INDUSTRIAL TRUCK COMPRISING A DEVICE FOR REDUCING TRANSVERSE VIBRATIONS

Abstract

The invention relates to an industrial truck, in particular a tri-lateral stacker, comprising a mast (8), a lateral push frame (34) that can move up and down on the mast (8), a lateral pusher (38) that is mounted on the lateral push frame (34) so as to be laterally movable transversely to the main direction of travel (G) of the industrial truck, so that said pusher has a degree of freedom of movement along the lateral push frame (34) that is oriented laterally, transversely to the main direction of travel (G) of the industrial truck, a load-supporting apparatus (36) that is arranged on the lateral pusher (38) and can move laterally, together with the lateral pusher (38), transversely to the main direction of travel (G) of the industrial truck using its degree of freedom of movement, a lateral push drive device (52) that can be controlled by a control device of the industrial truck for moving the lateral pusher (38) and the load-supporting apparatus (36) together along the lateral push frame (34), and comprising a device for reducing transverse vibrations, in particular vibrations having vibration components that are transverse to the main direction of travel (G) of the industrial track, wherein the industrial truck is characterised in that, in a vibration-damping operating mode, the lateral push drive device (52) can be operated as a component of the device for reducing vibrations, wherein, in the vibration-damping operating mode, said device allows the lateral pusher (38) to move relative to the lateral push frame (34) so as to reduce vibrations.

Claims

1. An industrial truck comprising: a mast; a lateral push frame that is operable to move up and down on the mast; a lateral pusher that is mounted on the lateral push frame so as to be laterally movable transversely to the main direction of travel of the industrial truck, such that said pusher has a degree of freedom of movement along the lateral push frame that is directed laterally, transversely to the main direction of travel of the industrial truck; a load-supporting apparatus that is arranged on the lateral pusher and is operable to move laterally, together with the lateral pusher, transversely to the main direction of travel of the industrial truck using its degree of freedom of movement; a lateral push drive device, which is operable to be controlled by a control device of the industrial truck, for moving the lateral pusher together with the load-supporting apparatus along the lateral push frame, and comprising a device for reducing transverse vibrations that are transverse to the main direction of travel of the industrial truck, wherein when in a vibration-damping operating mode, the lateral push drive device is operable as a component of the device for reducing vibrations, said lateral push drive device allowing the lateral pusher to carry out vibration-reducing movements relative to the lateral push frame in the vibration-damping operating mode.

2. The industrial truck according to claim 1, wherein the lateral push drive device comprises a controllable hydraulic motor or electric motor having a stator and an active element moveable relative to the stator the movement of which converted is convertible into a movement of the lateral pusher along the lateral push frame, wherein a generated motor force application is influenced by correspondingly controlling the motor, between the stator and the active element in order to cause the active element and the lateral pusher to move or to stop.

3. The industrial truck according to claim 2, wherein when the lateral push drive device is in the vibration-damping operating mode, the motor is set so as to generate a holding torque that is capable of being overcome such that the active element counteracts a movement out of its particular position relative to the stator with a resistance that is capable of being overcome.

4. The industrial truck according to claim 2, wherein when the lateral push drive device is in the vibration-damping operating mode, the motor is capable of being actuated in order to generate a holding and restoring torque for holding the active element in a particular target position relative to the stator, and for restoring the active element to the target position if the active element is deflected out of the target position.

5. The industrial truck according to claim 4, wherein the motor is controllable such that the holding and restoring torque can be modulated on the basis of the deflection of the active element out of the target position.

6. The industrial truck according to claim 2, wherein a movement-damping arrangement of the device for reducing vibrations is provided, which arrangement acts between the lateral push frame and the lateral pusher when the lateral push drive device is in the vibration-damping operating mode, functions according to the principle of friction.

7. The industrial truck according to claim 2, wherein a friction coupling is provided in the drive train of the lateral push drive device, and in that, when the lateral push drive device is in the vibration-damping operating mode, the motor is designed to prevent the active element from moving relative to the stator, the friction coupling allowing the lateral pusher to move relative to the lateral push frame in a braked manner as a result of inertial effects.

8. The industrial truck according to claim 2, wherein the device for reducing vibrations comprises a resiliently yielding restoring device, which restoring device is designed to force the lateral pusher into a particular target position relative to the lateral push frame if the lateral pusher is deflected out of the particular target position when the lateral push drive device is in the vibration-damping operating mode.

9. The industrial truck according to claim 8, wherein the restoring device comprises a torsion spring arrangement in a driveshaft in the drive train of the lateral push drive device.

10. The industrial truck according to claim 2, wherein the device for reducing vibrations comprises at least one sensor for detecting movements of the lateral pusher relative to the lateral push frame, which sensor is connected to the control device in order to control the lateral push drive device.

11. The industrial truck according to claim 2, wherein the device for reducing vibrations comprises at least one sensor for detecting a vibrational state of the industrial truck, the sensor being connected to the control device that enables the vibration-damping operating mode of the lateral push drive device on the basis of the signal from the sensor.

12. The industrial truck according to claim 2, wherein the device for reducing vibrations is operable to be activated and deactivated.

13. The industrial truck according to claim 2, wherein the device for damping vibrations dampens vibrations at the same time as the lateral pusher performs a regular lateral push operation, wherein a regular lateral push movement is superposed on vibration-damping movements.

14. The industrial truck according to claim 2, wherein when the lateral push drive device is in the vibration-damping operating mode, the motor is operable as a controlled, active vibration-damping element in order to drive the lateral pusher to carry out vibration-reducing movements if transverse vibrations occur on the lateral push frame.

15. The industrial truck according to claim 2, wherein when the lateral push drive device is in the vibration-damping operating mode, the motor is operable to be actuated such that it does not generate a motor force application between the stator and the active element that moves the active element, and allows relative movements between the stator and the active element and between the lateral push frame and the lateral pusher as a result of inertial effects.

16. The industrial truck according to claim 15, wherein the motor (is a hydraulic motor, which, when the lateral push drive device is in the vibration-damping operating mode, is operable to be hydraulically short-circuited by means of a flow resistor to generate a braking effect on relative movements between the stator and the active element of the motor and between the lateral push frame and the lateral pusher.

Description

[0029] Embodiments of the invention are explained in the following with reference to the figures.

[0030] 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.

[0031] FIG. 2 is a perspective view of a tri-lateral high bay stacker according to the invention that is similar to the tri-lateral high bay stacker from FIG. 1.

[0032] FIG. 3 is a side view of the assembly, shown in isolation, consisting of the lateral push frame and lateral pusher according to one embodiment, the lateral pusher being shown without its outer housing casing so that components of the lateral push drive device are visible.

[0033] FIG. 4 is a side view of the assembly, shown in isolation, consisting of the lateral push frame and lateral pusher according to another embodiment, the lateral pusher being shown without its outer housing casing so that components of the lateral push drive device are visible, the assembly from FIG. 4 differing from the assembly from FIG. 3 in that there is no coupling in the drive train of the lateral push drive device.

[0034] For the purposes of explaining the embodiment, the industrial truck in FIG. 1 and the industrial truck in FIG. 2 differ only marginally and are therefore not considered separately, but are jointly referred to and explained as the industrial truck. The industrial truck comprises a chassis 6, which is supported on the floor 4 by means of wheels 2, and a mast 8 that is fastened to the chassis 6 in an upright manner. The mast 8 is telescopically extendable, as can be seen in FIG. 1 from the extended position shown by dashed lines. A cab 12 is attached to the telescoping stage 10 of the mast 8 that can be extended the furthest such that said cab can move vertically. The cab 12 is formed as a raisable driver's cab, which comprises a frame having a cab floor, rear wall 14, side walls and an overhead guard 22 for the driver. A lateral push frame 34 is arranged in front of the cab 12.

[0035] A lateral pusher 38 designed as a pivoting pusher 38 and comprising a load-supporting apparatus 36 that is supported thereby is arranged on the front of the lateral push frame 34 so as to be laterally movable, transversely to the straight direction of travel G of the industrial truck. The pivoting pusher 38 comprises an extension arm 50 comprising an additional mast 40 of the load-supporting apparatus 36 that is arranged in the front of said pivoting pusher and on which a load-supporting fork 42, as the load-receiving means, can move vertically. The additional mast 40, together with the load-supporting fork 42, can be pivoted about the vertical axis 44 between the position clearly visible in FIG. 2, in which the load-supporting fork 42 (left-hand side in relation to the straight direction of travel G) is oriented laterally and a position in which the load-supporting fork 42 is oriented in an opposing lateral position.

[0036] FIG. 3 is a side view of the lateral push frame 34 and the lateral pusher 38 arranged thereon, with the extension arm 50 shown separately, the lateral pusher 38 being shown without its outer housing casing so that the lateral push drive device 52 is visible.

[0037] As already mentioned, the lateral push frame 34 is connected to the mast 8 by a support structure 24 comprising the cab support, and can be moved vertically on the mast together with the cab 12 in a manner known per se (cf. FIG. 1).

[0038] The lateral push drive device 52 comprises a rotary drive motor 54 as the motor, in the example a rotary drive motor formed as a hydraulic motor, which is fastened to the lateral pusher 38 by means of an upper motor mounting of the lateral pusher 38 so that the motor housing 57 and thus the motor stator are rigidly connected to the frame of the lateral pusher 38. The motor comprises a rotor as the movable active element, which is coupled to a driveshaft 56 for conjoint rotation. The driveshaft 56 is rotatably mounted on the lateral pusher 38 so that it can be driven by the rotary drive motor 54 so as to rotate about a substantially vertical axis 58. A first pinion 60, which is close to the drive motor, and a second pinion 62, which is remote from the drive motor, are provided on the driveshaft 56 for conjoint rotation, which pinions roll on correspondingly assigned racks 64 and 68, respectively, of the lateral push frame 34, so as to mesh therewith. The racks 64, 68 extend in parallel with one another in the lateral direction, transversely to the main direction of travel of the industrial truck and usually extend horizontally. By rotating the pinions 60 and 62, driven by the drive motor 54, the lateral pusher 38 and its extension arm 50 can therefore be moved relative to the lateral push frame 34 along the racks 64, 68, and therefore laterally transversely to the main drive direction of the industrial truck.

[0039] The lateral pusher 38 is guided on the lateral push frame 34 by means of a plurality of rollers. A first roller 66 supports the lateral pusher 38 in the direction of gravity on a first roller race 67 formed next to and in parallel with the rack 64.

[0040] Furthermore, a second roller 70, which is near the drive motor, and a third roller 72, which is remote from the drive motor, are provided on the driveshaft 56 near to the pinions 60 and 62, respectively, so as to be rotatable relative to the driveshaft 56, and roll on associated roller tracks 76 and 77, respectively, which are formed next to and in parallel with the racks 64 and 68, respectively. The second and the third rollers 70, 72 support tilting torques about a tilt axis that extends in parallel with the racks 64, 68.

[0041] Furthermore, a first guide component 78, which is near the drive motor, and a second guide component 80, which is remote from the drive motor, are provided on the lateral pusher 38 and are used to secure the lateral pusher 38 to the lateral push frame 34 and to guide it thereon.

[0042] It should be noted at this point that, in a modified embodiment of the assembly shown in FIG. 3 and FIG. 4, a friction wheel-friction rail arrangement can be provided between the driveshaft and the lateral push frame instead of a pinion-rack arrangement. In this case, the drive force-transmission engagement is then frictional meshing. According to a corresponding embodiment of the invention, the frictional meshing can be modulated in a controlled manner in order to reduce vibrations.

[0043] The embodiments of the invention shown put into practice the concept of providing the vibration-damping device between the cab 12 and the load-supporting apparatus 36 and, more specifically, between the lateral push frame 34 and the lateral pusher 38.

[0044] In one embodiment of the industrial truck in which the assembly is formed of the lateral push frame 34 and the lateral pusher 38 in the manner shown in FIG. 3, in order to activate the vibration-damping operating mode of the lateral push drive device 52, the motor 54 can be actuated such that it does not provide a drive torque for the driveshaft 56, but instead generates a holding torque which prevents the rotor of the drive motor from rotating relative to the motor stator. In FIG. 3, reference sign 84 is a schematic depiction of a friction coupling, which is interposed between the rotor of the drive motor and the driveshaft 56 and, when the lateral push drive device 52 is in the vibration-damping operating mode, is set such that, by overcoming the friction torque or the coupling force of the friction coupling 84, the driveshaft 56 can carry out rotational movements despite the rotor of the motor 54 being held in place, if, in the case of lateral vibrations of the lateral push frame 34, inertial forces act between the lateral push frame 34 and the lateral pusher 38 and bring about relative movements between the lateral pusher 38 and the lateral push frame 34 due to the braked rotational option of the driveshaft 56. In this case, due to the friction braking effect of the friction coupling, kinetic energy can be converted into heat, so that a vibration-damping effect takes place. If the lateral pusher 38 undesirably shifts out of a particular target position relative to the lateral push frame 34 when the lateral push drive device 52 is in the vibration-damping operating mode, once the vibration triggering the shift has subsided sufficiently, the motor 54 can be activated in a controlled manner in order to move the lateral push frame 34 back into the desired target position.

[0045] According to one variant of the above-mentioned embodiment, the coupling 84 can be provided with torsion spring properties, which act in that the drive side (drive-side coupling disc arrangement) and the output side (output-side coupling disc arrangement) constantly force the coupling 84 to assume a common relative target central rotary position, in which the torsion spring restoring force is minimal, whereas the torsion spring restoring force increases the further the coupling disc arrangements rubbing against one are rotationally deflected out of the common target central rotary position.

[0046] In one embodiment of the industrial truck in which the assembly is formed of the lateral push frame 34 and the lateral pusher 38 in the manner shown in FIG. 4, a friction coupling of the type indicated in FIG. 3 is not present. Instead, the assembly in FIG. 4 comprises the same device components as the assembly in FIG. 3. In the embodiment of the lateral push drive device 52 according to FIG. 4, depending on the variant of the device for reducing vibrations, the hydraulic motor 54 can be actuated in different ways in order to activate the vibration-damping operating mode of the lateral push drive device 52.

[0047] According to a variant of this type, it is provided for the motor 54 to be actuable such that it does not provide the driveshaft 56 with drive torque, but is set to a preferably (damped) “idling mode” so that the driveshaft 56 coupled to the rotor of the motor 54 can be rotated relative to the stator in order to carry out vibration-damping movements. According to a development of said variant, the hydraulic motor 54 can be short-circuited when the lateral push drive device 52 is in the vibration-damping operating mode so that the oil supply line and the oil removal line of the hydraulic motor 54 are directly interconnected by means of a throttling point, and therefore the driveshaft 56 can be rotated in a braked manner and thus the lateral pusher 38 can carry out a vibration-damping movement relative to the lateral push frame 34 in order to damp vibrations. In this variant, too, after the vibrations have subsided, the motor 54 can be activated in order to move the lateral pusher back into a particular target position.

[0048] In another variant of the assembly shown in FIG. 4, a torsion spring, for example a torsion bar 59, as is indicated in FIG. 4 by dashed lines, can be provided in the drive train between the rotary drive motor 54 and the driveshaft 56, which spring can operate if the driveshaft 56 is rotationally deflected relative to the rotor of the drive motor 54 as a result of lateral vibrations of the lateral push frame 34, in order to generate a resilient restoring force that counteracts the rotary deflection. Such a torsion spring can reduce vibrations when the motor 54 generates a holding torque in order to hold the rotor still relative to the stator. Such a torsion spring can, however, also reduce vibrations when the motor 54 exerts a torque on the driveshaft 56.

[0049] In addition to means for resiliently restoring components in the drive train between the motor and the lateral push frame, which components are deflected relative to one another, movement-damping systems, in particular friction-damping systems, can also be provided, which, at least in the vibration-damping mode of the lateral push drive device 52, exert a braking effect on a relative movement between the lateral pusher 38 and the lateral push frame 34 in order to convert kinetic energy into another form of energy, in particular heat.

[0050] According to another variant of the assembly shown in FIG. 4, the rotary drive motor can be designed to be operated as a controllable adjusting component for actively reducing vibrations so as to drive the lateral pusher 38 to carry out vibration-reducing movements. This can take place in the separate vibration-damping mode of the lateral push drive device 52. According to a specific variant, a regular lateral push process of the lateral pusher can be superposed on an active vibration-reducing mode of this kind, so that the motor 54 drives the lateral pusher 38 to perform a regular lateral push movement and at the same time generates a vibration-reducing movement that modulates or is superposed on the lateral push movement.

[0051] A control device is provided to control the motor 54 in the manner desired in each case. Furthermore, sensors are preferably provided which detect vibration amplitudes of the mast or components that are arranged thereon in a height-adjustable manner, the control device being able to process data from said sensors in order to control the motor 54 as a controllable adjusting component for actively reducing vibrations in terms of optimised vibration reduction. In this regard, sensors can also be provided which detect the movement of the lateral pusher relative to the pivoting push frame.

[0052] In very general terms, in an industrial truck according to the invention, measures can be taken in order to recover the kinetic vibrational energy, which is dissipated or converted in the vibration-damping mode, in a useful form of energy, such as electrical energy, for example by means of a thermoelectric converter.

[0053] Situation example: as the industrial truck travels in a narrow aisle of a high-bay warehouse, the device for reducing vibrations is activated, a device that generates a braking effect, for example a friction-damping arrangement, providing a braking effect adapted to the current situation. If, when travelling over uneven floors, transverse acceleration occurs on the mast 8 and on the cab support 24 and therefore on the lateral push frame 34, the device generating the braking effect and optionally a spring arrangement transmits the transverse acceleration to the lateral pusher comprising the load-supporting apparatus and any load supported thereon. If the inertial force of the “softly coupled” masses exceeds the value of the braking force set and the optionally parallel-acting spring force, the lateral pusher 38 and the lateral push frame 34 move relative to one another. This forward and backward movement relative to a particular target rest position reduces the overall vibration amplitude and kinetic energy is predominantly converted into heat.