EP0526907B1 - Process and apparatus for adjusting a preselected cleaning-width of a rotating cylindrical brush - Google Patents

Description

The invention relates to a method for setting a preselected sweeping mirror width of a roller broom rotatable about an axis according to the preamble of patent claim 1.

As is well known, vehicles with rotating roller brushes are used to clean surfaces such as roads or tarmacs at airfields. Important for an optimal cleaning result is among other things the correct sweeping mirror or the correct sweeping mirror width, i.e. the contact area between the rotating roller brush and the surface to be cleaned.

If the sweeping level is too low, the cleaning result is unsatisfactory, while if the sweeping level is too large, the roller brush will wear excessively. In addition, residues from the roller brush lead to an increased safety risk when cleaning roads or runways due to the increased wear.

The possibility of a one-time manual adjustment at the beginning of the cleaning work is inadequate, since the diameter of the roller broom decreases due to the constant wear and tear and thus the sweeping level is reduced. Even a readjustment carried out at larger intervals offers only a conditionally usable solution, since the cleaning properties deteriorate continuously by reducing the sweeping level between two settings and, in addition, the cleaning work may have to be interrupted for the new setting.

From DE-A-37 40 215 a device is known in which the roller diameter of the roller broom is determined and in which the distance of the axis of the roller broom from the surface to be cleaned is automatically changed depending on the decreasing diameter. As a result, however, the sweeping mirror can only be in keep within certain limits.

In this known device according to DE-A-37 40 215, sensor pins of a sensor are attached to a swivel arm, the sensor pins coming into contact with the outer surface of the roller broom during operation. They continuously generate pulses that are fed into the actuating device. If the roller brush becomes smaller in diameter due to wear, the impulses are interrupted. Both the roller brush and the swivel arm of the sensor have to be readjusted, whereupon pulses are again recorded in a further phase until a new readjustment is necessary due to the wear.

The known device is inaccurate because the diameter of the roller broom is not exactly determined, but only a certain diameter range is monitored in accordance with a permissible degree of wear.

The invention has for its object to provide a method for setting a preselected sweeping mirror width, which is a much more accurate determination of the roller diameter of the roller brush and a much more accurate setting of a desired sweeping mirror width enables to achieve an optimal cleaning result with little wear.

This object is achieved by the characterizing features of patent claim 1.

The invention is not limited to determining only the roller diameter of the roller broom. Rather, the actual distance between the axis and the surface to be cleaned is also measured in a new way.

This measured variable is compared with the target distance, which results from the recorded roll diameter. If the two values differ, the target distance is then readjusted. The additional determination of the actual distance between the axis and the surface to be cleaned can therefore advantageously be used to implement a control circuit in order to set a distance which corresponds to a desired constant sweeping level.

In an advantageous development of the invention it is provided that the actual distance between the axis and the surface to be cleaned is measured continuously, wherein the measured values supplied by the measuring device are averaged over time in order to derive the actual distance therefrom.

The temporal averaging can also determine the height of the static rest position of the axis above the surface to be cleaned, taking into account unevenness in the surface to be cleaned, and with the aid of the additionally measured roller diameter, it is possible to regulate the distance between the axis and the given cleaning surface. With a control circuit, the roller brush can be held above the surface in such a way that a pre-selected sweeping mirror width is always guaranteed.

A further development of the invention provides that an ultrasonic sensor is used as the measuring device, which is arranged in a stationary manner on the support and guide frame of the roller broom.

With the aid of ultrasound, the actual distance between the axis of the roller broom and the surface to be cleaned can be determined in a known manner in a simple manner, since ultrasound sensors are known per se, which is advantageous in economic terms. in the there is also the possibility of subsequently arranging the ultrasonic sensor on a supporting and guiding device of the roller broom. The actual distance is preferably determined at different measuring locations on the axis. This measure helps to ensure cylindrical wear of the roller brush.

The invention further relates to a device according to the preamble of claim 6. In view of this device, the invention has for its object to enable an accurate determination of the diameter of the roller broom and to create the conditions to perform an accurate adjustment of the desired sweeping mirror, the Sweeping level should remain as constant as possible. This is to create the prerequisite for an optimal cleaning result.

The invention achieves this aim by the characterizing features of patent claim 6.

The measuring device makes it possible to determine the actual actual distance between the axis of the roller brush and the surface to be cleaned, and with the aid of the control arrangement which is also provided for comparing the desired distance with the actual distance and the optimum distance between the axes can be specified to generate a setting variable derived from this.

It should be emphasized that both in the method and in the device, the measurement is carried out while the sweeper is running.

Fig. 1

eine perspektivische, schematische Ansicht einer Ausführungsform der erfindungsgemäßen Vorrichtung,

Fig. 2

eine Seitenansicht eines Walzenbesens im Reinigungsbetrieb und

Fig. 3

ein Prinzipschaltbild einer Regelschaltung bei einer Vorrichtung gemäß Fig. 1.

For better understanding, the invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing. Show it:

Fig. 1

2 shows a perspective, schematic view of an embodiment of the device according to the invention,

Fig. 2

a side view of a roller broom in the cleaning operation and

Fig. 3

2 shows a basic circuit diagram of a control circuit in a device according to FIG. 1.

The device for cleaning surfaces shown in FIG. 1 is generally arranged on a special vehicle and connected to it by a support and guide frame 40. The guide frame 40 supports a roller broom 14 which can be rotated about an axis 12, the axis 12 of which is supported on the surface 10 to be cleaned by means of a support and guide device 38 and can be adjusted at a distance h by means of an adjusting device 16.

Due to the adjustability of the distance h, the contact surface between the roller brush 14 and the surface 10 can also be set, this surface being referred to as a sweeping mirror b _sp .

The roller brush 14 is driven by a drive device 36 in the direction of rotation d and during the cleaning process the device is simultaneously moved in direction f over the surface to be cleaned. The distance h which can be changed by means of the adjusting device 16 and the associated size of the sweeping mirror b _sp are of crucial importance for the cleaning result.

For this purpose, the adjusting device 16 receives control signals from a measuring and control device 24 which, via a sensor device 18, the current roller diameter 2r determined. The sensor device 18 comprises a probe body 22 arranged on a rod 34, which can be moved on or away from the roller brush 14 via a feed device 26. In addition, a displacement measuring device 28 and an acceleration sensor 30 are provided.

To determine the roller diameter 2r, the probe body 22 is first moved in the direction of the roller broom by means of the feed device 26. It is expedient to arrange the feed device 26 such that the direction of travel is perpendicular to the axis 12. In its initial position, the probe body 22 is at a distance e from the axis 12.

If the surface of the feeler body 22 comes into contact with the lateral surface 20 of the roller broom, it is caused to vibrate by the bristles of the roller broom 14 running along the surface 32. These vibrations can be detected via an accelerometer 30, for example as structure-borne noise. The occurrence of the signal change recorded by the acceleration sensor 30 can then cause the measuring and control device 24 to stop the feed device 26.

Via the path measuring device 28, the travel distance z can then be detected and the roller diameter then results from the difference between the original distance e and the travel distance z. After detection of the travel path, the probe body 22 can then be moved back to its starting position in the opposite direction.

Wie die Zeichnung erkennen läßt, ist die der Mantelfläche 20 des Walzenbesens 14 zugewandte Oberfläche 32 des Tastkörpers 22 konvex ausgebildet. Dies hat den Vorteil, daß die Borsten des Walzenbesens 14 allmählich auf die Oberfläche 32 auf- und wieder ablaufen, so daß ein übermäßiger Verschleiß des Tastkörpers 22 und auch des Walzenbesens 14 an der Berührungsstelle vermieden wird.On the basis of the roller diameter 2r determined in this way, the distance h required for a predetermined sweeping mirror b _sp can be determined, specifically using the formula

$\text{h = √}\overline{{\text{r² - 1/4 b²}}_{\text{sp}}}$

As the drawing shows, the surface 32 of the probe body 22 facing the lateral surface 20 of the roller broom 14 is convex. This has the advantage that the bristles of the roller brush 14 gradually run up and down on the surface 32, so that excessive wear of the probe body 22 and also of the roller brush 14 at the point of contact is avoided.

In addition, there is a very clear contact position of the probe body 22 with the lateral surface 20 of the roller 14. This in turn has the advantage that the desired sweeping mirror b _sp can be set very precisely and optimal cleaning results can thus be achieved.

In order to be able to determine the uniformity of the roller diameter, it is advisable to use several measuring locations, e.g. measured at the measuring points a and b. Several, e.g. two sensor devices 18 can be provided, or a single sensor device 18 can also be used, which is then axially connected to the different measuring locations, e.g. a and b.

If uneven wear is found, the roller brush 14 can then be aligned differently from the surface 10, so that the difference in wear is compensated for again and a uniform sweeping level b _{sp is} achieved. In this way, the cleaning effect can be kept optimal over the entire width of the broom until the roller brush 14 is completely worn.

Preferably, the probe body 22 is only brought to the lateral surface 20 of the roller broom 14 at predetermined time intervals, and then withdrawn again.

This also reduces the wear on both the probe body 20 and the roller brush 14. Since the measured value acquisition takes up very little time, the measurements can be repeated at short time intervals, so that while maintaining the advantage of low wear and increased brush wear, monitoring and measurement of the roller diameter 2r adapted to the task is possible.

To further improve the cleaning effect, the drive device 36 for the roller brush 14 is also connected to the control device 24. The roller broom 14 is controlled in such a way that the speed is changed as a function of the roller diameter 2r in order to achieve a constant peripheral speed. With this control, the sensor device 18 already described and the control device 24 can also be used.

Fig. 2 shows a side view of the roller brush 14 in the sweeping mode. There is a contact surface between the roller brush 14 and the surface to be cleaned, which is shown here as a sweeping mirror b _sp . The distance h and half the roll diameter r are also shown. The relationship between the distance h, the roller diameter 2r and derive the sweeping mirror b _sp according to the formula mentioned above.

In the manner described so far, the distance h required for a predetermined sweeping mirror b _sp can be determined and set on the basis of the determined roller diameter 2r. However, it still lacks control over the actual display after setting actual distance h, _the b for the actual cleaning width is significantly _sp.

In order to enable not only a rigid setting, but also a regulation of the distance of the axis 12 above the surface 10 and thus an optimal setting of a desired sweeping mirror width b _sp , the distance h of the axis 12 above the surface becomes continuous during the sweeping operation 10 determined.

For this purpose, an ultrasonic sensor 42 is arranged on the support and guide frame 40, which continuously determines the actual distance h _ist . The height of the static rest position of the axis 12 above the surface 10 is determined by a temporal averaging of the distance from the surface 10 provided by the ultrasonic sensor 42.

Together with the measurement of the roll diameter 2r described above, the setpoint of the height h _{should be set for} the axis 12 according to the above formula for the control of the height h of the axis 12 above the surface 10.

With the aid of a control arrangement 44 shown in FIG. 3, it is possible to hold the roller brush 14 over the surface 10 in such a way that a preselected sweeping mirror width b _sp is always guaranteed. The control arrangement 44 comprises a controller 46, which is followed by the adjusting device 16. A measuring transducer 48 connects to the adjusting device 16, as a result of which the control loop is closed.

If due to the 2r on the basis of the roll diameter determined nominal distance h _{is intended} and actual distance actually determined between the h _is a deviation results, causes the control device 44, a readjustment in the sense that the target distance set via the adjustment device 16 to maintain the preselected sweeping mirror width b _sp .

Claims (9)

1. Method of adjusting a preselected cleaning width of a cylindrical brush (14) rotatable about an axis (12) for cleaning surfaces (10), such as roads, taxiing areas on aerodromes or the like, wherein the distance between the axis and the surface to be cleaned is modified for adjusting the cleaning width, and wherein, for determining the theoretical distance, the cylinder diameter is detected by means of a sensor device (18), in that a sensing body (22) is brought into contact with the cylindrical surface (20) of the cylindrical brush (14) and from this the necessary distance is adjusted by means of an adjusting device (16), characterized in that the actual distance between the axis (12) and the surface (10) to be cleaned is measured by means of a measuring device (42) and is compared with the theoretical distance obtained from the detected cylinder diameter, and that, when deviations occur, the adjusting device (16) is controlled from a controller (46) to readjust to the theoretical distance.
2. Method according to Claim 1, characterized in that the actual distance between the axis and the surface to be cleaned is continually measured.
3. Method according to Claim 1 or 2, characterized in that a time averaging of the measured values supplied by the measuring device is carried out, in order to derive the actual distance from this.
4. Method according to one of Claims 1 to 3, characterized in that an ultrasonic sensor is used as measuring device.
5. Method according to one of the preceding Claims 1 to 4, characterized in that the actual distance is established at different measuring positions along the axis.
6. Apparatus for adjusting a preselected cleaning width of a cylindrical brush (14) rotatable about an axis (12) for cleaning surfaces (10), such as roads, taxiing areas or the like, comprising an adjusting device (16) for the distance (h) between the axis (12) and the surface (10) to be cleaned for adjusting the cleaning width (b_sp), wherein a sensor device (18) is provided for determining the cylinder diameter (2r), which comprises a sensing body (22) which can be brought into contact with the cylindrical surface (20) of the cylindrical brush (14), and comprising a measuring and regulating device (24), disposed between the sensor device (18) and the adjusting device (16), by means of which (regulating device) the cleaning width (b_sp) of the cylindrical brush (14) can be adjusted via the adjusting device (16) as a function of the cylinder diameter (2r), characterized in that a measuring device (42) is provided for determining the actual distance (h_ist) between the axis (12) and the surface (10) to be cleaned and a control assembly (44) is provided for comparing the theoretical distance (h_soll) with the actual distance (h_ist) and for generating an adjustment variable of the distance (h) of the axis (12) to the theoretical distance (h_soll).
7. Apparatus according to Claim 6, characterized in that the measuring device is formed of an ultrasonic sensor (42), which is mounted on a supporting and guiding frame (40) for the cylindrical brush (14).
8. Apparatus according to Claim 6 or 7, characterized in that several ultrasonic sensors are disposed at different positions along the axis.
9. Apparatus according to Claim 6, characterized in that the sensor device (18) comprises a feed device (26) on which the sensing body (22) is mounted, and also a displacement measuring device (28) and an acceleration pick-up (30).

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