INDUSTRIAL TRUCK WITH OPTICAL LIFTING HEIGHT MEASUREMENT

• US 20090319134A1
• Filed: 06/19/2009
• Published: 12/24/2009
• Est. Priority Date: 06/19/2008
• Status: Active Grant

• Current Assignee: Jungheinrich AG
• Original Assignee: Jungheinrich AG
• Inventors: HAEMMERL, Robert, Schoettke, Carsten
• Granted Patent: US 8,600,628 B2
• Time in Patent Office: Days
• US Class Current: 701/50
• CPC Class Codes: B66F 9/0755 Position control; Position detectors
• CPC Class Codes: B66F 9/08 Masts; Guides; Chains
• CPC Class Codes: B66F 9/24 Electrical devices or systems

Abstract

The invention relates to an industrial truck, comprising a vehicle frame, a lifting framework (14), the lifting framework (14) having a first lifting frame (20) which is attached to the vehicle frame, and at least one lifting arrangement (22, 24) which is movable in the vertical direction (V) relative to the first lifting frame (20), and a measuring arrangement (32, 38, 40) which is provided in order to detect a movement of the first lifting frame (20) and/or of the lifting arrangement (22, 24) relative to the vehicle frame. In this case, it is provided according to the invention that the measuring arrangement comprises at least one optical sensor (32) by means of which the movement of the first lifting frame (20) and/or of the lifting arrangement (22, 24) can be sensed contactlessly. Furthermore, the invention proposes a method for determining the lifting height in a lifting framework of an industrial truck, with the distance covered by the first lifting frame (20) and/or by the lifting arrangement (22, 24) being detected by sensing of a surface (36) of the first lifting frame (20) or of the lifting arrangement (22, 24) by means of an associated optical sensor (32).

Claims

1. An industrial truck, comprising

a vehicle frame (12),

a lifting framework (14), the lifting framework (14) having a first lifting frame (20) which is attached to the vehicle frame (12), and at least one lifting arrangement (16, 18, 22, 24) which is movable in the vertical direction (V) relative to the first lifting frame (20),

a measuring arrangement (32, 32′

, 38, 40) which is provided in order to detect a movement of the first lifting frame (20) and/or of the lifting arrangement (16, 18, 22, 24) relative to the vehicle frame (12), the measuring arrangement comprising at least one optical sensor (32, 32′

), wherein the movement of the first lifting frame (20) and/or of the lifting arrangement (16, 18, 22, 24) can be sensed contactlessly by the measuring arrangement (32, 32′

, 38, 40), with the coincidental surface design of the lifting frame (20) and/or of the lifting arrangement (16, 18, 22, 24) being sensed by the optical sensor (32, 32′

).

2. The industrial truck as claimed in claim 1, wherein the optical sensor (32) is fastened to the first lifting frame (20) and faces a surface (36) of the vertically movable lifting arrangement (16, 18, 22, 24) such that the movement of the lifting arrangement (16, 18, 22, 24) relative to the first lifting frame (20) can be detected.

3. The industrial truck as claimed in claim 1, wherein the lifting arrangement (16, 18, 22, 24) has at least one second lifting frame (22, 24) which can be displaced telescopically in the vertical direction (V) with respect to the first lifting frame (20), the second lifting frame (22) being guided on the first lifting frame (20).

4. The industrial truck as claimed in claim 3, wherein the optical sensor (32) is directed toward a surface (36) of the at least one second lifting frame (22) such that the movement of the second lifting frame (22) relative to the first lifting frame (20) can be detected.

5. The industrial truck as claimed in claim 3, wherein, in the event of a plurality of second lifting frames (22, 24) which are guided telescopically on one another in the vertical direction (V), an in particular stepped-up or stepped-down vertical movement coupling between the second lifting frames (22, 24) is provided.

7. The industrial truck as claimed in claim 1, characterized in that the optical sensor (32) is designed in such a manner that two movement components which are orthogonal with respect to each other can be detected in one sensing plane.

8. The industrial truck as claimed in claim 1, characterized in that at least one visually recognizable marking (38, 38′

) facing the optical sensor (32, 32′

) is arranged on the lifting arrangement (16, 18, 22, 24).

9. The industrial truck as claimed in claim 8, characterized in that the marking (38, 38′

) is designed in the form of an additional component (40) attached to the lifting arrangement or to the second lifting frame, or in the form of a change in color or a change in surface structure on the lifting arrangement (16, 18, 22, 24) or on the second lifting frame (22), or such like.

10. The industrial truck as claimed in claim 8, characterized in that the marking (38, 38′

) is provided at a predetermined reference position on the lifting arrangement (16, 18, 22, 24) or on the second lifting frame (22) such that a position of the marking (38, 38′

), which position is detected by the sensor (32, 32′

), can be compared with the absolute reference position.

11. The industrial truck as claimed in claim 1, characterized in that the first lifting frame (20) is coupled to the vehicle frame (12) in such a manner that the entire lifting framework (14) can be pivoted about a pivot axis which is substantially orthogonal to the straight-ahead direction of travel and lies in a plane substantially parallel to the underlying surface.

12. The industrial truck as claimed in claim 11, wherein the optical sensor or a further optical sensor is attached to the industrial truck, in particular to the vehicle frame, in such a manner that the pivoting movement of the lifting framework can be detected.

13. The industrial truck as claimed in claim 1, wherein the lifting arrangement (16, 18, 22, 24) comprises a load pickup means (18) and/or a driver'"'"'s cab (16), with the load pickup means (18) and/or the driver'"'"'s cab (16) being attached in particular to a lifting frame and/or to the second lifting frame (22, 24).

14. The industrial truck as claimed in claim 13, wherein an optical sensor (32′

) is attached to the load pickup means (18) and/or to the driver'"'"'s cab (16), said sensor being directed toward a surface of one of the second lifting frames (24) such that the vertical movement of the load pickup means (18) and/or of the driver'"'"'s cab (16) relative to said second lifting frame (24) can be detected.

15. The industrial truck as claimed in claim 13, wherein, in the event of a driver'"'"'s cab (16) being attached to the second lifting frame (24), a further lifting apparatus for a load pickup means (18) attached to the driver'"'"'s cab (16) is provided, with a further optical sensor being provided by means of which the relative movement between said load pickup means (18) and the driver'"'"'s cab (16) can be detected.

16. A method for determining the lifting height in a lifting framework (14) of an industrial truck (10) as claimed in claim 1, with the distance covered by the first lifting frame (20) and/or the lifting arrangement (16, 18, 22, 24) being detected by sensing of a surface (36, 44) of the first lifting frame (20) or of the lifting arrangement (16, 18, 22, 24) by means of an associated optical sensor (32, 32′

).

17. The method as claimed in claim 16, with, during a pivoting movement of the first lifting frame or during the lifting movement of the lifting arrangement (16, 18, 22, 24):

a marking (38, 38′

) on the first lifting frame or on the lifting arrangement (16, 18, 22, 24) being detected;

the position of the marking (38, 38′

), which position is detected by incremental measurement of the distance, being compared with a stored, absolute position reference value of said marking; and

a corresponding signal being provided if a predetermined difference between a position measured value and position reference value for the marking is exceeded.

6. An industrial truck, comprising

a vehicle frame (12),

a lifting framework (14), the lifting framework (14) having a first lifting frame (20) which is attached to the vehicle frame (12), and at least one lifting arrangement (16, 18, 22, 24) which is movable in the vertical direction (V) relative to the first lifting frame (20),

a measuring arrangement (32, 32′

, 38, 40) which is provided in order to detect a movement of the first lifting frame (20) and/or of the lifting arrangement (16, 18, 22, 24) relative to the vehicle frame (12), the measuring arrangement comprising at least one optical sensor (32, 32′

), wherein the movement of the first lifting frame (20) and/or of the lifting arrangement (16, 18, 22, 24) can be sensed contactlessly by the measuring arrangement (32, 32′

, 38, 40), with the lifting arrangement (16, 18, 22, 24) having at least one second lifting frame (22, 24) which can be displaced telescopically in the vertical direction (V) with respect to the first lifting frame (20), with the second lifting frame (22) being guided on the first lifting frame (20) and with, in the event of a plurality of second lifting frames (22, 24) which are guided telescopically on one another in the vertical direction (V), an in particular stepped-up or stepped-down vertical movement coupling between the second lifting frames (22, 24) is provided.