Industrial truck having increased static or quasi-static tipping stability

• US 7,706,947 B2
• Filed: 04/06/2005
• Issued: 04/27/2010
• Est. Priority Date: 04/07/2004
• Status: Expired due to Fees

• Current Assignee: Linde Material Handling GmbH (Superlift Holding SARL)
• Original Assignee: Linde Material Handling GmbH (Superlift Holding SARL)
• Inventors: Carlitz, Andreas, Roth, Jurgen, Schroder, Frank, Bozem, Gerhard, Gotz, Bernhard
• Primary Examiner(s): Keith; Jack W.
• Assistant Examiner(s): Dager; Jonathan M
• Application Number:
  US11/099,992
• Publication Number:
  US 20050281656A1
• Time in Patent Office: 1,847 Days
• Field of Search: 180/222, 180/223, 180/224, 180/226, 180/229, 180/233, 180/237, 701/50, 701/54
• US Class Current: 701/50
• CPC Class Codes: B66F 17/003 for fork-lift trucks

Abstract

A forward-control counterweight fork-lift truck has a liftable and tiltable load-lifting device (1), a traction drive and operating drives for the movement of the load-lifting device (1). A calculation model (D) is stored in a control device (SE), to which directly or indirectly acting sensors (S) are connected for detecting the lifting load (L), the lifting height (H), the tilting angle (WM), the load torque (M), the direction of travel (R), the driving speed (V), and the steering angle (WL). The control device (SE) is designed to determine a driving and load state (Z) based on the detected physical variables (L, H, WM, M, R, V, WL) and the stored calculation model (D) and is operatively connected to the traction drive and the operating drives. Depending on the driving and load state (Z) determined, the operating speed, starting and braking acceleration, and driving speed are each reduced.

Claims

1. An industrial truck having improved static or quasi-static tipping stability, comprising:

a liftable and tiltable load-lifting device;

a traction drive and operating drives for movement of the load-lifting device;

a control device designed to store a calculation model, which is based on vehicle-specific information, for static and/or quasi-static tipping behavior of the industrial truck; and

directly or indirectly acting sensors connected to the control device for detecting physical variables including a lifting load, a lifting height, a tilting angle, a load torque, a direction of travel of the industrial truck, a driving speed of the industrial truck, and a steering angle,

wherein the control device includes a driving-state observer designed to determine a driving and load state based on the detected physical variables and the stored calculation model and operatively connected to the traction drive and the operating drives such that, depending on the driving and load state determined, one or more of the operating speed of the load lifting device or starting and braking acceleration of the industrial truck which can be achieved or are achieved, are reduced,

wherein said industrial truck is a forward control counterweight fork-lift truck,

wherein the control device is designed to give in a state diagram for the driving speed of the fork-lift truck and the lifting height of the load lifting device a first operating range and a second operating range and the first operating range is defined by a limiting lifting height of the load lifting device and a limiting driving speed of the fork-lift truck and represents the static or quasi-static range in which the risk of tipping accidents of the fork-lift truck is at its lowest and the second operating range is defined by the limiting driving speed of the fork-lift truck and a lifting height of the load lifting device greater than the limiting lifting height of the first operating range and represents the static or quasi-static range in which the risk of tipping accidents of the fork-lift truck is greater than that of the first operating range,

wherein the control device is further designed to intervene when said driving and load state is determined to be in said second operating range to increase the tipping stability of the fork-lift truck by reducing one or more of the operating speed of the load-lifting device or the starting and braking acceleration of the fork-lift truck, and

wherein the control device is further designed to reduce the starting and braking acceleration of the fork-lift truck which can be achieved or are achieved while allowing the lifting operation of the load-lifting device when the driving and load state is determined to be in at least the second operating range in order to increase the tipping stability of the fork-lift truck.

2. The industrial truck according to claim 1, wherein vehicle-specific information contained in the control device at least comprises data on the dimensions and the weights of the fork-lift truck and the load-lifting device and on the load.

3. The industrial truck according to claim 1, wherein the control device is designed to monitor at least the following driving maneuvers which are critical to tipping:

braking whilst traveling forward with the vehicle being inclined forward, accelerating whilst reversing with the vehicle being inclined forward, braking out of reverse travel on a bend with the vehicle being inclined perpendicular to the tipping axis, and accelerating forward on a bend with the vehicle being inclined perpendicular to the tipping axis.

4. The industrial truck according to claim 2, wherein the control device is designed to monitor at least the following driving maneuvers which are critical to tipping:

braking whilst traveling forward with the vehicle being inclined forward, accelerating whilst reversing with the vehicle being inclined forward, braking out of reverse travel on a bend with the vehicle being inclined perpendicular to the tipping axis, and accelerating.