INDUSTRIAL TRUCK WITH IMPROVED BATTERY-SUPPORTING STRUCTURE

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The field of the present invention concerns an industrial truck, such as a forklift truck, including an improved structure for supporting an electrical battery of the industrial truck.BACKGROUND OF THE INVENTION

[0002] Forklift trucks including a chassis (or frame), a mast pivotally mounted on the chassis and a fork slidably mounted on the mast are known in the art. The fork is used to lift a load, for example for transporting ware in a store. The mast can be typically tilted with respect to the chassis to facilitate loading and unloading of the ware.

[0003] In the recent years, the industrial trucks have been equipped with one or more electrical traction motors and, accordingly, with an electrical battery assembly (or pack) to supply power to the at least one electrical motor. In some known industrial trucks, the frame is formed with a recess that is laterally open to allow insertion / extraction of the battery using another forklift truck or a transpallet, e.g. in case a discharged battery must be replaced to ensure continued operation of the forklift truck. In this known art, however, the battery assembly is supported by the frame of the forklift truck; since the weight of the battery pack is relatively consistent, the frame needs to be opportunely dimensioned to have a sufficient mechanical resistance; this renders the frame design complex and expensive.

[0004] US 2018 / 079632 A1 relates to an industrial truck with multi-part vehicle frame according to the preamble of claim 1.SUMMARY OF THE INVENTION

[0005] In view of the above, it is an object of the present invention to provide an industrial truck which ensures a proper support of the battery assembly and an easy insertion / extraction of the battery assembly, while achieving a simplified and cheap construction of the truck frame.

[0006] In view of the above object, the present invention proposes an industrial truck according to claim 1, including: a frame including a recess for receiving an electric battery assembly, a lifting assembly mounted on the frame for lifting a load, and a counterweight fixed to the frame opposite to the lifting assembly for balancing the weight of the lifting assembly and of a load lifted by the lifting assembly; characterized in that the counterweight is formed with an integral single piece which includes a surface for supporting the electric battery assembly when the electric battery assembly is positioned in the recess of the frame.

[0007] Thanks to the invention, since a surface supporting the battery assembly is formed by the counterweight in one piece, the structure of the frame can be considerably simplified and, accordingly, the cost of the industrial truck can be highly reduced.

[0008] According to an embodiment, the electric battery assembly is supported by the surface formed by the counterweight on a rear side and by two front surfaces on a front side, wherein the two front surfaces are formed on the frame. Hence, the battery assembly can be supported in a stable manner with a simplified frame structure.

[0009] According to an embodiment, the counterweight is connected to an upper portion of an axle structure of the industrial truck. According to an embodiment, the counterweight extends above substantially the whole extension of the axle structure of the industrial truck both in a longitudinal and in a transversal direction of the industrial truck. According to an embodiment, the axle structure of the industrial truck is connected to the frame through the counterweight. Hence, the counterweight has a bulky spatial extension, thus guaranteeing a stable balanced operation of the truck, as well as a structural function of connecting the axle structure to the frame.

[0010] According to the invention, the counterweight includes a main body positioned above an axle structure of the industrial truck and an arm portion protruding downwards from the main body between a front axle and a rear axle of the industrial truck, wherein the arm portion includes a protrusion forming the surface for supporting the electric battery assembly. Hence, the counterweight can provide a supporting surface for supporting the battery assembly with a suitable shape by minimizing the consumption of material and the manufacturing costs.

[0011] According to an embodiment, the surface for supporting the electric battery assembly is at the height of the wheels of the industrial truck, preferably below the height of a central axis of the wheels. This allows achieving a suitable position of the battery assembly that can improve stability of the industrial truck while driving.

[0012] According to an embodiment, the frame includes a first lateral element and a second lateral element extending from a rear axle to a front axle of the industrial truck on opposite sides of the industrial truck, wherein the counterweight has a structural function of connecting the first lateral element and the second lateral element to each other. This allows to achieve a closed structure by means of the frame and of the counterweight, thereby achieving a desired mechanical resistance and a properly balanced industrial truck.

[0013] The recess in the frame for receiving the electric battery assembly and a lateral opening in the frame for inserting the electric battery assembly into the recess are open downwardly, to enable the lateral insertion / extraction of the electric battery assembly using a fork. This enable an easy insertion / extraction of the battery assembly in case the battery assembly needs to be replaced rapidly by means of another forklift truck or a transpallet.

[0014] According to an embodiment, the weight of the counterweight is between 25% and 150% of the maximum load weight that can be lifted by the lifting assembly or between 1000 Kg and 10.000 Kg. This ensures a proper balance of the industrial truck under a wide range of operations.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other advantages of the present invention will be illustrated with reference to an example embodiment of the invention, described with reference to the appended drawings listed as follows. Fig. 1 shows a view of an industrial truck according to the invention, in which the cabin of the driver is removed; Figs. 2 and 3 show the counterweight of the industrial truck according to the invention; Fig. 4 shows the frame of the industrial truck according to the invention; Fig. 5 shows a view of the lower side of industrial truck according to the invention; Fig. 6 shows a view of the industrial truck from above showing the recess for supporting the battery assembly; Fig. 7 shows the battery assembly inserted in the recess in the frame of the industrial truck. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Figure 1 shows an industrial truck 10 according to an embodiment of the present invention, e.g. a forklift truck. The industrial truck 10 includes a frame 12, and a lifting assembly 11 mounted on the frame 12. Preferably, as shown in figure 1, the lifting assembly 11 is mounted close to a front axle of the truck 10. For example, the lifting assembly may include a mast 11a pivotally mounted on the frame 12 and a lifting element 19 (e.g. plate for supporting a fork) for lifting a load (not shown); the lifting element 19 is mounted on the mast 11a in a slidable manner along the mast 11a; the mast 11a may be pivotally mounted on the frame 12 around a pivot, which is preferably located close to the front axle of the truck 10; however, the mast 11a and the lifting assembly 11 could be positioned also close to the rear axle of the truck.

[0017] The industrial truck 10 is electrically driven; for example, the industrial truck 10 may include one or more electrical motors for the driving the wheels of the truck. The electrical motor(s) can be any suitable electrical motor such as a reluctance, induction or permanent magnet motor, or the like. Further, the industrial truck 10 might include two wheels on the front axle and one or two wheels on the rear axle. In the example in figure 1, the industrial truck 10 includes two front wheels and two rear wheels.

[0018] As shown in figures 1, 6 and 7, the frame 12 includes a recess 14 for receiving an electric battery assembly 40. For example, the electric battery assembly 40 is arranged to supply power to the electric motors for driving the truck wheel. However, the electric battery assembly 40 may supply power to any function of the industrial truck. The electric battery assembly 40 may be formed according to any known art, e.g. including an external housing in which a battery pack or one or more battery modules are accommodated. The term "electric battery assembly" is hereby understood as any electric power storage system known in the art, including one or more electric energy storing elements.

[0019] The recess 14 extends in a longitudinal direction from a rear axle to a front axle of the industrial truck, advantageously for at least 50% of the distance between the front axle and the rear axle. The recess 14 extends in a transversal direction from a right lateral side to a left lateral side of the industrial truck, advantageously for at least 75% of the transversal width of the industrial truck. This allows to provide sufficient space to receive a large battery assembly with satisfactory storage capacity.

[0020] The industrial truck 10 includes a counterweight 13 fixed to the frame 12 opposite to the lifting assembly 11 for balancing the weight of the lifting assembly 11 and of a load lifted by the lifting assembly. For example, the weight of the counterweight 13 can be correlated with the maximum load that can be lifted by the lifting assembly; according to an embodiment, the weight of the counterweight 13 may be between 25% and 150% of the maximum load liftable by the lifting assembly 11, most preferably between 90% and 120% of the maximum load liftable by the lifting assembly 11. In one concrete example, the weight of the counterweight may be between 1.000 Kg and 10.000 Kg. In more detail, the weight of the counterweight may be between 1.000 Kg and 10.000 Kg wherein the maximum load liftable by the lifting assembly 11 is between 1.000 Kg and 15.000 Kg. Preferably, the counterweight 13 forms a rear frame of the industrial truck 6. The counterweight 13 is advantageously made of cast iron.

[0021] As well shown in figure 1, 2, 6 and 7, the counterweight 13 is formed with an integral single piece which includes a surface 23 for supporting the electric battery assembly 40 when the electric battery assembly 40 is positioned in the recess 14 of the frame 12.

[0022] The counterweight 13 is directly connected to an upper portion of an axle structure 15 of the industrial truck. In the example shown in the figures, the counterweight 13 is positioned above the rear axle structure 15 of the industrial truck. Preferably, the counterweight 13 includes a main body 22 positioned above the axle structure 15 of the industrial truck and an arm portion 17 protruding downwards from the main body 22 between a front axle and a rear axle of the industrial truck (see figs. 1 and 2). The arm portion 17 includes a protrusion 18 forming the surface 23 for supporting the electric battery assembly 40. The protrusion 18 extends from a lower end of the arm portion 17, opposite to the main body 22. The surface 23 is advantageously placed in a central position with respect to a transversal direction of the industrial truck 10, i.e. in a position between the right side and the left side of the industrial truck 10. The arm portion 17 has advantageously a tapered shape, being wider on the side of the main body 22 and thinner on the side of the protrusion 18. The arm portion 17 has a substantially vertical extension. The protrusion 18 has a substantially horizontal extension.

[0023] Preferably, as well shown at figure 6, the industrial truck 10 includes three supporting surfaces for supporting the battery assembly 40, i.e. the surface 18 formed by the counterweight 13 on a rear side of the battery assembly and two front surfaces 32, 33 on a front side of the battery assembly. The two front surfaces 32, 33 are formed on the frame 12, preferably on a lower plate 31 of the frame as shown in figures 5 and 6. The supporting surfaces 18, 32 and 33 define localized points for supporting the battery assembly. For example, one or more of the surfaces 18, 32 and 33 can have an extension in the transversal direction of the industrial truck in the range 5%-20% of the total width of the industrial truck. According to an embodiment, the surface 23 has a width in a transversal direction of the industrial truck (i.e. from a left to a right side of the truck) that is larger than a width of the surface 23 in a longitudinal direction of the industrial truck (i.e. from a rear side to a front side of the truck). Preferably, the supporting surfaces 32 and 33 are positioned close to opposite corners of the battery assembly 40, i.e. close to opposite lateral sides of the frame 12. However, also a continuous supporting surface could be formed in the lower plate 31 to support continuously the battery assembly 40 from a left side to a right side of the battery assembly 40. A continuous supporting surface might have an L-shape, e.g. extending along the plates 31 and 31a of the frame 12 (see fig. 6). Preferably, on the rear side of the battery assembly, or more generally on the side of the battery assembly 40 facing the counterweight 13, the battery assembly 40 is supported in use only by the surface 23 of the counterweight, and not by an element of the frame 12. Hence, the frame structure can be highly simplified.

[0024] Preferably, the counterweight 13 extends above substantially the whole extension of the axle structure 15 of the industrial truck both in a longitudinal and in a transversal direction of the industrial truck, as well shown in figure 5. The axle structure 15 is connected to the frame 12 through the counterweight 13. Specifically, the axle structure 15 is fixed directly to the lower side of the counterweight according to any known technique, for example being received in the seat 27 formed in the counterweight 13 and being fixed using any know fastening element and the holes 26 on opposite sides of the seat 27 (see figure 3).

[0025] As shown in figure 2, the counterweight includes also a rear wall 25, extending substantially vertically from the main body 22 and forming the rear part of the industrial truck 10.

[0026] As well shown in figures 1 and 4, the frame 12 includes a first lateral element 20 and a second lateral element 21 extending from a rear axle to a front axle of the industrial truck on opposite sides of the industrial truck. The counterweight 13 has a structural function of connecting the first lateral element 20 and the second lateral element 21 to each other. In one embodiment, the counterweight includes holes 24 (preferably two on each side) to receive fastening means 16 (e.g. screws) for connecting the frame 12 to the counterweight 13 (see figure 1 and 2). The counterweight 13 is connected directly to each of the first lateral element 20 and the second lateral element 21 of the frame.

[0027] Preferably, the lateral element 21 of the frame 12 has an arc-shaped form so as to define the lateral opening 34 of the frame for the insertion / extraction of the battery assembly 40 into / from the recess 14. The other lateral element 20 may be advantageously be closed, i.e. it may form a closed lateral wall of the industrial truck. On the front side, the lateral elements 20 and 21 may be connected to each other by a transversal element 28 of the frame 12 (see fig. 4). The frame 12 includes also two flanges 29 (fig. 4) that form connecting means for connecting to a front axle structure 30 (see fig. 5) of the industrial truck. The lower plate 31, on which the supporting surfaces 32, 33 are formed, is connected to the transversal element 28 of the frame 12. On the rear side, the frame 12 includes two bent portions in which holes 50 are formed for connecting the frame 12 to the counterweight 13 by means of the fastening means 16, e.g. screws.

[0028] The surface 23 for supporting the electric battery assembly 40 is at the height of the wheels of the industrial truck, preferably below the height of a central axis of the wheels. This allows to place the battery assembly as low as possible in the frame, thereby improving stability of the truck. The recess 14 in the frame 12 for receiving the electric battery assembly 40 and the lateral opening 34 in the frame 12 for inserting the electric battery assembly into the recess 14 are open downwardly, to enable the lateral insertion / extraction of the electric battery assembly, e.g. using a fork of another forklift truck or a transpallet or any other suitable device for lifting the battery assembly 40 by inserting a lifting element under the battery assembly positioned in the recess 14 and translating it outside the recess 14 through the lateral opening 34. The battery assembly 40 can be laterally inserted into the recess 14 in the frame through the lateral opening 34 in the frame. The recess 14 and the lateral opening 34 are configured to allow the insertion and the extraction of the battery assembly 40 through the opening 34; the direction of the insertion / extraction is substantially parallel to the rear axle of the industrial truck. This allows to easily replace the battery assembly, despite its relevant weight.

[0029] The above description of embodiments applying the innovative principles of the invention is provided solely for the purpose of illustrating said principles and must thus not be considered as limiting the scope of the invention as defined by the attached claims.

Claims

1. An industrial truck (10) including: a frame (12) including a recess (14) for receiving an electric battery assembly (40) and a lateral opening (34) for inserting the electric battery assembly into the recess (14), a lifting assembly (12) mounted on the frame for lifting a load, and a counterweight (13) fixed to the frame (12) opposite to the lifting assembly for balancing the weight of the lifting assembly and of a load lifted by the lifting assembly; wherein the recess (14) and the lateral opening (34) are open downwardly to enable the lateral insertion of the electric battery assembly (40) in the recess (14) and the lateral extraction of the electric battery assembly (40) from the recess (14) using a fork, characterized in that the counterweight (13) is formed with an integral single piece which includes a surface (23) for supporting the electric battery assembly (40) when the electric battery assembly (40) is positioned in the recess (14) of the frame (12), wherein the counterweight (13) includes a main body (22) positioned above an axle structure (15) of the industrial truck and an arm portion (17) protruding downwards from the main body (22) between a front axle and a rear axle of the industrial truck, wherein a protrusion (18) extends from the arm portion (17), the protrusion forming the surface (23) for supporting the electric battery assembly (40).

2. An industrial truck (10) according to any of the preceding claims, wherein the electric battery assembly (40) is supported by the surface (23) formed by the counterweight (13) on a rear side and by two front surfaces (32, 33) on a front side, wherein the two front surfaces (32, 33) are formed on the frame (1).

3. An industrial truck (10) according to any of the preceding claims, wherein the counterweight (13) is directly connected to an upper portion of an axle structure (15) of the industrial truck.

4. An industrial truck (10) according to any of the preceding claims, wherein the counterweight (13) extends above substantially the whole extension of the axle structure (15) of the industrial truck both in a longitudinal and in a transversal direction of the industrial truck.

5. An industrial truck (10) according any of the preceding claims, wherein the axle structure (15) of the industrial truck is connected to the frame (12) through the counterweight (13).

6. An industrial truck (10) according to any of the preceding claims, wherein the surface (23) for supporting the electric battery assembly (40) is at the height of the wheels of the industrial truck, preferably below the height of a central axis of the wheels.

7. An industrial truck (10) according to any of the preceding claims, wherein the frame (12) includes a first lateral element (20) and a second lateral element (21) extending from a rear axle to a front axle of the industrial truck on opposite sides of the industrial truck, wherein the counterweight (13) has a structural function of connecting the first lateral element (20) and the second lateral element (21) to each other.

8. An industrial truck according to any of the preceding claims, wherein the weight of the counterweight (13) is between 25% and 150% of the maximum load that can be lifted by the lifting assembly or between 1.000 Kg and 10.000 Kg.