] For optimizing and automating in-house transport in enterprises, autonomous and thus self-driving transport vehicles, so-called AGVs (automated guided vehicles), are increasingly being used for in-house transport. For this purpose, various forms of compact and flat self-driving transport vehicles constructed as platform vehicles are used more often, which drive under a goods carrier, such as a pallet or a roll cart, and are slightly lifted if necessary in order to horizontally move and lower the goods carrier again. Here, these autonomous transport vehicles are automatically and thus autonomously controlled and navigated.

[0004] An application area of such autonomous transport vehicles in in-house transport is, for example, transporting pallets or roll carts from a storage location to a sorting station and back, or from a sorting station to a production station.

[0005] Depending on the task, the goods, the goods carrier and the surrounding environment, different requirements are placed on such autonomous transport vehicles, and thus there are also different types, sizes and embodiments of such autonomous transport vehicles.

[0006] In order to meet the requirements placed on such autonomous transport vehicles in terms of small scheduling space, compact external dimensions and low manufacturing costs in the best possible compromise, such autonomous transport vehicles with a chassis having three axles are known, in which the intermediate axle is configured as a driven axle (drive axle), while the front axle and the rear axle are each configured as non-driven axles with steerable wheels. As long as the drive wheels of the intermediate axle can run and be controlled independently of each other, the driving direction can be forced to change and steering can be performed by different rotational speeds and / or rotational directions of the two drive wheels of the intermediate axle, wherein the transport vehicle can rotate about its center point in place.

[0007] In such driverless transport vehicles with a chassis having three axes, it is ensured that the drive wheels are always sufficiently loaded so that the driving torque can be reliably transmitted to the roadway.

[0008] For this purpose, in such driverless transport vehicles with a chassis having three axes, a chassis concept is known in which the intermediate axis designed as the drive axis is arranged vertically below a connection plane by a defined amount, the connection plane connecting the non-driven front axle and the non-driven rear axle. When driving on a flat roadway, the drive axle always bears the vast majority of the total load. Of the other two axles (front axle / rear axle), only one of these two axles always supports, while the other axle is suspended. When the load changes (e.g., due to braking deceleration), the transport vehicle can thus be tilted slightly about the transverse axis until the other axle comes into contact with the roadway and thus transfers the support load from the one axle to the other axle. However, the disadvantage of this chassis concept is that the transport vehicle is only suitable for roadways with low ground unevenness and small ramp angles. In addition, due to the tilting of the vehicle about the transverse axis, discontinuity occurs during the driving of the transport vehicle. In addition, in this chassis concept, it is required that the drive axle be designed to meet the total load of the transport vehicle.

[0009] In addition, a chassis concept is known in such driverless transport vehicles with a chassis having three axes, in which, for example, in the case of using spring elements, load compensation is achieved between the three axes. However, the disadvantage of this chassis concept is that the chassis has a complex and laborious structure and the load compensation between the three axes may be incomplete depending on the loading state of the transport vehicle. Summary of the Invention

[0010] The object on which the present invention is based is to provide a driverless transport vehicle of the type described at the beginning, in which the load distribution of the three axes is improved.

[0011] According to the present invention, this object is solved in that the intermediate axle and the front axle of the chassis are arranged on a first cantilever, the first cantilever being articulated to the load-bearing frame by means of a first articulation axis having a horizontal swivel axis extending in the vehicle transverse direction, and the rear axle of the chassis is arranged on a second cantilever, the second cantilever being articulated to the intermediate axle or the first cantilever by means of a second articulation axis having a horizontal swivel axis extending in the vehicle transverse direction, wherein the second cantilever is connected to the load-bearing frame by means of a coupling element, the coupling element being articulated to the second cantilever and to the load-bearing frame.

[0012] Using the chassis according to the present invention, the distribution of inertial forces and thus the load distribution onto three axes are achieved, and this load distribution is always defined during driving on a driving lane with significant unevenness and on a slope in each loading state of the transport vehicle. A transport vehicle provided with the chassis according to the present invention can travel in the case of large ground unevenness and large slope angles and the chassis has a simple structure.

[0013] In the transport vehicle according to the present invention, the load-bearing frame is connected to the chassis, on the one hand, by a first cantilever via a first articulation axis, and on the other hand, by a second cantilever pivotable about a second articulation axis on the intermediate axle or on the first cantilever via a coupling element, which coupling element is articulatedly connected not only to the second cantilever but also to the load-bearing frame. By means of the coupling element, the force can be transferred in a simple manner between the load-bearing frame and the second cantilever, and the length compensation required when the second cantilever pivots about the second articulation axis can be achieved in a simple manner, the second articulation axis being arranged on an intermediate axle pivotable about the first articulation axis or on a first cantilever pivotable about the first articulation axis.

[0014] According to an advantageous embodiment of the present invention, the first articulation axis is arranged longitudinally of the vehicle between the intermediate axle and the front axle.

[0015] If, according to a configuration of the present invention, the second articulation axis is arranged coaxially with the rotational axis of the wheel of the intermediate axle, particular advantages are obtained. Thus, the second cantilever is rotatably supported or pivotable about the rotational axis of the wheel of the intermediate axle (for example on the intermediate axle). This enables a simple structure. Alternatively, the second articulation axis can be arranged parallel to the rotational axis of the wheel of the intermediate axle and can be arranged in the vicinity of the rotational axis of the wheel of the intermediate axle, for example on the first cantilever or the intermediate axle.

[0016] According to an advantageous configuration of the present invention, the coupling element is arranged longitudinally of the vehicle between the intermediate axle and the rear axle.

[0017] If, according to an advantageous expansion of the present invention, the first articulation axis comprises two articulation connections which are arranged spaced apart from one another transversely of the vehicle, particular advantages are obtained. By means of such two articulation connections which are arranged coaxially with respect to the first articulation axis and spaced apart from one another transversely of the vehicle, not only the force between the load-bearing frame and the first cantilever can be transferred on the first articulation axis, but also, additionally, the torque about the longitudinal axis of the vehicle of the transport vehicle from the load-bearing frame to the first cantilever.

[0018] If the articulated connection parts are respectively configured as bolt connection parts, special advantages are obtained in terms of the simple structure of the first articulation axis. Here, the two bolt connection parts constituting the first articulation axis can have two independent bolts or a common bolt.

[0019] According to an expansion scheme of the present invention, the bolt connection part between the first cantilever of the chassis and the load-bearing frame can be configured as a usual load-measuring bolt, so that the loading state of the transport vehicle can be measured relatively accurately in terms of the gravity and the center-of-gravity position of the received load.

[0020] According to an advantageous expansion scheme of the present invention, the wheels of the intermediate axle are respectively supported rotatably about the rotation axis in or on the wheel carrier, wherein the wheel carrier is fastened to the first cantilever. Therefore, the wheel carrier is fixedly connected to the first cantilever, and thus a simple structure of the chassis can be achieved.

[0021] If, according to an advantageous configuration mode of the present invention, the second articulation axis includes at least one bearing ring arranged on the second cantilever and rotatably supported on the toroidal surface of the wheel carrier, a simple and low-cost structure can be achieved for the second articulation axis. Here, the toroidal surface can be produced at low cost by a correspondingly machined surface on the outer periphery of the wheel carrier, and the second cantilever is rotatably supported on the correspondingly machined surface by the bearing ring.

[0022] Advantageously, a sliding bearing is arranged between the toroidal surface of the wheel carrier and the bearing ring. By using this sliding bearing, low friction force can be achieved on the second articulation axis.

[0023] According to an advantageous configuration mode of the present invention, the coupling element has at least one tension-compression rod, which is articulated to the second cantilever by means of a third articulation axis having a horizontal swivel axis extending in the vehicle transverse direction, and the tension-compression rod is articulated to the load-bearing frame by means of a fourth articulation axis having a horizontal swivel axis extending in the vehicle transverse direction. Therefore, the load-bearing frame is connected to the rotatable second cantilever by the coupling element, and the coupling element is articulated to the second cantilever and the load-bearing frame by two horizontal articulation axes, so that the coupling element can be composed of a simply structured tension-compression rod that only transmits the corresponding tensile force or pressure in one direction, i.e., the longitudinal direction of the coupling element.

[0024] If the third articulation axis and the fourth articulation axis are respectively configured as articulated connection parts, and the articulated connection parts are configured as bolt connection parts, advantages are obtained in terms of simple structure. According to an expansion scheme of the present invention, one or two bolt connection parts between the coupling element and the load-bearing frame can be configured as usual load-measuring bolts, so that the loading state of the transport vehicle can be measured relatively accurately in terms of the gravity and the center-of-gravity position of the received load.

[0025] According to an advantageous embodiment of the invention, the load-bearing frame has a longitudinal carrier extending in the longitudinal direction of the vehicle, on which a first articulation axis is arranged, and the coupling element is articulated to the longitudinal carrier. Thereby, a simple and low-cost structure of the load-bearing frame can be achieved. The longitudinal carrier is preferably configured as an elongated, bending-resistant and torsion-resistant longitudinal carrier, such that the longitudinal carrier requires less installation space and the transport vehicle has a compact structure with a small size.

[0026] According to an advantageous configuration of the invention, the longitudinal carrier is arranged centrally in the transverse direction of the vehicle. Thereby, the longitudinal carrier can utilize the installation space between the two wheel carriers of the two wheels of the intermediate axle and can be arranged between these two wheel carriers of the wheels of the intermediate axle. Thus, the transport vehicle has a compact vertical dimension and is thus configured as a flat-structured transport vehicle that can travel under a load carrier to be transported, such as a pallet or a delivery van.

[0027] According to an advantageous configuration of the invention, the longitudinal carrier is widened in the region of the front axle and in the region of the rear axle. This enables the load of the received load carrier to be reliably received by the load-bearing frame in a simple manner.

[0028] According to an advantageous expansion of the invention, the load-bearing frame is provided with support elements in the regions of the four outer corners of the vehicle, and these support elements are provided for supporting the vehicle on the roadway surface. The tipping stability of the transport vehicle can be improved in a simple manner by means of the additional support elements. The support elements arranged and fastened on the load-bearing frame are preferably arranged on the load-bearing frame such that the support elements are arranged as close as possible to the four outer corners of the transport vehicle and have a small vertical spacing relative to the roadway, such that the support elements are located as close as possible above the roadway without disturbing the normal driving operation. If the transport vehicle is to tip over during operation, for example due to a malfunction, one of the support elements comes into contact with the roadway, thereby expanding the support base of the transport vehicle and preventing the transport vehicle from tipping over further.

[0029] According to an embodiment of the invention, the load-receiving platform can be constituted by the load-bearing frame. Thus, the load received by the load-receiving platform is directly received by the load-bearing frame.

[0030] According to an alternative embodiment of the invention, the load-receiving platform is fixedly fastened to the load-bearing frame. Thus, the load received on the load-receiving platform is received via the load-receiving platform rigidly fastened to the load-bearing frame.

[0031] According to an alternative embodiment of the present invention, the load receiving platform is arranged on the carrier frame by means of a lifting device so as to be liftable and lowerable in the vertical direction. Accordingly, the load received on the load receiving platform is received via the load receiving platform arranged on the carrier frame in a liftable and lowerable manner. For this purpose, a corresponding lifting device may be provided between the carrier frame and the load receiving platform, by means of which the load receiving platform and the load can be lifted and lowered.

[0032] According to an advantageous embodiment of the present invention, the wheel units of the front axle and / or the rear axle are each configured as undriven and passively steerable wheel units. Herein, the corresponding wheel units on the front axle and / or on the rear axle can be advantageously passively steered by caster.

[0033] According to an alternative embodiment of the present invention, the wheel units of the front axle and / or the rear axle are each configured as undriven and actively steerable wheel units. The corresponding wheel units on the front axle and / or on the rear axle can be advantageously actively steered by corresponding steering drive devices.

[0034] According to an alternative embodiment of the present invention, the wheel units of the front axle and / or the rear axle are each configured as driven and actively steerable wheel units. Herein, the corresponding wheel units on the front axle and / or on the rear axle can be advantageously driven by corresponding drive units, such as drive motors, and actively steered by corresponding steering drive devices. Herein, in combination with the driven intermediate axle, the driving force can be distributed to all wheels. Alternatively, the intermediate axle may be provided with undriven and non-steering wheels, which enables a low-cost structure of the intermediate axle.

[0035] According to an advantageous embodiment of the present invention, the wheel units of the front axle and / or the rear axle are each configured as double wheels, which have two wheels arranged at intervals. If the wheel unit is passively steered, such double wheels can be used to reduce the torque for steering the wheel unit. In addition, an intermediate space is formed between the two wheels of the double wheel, and this intermediate space can be used to mount additional components, such as sensors, actuators or connecting elements.

[0036] According to an advantageous embodiment of the present invention, the front axle and / or the rear axle have wheel units arranged centrally in the vehicle transverse direction of the transport vehicle.

[0037] Alternatively, the front axle and / or the rear axle may be configured as swing axles having two wheel units, in particular swing axles having two passively steerable wheel units.

[0038] According to an advantageous embodiment of the invention, the wheels of the intermediate axle are configured as drive wheels, which are each driven by a drive unit, in particular an electric drive unit, wherein the wheel carrier is configured as the housing of the drive unit. The speeds of the two drive wheels are preferably controllable or adjustable in terms of rotational speed independently of one another. Thus, by means of the different rotational speeds and / or rotational directions of the two drive wheels of the intermediate axle, a change in the driving direction and thus steering can be forced. In addition, the transport vehicle can thereby be rotated about its central point in place.

[0039] As long as the wheel units of the front axle and / or the rear axle are configured as driven and actively steerable wheel units, according to an advantageous configuration of the invention, the wheels of the intermediate axle can be configured as non-driven wheels.

[0040] The transport vehicle according to the invention has a series of advantages.

[0041] The chassis and the load-bearing frame are space-saving and low-cost and enable a space-saving and low-cost implementation of the transport vehicle.

[0042] A statically determined load distribution is achieved by hingedly attaching a first cantilever with an intermediate axle and a front axle to the load-bearing frame and hingedly attaching a second cantilever with a rear axle to the intermediate axle or the first cantilever and connecting the second cantilever to the load-bearing frame by means of a coupling element. The load-bearing frame, which is resistant to bending and torsion, receives the payload as well as the cover and components of the driverless transport vehicle, such as the battery, the lifting motor of the lifting device of the load receiving platform, the electronic control device for controlling the two drive wheels and for controlling the lifting motor, and sensors, such as sensors for monitoring the environment and / or for navigating the driverless transport vehicle. The load-bearing frame is connected to the two cantilevers and thus to the chassis via the hinge axis and the hinged coupling element, such that the reaction forces to the gravity as well as to the driving and braking forces are advantageously distributed over the three axles of the chassis. By selecting the spacing of the hinge axis relative to the axle, an optimized load distribution can be constructed on the chassis, from which a high tipping stability in the vehicle travel direction, a high tipping stability in the vehicle transverse direction and thus a favorable load of the three axles and wheels transverse to the travel direction, a favorable ground pressure and sufficient traction for driving and braking at the drive wheels result.

[0043] In summary, a compact and flexible driverless transport vehicle with a chassis having three axles is achieved, wherein in each loading state, when driving over a roadway with significant roadway unevenness and when driving over a ramp, the inertial forces on the three axles of the chassis are always limited.

[0044] The load distribution that is always defined on the three axes of the chassis and is achieved by means of the chassis according to the invention enables the wheels, axles, brakes, and wheel supports to be dimensioned precisely according to the load, without having to take into account the additional effect of uncertainties in the load distribution. As a result, a space-saving and cost-effective embodiment of the chassis can be achieved.

[0045] An optimized compromise is determined between manufacturing costs, wear, roadway loading, traction, and rollover safety and is implemented structurally in the chassis. In the case of a correspondingly designed chassis, even if the drive wheels are brought to a standstill in an emergency, the maximum braking deceleration can be limited, which would otherwise be significantly greater than the design value in the case of light to medium loads and could lead to instability of the received load or the transport vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The further advantages and details of the invention are explained in detail by means of the embodiments shown in the schematic drawings. Shown here are:

[0047] Figure 1 A perspective view of an autonomous transport vehicle according to the invention;

[0048] Figure 2 Figure 1 of a transport vehicle with a raised load receiving platform;

[0049] Figure 3 without a covering member Figure 1 and 2 of a transport vehicle;

[0050] Figure 4 A perspective view of the load-bearing frame and chassis of a transport vehicle according to the invention;

[0051] Figure 5 Another perspective view of the load-bearing frame and chassis of a transport vehicle according to the invention;

[0052] Figure 6 An exploded view of the load-bearing frame and chassis of a transport vehicle according to the invention;

[0053] Figure 7 A view of the load-bearing frame and chassis of a transport vehicle according to the invention on a flat road;

[0054] Figure 8 A view of the load-bearing frame and chassis of a transport vehicle according to the invention on a road with a depression; and

[0055] Figure 9 A view of the load-bearing frame and chassis of a transport vehicle according to the invention on a road with a protrusion. DETAILED DESCRIPTION OF THE INVENTION

[0056] exist Figures 1 to 3 1 shows an unmanned, in particular autonomous, transport vehicle 1 according to the invention. The transport vehicle 1 is designed for horizontal transport of a load carrier (not shown in detail), such as a pallet or a flatbed truck.

[0057] The transport vehicle 1 has a movable chassis 2 provided with a carrying frame 3 and a chassis 4, and has a load receiving platform 5 arranged above the chassis 2 for receiving a cargo carrier.

[0058] The undercarriage 2 has covering members 6 arranged on the supporting frame 3 , under which covering members the supporting frame 3 and the chassis 4 are arranged. Figure 1 and 2 A transport vehicle 1 is shown with a covering member 6. Figure 3 The covering member 6 is not shown.

[0059] In the embodiment shown, the load receiving platform 5 is arranged on the supporting frame 3 in a manner that it can be raised and lowered in the vertical direction. Figure 2 and 3 The lifting device 7 shown in FIG. 1 is connected to the load receiving platform 5 .

[0060] The load-bearing frame 3 and the chassis 4 are arranged in the vertical direction below the load receiving platform 5. The transport vehicle 1 is thus designed as a flat and compact self-propelled transport vehicle, which enables it to travel under the cargo carrier to be transported and to lift the cargo carrier using the load receiving platform 5 in order to transport the cargo carrier horizontally and to put it down again. The transport vehicle 1 is automatically or autonomously navigated and controlled, alternatively the operation of the transport vehicle 1 can also be remotely controlled.

[0061] The chassis 4 of the transport vehicle 1 according to the invention consists of three axles and is composed of an intermediate axle 10 with two non-steering wheels 10a, 10b, a front axle 11 with at least one steerable wheel unit 11a and a rear axle 12 with at least one steerable wheel unit 12a.

[0062] Next, with the help of Figures 4 to 6 The structures of the supporting frame 3 and the chassis 4 are described in detail.

[0063] The intermediate axle 10 and the front axle 11 of the chassis 4 are arranged on a first cantilever 15, which is connected to the supporting frame 3 in an articulated manner by means of a first articulation axis G1. The first articulation axis G1 has a horizontal pivot axis S1 extending in the vehicle transverse direction Q. The first cantilever 15 is designed as a bending-proof and torsion-proof cantilever. The first cantilever 15 extends forward in the vehicle longitudinal direction L.

[0064] The rear axle 12 of the chassis 4 is arranged on the second cantilever 16. The second cantilever 16 is articulated to the intermediate axle 10 or the first cantilever 15 by means of a second articulation axis G2. The second articulation axis G2 has a horizontal swivel axis S2 extending in the vehicle transverse direction Q. The second cantilever 16 is articulated to the load-bearing frame 3 by means of a coupling element 20. The second cantilever 16 is configured as a cantilever that is resistant to bending and torsion. The second cantilever 16 extends rearward in the vehicle longitudinal direction L.

[0065] As can be seen in Figures 4 to 6 the first articulation axis G1 is arranged between the intermediate axle 10 and the front axle 11 in the vehicle longitudinal direction L.

[0066] In the illustrated embodiment, as can be seen in Figures 4 to 6 the second articulation axis G2 is arranged coaxially with the rotational axes D of the two wheels 10a, 10b of the intermediate axle 11, such that the second cantilever 6 is arranged so as to be pivotable about the rotational axis D of the intermediate axle 10.

[0067] As can be seen in Figures 4 to 6 the coupling element 20 is arranged between the intermediate axle 10 and the rear axle 12 in the vehicle longitudinal direction L.

[0068] Thus, the load-bearing frame 3 is connected to the chassis 4, firstly by means of the fixed first cantilever 15 via a first articulation connection G1, and secondly by means of the pivotable second cantilever 16 via a coupling element 20.

[0069] As is shown in detail in Figures 4 to 6 in the illustrated embodiment, the two wheels 10a, 10b of the intermediate axle 10 are each supported in wheel carriers 30a, 30b so as to be rotatable about the rotational axis D. The wheel carriers 30a, 30b are rigidly and thus fixedly fastened to the first cantilever 15. For this purpose, a first fastening flange 31a is also constructed on the first cantilever 15, on which the first wheel carrier 30a can be fastened, for example, by means of fastening screws 32. For this purpose, a second fastening flange 31b is constructed on the first cantilever 15, on which the second wheel carrier 30b can be fastened, for example, by means of fastening screws not shown in detail. In the illustrated embodiment, the second fastening flange 31b is integrally constructed on the first cantilever 15. In the illustrated embodiment, the first fastening flange 31a is constructed on a flange plate 33, which is fastened to the cantilever 15, for example, by means of fastening screws 34.

[0070] In the illustrated embodiment, the second articulation axis G2 is constituted by two bearing rings 40a, 40b fastened to the second cantilever 16. The bearing ring 40a is rotatably supported on the toroidal surface 41a of the wheel carrier 30a. Correspondingly, the bearing ring 40b is rotatably supported on the toroidal surface 41b of the wheel carrier 30b. The toroidal surfaces 41a, 41b are arranged concentrically with respect to the rotational axis D of the wheels 10a, 10b. Thus, the second cantilever 16 is supported so as to be rotatable or pivotable about the intermediate axis 10 of the chassis 4.

[0071] Sliding bearings (not shown in detail), for example plastic sliding bearings, may be arranged between the toroidal surfaces 41a, 41b of the wheel carriers 30a, 30b and the corresponding bearing rings 40a, 40b.

[0072] In the illustrated embodiment, the first articulation axis G1 comprises two articulated connection portions G1a, G1b which are arranged spaced apart from each other in the vehicle transverse direction Q. The two articulated connection portions G1a, G1b are each configured as bolted connection portions. The articulated connection portion G1a is constituted by a receiving hole 25a in the side plate 26a of the first cantilever 15 and a receiving hole in the flange plate 27a of the load-bearing frame 3, in which a bolt 28 of the bolted connection portion is arranged. The receiving hole 25a for the bolt 28 in the side plate 26a of the cantilever 15 is constituted in the illustrated embodiment by a semi-circular groove in the side plate 26a and a half-shell 29a fastened to the side plate 26a, which half-shell is provided with a second semi-circular groove. The articulated connection portion G1b is constituted by a receiving hole 25b in the side plate 26b of the first cantilever 15 and a receiving hole in the flange plate 27b of the load-bearing frame 3, in which a bolt 28 of the bolted connection portion is arranged. The receiving hole 25b for the bolt 28 in the side plate 26b of the cantilever 15 is constituted in the illustrated embodiment by a semi-circular groove in the side plate 26b and a half-shell 29b fastened to the side plate 26b, which half-shell is provided with a second semi-circular groove. In the illustrated case, a common bolt 28 is provided for the two articulated connection portions G1a, G1b.

[0073] The bolt 28 may be configured as a load cell bolt.

[0074] The two articulated connection portions G1a, G1b which constitute the first articulation axis G1 and are arranged spaced apart from each other in the vehicle transverse direction Q enable the transmission of forces and the transmission of torque about the vehicle longitudinal axis L between the load-bearing frame 3 and the first cantilever 15.

[0075] The coupling element 20 has at least one tension-compression rod 50 and is provided with two hinge parts. For this purpose, the coupling element 20 is articulated to the second cantilever 16 by means of a third hinge axis G3, which has a horizontal swivel axis S3 extending in the vehicle transverse direction Q, and the coupling element is articulated to the load-bearing frame 3 by means of a fourth hinge axis G4, which has a horizontal swivel axis S4 extending in the vehicle transverse direction Q.

[0076] The third hinge axis G3 and the fourth hinge axis G4 are each configured as hinge connections, and the hinge connections are configured as bolt connections. The hinge connection forming the third swivel axis G3 consists of a receiving hole 51 of the second cantilever 16 and a receiving hole 52 of the tension-compression rod 50, and a bolt 53 of the bolt connection is arranged in these receiving holes. The hinge connection forming the fourth hinge axis G4 consists of a receiving hole 55 of the load-bearing frame 3 and a receiving hole 56 of the tension-compression rod 50, and a bolt 57 of the bolt connection is arranged in these receiving holes.

[0077] The bolt 53 and / or the bolt 57 can be configured as a force-measuring bolt.

[0078] Therefore, the coupling element 20 configured as a tension-compression rod 50 and coupled to the second cantilever 16 and the load-bearing frame 3 by two hinge axes G3, G4 only transmits forces in the direction between the load-bearing frame 3 and the second cantilever 16, that is, in the longitudinal direction of the coupling element 20.

[0079] In the illustrated embodiment, the load-bearing frame 3 has a longitudinal carrier 3a extending in the vehicle longitudinal direction L, on which a first hinge axis G1 is arranged and the coupling element 20 is articulated to the longitudinal carrier at the fourth hinge axis G4. The longitudinal carrier 3a is configured as a longitudinally and torsionally resistant longitudinal carrier.

[0080] The longitudinal carrier 3a of the load-bearing frame 3 is arranged centrally in the vehicle transverse direction Q. An intermediate space is formed between two fastening flanges 31a, 31b, which are arranged on the first cantilever 15 and to which the wheel carriers 30a, 30b are fastened, and the longitudinal carrier 3 can be arranged or immersed in this intermediate space. Therefore, the longitudinal carrier 3a utilizes the space between the two wheel carriers 30a, 30b. This enables a flat structural design of the transport vehicle.

[0081] The longitudinal carrier 3a and thus the load-bearing frame 3 are widened respectively in the region of the front axle 12 and in the region of the rear axle 13a and are provided with lifting devices 7 in the widened end regions, so that the load received by the load receiving platform 5 is received by the widened end regions of the load-bearing frame 3.

[0082] In the illustrated embodiment, the load-bearing frame 3 is provided with support elements 60, 61, 62, 63 in the form of pedestals in the regions of the four outer corners of the transport vehicle 1, which support elements have a small spacing relative to the roadway during normal driving operation and come into contact with the roadway when the transport vehicle 1 tips over.

[0083] In the illustrated embodiment, the two wheels 10a, 10b of the intermediate axle 10 are each configured as drive wheels, which are each driven by a drive unit, for example an electric drive unit. Accordingly, the intermediate axle 10 is configured as a drive axle having two drive units, which drive units are fixedly connected to the first cantilever 15. Here, the drive units can each consist of a traction electric motor, which directly or with a transmission interposed therebetween drives the respective wheels 10a, 10b. The two drive units are controllable or adjustable independently of one another with respect to rotational speed and direction of rotation, such that the transport vehicle 1 can be steered and can be rotated in place by different rotational speeds at the two wheels 10a, 10b and different directions of rotation of the wheels 10a, 10b. Here, the wheel carriers 30a, 30b are configured as the housings of the drive units.

[0084] In the illustrated embodiment, the wheel unit 11a of the front axle 11 is configured as a non-driven and passively steerable wheel unit 11a. The wheel unit 11a is supported on the front end of the first cantilever 15 in a rotatable manner about a vertical axis V1 by means of respective bearings. The wheel unit 11a has a caster and is passively steered by this caster.

[0085] The wheel unit 11a of the front axle 11 is arranged centrally in the vehicle transverse direction Q.

[0086] The wheel unit 11a of the front axle 11 is configured as a double wheel, which has two wheels 70, 71 arranged laterally spaced apart from one another.

[0087] For this purpose, the two wheels 70, 71 are supported in a rotatable manner about a common horizontal axis of rotation D10 in a swivel plate 72, which swivel plate is supported in a rotatable manner about a vertical axis V1 in the first cantilever 15. Here, the horizontal axis of rotation D10 is spaced apart from the vertical axis V1 in the horizontal direction, wherein this spacing constitutes the caster for the passive steering of the wheel unit 11a.

[0088] In the illustrated embodiment, the wheel unit 12a of the rear axle 12 is configured as a non-driven and passively steerable wheel unit 12a. The wheel unit 12a is supported on the rear end of the second cantilever 16 in a rotatable manner about a vertical axis V2 by means of respective bearings. The wheel unit 12a has a caster and is passively steered by this caster.

[0089] The wheel unit 12a of the rear axle 12 is arranged centrally in the vehicle transverse direction Q.

[0090] The wheel unit 12a of the rear axle 12 is configured as a double wheel having two wheels 75, 76 arranged laterally spaced apart from each other.

[0091] For this purpose, the two wheels 75, 76 are rotatably supported in a turntable 77 about a common horizontal rotation axis D11, and the turntable is rotatably supported in the second cantilever 16 about a vertical axis V2. Here, the horizontal rotation axis D11 is spaced apart from the vertical axis V2 in the horizontal direction, and this spacing constitutes the caster angle for the passive steering of the wheel unit 12a.

[0092] Thus, in the illustrated embodiment, the intermediate axle 10 of the chassis 4 is configured as a driven axle, which consists of two drive units fixedly connected to the first cantilever 15 that is resistant to bending and torsion. The first cantilever 15 carries the non-driven front axle 11 of the chassis 4, and the non-driven front axle includes a passively steerable wheel unit 11a. The second cantilever 16 that is resistant to bending and torsion carries the non-driven rear axle 12 of the chassis 4, and the non-driven rear axle includes a passively steerable wheel unit 12a. The second cantilever 16 is rotatable or pivotable about the rotation axis D (articulation axis G2) of the wheels 10a, 10b of the intermediate axle 10. The articulation axis G2 is simply and inexpensively manufactured by bearing rings 40a, 40b arranged on the second cantilever 16, and these bearing rings run on toroidal surfaces 41a, 41b manufactured on the housings of the drive units 30a, 30b. The carrier frame 3 is connected to the chassis 4, first connected by a fixed first cantilever 15 through a first articulated connection G1, which is composed of two articulated connections G1a, G1b arranged spaced apart from each other in the vehicle transverse direction Q, and second connected by a coupling element 20 having two articulations (articulation axes G3, G4) with the second cantilever 16 pivotable about the intermediate axle 10.

[0093] A covering member 6 is fastened to the carrier frame 3. In addition, other components of the driverless transport vehicle 1 not shown in detail are fastened to the carrier frame 3, such as a battery, a lifting motor of the lifting device 7, an electric drive unit for controlling the two wheels 10a, 10b, an electronic control device for controlling the lifting motor, and sensors, such as sensors for monitoring the environment and / or for navigating the driverless transport vehicle.

[0094] In Figure 7 FIG. shows the carrier frame 3 and the chassis 4 of the transport vehicle 1 according to the invention on a flat driving lane FB. The wheels 10a, 10b of the intermediate axle 10, the wheel unit 11a of the front axle 11, and the wheel unit 12a of the rear axle 12 are in contact with the ground.

[0095] Figure 8Shows the load-bearing frame 3 and the chassis 4 of the transport vehicle 1 according to the invention when driving through a depression in the driving lane FB, wherein the intermediate axle 10 is located in the depression of the driving lane FB. The wheels 10a, 10b of the intermediate axle 10, the wheel units 11a of the front axle 11 and the wheel units 12a of the rear axle 12 are in contact with the ground. Relative to Figure 7 , the first cantilever 15 swings clockwise about the first articulation axis G1, such that the intermediate axle 10 swings downward and the front axle 11 swings upward. By the downward swinging movement of the intermediate axle 10, the second cantilever 16 coupled to the intermediate axle 10 about the second articulation axis G2 swings counterclockwise, and this second cantilever is articulatedly coupled to the load-bearing frame 3 by means of a coupling element 20 having two articulation parts (articulation axes G3, G4), such that the rear axle 12 swings upward. Here, the coupling element 20 can achieve the length compensation required when the second cantilever 16 swings.

[0096] Figure 9 Shows the load-bearing frame 3 and the chassis 4 of the transport vehicle 1 according to the invention when driving over a protrusion on the driving lane FB, wherein the intermediate axle 10 is located on the protrusion of the driving lane FB. The wheels 10a, 10b of the intermediate axle 10, the wheel units 11a of the front axle 11 and the wheel units 12a of the rear axle 12 are in contact with the ground. Relative to Figure 7 , the first cantilever 15 swings counterclockwise about the first articulation axis G1, such that the intermediate axle 10 swings upward and the front axle 11 swings downward. By the upward swinging movement of the intermediate axle 10, the second cantilever 16 coupled to the intermediate axle 10 about the second articulation axis G2 swings clockwise, and this second cantilever is articulatedly coupled to the load-bearing frame 3 by means of a coupling element 20 having two articulation parts (articulation axes G3, G4), such that the rear axle 12 swings downward. Here, the coupling element 20 can achieve the length compensation required when the second cantilever 16 swings.

Claims

1. An unmanned transport vehicle (1), the unmanned transport vehicle having a load-bearing frame (3), a chassis (4) and a load receiving platform (5) for receiving a goods carrier, wherein, The load receiving platform (5) is arranged on the carrier frame (3), and the carrier frame (3) and the chassis (4) are arranged vertically below the load receiving platform (5), wherein the chassis (4) has an intermediate axle (10) with two non-steering wheels (10a, 10b), a front axle (11) with at least one steering wheel unit (11a), and a rear axle (12) with at least one steering wheel unit (12a), characterized in that the intermediate axle (10) and the front axle (11) of the chassis (4) are arranged on a first cantilever (15), the first cantilever is articulated to the carrier frame (3) by means of a first articulation axis (G1), the first articulation axis has a horizontal swivel axis (S1) extending in the vehicle transverse direction (Q), and the rear axle (12) of the chassis (4) is arranged on a second cantilever (16), the second cantilever is articulated to the intermediate axle (10) or to the first cantilever (15) by means of a second articulation axis (G2), the second articulation axis has a horizontal swivel axis (S2) extending in the vehicle transverse direction (Q), wherein the second cantilever (16) is connected to the carrier frame (3) by means of a coupling element (20), the coupling element is articulated to the second cantilever (16) and to the carrier frame (3), wherein the wheels (10a, 10b) of the intermediate axle (10) are each rotatably supported about a rotation axis (D) in or on wheel carriers (30a, 30b), wherein the wheel carriers (30a, 30b) are fastened to the first cantilever (15), wherein the second articulation axis (G2) includes at least one bearing ring (40a; 40b) arranged on the second cantilever (16), the bearing ring is rotatably supported on the toroidal surface (41a; 41b) of the wheel carrier (30a; 30b), and wherein a sliding bearing is arranged between the toroidal surface (41a; 41b) of the wheel carrier (30a; 30b) and the bearing ring (40a; 40b).

2. The driverless transport vehicle according to claim 1, characterized in that, The first articulation axis (G1) is arranged in the vehicle longitudinal direction (L) between the intermediate axle (10) and the front axle (11).

3. The driverless transport vehicle according to claim 1 or 2, characterized in that The second articulation axis (G2) is arranged coaxially with the rotation axis (D) of the wheels (10a, 10b) of the intermediate axle (10).

4. The driverless transport vehicle according to claim 1 or 2, characterized in that The coupling element (20) is arranged in the vehicle longitudinal direction (L) between the intermediate axle (10) and the rear axle (12).

5. The driverless transport vehicle according to claim 1 or 2, characterized in that, The first articulation axis (G1) includes two articulation connections (G1a, G1b), the two articulation connections are arranged spaced apart from each other in the vehicle transverse direction (Q).

6. The driverless transport vehicle according to claim 5, wherein The articulation connections (G1a, G1b) are each configured as bolted connections.

7. The driverless transport vehicle according to claim 1 or 2, characterized in that, The coupling element (20) has at least one tension-compression rod (50), which is articulated to the second cantilever (16) by means of a third articulation axis (G3) having a horizontal swivel axis (S3) extending in the vehicle transverse direction (Q), and which is articulated to the load-bearing frame (3) by means of a fourth articulation axis (G4) having a horizontal swivel axis (S4) extending in the vehicle transverse direction (Q).

8. The driverless transport vehicle according to claim 7, wherein The third articulation axis (G3) and the fourth articulation axis (G4) are each configured as an articulation connection, which is configured as a bolt connection.

9. The driverless transport vehicle according to claim 1 or 2, characterized in that The load-bearing frame (3) has a longitudinal carrier (3a) extending in the vehicle longitudinal direction (L), on which the first articulation axis (G1) is arranged, and the coupling element (20) is articulated to the longitudinal carrier.

10. The driverless transport vehicle according to claim 9, wherein The longitudinal carrier (3a) is arranged centrally in the vehicle transverse direction (Q).

11. The driverless transport vehicle according to claim 9, wherein, The longitudinal carrier (3a) is widened in the region of the front axle (11) and in the region of the rear axle (12).

12. The driverless transport vehicle according to claim 1 or 2, characterized in that, The load-bearing frame (3) is provided with support elements (60, 61, 62, 63) in the regions of the four outer corners of the transport vehicle (1), and the support elements are arranged for supporting the transport vehicle (1) on the driving lane surface (FB).

13. The driverless transport vehicle according to claim 1 or 2, characterized in that, The load receiving platform (5) is constituted by the load-bearing frame (3).

14. The driverless transport vehicle according to claim 1 or 2, characterized in that, The load receiving platform (5) is fixedly fastened to the load-bearing frame (3).

15. The driverless transport vehicle according to claim 1 or 2, characterized in that, The load receiving platform (5) is arranged on the load-bearing frame (3) by means of a lifting device (7) so as to be liftable and lowerable in the vertical direction.

16. The driverless transport vehicle according to claim 1 or 2, characterized in that, The wheel units (11a, 12a) of the front axle (11) and / or the rear axle (12) are each configured as undriven and passively steerable wheel units.

17. The driverless transport vehicle according to claim 1 or 2, characterized in that, The wheel units (11a, 12a) of the front axle (11) and / or the rear axle (12) are each configured as undriven and actively steerable wheel units.

18. The driverless transport vehicle according to claim 1 or 2, characterized in that, The wheel units (11a, 12a) of the front axle (11) and / or the rear axle (12) are each configured as driven and actively steerable wheel units.

19. The driverless transport vehicle according to claim 1 or 2, characterized in that, The wheel units (11a; 12a) of the front axle (11) and / or the rear axle (12) are each configured as dual wheels having two wheels (70, 71; 75, 76) arranged at a distance from each other.

20. The driverless transport vehicle according to claim 1 or 2, characterized in that, The front axle (11) and / or the rear axle (12) has wheel units (11a, 12a) arranged centrally in the vehicle transverse direction (Q).

21. The driverless transport vehicle according to claim 1 or 2, characterized in that, The front axle (11) and / or the rear axle (12) is configured as a swing axle having two wheel units.

22. The driverless transport vehicle according to claim 1 or 2, characterized in that, The wheels (10a, 10b) of the intermediate axle (10) are configured as drive wheels, which are each driven by a drive unit, wherein the wheel carriers (30a, 30b) are configured as the housings of the drive units.

23. The driverless transport vehicle according to claim 1 or 2, characterized in that, The wheels (10a, 10b) of the intermediate axle (10) are configured as undriven wheels.

24. The driverless transport vehicle according to claim 1, wherein The driverless transport vehicle (1) is used for transporting a cargo carrier.

25. The driverless transport vehicle according to claim 22, wherein The drive unit is an electric drive unit.

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