DE102010002744A1 - Arrangement for determining absolute steering angles with steerable drive device of industrial truck, has distance sensor for determining angles, where distance between distance sensor and cam track is determined independence of angles - Google Patents

Abstract

The arrangement has a distance sensor (5) for determining steering angles (alpha). Distance (d) between the distance sensor and a cam track (6) for determination of the steering angles is determined independence of the steering angles. The distance sensor is fixed at a frame plate (7) of a vehicle frame. The distance to the distance sensor is changed along the cam track related to a steering axle (4) in an axial direction or in a radial direction. A position sensor (9) is assigned to another cam track.

Description

The present invention relates to an arrangement for determining absolute steering angles in a steerable drive device of a truck according to the closer defined in the preamble of claim 1. Art.

For example, from the document DE 10 2004 005 869 A1 is a drive unit, in particular a unicycle engine for a battery-powered vehicle known. The drive unit includes a power steering having a power steering motor and a steering gear unit, so that a transmission of steering movements is made possible. At the steering gear, a potentiometer for angle measurement is provided. In the known drive unit neither an absolute steering angle determination nor a steering angle determination in a 360 ° steering is possible.

Furthermore, from the document DE 43 07 544 A1 an arrangement for detecting the rotational position of a rotary body known. As a rotational body of the rotor of an electric machine is provided, the rotational angle position is detected. On the rotor, a donor body is provided with a spiral-shaped peripheral contour in the manner of a worm. For detecting the angular position, a magnet and a field sensor assigned thereto are provided.

The present invention is based on the object to propose an arrangement for detecting absolute steering angles in a steerable drive device of a truck with which it is possible in the simplest way even in the specific space situation in the field of steerable drive means of the truck to determine a steering angle position absolutely ,

This object is achieved with the features of claim 1, wherein further advantageous embodiments of the dependent claims and the drawings.

An arrangement is provided for determining or measuring absolute steering angles in a steerable drive device of an industrial truck with at least one detection device for determining the steering angle, wherein the detection device comprises at least one distance sensor or the like, which varies depending on the steering angle distance between the distance sensor and detected at least one associated curved path for determining the steering angle.

Thereby, an absolute steering angle measurement can be realized by using the mathematical relationship between the detected distance and the steering angle, the absolute steering angle is determined or calculated without a rotation angle sensor is required. Only by the predetermined course of the curved path can be closed by the thereby changing distance to the steering angle. The required calculations can be performed either directly by the distance sensor or by a coupled processing device.

Preferably, the distance varying along the curved path extending about the steering axis may be proportional to the steering angle. There are also other dependencies possible, which are quasi chosen by the course of the curved path used. However, it has been shown that a proportional relationship significantly reduces the computational effort for determining the steering angle.

As part of a possible embodiment of the invention can be provided that the curved path is provided for example on a steering movements exporting or transmitted steering wheel of the drive device of the truck. However, it is also possible that the curved path z. B. is attached in the form of a cam to other components of the steerable drive device. If the cam track is provided on steerable or movable components of the drive device, such as the turntable or the steering gear or the transmission gear, for example, the distance sensor can be fixed to a frame plate or the like of the vehicle frame of the truck. However, the distance sensor can also be arranged on other stationary components of the drive device or the arrangement positions of distance sensor and curved path can be reversed.

Regardless of the respective arrangement position of curved path and distance sensor, the curved path can be configured such that the distance between the distance sensor along the curved path relative to the steering axis in the axial or in the radial direction changes to determine the respective steering angle over the detected distance. As a possible example of an axially or radially varying cam track, which is integrated, for example, in the steering wheel, may be called a running in the circumferential direction of the steering wheel groove or the like with varying depth. However, the curved path can also be attached as a separate component to the steerable part of the drive device whose axial or radial distance to the distance sensor is increased or decreased in dependence on the angular position.

As part of a possible embodiment of the invention can be provided that an eccentrically arranged to the steering axis and z. B. circular cam track is provided so that the distance for steering angle positions less than / equal to ± 90 ° in the one steering direction is greater and in the other steering direction is smaller than the zero position. In this way, a distinction of the steering direction in the steering angle determination due to each steering direction 0 to + 90 ° or 0 to -90 ° associated characteristic curve of the curved path is readily possible.

In order to enable absolute steering angle determination, for example, also with industrial trucks with so-called 360 ° steering, it can be provided according to a further development that an archimedean spiral or the like running around the steering axis is used as the curved path, wherein the distance at the zero positions is 0 ° and at 360 ° different, z. B. is maximum and minimal. In this way, the course of the distance in the range of 0 ° to 360 ° is formed angle-proportionally variable.

Regardless of the respective embodiments, it can also be provided in the arrangement according to the invention that at least one position sensor or the like is provided for determining the steering direction. The position sensor may be associated with, for example, an additional curved path or the like, so that the steering direction is indicated by the position sensor in addition to the detection of the angle of rotation by the distance sensor.

Hereinafter, the present invention will be further explained with reference to the drawings. Show it:

1 schematic, partially sectional view of a possible embodiment of an inventive arrangement for determining steering angles in a steerable drive means of a truck;

2 a schematic view of a possible embodiment of a curved path of the arrangement according to the invention; and

3 a schematic view of another possible embodiment of a curved path of the arrangement according to the invention.

In 1 is a possible embodiment of an inventive arrangement for determining absolute steering angles α at a steerable drive means of a material handling vehicle. The steerable drive device comprises a drive motor not shown, which is usually rigidly or fixedly attached to a vehicle frame of the truck. The drive shaft of the drive motor is with a transmission gear 1 for driving a vehicle wheel 2 coupled. The transmission gearbox 1 is over a steering wheel 3 rotatable about a steering axis 4 mounted on the vehicle frame, so that the transmission gear 1 with the steering wheel 3 around a steering axle 4 is rotatable to appropriate steering movements with the vehicle 2 perform.

In order to be able to determine an absolute steering angle α in the industrial truck, the arrangement according to the invention has a detection device in the region of the steerable drive device. The detection device consists of a distance sensor 5 standing at a frame plate 7 the truck is held stationary. The distance sensor 5 serves a distance d between the distance sensor 5 and a curved track 6 to detect the steering angle α. The curved path 6 is designed such that the distance varies depending on the steering angle α.

According to 1 is as possible execution of the curved path 6 a groove 8th in the circumferential direction in the steering wheel 3 integrated, with the groove 8th one related to the steering axle 4 having in the axial direction changing depth T. By the axial insertion or groove 8th results in a functional relationship between the depth T and the steering angle α over the circumference of the steering wheel rim 3 in the form of T = f (α).

The partially cut view according to 1 shows on the right side a smaller depth T at a steering angle α of, for example, 0 ° and on the left a greater depth T in the groove 8th at a steering angle α of z. B. 180 °. As a result, during steering movements by the distance sensor 5 minus an offset value O, the changing distance d, which is for example proportional to the absolute steering angle α, is detected. As a result, with the arrangement according to the invention, the absolute steering angle α can be determined or calculated from the given mathematical relationship and the detected distance d. The functional relationship between the steering angle α and the distance d between the distance sensor 5 and the curved path 6 is determined by the spatial course of the curved path 6 certainly.

In the 2 and 3 are exemplary two different courses of possible curved paths 6 . 6A . 6B shown. In 2 is an approximately circular curved path 6A shown, which is eccentric to the steering axle 4 with an eccentricity e runs. This results in a preferred curved path 6A For example, for steering angle positions less than or equal to ± 90 °. Starting from the zero position at a steering angle α of 0 °, the distance d between the distance sensor 5 and the curved path 6A smaller with a left turn and larger with a right turn than with a steering angle α of 0 °. Thus, the respective existing steering angle α can be clearly determined with the arrangement according to the invention.

In 3 is a curved track 6B shown as an Archimedean spiral around the steering axis 4 from 0 to + 180 ° and from 0 to -180 °. This version of the curved path 6B is suitable in conjunction with the position sensor 9 and the depression or survey 10 especially for so-called 360 ° steering, as the distance d is different for the zero positions of the steering angles of 0 ° and 180 °. How out 3 can be seen, the distance at the steering angle of 0 ° is minimal and at the steering angle α of 180 ° maximum. In this way, the two zero positions can be clearly distinguished.

In particular from the 1 and 3 is another possible embodiment of the arrangement according to the invention can be seen in the next to the distance sensor 5 an additional position sensor 9 fixed to the frame plate 7 of the truck is provided. The position sensor 9 is assigned to another curved track, which in 3 a circumferentially changing depression or elevation 10 is. In this way, the position sensor 9 due to the changing nature of the survey 10 recognize in which direction the steering wheel 3 is rotated in the context of a steering movement.

LIST OF REFERENCE NUMBERS

1

up gear

2

vehicle

3

turntable

4

steering axle

5

Distance sensor

6, 6A, 6B

cam track

7

frame plate

8th

groove

9

position sensor

10

survey

α

steering angle

d

Distance between distance sensor and curved path

T

Depth of the groove

O

offset value

e

eccentricity

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102004005869 A1 [0002]
• DE 4307544 A1 [0003]

Claims (10)

Arrangement for determining absolute steering angles (α) in the case of a steerable drive device of an industrial truck, with at least one detection device for determining the steering angle (α), characterized in that at least one distance sensor ( 5 ) is provided, the one in dependence of the steering angle (α) changing distance (d) between the distance sensor ( 5 ) and at least one associated curved path ( 6 . 6A . 6B ) for determining the steering angle (α) detected. Arrangement according to claim 1, characterized in that along a about the steering axis ( 4 ) extending cam track ( 6 . 6A . 6B ) changing distance (d) is proportional to the steering angle (α). Arrangement according to one of the preceding claims, characterized in that the curved path ( 6 . 6A . 6B ) on a steering wheel ( 3 ) of the drive device of the truck is provided. Arrangement according to one of the preceding claims, characterized in that the distance sensor ( 5 ) fixed to a frame plate ( 7 ) of the vehicle frame is attached. Arrangement according to one of the preceding claims, characterized in that the curved path ( 6 . 6A . 6B ) is configured such that the distance (d) to the distance sensor ( 5 ) along the curved path ( 6 . 6A . 6B ) relative to the steering axle ( 4 ) changed in the axial direction or in the radial direction. Arrangement according to one of the preceding claims, characterized in that as a curved path ( 6 . 6A . 6B ) one in the circumferential direction of the steering wheel rim ( 3 ) running groove ( 8th ) is provided with varying depth (T). Arrangement according to one of the preceding claims, characterized in that one to the steering axis ( 4 ) eccentrically arranged and circular curved track ( 6A ) is provided, so that the distance (d) for steering angle positions smaller ± 90 ° in the one steering direction is greater and in the other steering direction is smaller than the zero position at a steering angle of 0 °. Arrangement according to one of the preceding claims, characterized in that with 360 ° steering as a curved path ( 6B ) one around the steering axle ( 4 ) from 0 to + 180 ° and from 0 to -180 ° extending Archimedean spiral is provided, wherein the distance (d) is different at the zero positions at a steering angle (α) of 0 ° and 180 °. Arrangement according to one of the preceding claims, characterized in that for detecting the steering direction at least one position sensor ( 9 ) is provided. Arrangement according to claim 9, characterized in that the position sensor ( 9 ) is associated with an additional curved path.

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