INDUSTRIAL TRUCK COMPRISING A DEVICE FOR REDUCING VIBRATIONS

Abstract

The invention relates to an industrial truck comprising

a chassis (6),
a mast (8) arranged on the chassis (6) in an upright position, a load-carrying apparatus (36), which has at least one load-receiving means (42) for receiving a load that is to be transported,
a support structure (9) that supports the load-carrying apparatus (36) on the mast (8) and can be moved, together with the load-carrying apparatus (36), upwards and downwards on the mast (8), and comprising
a device (54) for reducing vibrations,
wherein the device (54) for reducing vibrations has at least one additional mass body (60), which is supported by the mast (8) or the components connected thereto and is not constantly rigidly coupled to the mast (8) or the support structure (9) or the load-carrying apparatus (36), but is movably mounted by means of a bearing arrangement (62) such that it is movable relative to the mast (8) in response to mast vibrations, in particular to mast vibrations having horizontal vibration components, in order to counteract mast vibrations.

Claims

1.-16. (canceled)

17. An industrial truck comprising a chassis, a mast arranged on the chassis in an upright position, a load-carrying apparatus, which has at least one load-receiving means for receiving a load that is to be transported, a support structure that supports the load-carrying apparatus on the mast and can be moved, together with the load-carrying apparatus, upwards and downwards on the mast, and comprising a device for reducing vibrations, wherein the device for reducing vibrations has at least one additional mass body which is supported by the mast and is not constantly rigidly coupled to the mast or the support structure or the load-carrying apparatus, but is movably mounted by means of a bearing arrangement such that the at least one additional mass body is movable relative to the mast in response to mast vibrations in order to counteract mast vibrations.

18. The industrial truck of claim 17, wherein the device for reducing vibrations has at least one damping system that influences the movement of the at least one additional mass body relative to the mast, wherein the at least one damping system is a passive damping system or an active damping system.

19. The industrial truck of claim 18, wherein the at least one damping system comprises a friction-damping arrangement.

20. The industrial truck of claim 18, wherein the at least one damping system comprises at least one of a hydraulic friction-damping cylinder or a pneumatic friction-damping cylinder.

21. The industrial truck of claim 18, wherein the at least one damping system comprises a spring arrangement.

22. The industrial truck of claim 21, wherein the spring arrangement comprises at least one of a mechanical spring or a hydropneumatic accumulator arrangement.

23. The industrial truck of claim 18, wherein the at least one damping system comprises at least one active component, the active component of the damping system directly or indirectly acting between the at least one additional mass body and the mast and the components connected thereto in order to apply pressure to the at least one additional mass body in a manner that reduces mast vibrations.

24. The industrial truck of claim 23, wherein the at least one active component comprises one or more of a controllable hydraulic cylinder, a controllable pneumatic cylinder, a controllable electric motor, or an electromagnetic arrangement.

25. The industrial truck of claim 24, wherein the at least one active component comprises a controllable electric motor, and the controllable electric motor is a servomotor.

26. The industrial truck of claim 17, wherein the bearing arrangement is a linear bearing arrangement, which allows for a horizontal movement of the at least one additional mass body, transversely to a normal main direction of travel of the industrial truck.

27. The industrial truck of claim 17, wherein the bearing arrangement is a self-aligning bearing arrangement, which allows for a pendulum movement of the at least one additional mass body.

28. The industrial truck of claim 27, wherein the pendulum movement of the at least one additional mass body is in a plane transverse to a normal main direction of travel of the industrial truck.

29. The industrial truck of claim 17, wherein the bearing arrangement which mounts the at least one additional mass body such that the at least one additional mass body is movable relative to the mast and the components connected thereto, is directly arranged on the mast at a position on the upper half of the mast.

30. The industrial truck of claim 29, wherein the position of the bearing arrangement on the upper half of the mast is at the upper end of the mast.

31. The industrial truck of claim 17, wherein the bearing arrangement that mounts the at least one additional mass body such that the at least one additional mass body can move relative to the mast is supported by the support structure and can be moved upwards and downwards on the mast together therewith.

32. The industrial truck of claim 31, wherein the bearing arrangement that mounts the at least one additional mass body such that the at least one additional mass body can move relative to the mast is arranged directly on at least one of the support structure or the load-carrying apparatus.

33. The industrial truck of claim 31, wherein a cab is fastened to the support structure and is movable upwards and downwards on the mast together with support structure, the bearing arrangement that mounts the at least one additional mass body such that the at least one additional mass body can move relative to the mast being arranged on the cab.

34. The industrial truck of claim 17, wherein the industrial truck is designed as a sideloader, the support structure having a lateral push frame on which a lateral push device, which is connected to the load-carrying apparatus, is mounted for combined lateral movement with the load-carrying apparatus, transversely to a normal main direction of travel of the industrial truck, and can be driven by means of a lateral push drive apparatus, the bearing arrangement that mounts the at least one additional mass body such that the at least one additional mass body can move relative to the mast being arranged on the lateral push frame.

35. The industrial truck of claim 17, wherein the device for reducing vibrations is selectively activatable and deactivatable.

36. The industrial truck of claim 35, wherein the device for reducing vibrations is automatically activatable and deactivatable depending on an operating state of the industrial truck.

37. The industrial truck of claim 35, wherein the device for reducing vibrations is automatically activatable and deactivatable depending on surroundings of the industrial truck.

Description

[0028] Embodiments of the invention will be described below with reference to the Figs., in which.

[0029] FIG. 1 is a side view of an embodiment of an industrial truck according to the invention, which is designed as a tri-lateral high-bay stacker.

[0030] FIG. 2a and FIG. 2b are a rear view (FIG. 2a) and a perspective view (FIG. 2b) of a lateral push frame of an industrial truck of the design shown in FIG. 1, comprising an additional mass body, which is provided on the lateral push frame and has a spring centering device in a linear sliding bearing.

[0031] FIG. 3 is a rear view of a corresponding lateral push frame comprising an additional mass body, which is provided on said frame and the movement of which in a linear sliding bearing can be electromagnetically influenced.

[0032] FIG. 4 is a perspective view of a cab frame of an industrial truck of the design shown in FIG. 1, comprising an additional mass body provided in the base region of the cab frame.

[0033] According to FIG. 1, the industrial truck which is designed as a tri-lateral high-bay stacker comprises a chassis 6 supported by means of wheels 2 on the ground 4 and a mast 8 vertically fastened to the chassis 6. The mast 8 is constructed of multiple parts so as to be telescopically extendable, as can be seen from FIG. 1 by the extended position indicated by dashed lines. At the furthest extendable telescopic stage 10 of the mast 8, a support structure 9 in the form of a cab carrier is attached such that it can move vertically. The support structure 9 has a cantilever arrangement 24 in the form of a boom, which projects forwards from the mast 8 in the main direction of travel G of the industrial truck and braces the underneath of a platform 11 of a cab 12 and supports a lateral push frame 34 at its projecting end.

[0034] The cab 12 is designed as a lifting driver's cabin, which has a frame comprising the cab platform 11 as the cabin floor, a back wall, side walls and a driver overhead guard 22. At the front of the cab 12, the lateral push frame 34 is fixed to the cantilever arrangement 24.

[0035] A lateral push device 38 constructed as a pivoting pusher is arranged on the lateral push frame 34 so as to be laterally movable, transversely to the straightforward direction of travel G of the industrial truck. The lateral push device 38 is connected to a load-carrying apparatus 36, which has an additional mast 40 arranged on the front of the lateral push device 38, on which additional mast a load-carrying fork 42 having a fork-carrying arrangement is vertically movable in the form of load-carrying element. The additional mast 40 can be pivoted together with the load-carrying fork 42 about the vertical axis 44 between the position shown in FIG. 1, in which the load-carrying fork 42 and its load-carrying arms 43 are oriented laterally (transverse orientation to the left in relation to the straightforward direction of travel G), and a position in which they are oriented in an opposing lateral position (transverse orientation to the right) of the load-carrying arms 43.

[0036] The special feature of the industrial truck is a device 54 for reducing vibrations, which is designed in particular to reduce and to dampen vibrations having horizontal deflection components transverse to the main direction of travel G of the industrial truck. In the embodiment according to FIG. 1, the device 54 for reducing vibrations is arranged on the upper edge of the furthest extendable telescopic stage 10 of the mast 8. It is indicated purely schematically in FIG. 1 and, in its simplest form, comprises a linear sliding bearing as the bearing arrangement 62, having an additional mass body 60, which is guided thereby to move horizontally, transversely to the main direction of travel G of the industrial truck and a vibration-damping system influencing the movement of the additional mass body 60 relative to the mast 8. In principle, the device 54 for reducing vibrations can be designed in the manner that is described below with reference to FIGS. 2a to 4, for example.

[0037] The additional mass body 60 can and should have a quite considerable mass of, for example, at least 50 kg, preferably at least 100 kg, in order to constitute an efficient counter-momentum mass when mast vibrations occur. It expediently consists of a material of high density, in order to keep the volume and space required therefor as low as possible. According to one embodiment of the invention, the additional mass body consists of at least one metal block.

[0038] The bearing arrangement 62 can, for example, be designed as a sliding bearing and/or as a roller bearing, etc. and, as part of the device 54 for reducing vibrations, constitutes an interface between the additional mass body and the mast 8, which allows for vibration-reducing movements of the additional mass body 60 relative to the mast 8, which movements have horizontal movement components transverse to the main direction of travel (straightforward direction of travel) G of the industrial truck.

[0039] The vibration-damping system, which in the simplest form is passive, can be active or semi-active in other embodiments.

[0040] At least in the passive variant, said vibration-damping system preferably comprises a friction-damping arrangement, which has a braking effect on the movement of the additional mass body relative to the mast 8, in order to convert kinetic energy into another form of energy, in particular heat, such that vibrations of the industrial truck, in particular of the mast 8, are damped. Such a friction-damping arrangement can, for example, comprise friction surfaces that are provided with friction linings and rub against one another. A hydraulic cylinder comprising, for example, cylinder chambers short-circuited by means of a throttle point and optionally a pneumatic or hydropneumatic spring-type accumulator connected thereto, can also be an element of the damping system. In a preferred embodiment, the damping system can comprise a spring arrangement, for example a mechanical spring arrangement, which counteracts deflection of the additional mass body relative to the bearing arrangement and to the mast with a resilient reset tendency.

[0041] It should be pointed out that, according to variants of the damping system, the rigidity of spring arrangements of the damping system and/or the frictional effect of friction-damping arrangements can be controllable depending on certain operating parameters or operating conditions of the industrial truck, in order to modulate the vibration-damping effect as required.

[0042] One application example: while the industrial truck is travelling in a narrow aisle of a high-bay warehouse, the device for reducing vibrations would, for example, be activated, a friction-damping arrangement of the damping system providing a frictional effect adapted to the current situation. If, when the industrial truck is travelling over uneven ground, transverse acceleration occurs at the mast 8 and therefore at the additional mass body, the transverse acceleration is transferred to the additional mass body via the bearing arrangement, the friction-damping arrangement and a spring arrangement of the damping system interacting with said friction-damping arrangement. If the inertial force of the relevant “decoupled or soft-coupled” masses exceeds the value of the adjusted frictional force and the spring force acting in parallel, relative movement occurs between the additional mass body and its bearing arrangement and the mast 8. This relative movement backwards and forwards relative to a target zero position reduces the overall vibration amplitude of the mast 8 and kinetic energy is primarily converted into heat in the friction-damping arrangement.

[0043] In one corresponding variant, the damping system can have at least one actuator in the form of an active component in addition to or alternatively to passive components. Such an actuator can, for example, be formed by a controllable hydraulic or pneumatic cylinder or a controllable electric motor or by an electromagnetic arrangement, and acts between the additional mass body and the bearing arrangement mounting said additional mass body and the mast 8 in order to force the additional mass body 60 back in the event of its deflection out of its target zero position.

[0044] A control device is provided in such an active system in order to control the active components. Furthermore, sensors can be provided which detect the vibration amplitudes of the mast or components arranged thereon in a height-adjustable manner, it being possible for the control device to process data from said sensors in order to control the active components in the sense of optimised vibration reduction. In this sense, sensors can also be provided which detect the relative movement of the additional mass body to the bearing arrangement that mounts said additional mass body and to the mast 8.

[0045] The lateral push frame 34 of an industrial truck of the design shown in FIG. 1 is shown in isolation in FIGS. 2a and 2b. A corresponding industrial truck equipped with said lateral push frame constitutes a further embodiment of the invention in that the device 54 for reducing vibrations is provided on or integrated in the lateral push frame 34. In this case, the device 54 for reducing vibrations can be moved vertically on the mast together with the lateral push frame 34 and the support structure 9.

[0046] The lateral push frame 34 has horizontal cross rails 52, 53, which are arranged on top of one another, project forwards and extend horizontally, transversely to the normal main direction of travel G of the industrial truck, the device 54 for reducing vibrations being accommodated in a hollow space 55 in the lower cross rail 53. In FIG. 2a, an additional mass body 60 of said device for reducing vibrations can be seen in a linear sliding bearing 62, inside the hollow space 55 that is shown partly open at the rear, which bearing allows for relative movement of the additional mass body 60 along the lower cross rail 53 relative to the lateral push frame 34. The additional mass body 60 and the sliding bearing 62 are provided with friction surfaces which touch each other such that the additional mass body 60 experiences a braking effect as a result of friction during its movements within the sliding bearing 62 which are triggered in the case of transverse vibrations of the mast. This converts kinetic energy into heat.

[0047] According to FIG. 2a, the additional mass body 60 is located in a target zero position (central position), which it normally assumes in the absence of vibrations of the mast. On either side of the additional mass body 60, mechanical return springs 64 are provided in the slide bearing 62, one axial end of which springs rests on the additional mass body 60 and the other axial end of which springs rests on a particular axial end of the sliding bearing 62. The return springs 64 are designed to pretension the additional mass body 60 towards its target zero position such that the additional mass body 60 is forced back towards its target zero position by means of the return springs 64 in the event of any displacement out of the target zero position.

[0048] FIG. 3 shows a corresponding lateral push frame 34 in a perspective view corresponding to FIG. 2a, comprising a device 54′ for reducing vibrations which is likewise accommodated in the hollow space 55 in the lower cross rail 53. The device 54′ for reducing vibrations in FIG. 3 comprises active adjusting means for influencing the movement of the additional mass body 60 relative to the lateral push frame 34. These adjusting means are electromagnets 65, which are controllable by means of a control device (not shown), in order to accelerate or decelerate the additional mass body 60, which is linearly guided horizontally in the bearing arrangement 62, transversely to the normal main direction of travel G of the industrial truck concerned, this occurring, for example, depending on sensor information regarding the vibration state of the mast of the industrial truck concerned in a manner that dampens vibrations of the mast. The bearing arrangement 62 can be configured as a low-friction sliding bearing.

[0049] Instead of an electromagnet arrangement of the type indicated in FIG. 3, hydraulic cylinders or electric motors, for example, can also be considered as adjusting means.

[0050] FIG. 4 shows a support structure 9 in isolation in the form of a cab carrier of an industrial truck of the design shown in FIG. 1. An industrial truck equipped therewith constitutes another embodiment of the invention in that a device 54 for reducing vibrations is arranged underneath the cab platform 11, which is supported on the support structure 9, in the base region of the cab, preferably on the support structure 9. In this example, the device 54 is a passive system as is also shown in FIG. 2a. An active vibration-damping system could also be accommodated just as well in the installation position according to FIG. 4, as is shown in FIG. 3.

[0051] It should be pointed out that an industrial truck according to the invention can have a plurality of devices 54 for reducing vibrations, it being possible for these devices 54 to be accommodated at different points, such as those shown in the embodiments. In this case, these can be active and/or passive vibration-reducing systems.