Fork arm and logistics vehicle

Abstract

The invention relates to a fork arm (1) for preferably automated logistics vehicles (2), comprising at least one fork spine (3), a fork knee (4), and a fork blade (5), wherein securing elements (6) are arranged on the fork spine (3) in order to secure to a logistics vehicle (2). The fork blade (5) is designed to form a cavity (9) from a cover layer (10) and a rear layer (11) which are connected together, in particular screwed together, via securing means (12), in particular screws (12a).

Description

[0001] The invention relates to a fork and a logistics vehicle therefor, as described in claims 1 and 11.

[0002] Forks are typically made from solid material, with the fork back, fork knee, and fork blade forged from a single block. Fasteners, particularly eyelets and hooks, are attached to the fork back and are preferably welded to the fork back. Such forks made from solid material have the major disadvantage of being very heavy, requiring a correspondingly large logistics vehicle to prevent tipping.

[0003] US 2008 / 178690 A1 discloses a fork tine consisting of a one-piece L-shaped backing and cover layer, the backing having a recess in the form of a hollow space for accommodating sensors. The cover layer is attached to the backing with a screw connection to protect the sensors. JP S4842458 Y1 discloses a fork tine formed from a U-shaped cover layer and backing. The cover layer and backing are formed as a one-piece, L-shaped structure.

[0004] Furthermore, a fork tine is known from JP S5110548 Y1 in which an L-shaped reinforcing element is inserted into the cavity of the fork blade and the fork back.

[0005] JP S5135873 U discloses the preamble of claim 1. From JP S5135873 U a fork tine is known which is formed from two L-shaped elements.

[0006] Furthermore, EP 0739854 A1 discloses a fork tine in which at least one part of the fork tine, in particular the fork back, the fork knee, or the fork blade, consists of several individual adjacent layers. The multiple layers are welded together to form the shape of the fork tine. A disadvantage of this is that deformation can occur due to the high heat generated during the welding process.

[0007] EP 0 739 854 A1 proposes the creation of a fork tine composed of several layers that can be manufactured cost-effectively, even in very small batch sizes, with low energy consumption and using universal tools in a wide variety of shapes and dimensions. This involves producing easily manufactured discs as parts of the forks, which are immovably connected to one another by fastening elements such as screws, rivets, or pins, or by gluing or welding. Thus, forks manufactured from a large number of individual discs have a similar weight to, for example, forks made from solid material and manufactured by forging.

[0008] Furthermore, DE 102019102846 A1 describes a fork tine, in particular for industrial trucks, which is attached or can be attached to a carrier guided by a lifting device. The load-handling device, which is formed by the fork back and the fork knee, is formed from at least two discs or profiles, each spaced apart from one another, which are connected to the carrier on the one hand and are enclosed by at least regions of a fork blade consisting of at least one longitudinal hollow profile on the other hand, wherein the longitudinal hollow profiles are firmly connected to the discs.

[0009] Furthermore, EP 3659961 A1 discloses a fork, in particular a fork blade, for an industrial vehicle such as a forklift, and a method for its production. The fork comprises an elongated body portion, a fork tip, and a fork end, which are connected, in particular welded, to form the fork, in particular the fork blade. The elongated body portion can be of any length and can have multiple hollow chambers.

[0010] DE 4315891 C1 discloses a fork for forklift trucks that is approximately L-shaped. To produce such a fork, which enables fast, cost-effective, and precise production at low cost in production facilities, it is proposed that the fork blade and fork back consist of profile or bar sections, with a reinforcement welded into the fork blade and a fork tip made of a forged part welded to the end of the fork blade.

[0011] A disadvantage of the previously described state-of-the-art technology is that the production of the fork tine is very complex, and the high heat exposure during welding of the individual parts can lead to distortion, which can lead to the fork tine becoming unusable. A further disadvantage is that the production, especially the welding of the parts, can only be carried out by appropriately trained specialists, especially welders, which drives up production costs.

[0012] The rapidly growing market for automated logistics vehicles, especially self-driving forklifts, is changing the requirements for the very heavy forks that are still common today.

[0013] The object of the invention is therefore to create a fork tine and a logistics vehicle therefor, with which on the one hand the above-mentioned disadvantages are avoided and on the other hand they can be produced in the smallest batch sizes with low energy consumption and maximum possible flexibility in shape and dimensions.

[0014] This object is achieved by the invention according to claim 1.

[0015] The fork tine is characterized in that the fork blade and the fork back are connected to one another, in particular screwed, via fastening means, in particular screws, wherein the fork knee is designed to correspond to the hollow space.

[0016] This is advantageous because it allows for simple and cost-effective production, with the individual elements simply being bolted together, requiring no specialized personnel such as welders. Furthermore, the fork must be as light as possible to optimize the vehicle's energy balance, especially for counterbalanced forklifts, while also creating space for various sensors. The increasing densification of production facilities, in order to optimally utilize available space, requires that the weight above the tipping point be kept as light as possible. This allows for the use of the smallest possible counterbalanced forklift while simultaneously delivering a high payload.

[0017] At the same time, the load capacity of the forks can be influenced by the fasteners or reinforcement elements used, meaning that a higher or lower load capacity can be achieved by using more or fewer fasteners or reinforcement elements. This allows for adaptation to the loads to be lifted, which affects the manufacturing costs and the weight of the fork.

[0018] In addition, a standardized manufacturing process with consistently high quality can be guaranteed, as appropriate torque tools can be used to fasten the screw connection, which tighten each fastener with a defined torque.

[0019] Another key advantage of the modular design is that the cover layer and the backing layer are preferably made of thin-walled, straight sheets formed using a cold-bending process, allowing for easy adjustment of the fork's shape. Customer requests can thus be implemented quickly and easily.

[0020] It is advantageous that the fork knee is designed to correspond to the hollow space and can be inserted over a portion of the hollow space of the fork back and the fork blade. This means that the fork knee can be inserted into the hollow space over a defined length and connected to the cover layer and back layer, forming an L-shaped fork tine for use in logistics vehicles or forklift trucks. This also makes it possible, for example, to easily replace the fork blade at a later date by loosening the fasteners connecting the fork blade to the fork knee, pulling the fork blade off the fork knee, and fitting and screwing on a different fork blade, for example one with a shorter fork length.

[0021] The arrangement of the mounting holes for the fork knee is planned to be standardized. However, the arrangement of the mounting holes for the fork back and the fork blade can be the same or different.

[0022] To enable the fork knee to be attached to the fork blade and / or fork back, the fork knee has holes for the fasteners. These holes are designed correspondingly on the cover and back of the fork blade and fork back, allowing the components to be connected into a single unit. This creates a lightweight, L-shaped fork that can replace the heavy forks of the prior art while maintaining a virtually identical load capacity. As already mentioned, the modular design makes it possible to easily and cost-effectively produce a wide variety of forks for different load capacities.

[0023] According to the invention, the fork back is also formed by a cover layer and a back layer, which are connected, in particular screwed, to each other via fastening means, in particular screws. This in turn creates a hollow space between the two elements, which achieves a significant weight saving with a high load capacity and also leaves sufficient space for electronics, in particular sensors, integrated into the fork tine.

[0024] An advantageous design is one in which the cover layer is made from a U-shaped, folded sheet metal and the backing layer is made from a flat sheet metal. This ensures that a bending process, in particular a cold bending process, only needs to be applied to one part or element, namely the cover layer, to produce the fork tine, thereby saving manufacturing costs and time. It is of course also possible to produce a reversed structure, i.e. a flat cover layer and a U-shaped backing layer. It has proven advantageous in this case that the flat part is not positioned between the folded side parts of the backing layer, but rather rests on the end faces of the side parts.

[0025] A design in which the cover layer and the back layer are formed from a U-shaped folded plate, particularly a steel plate, is also advantageous. It is possible for one of the two U-shaped parts to be designed such that it can be arranged between the folded side parts of the additional element, or for the cover layer and the back layer to be joined via the end edges of the side parts, thus requiring a shorter edge length and increasing rigidity.

[0026] A design in which reinforcement elements are arranged in the hollow space between the cover layer and the backing layer is advantageous. This allows the load-bearing capacity or load capacity of the fork to be increased with little effort and, above all, little increase in weight. Furthermore, the load-bearing capacity can be increased or decreased by changing the distance height or spacing between the cover layer and backing layer or by changing the sheet thickness. This type of construction is made possible by the modular design of the fork. Before the two elements, i.e. the cover layer and the backing layer, are screwed together, the reinforcement elements can first be positioned accordingly, for example, on the backing layer. The cover layer can then be placed over it and screwed in place.

[0027] A design in which the reinforcement elements accommodate the fasteners is advantageous. This ensures that the cavity is only slightly reduced, leaving sufficient space for the sensors and electronics. It also allows for smaller dimensions of the fasteners, especially the screws, since the force acts on the reinforcement elements and no longer on the fasteners, whose sole task is to hold the two parts, especially the top layer and the back layer, in position relative to each other.

[0028] However, a design in which the cover layer of the fork back and fork blade has recesses to accommodate the fasteners, especially the screw head, to create a flat surface is also advantageous. This ensures that no obstructive fasteners protrude above the surface of the cover layer, so that when positioning the fork tine, it can be easily inserted into a load carrier or pallet, especially a Euro pallet. This prevents the cover layer from getting caught when picking up the load or pallet, as the surface is flat.

[0029] A design that provides additional holes for attaching additional accessories is advantageous. This makes it possible, for example, to have some or all of the holes threaded so that appropriate accessories, such as eyelets or rings with a threaded element, can be screwed in. This also makes it easy to attach the fork to a logistics vehicle.

[0030] A design in which the fork knee has a joint for folding up the fork blade is advantageous, with the joint preferably being hydraulically or electrically controlled. This makes it possible to fold up the fork blade when the fork is not needed, thus enabling space-saving movement of a logistics vehicle.

[0031] A design in which sensors, cables, and electronic control units are located in the hollow space of the fork blade and fork back, which can be connected to a logistics vehicle via a connector on the fork back, is advantageous. This allows the fork to be adapted, equipped, and expanded to meet current requirements, particularly the specifications of Industry 4.0. Subsequent expansion is also possible, as only certain parts require mechanical reworking or replacement.

[0032] Furthermore, the object of the invention is achieved by a logistics vehicle, in particular a self-propelled logistics vehicle, comprising at least one base vehicle with a lifting device for transporting loads, preferably onto a load carrier or a pallet, in particular a Euro pallet, in which a fork tine according to one of claims 1 to 10 is attached to the lifting device.

[0033] The invention is explained in more detail with reference to the embodiments shown in the drawings, whereby the invention is not limited to these embodiments.

[0034] They show: Fig. 1 is a schematic representation of a fork tine for logistics vehicles or forklift trucks, in a simplified, schematic representation; Fig. 2 is a side view of the fork tine, in a simplified, schematic representation; Fig. 3 is a sectional representation of the fork tine, in a simplified, schematic representation; Fig. 4 is a sectional representation through the fork blade, in a simplified, schematic representation; Fig. 5 is another embodiment of the design of the fork tine, in section and in a simplified, schematic representation; Fig. 6 is another embodiment of the design of the fork tine, in section and in a simplified, schematic representation; Fig. 7 is an embodiment of a logistics vehicle with a fork tine mounted thereon, in a simplified, schematic representation.

[0035] By way of introduction, it should be noted that in the various embodiments, identical parts are provided with identical reference symbols or component designations, whereby the disclosures contained in the entire description can be applied mutatis mutandis to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the described figure and, if the position changes, is to be applied mutatis mutandis to the new position. Individual features or combinations of features from the illustrated and described embodiments can also represent independent inventive solutions in their own right.

[0036] In the Fig. 1 to 7 a fork 1 and an application example on a logistics vehicle 2 are shown.

[0037] Such forks 1 typically have an L-shaped configuration and are divided into three different sections, namely a fork back 3, a fork knee 4, and a fork blade 5. The fork back 3 serves for attachment to logistics vehicles or forklifts, so that corresponding fastening elements 6 are provided. A load 7 to be transported, which is preferably positioned on a pallet 8, in particular a Euro pallet 8, is picked up on the fork blade and then transported by the logistics vehicle 2 or forklift to a defined storage location.

[0038] It is therefore essential that such forks 1 have an optimal ratio between dead weight and load capacity in order to be able to use a smaller-sized logistics vehicle 2 on the one hand, and to be able to transport a higher load 7 on the other. This results in a smaller space requirement, in particular a smaller turning circle, and improved energy efficiency.

[0039] According to the invention, at least the fork blade 5 is of modular construction, wherein the fork blade 5 is formed from a cover layer 10 and a back layer 11 to form a cavity 9, which are connected, in particular screwed, to one another via fastening means 12, in particular screws 12a. According to the invention, to further reduce weight, the fork back 3 is also of modular construction, consisting of a cover layer 10 and a back layer, which are connected or screwed to one another via fastening means 12, in particular screws 12a.

[0040] The fork back 3 and the fork blade 5 are made of thin-walled, straight sheets, preferably formed using a cold-bending process. One or more reinforcing elements 13, in particular metal spacers, which may also be made of a metal alloy, are arranged in the vertical fork blade 5 and the horizontal fork back. The reinforcing elements preferably have bores through which the fastening means 12, in particular screws 12a, extend.

[0041] This creates a hollow space 9 in the fork blade 5 and the fork back 3, which significantly contributes to the weight savings of the fork tine 1 and provides space for electronics and / or sensors 14 and cabling. This optimally utilizes the stress distribution with tension and compression zones and the neutral axis in the fork tine 1. The compact fork knee 4 also further improves the ratio of deflection to occurring stresses. The compact fork knee 4 is preferably manufactured from high-strength tempered cast iron, including subsequent mechanical processing, or cut from a rolled steel part, including subsequent mechanical processing. A plasma, laser, or waterjet process can be used as the cutting process.Alternatively, it can also be manufactured using previously known and conventional manufacturing methods and then connected to the fork back and fork blade via fastening means 12, in particular a screw connection. This means that the individual sheets, i.e. the cover layer 10 and the back layer 11, for the fork blade 5 and the fork back 3, are connected to the fork knee 4 via the fastening means 12, for which purpose corresponding bores are previously drilled in the fork knee 4. However, a manufacturing method is also possible in which the cover layers 10 and back layers 11 are first lightly screwed together using the reinforcing elements and then the fork knee is inserted into the cavity 9 and screwed to the fastening means 12, after which all fastening means 12 are screwed tight with a specified torque.

[0042] Preferably, the reinforcing elements 13, in particular the bore arranged therein, are provided with a thread, so that the fastening means 12, in particular the screws 12a, are screwed directly to the reinforcing elements 13, as can be seen from Fig. 3is visible. This makes it easy for, for example, the reinforcing elements 13 to be connected to the reserve layer 11 via the fastening means 12, after which only the cover layer 10 then needs to be placed on top and screwed to the reinforcing elements 13 via fastening means 12. For this purpose, the cover layer 10 and the reserve layer have so-called countersunk holes into which the head, in particular the screw head, of the fastening means 12 is received, so that no interfering parts protrude above the surface of the cover layer 10 or reserve layer 11. It is also possible for the holes in the fork knee 4 to be provided with threads corresponding to the fastening means 12, so that the cover layer 10 and the reserve layer 11 are fastened independently of one another directly to the fork knee 4.

[0043] When dimensioning the fork tine 1, it is possible that the fork knee 4, the fork blade 5 and the fork back 3 can be designed for the respective locally occurring maximum stress amplitude and thus allow different sheet materials and material thicknesses to be used that are optimized for the respective load-bearing capacity, without taking the weldability of the materials into account, ie that the cover layer 10 and the back layer 11 as well as the fork knee 4 are formed from different materials, whereby a material composition can be used that does not have to be weldable, since the fork tine 1 is constructed completely without welded joints.

[0044] It is advantageous if, in applications subject to wear, the fork blade 5, in particular the cover layer 10 of the fork blade 5, is made of wear-resistant sheet metal. This makes it possible for the individual parts, in particular the wearing parts, to be replaced easily and cost-effectively in the event of repairs. By completely eliminating weld seams, all connections are made as screw connections, which means that any material combination can be used. This not only eliminates a complex manufacturing step, but also eliminates the introduction of additional heat, meaning that no structural change can occur in the fork material and subsequent heat treatment is necessary. A further major advantage of eliminating weld seams is that thermal distortion can no longer occur, meaning that subsequent straightening of the fork tines 1 is no longer necessary.

[0045] Basically, the fork blade 5 and / or the fork back 3 is constructed in such a way that at least one element, in particular the cover layer 10, is U-shaped, wherein the side parts 15 are produced by a bending process, as can be better seen from Fig. 4 This shows that the reserve layer 11 is accommodated between the side parts 15, with the cavity 9 being formed between the cover layer 10 and the reserve layer. Of course, it is possible for the reserve layer to rest on the end faces of the side parts 15, which in turn forms the cavity 9.

[0046] In order to increase the load-bearing capacity of the fork tine 5 and / or the fork back 3, reinforcing elements 13 are arranged between the cover layer 10 and the back layer 11 so that when the load acts on the cover layer 10, the cover layer cannot be pressed, in particular deformed, in the direction of the back layer 11. The reinforcing elements 13 are preferably provided with a bore which is designed such that the fastening means 12 can be received therein, i.e. such that the fastening means 12 run through the reinforcing elements 13, thereby achieving a space-saving arrangement so that sufficient space remains for the electronics and / or sensors 14 in the cavity 9. The use of reinforcing elements 13 has the advantage that they are distributed over the surface of the cover layer 10 or back layer 11 in such a way as to achieve the highest possible load-bearing capacity with the lowest possible weight of the fork tine 1.

[0047] Of course, another modular design is also possible, in which the cover layer 10 and the back layer 11 of the fork blade 5 and / or the fork back 3 have a U-shaped design, as shown in the Figures 5 and 6 shown in the figure. Fig. 5 The two elements, i.e., the cover layer 10 and the back layer 11, are designed such that a part, preferably the back layer 11, is inserted between the side parts 15 of the cover layer 10, and to increase the load-bearing capacity, reinforcing elements 13 with fastening means 12 running through the center are used. It is also possible for the cover layer 10 and the back layer 11 to be connected to one another, in particular screwed, via the side parts 15, which are produced using a bending process, using fastening means 12.

[0048] During training in Fig. 6On the other hand, the cover layer 10 and the back layer 11 are of the same width, so that the end faces of the side parts 15 of the cover layer 10 and the back layer 11 lie on top of one another, wherein the reinforcing elements 13 with fastening means 12 running therein are preferably inserted in the cavity 9 in order to increase the load-bearing capacity.

[0049] Furthermore, in Fig. 7 an application example of the fork tine 1 on a logistics vehicle 2 is shown, which, however, is only shown schematically, since all logistics vehicles 2 and / or forklifts available on the market can be used for the fork tine 1 according to the invention.

[0050] It can be seen that one or more fastening elements 6 are arranged on the fork back 3, in particular on the rear portion 11 of the fork back 3. These fastening elements 6 can be inserted into holes provided for this purpose in the rear portion 11, for which purpose threaded holes are preferably provided so that the fastening elements, for example hooks or eyes, can be screwed in. For the sake of completeness, it should be mentioned that, of course, a wide variety of prior art systems for fastening a fork tine 1 to a logistics vehicle 2 can be used and fastened, with corresponding fastening points or holes or even adapter plates being provided for this purpose.

[0051] Thanks to the special modular design of the fork tine 1, it is now easily possible to arrange electronics and / or sensors 14 in the fork back 3 and the fork blade 5, for which purpose the wiring harness 16 can be laid in the cavity 9. Appropriate recesses for the sensors 14 can be provided in the cover layers 10 and / or reserve layers 11. For example, weight sensors can be arranged in the cover layer 10 of the fork blade 5, which determine the load capacity and store it, for example, in a database in the electronics or a control unit 17 in the logistics vehicle 2, so that analyses of the transported loads 7 can be carried out at any time.

[0052] For the sake of completeness, it should be mentioned that the fork knee 4 can have a joint (not shown), whereby the fork blade 5 is folded up when it does not need to carry a load 7. Furthermore, since the horizontal and vertical areas are realized using sheet metal, it is also possible to cost-effectively manufacture tabs, which can be used as lifting and assembly aids for the fork tines 1. Furthermore, it is possible for the compact fork knee to be manufactured primarily from a process-monitored and fatigue-resistant tempered steel cast, so that a stress-optimized geometry with relevant cable feedthroughs and outlets can be created through the manufacturing process. A further advantage of manufacturing the fork knee as a separate component is that all other components are no longer subjected to thermal stress, as is the case with forging or upset forging processes used in the prior art.It should also be mentioned that a fork tip 18 or other end pieces can be attached to the illustrated modular fork blade 3 on the opposite side to the attached fork knee 4.

[0053] It can therefore be said that the fork tine 1 according to the invention is constructed in such a way that a compact fork knee 4, which consists primarily of high-strength tempered cast iron including subsequent mechanical processing or cut from a rolled steel part (plasma, laser, or water jet) including mechanical post-processing, is connected to the fork back 3 and the fork blade 4 via screw connections 12, thus enabling production entirely without weld seams. Of course, additional accessories 19, such as eyelets, tabs, etc., which cannot be attached via a screw connection 12, can also be welded to the fork tine 1.

[0054] It is also mentioned that not all holes in the cover layer 10 and / or the backing layer 11 are provided with a fastening element 12, but rather that, depending on the required load capacity, corresponding reinforcement elements 13 are arranged to which the cover layer 10 and the backing layer 11 are screwed. This allows for standardized cutting or standardized production for a wide variety of fork tines 1 with different load capacities.

[0055] Furthermore, in Fig. 7 an application example of the fork tine 1 according to the invention is shown, in which a base vehicle 20 with a lifting device 21 for transporting loads 7, preferably on a load carrier or pallet, in particular a Euro pallet 8, is shown, wherein the fork tine 1 according to the invention is mounted on the lifting device 21, as described above.

[0056] For the sake of clarity, it should be noted that the invention is not limited to the illustrated embodiments, but may also include further developments. In particular, the embodiments or individual features of the embodiments may also be combined with one another.

Claims

1. Fork tine (1) for preferably automated logistics vehicles (2), comprising at least a shank (3), a heel (4) and a blade (5), wherein fastening elements (6) are arranged on the shank (3) for attachment to a logistics vehicle (2), whereby the blade (5) and the shank (3) are formed from a top layer (10) and a rear layer (11) to form a cavity (9), wherein the heel (4) can be inserted over a partial region of the cavity (9) of the shank (3) and the blade (5), characterized in that the blade (5) and the heel (3) are connected to each other, in particular screwed together, via fastening means (12), in particular screws (12a), wherein the heel (4) is designed to correspond to the cavity (9).

2. Fork tine (1) according to claim 1, characterized in that the top layer (10) is formed from a sheet folded into U-shape and the rear layer (11) is formed from a flat sheet.

3. Fork tine (1) according to claim 1, characterized in that the top layer (10) and the rear layer (11) are formed from a plate, in particular a steel plate, folded into U-shape.

4. Fork tine (1) according to one of the preceding claims, characterized in that reinforcing elements (13) are arranged in the cavity (9) between the top layer (10) and the rear layer (11).

5. Fork tine (1) according to one of the preceding claims, characterized in that the reinforcing elements (13) accommodate the fastening means (12).

6. Fork tine (1) according to one of the preceding claims, characterized in that the top layer (10) of the shank (3) and of the blade (5) has recesses to accommodate the fastening means (12), in particular the screw head, to form a flat surface.

7. Fork tine (1) according to one of the preceding claims, characterized in that the top layer (10) of the shank (3) and of the blade (5) comprises further bores for attachment of additional auxiliary means (18).

8. Fork tine (1) according to one of the preceding claims, characterized in that the heel (4) has bores to accommodate the fastening means (12).

9. Fork tine (1) according to one of the preceding claims, characterized in that the heel (4) has a joint for folding up the blade (5), wherein the joint is preferably hydraulically or electrically controllable.

10. Fork tine (1) according to one of the preceding claims, characterized in that sensors (14), lines (16) and electronic control units (17) are arranged in the cavity (9) of the blade (5) and of the shank (3), which can preferably be connected to a logistics vehicle (2) via a connecting plug on the shank (3).

11. Logistics vehicle (2), comprising at least a base vehicle (20) with a lifting device (21) for transporting loads (7) preferably onto a load carrier (8) or on a pallet (8), in particular a Euro pallet (8), characterized in that a fork tine (1) according to one of claims 1 to 10 is attached to the lifting device (21).

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