INDUSTRIAL TRUCK WITH LOAD WHEEL UNIT

Description

[0001] The invention relates to an industrial truck with at least one load roller unit, which is formed at a free end of a wheel arm of the industrial truck, comprising at least one non-driven load roller, which is arranged to be rotatable about a substantially horizontally extending roller axis, and an adjustment assembly, which on the one hand carries the roller axis and which on the other hand is designed to adjust the position of the roller axis in the vertical direction relative to a bearing element.

[0002] Such load roller units are known from the prior art. They make it possible, in particular, to compensate for manufacturing tolerances in over-determined chassis of industrial trucks, which may result, for example, from welding distortion or the like.

[0003] For example, load roller units are known in which the adjustment assembly comprises an eccentric element which is rotatably mounted on the bearing element and on which the roller axis is arranged off-center. By rotating the eccentric element, the position of the roller axis in the vertical direction relative to the bearing element can be adjusted. However, the disadvantage of this is that the width of the load roller and thus its load-bearing capacity is reduced by the additional eccentric element. And secondly, when rotating the eccentric element in the course of adjusting the height of at least one load roller, the horizontal position of the roller axis and thus the wheelbase of the industrial truck is also changed, which is particularly important for driverless industrial trucks, also known as AGVs ( a automated g guided v ehicles), can cause problems with odometric navigation.

[0004] In this context, roller units designed for use on the vehicle bodies of industrial trucks are known, for example, from EP 0 214 387 A1, EP 3 222 491 A1, US 2009 / 205 164 A1, and EP 2 165 893 A2. Reference is also made to GB 958 184 A and US2018 / 251145A1, which also disclose roller arrangements for other applications. Document US2018 / 251145A1 discloses an industrial truck according to the preamble of claim 1.

[0005] It is therefore an object of the present invention to provide an industrial truck with a load roller unit of the type mentioned above with improved properties.

[0006] This object is achieved by an industrial truck of the type mentioned above with at least one load roller unit, in which the adjustment assembly comprises a substantially horizontally extending swing element which carries the roller axis and is pivotable on the bearing element about a substantially horizontally extending pivot axis, and in which at least one adjustable stop element is provided on one of the elements, bearing element or swing element, which stop element is intended to limit the pivoting movement of the swing element in cooperation with a stop surface provided on the other element, swing element or bearing element. Since the swing element extends substantially horizontally, the at least one load roller moves substantially only vertically when the swing element is pivoted, so that its horizontal movement is neglected.This allows for safe odometric navigation despite the adjustment options, as the wheelbase of the truck remains virtually unchanged. It is also possible to specifically trim the truck's chassis, for example, aligning the truck frame parallel to the ground.

[0007] Furthermore, it is conceivable to adjust the at least one stop element such that the swing element, starting from a precisely horizontal position, can only be pivoted to larger pivot angles between the swing element and the bearing element. In return, however, two load roller units according to the invention would then have to be provided in order to compensate for both error directions.

[0008] For example, the stop element can be formed by a screw. Both cap screws and threaded stud screws can be used as stop elements. To ensure surface contact between the stop element and the stop surface in every pivoting position, the screw can advantageously be designed as a ball-end thrust screw. Furthermore, the screw can be secured against unintentional twisting or loosening by clamping and / or gluing and / or locking. If the screw is arranged on the bearing element, it can be easily accessible for adjustment through an opening provided in the bearing element.

[0009] The at least one stop element can, for example, be arranged at a position between the pivot axis and the roller axis. In this way, the stop element can prevent the load roller from pivoting too far.

[0010] In addition or alternatively to the at least one stop element, the load roller unit can further comprise at least one spring element between the bearing element and the swing element. As a result of this spring element, the position of the at least one load roller can adjust automatically depending on the load acting on it. For example, such a spring element can absorb dynamic shock loads, such as those that occur when driving over uneven surfaces or thresholds. The at least one spring element can be formed, for example, by a compression spring or an elastic buffer, such as a polyurethane buffer or rubber buffer.

[0011] In order to prevent the load roller from pivoting out too far, a further stop could in principle also be provided, which is arranged on the side of the pivot axis facing away from the roller axis. This further stop can prevent the load roller from folding out downwards in an uncontrolled manner. Preferably, however, the further stop can allow the load roller to fold out downwards at least far enough to allow easy access to its axle bolt. The further stop can also be formed by a stop element. In principle, however, it is also conceivable for it to be formed by a stop surface of the bearing element.

[0012] In order to reduce, if not completely prevent, any impairment of the function of a scanning device whose scanning plane extends directly above the load roller unit, it is further proposed that the swing element be designed to be closed above the at least one load roller. Without such a cover, there would be a risk that dust stirred up by the at least one load roller could be detected as an obstacle by the scanning device's evaluation software, which could even lead to an abrupt emergency stop of the industrial truck.

[0013] In principle, it is conceivable for the bearing element to be formed integrally with the wheel arm of the industrial truck. However, to simplify the installation of the load roller unit on a wheel arm of the industrial truck, it is advantageous if the bearing element is a separate component from the wheel arm. The separate bearing element can be connected to the wheel arm, for example, by screwing or welding.

[0014] The overall height of the load roller unit can, for example, be a maximum of 75 mm. The diameter of at least one load roller can, for example, be a maximum of 75 mm, or a maximum of 70 mm if a dust cover is used. This ensures that the load roller unit can be positioned completely below the scanning area of ​​the scanning device, which can, for example, be located at a height of 75 mm to 125 mm.

[0015] As stated above, the invention relates to an industrial truck with at least one load roller unit designed in this way.

[0016] Advantageously, the industrial truck can be a five-wheeled wheel-arm-supported vehicle. Two load roller units, at least one of which is a load roller unit according to the invention, can be arranged at the front end of the wheel arms. The drive wheel can be arranged centrally in the region of a drive part of the industrial truck. A support roller unit can be located on the right and left sides of the drive part.

[0017] In principle, the industrial truck can also be a four-wheeled wheel-arm-supported vehicle in which the drive wheel is positioned off-center and - compared to the five-wheel concept - replaces one of the support roller units.

[0018] It should also be noted that the orientation terms "horizontal" and "vertical" refer to the truck's normal operating condition, in which it rests on a substantially horizontal, level surface. The same applies to the terms "top," "bottom," and the like.

[0019] The invention will be explained in more detail below with reference to the accompanying drawings, which show: Figure 1 shows a perspective view of an industrial truck according to the invention; Figure 2 shows a perspective view obliquely from above of a first embodiment of the corresponding load roller unit; Figure 3 shows an exploded view of the load roller unit of the Figure 2 ; Figures 4 to 6 are sectional side views of the corresponding load roller unit, where Figure 4 shows a neutral position of the load roller, Figure 5 a swiveled-in position of the load roller and Figure 6a pivoted-out position of the load roller; and Figure 7 shows a sectional side view of a second embodiment of the corresponding load roller unit.

[0020] In Figure 1 An industrial truck according to the invention is generally designated 10. The industrial truck 10 can, for example, be a driverless industrial truck, also known as an AGV ( a automated g guided vehicle). It comprises a frame 12 to which a housing 14 is attached. The housing 14 contains all the components required for the operation of the industrial truck 10, in particular a drive that enables the movement of the industrial truck 10 on a surface U, a drive that enables the lifting and lowering of the lifting forks 16, the batteries required to power the drives, a control unit for controlling the drives, and sensors for detecting the surroundings of the industrial truck 10, and the like. Furthermore, the industrial truck 10 comprises wheel arms 18, which are also connected to the frame 12 of the industrial truck 10.

[0021] At the free ends 18a of the two wheel arms 18, a load roller unit 30 is arranged, the structure of which is described below with reference to the Figures 2 to 6 will be explained in more detail.

[0022] Each of the load roller units 30 comprises at least one non-driven load roller 32, which is arranged to rotate about a substantially horizontally extending roller axis A by means of an axle pin 34. The axle pin 34 is mounted in a swing element 36 extending substantially horizontally, which in turn is pivotally mounted about a substantially horizontally extending pivot axis B on a bearing element 40 via a further axle pin 38. In this way, the swing element 36 and with it the load roller 32 can pivot in the vertical direction H.

[0023] To prevent the swinging element 36 from pivoting upwards too far, an adjustable stop element 42 is provided on the bearing element 40. In the illustrated embodiment, the stop element 42 is arranged between the pivot axis B and the roller axis A. Furthermore, it is formed by a threaded pin, more precisely a ball pressure screw, which is screwed into a threaded bore 40a of the bearing element 40.

[0024] Through the interaction of the stop element 42 with a stop surface 36a provided on the swing element 36, the pivoting movement of the swing element 36 can be limited to a desired extent. Figure 4 for example, a neutral position in which the swing element 36 is arranged substantially horizontally, Figure 5 a slightly swiveled position and Figure 6 a slightly swung-out position.

[0025] In addition or alternatively to the stop element 42, a spring element 44 can also be arranged between the bearing element 40 and the swing element 36, as shown in Figure 3 is indicated schematically. Such a spring element 44 enables the load roller 32 to adapt to the loads acting on it. For example, the spring element 44 can absorb dynamic shock loads, such as those that occur when driving over uneven surfaces or thresholds. The spring element 44 can be formed by a compression spring, an elastic buffer, for example a polyurethane buffer or rubber buffer, or the like. In addition, it can also be integrated into the stop element 42, for example as a spring preloading the ball of the ball pressure screw.

[0026] In order to further prevent the load roller 32 from folding downwards in an uncontrolled manner, a further stop can be provided, which is formed by a further stop element 46 and a stop surface 36b of the swing element 36. This further stop 46 / 36b can be arranged on the side of the pivot axis B facing away from the roller axis A.

[0027] In the illustrated embodiment, the bearing element 40 is designed as a separate component. However, it would also be conceivable to form the bearing element 40 as a single piece with the wheel arm 18.

[0028] In Figure 7 a second embodiment of a load roller unit according to the invention is shown, which essentially corresponds to the embodiment of Figures 2 to 6 Therefore, in Figure 7 analogous parts are provided with the same reference numerals as in the Figures 2 to 6 , but increased by the number 100. In addition, the load roller unit 130 of the Figure 7are described below only insofar as they differ from the load roller unit 30 of the Figures 2 to 6 to whose description express reference is hereby made.

[0029] In the load roller unit 130, the swing element 136 is designed to be closed above the load roller 132. In particular, a section 136c of the swing element 136 forms a dust cover that prevents dust stirred up by the load roller 132 from entering the "visible area" of the scanning devices directly above the load roller unit and impairing their function.

Claims

1. Industrial truck (10), comprising at least one load roller unit (30) at a free end (18a) of a wheel arm (18) of the industrial truck (10), the load roller unit (30) comprising - at least one unpowered load roller (32), which is rotatably arranged around an essentially horizontal roller axis (A), and - an adjustment assembly which on one hand supports the roller axis (A) and on the other hand is designed to adjust the position of the roller axis (A) in the vertical direction (H) relative to a bearing element (40), wherein the bearing element (40) is formed integrally with or connected to the wheel arm (18), wherein the adjustment assembly comprises a substantially horizontally extending swing element (36) supporting the roller axis (A), which is pivotable on the bearing element (40) about a substantially horizontally extending pivot axis (B), characterized in that on one of the elements, bearing element (40) or swing element, at least one adjustable stop element (42) is provided, which is designed to interact with a stop surface (36a) provided on the respective other element, swing element (36) or bearing element, to limit the pivoting movement of the swing element (36).

2. Industrial truck (10) according to claim 1, wherein the stop element (42) is formed by a screw.

3. Industrial truck (10) according to claim 1 or 2, wherein at least one stop element (42) is arranged at a position located between the pivot axis (B) and the roller axis (A).

4. Industrial truck (10) according to any one of claims 1 to 3, wherein at least one spring element (44) is provided between the bearing element (40) and the swing element (36).

5. Industrial truck (10) according to any one of claims 1 to 4, wherein at least one further stop (46 / 36b) is arranged on the side of the pivot axis (B) facing away from the roller axis (A).

6. Industrial truck (10) according to any one of claims 1 to 5, wherein the swing element (136) is formed closed above the at least one load roller (132).

7. Industrial truck (10) according to any one of claims 1 to 6, wherein the bearing element (40) is a component separately formed from the wheel arm (18).