Narrow aisle truck with measures for preventing mast vibrations and for compensating for mast deformations

Patent metadata

Field	Value
Publication number	US-12291440-B2
Application number	US-202117352803-A
Country	US
Kind code	B2
Filing date	Jun 21, 2021
Priority date	Jun 22, 2020
Publication date	May 6, 2025
Grant date	May 6, 2025

Abstract

The present invention involves a narrow aisle truck comprising: a vehicle body having length and width directions; wheels assigned to the vehicle body and arranged on two axes running in the width direction and configured to drive and steer the truck; a drive system configured to exert an acceleration torque on at least one of the wheels; a mast extending substantially vertically with respect to the length direction of the vehicle body between the two axes; at least one detection unit to detect at least one state parameter; at least one actuator to cause a movement of the mast relative to the vehicle body; and a control unit to: determine a current state, determine an effect of an actuation of the at least one actuator on the current state, and activate the at least one actuator to reduce a difference between the determined current state and a predetermined target state.

First claim

The invention claimed is:

1. A narrow aisle truck, comprising:
a vehicle body having a length direction and a width direction;
wheels assigned to the vehicle body and arranged on two axes running in the width direction of the vehicle body and configured to drive and steer the narrow aisle truck when driving on a driving surface;
a drive system configured to exert an acceleration torque on at least one of the wheels;
a mast extending substantially vertically, between the two axes, with respect to the length direction of the vehicle body wherein the mast is movably mounted relative to the vehicle body in a floating manner with respect to a bearing plane by a bearing arrangement, wherein the bearing arrangement allows the mast to pivot relative to the vehicle body with respect to at least two degrees of freedom of movement;
at least one detection unit configured (A) to detect at least one state parameter of one or more of (i) the narrow aisle truck or (ii) surroundings of the narrow aisle truck and (B) to output corresponding data;
at least two actuators, each actuator of the at least two actuators configured to move the bearing arrangement relative to the vehicle body to cause pivot movements of the mast relative to the vehicle body, each pivot movement corresponding to a respective degree of freedom of the at least two degrees of freedom; and
a control unit operatively coupled to the at least one detection unit and the at least two actuators and configured to:
determine a current state of the narrow aisle truck based on the at least one state parameter detected by the at least one detection unit;
determine an effect of an actuation of one or more of the at least two actuators on the current state; and
activate at least one of the at least two actuators to reduce a difference between the determined current state and a predetermined target state, wherein the predetermined target state corresponds to the mast being vertically aligned regardless of a slope of the driving surface.

2. The narrow aisle truck of claim 1 , wherein the control unit is further operatively coupled to the drive system and is further configured to:
determine an effect of a modulation of the acceleration torque exerted by the drive system on at least one wheel on the current state; and
control the drive system so that the difference between the determined current state and predetermined target state is reduced.

3. The narrow aisle truck of claim 1 , wherein the at least one detection unit is configured to detect an inclination of one or more of the vehicle body, the mast, or the driving surface relative to a horizontal, wherein the inclination is transverse to the length direction of the narrow aisle truck.

4. The narrow aisle truck of claim 1 , wherein the at least one detection unit is configured to detect, for one or more of (A) the vehicle body or (B) the mast, one or more of (i) an acceleration or (ii) a vibration.

5. The narrow aisle truck of claim 1 , wherein the at least one detection unit is configured to detect a relative or absolute position of the narrow aisle truck, and wherein the detection unit is also assigned a memory unit operatively coupled to the control unit, wherein topology data pertaining to the driving surface accessible to the narrow aisle truck is stored in the memory unit.

6. The narrow aisle truck of claim 1 , wherein the control unit is further configured to classify possible disturbances on the basis of the at least one state parameter detected by the at least one detection unit.

7. The narrow aisle truck of claim 1 , wherein at least one of the at least two actuators comprises one or more of: a single-acting hydraulic cylinder, a double-acting hydraulic cylinder, a linear motor, a stepping motor, a threaded spindle, a rack drive, an electromagnet or a piezo element.

8. The narrow aisle truck of claim 1 , wherein at least one of the at least two actuators comprises a hydraulic cylinder with a variable spring preload.

9. The narrow aisle truck of claim 1 , wherein the bearing arrangement comprises a damping element configured to dampen a movement of the mast relative to the vehicle body along at least one direction.

10. The narrow aisle truck of claim 1 , wherein the bearing plane that extends substantially vertically and in the width direction of the vehicle body, wherein at least one of the at least two actuators is configured to displace the mast in the vertical direction relative to the vehicle body.

11. The narrow aisle truck of claim 10 , wherein, as a result of a coupling of the at least one actuator to the mast, an effective axis running in a substantially horizontal direction is formed for displacing the mast in the vertical direction so that an actuation of the at least one actuator to move the bearing arrangement relative to the vehicle body leads to a pivoting of the mast about the effective axis.

12. The narrow aisle truck of claim 10 , wherein the at least two actuators comprise two actuators arranged on opposite sides of the mast.

13. The narrow aisle truck of claim 1 , further comprising a further bearing arrangement configured to allow a pivoting of the mast about an axis extending perpendicular to the bearing plane, wherein an arranged actuator drives the pivoting.

14. The narrow aisle truck of claim 13 , wherein the further bearing arrangement is also configured to allow the mast to pivot about a further axis lying in the bearing plane.

15. The narrow aisle truck of claim 13 , wherein the further bearing arrangement and at least one of the at least two actuators are arranged on opposite sides of the mast with respect to the width direction of the vehicle body.

16. The narrow aisle truck of claim 15 , wherein an effective axis running substantially in a horizontal direction is formed by the at least one actuator for pivoting the mast and the further bearing arrangement, wherein the narrow aisle truck comprises a coupling of the at least one actuator and the further bearing arrangement to the mast so that an actuation of the actuator to move the bearing arrangement relative to the vehicle body leads to a pivoting of the mast about the effective axis.

17. The narrow aisle truck of claim 1 , wherein the mast is mounted by means of the bearing arrangement in a manner allowing a vertical movement, wherein the mast is mounted movably with respect to the width direction of the vehicle body by means of a further bearing arrangement, wherein at least one actuator is configured to move the mast in a region of the further bearing arrangement in the width direction of the vehicle body to cause the mast to pivot by elastic torsion.

18. The narrow aisle truck of claim 17 , wherein the bearing arrangement is movable with respect to the vehicle body by a first actuator of the at least two actuators and, wherein an effective axis running in a substantially horizontal direction is formed by the further bearing arrangement so that an actuation of the first actuator to move the bearing arrangement relative to the vehicle body leads to a pivoting of the mast about the effective axis.

19. The narrow aisle truck of claim 1 , further comprising a further bearing arrangement configured to allow the mast to pivot about a stationary pivot axis running in the length direction of the vehicle body, wherein at least one of the at least two actuators is configured to cause the mast to pivot about the pivot axis.

20. The narrow aisle truck of claim 19 , wherein the further bearing arrangement is further configured to allow a movement

Assignees

• Jungheinrich Ag

Inventors

• Schöttke Carsten
• Bibernell Hubert
• Schönauer Michael

Classifications

• B66F9/22

  Hydraulic devices or systems · CPC title

• B66F9/07559

  Stabilizing means · CPC title

• B66F9/105 Primary

  Articulated, i.e. front chassis with wheels and mast rotatable relative to rear chassis with wheels · CPC title

• B66F9/08

  Masts; Guides; Chains · CPC title

• B66F9/24

  Electrical devices or systems · CPC title