Method for determining the tread depth of a vehicle tire

Abstract

A procedure with the following steps is proposed: a) Providing a vehicle tyre (1) with a tread depth, b) arranging the vehicle tyre (1) on a drive-over device (2), c) Activation of an optical measuring device, wherein a plurality of fiber optics (4, 5) are integrated in the overtravel device (2), whereby laser beams are emitted by the fibre optics (4) and are reflected on the surface of the tyre profile, where the reflected laser radiation is used to measure depth dimensions at different positions in the tire profile, d) Evaluation of the measured data with a computer unit, e) Determination of a tread depth for the vehicle tyre (1).

Description

[0001] The invention relates to a method for determining a tread depth of a vehicle tire.

[0002] It is known to use tire pressure monitoring on vehicle tires to reliably detect pressure loss.

[0003] There are also various approaches to determining the tread depth of a vehicle tire using a tire sensor. However, most of these concepts have not been implemented due to their various disadvantages.

[0004] The object of the invention was to provide a method with which the determination of a profile depth can be carried out simply and with a high degree of accuracy.

[0005] The task is solved using a procedure with the following steps: a) Providing a vehicle tyre with a tread depth, b) placing the vehicle tyre on a drive-over device, c) Activation of an optical measuring device, wherein a plurality of fiber optics are integrated into the overhead device, whereby laser beams are emitted by the fiber optics, which are reflected on the surface of the tire tread, where the reflected laser radiation is used to measure depth dimensions at different positions in the tire profile, d) Evaluation of the measured data with a computer unit, e) Determination of a tread depth for the vehicle tire.

[0006] A particular advantage of the invention is that the new method allows the tread depth of the vehicle tire to be determined in a simple manner and with high accuracy.

[0007] The diameter of the individual fiber optics is relatively small.

[0008] This allows a large number of fiber optics to be arranged side by side in the drive-over device. The tire tread can be scanned from a large number of measuring points, and the tread depth can be measured with high accuracy.

[0009] In an advantageous development of the invention, it is provided that the individual fiber optics in the traversing device are arranged at a regular distance between 7 and 12 mm. This significantly improves the measuring accuracy.

[0010] In a further advantageous development of the invention, it is provided that the individual fiber optics have a diameter between 100 and 2000 micrometers.

[0011] Due to their small diameter, the fiber optics can be placed relatively close to one another.

[0012] In a further advantageous development of the invention, the over-travel device alternates between a signal fiber optic system for emitting the laser beam and a receiver fiber optic system for analyzing the reflected laser radiation. This achieves a high degree of measurement accuracy for the profile depth.

[0013] In a further advantageous development of the invention, it is provided that the signal fiber optics are connected to a laser signal source and the receiver fiber optics are connected to an evaluation unit.

[0014] In a further advantageous development of the invention, the measurement frequency is controlled by a pulsed laser signal source. This allows the measurement frequency to be easily adapted to different measurement conditions.

[0015] In a further advantageous development of the invention, it is provided that the crossing device is arranged in a flexible mat.

[0016] The fiber optics can be easily integrated into a flexible mat. Furthermore, the mat can be easily positioned in different locations, for example, in a workshop.

[0017] The invention is described in more detail below using an exemplary embodiment.

[0018] It shows: Fig. 1: a vehicle tire with a drive-over device, Fig. 2: a section of the side view in the Fig. 1, Fig. 3: a top view of the crossing device.

[0019] The Fig. Figure 1 shows a vehicle tire 1 with a tread 3 arranged on the overrun device 2. The vehicle tire 1 is moved at a slow speed over the overrun device 2. Alternatively, the vehicle tire 1 can be brought to a temporary stop on the overrun device 2. The overrun device 2 is a flexible mat in which a plurality of fiber optics are integrated.

[0020] The Fig. 2 shows a partial section of the Fig. 1. A plurality of individual fiber optics are integrated into the override device 2. A signal fiber optic 4 is arranged alternately next to a receiver fiber optic 5. The signal fiber optics 4 and receiver fiber optics 5 are arranged essentially parallel to each other. They are also aligned perpendicular to the vehicle tire. Laser beams are emitted onto the tire tread using the individual signal fiber optics. The reflections are received by the individual receiver optics 5. The tire tread can be measured in the ground contact patch using the reflected radiation.

[0021] The Fig.Figure 3 shows a section of the overhead device 2 in a top view. The signal fiber optics 4 and receiver fiber optics 5 are arranged at a close distance from one another. Essentially, a signal fiber optic 4 is arranged alternately next to a receiver fiber optic 5. The signal fiber optics 4 are connected to a pulsed signal source 6 via individual fiber optics. A specific measurement frequency can be set using the pulsed signal source 6. The receiver fiber optics 5 are connected to an evaluation unit 7 via fiber optic cables. The evaluation unit 7 evaluates the measurement results and subsequently determines a tread depth for the vehicle tire. The evaluation unit can comprise photodiodes and / or a laser spectrometer for analyzing the reflected radiation. List of reference symbols 1 vehicle tire 2 crossing device in the form of a mat 3 tread strips with tire profile 4 Signal fiber optics 5 Receiver fiber optics 6 Signal source 7 Evaluation unit

Claims

[1] Method for determining a tread depth of a vehicle tire (1) with a tread (3) comprising the following steps: a) Providing a vehicle tyre (1) with a tread depth, b) arranging the vehicle tyre (1) on a drive-over device (2), c) Activation of an optical measuring device, wherein a plurality of fiber optics (4, 5) are integrated in the overtravel device (2), whereby laser beams are emitted by the fibre optics (4) and are reflected on the surface of the tyre profile, where the reflected laser radiation is used to measure depth dimensions at different positions in the tire profile, d) Evaluation of the measured data with a computer unit, e) Determination of a tread depth for the vehicle tyre (1). [2] Method according to claim 1, characterized bythat the individual fiber optics (4,5) in the traversing device are arranged at a regular distance between 7 and 12 mm. [3] Method according to one of the preceding claims, characterized by that the individual fiber optics (4,5) have a diameter between 100 and 2000 micrometers. [4] Method according to one of the preceding claims, characterized by that a signal fiber optic (4) for the emission of the laser beam and a receiver fiber optic (5) for analyzing the reflected laser radiation are arranged alternately in the overtravel device. [5] Method according to one of the preceding claims, characterized by that the signal fiber optics (4) are connected to a laser signal source (6) and the receiver fiber optics (5) are connected to an evaluation unit (7). [6] Method according to one of the preceding claims, characterized bythat the measuring frequency is controlled by a pulsed laser signal source (6). [7] Method according to one of the preceding claims, characterized by that the crossing device (2) is arranged in a flexible mat.

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