EP3492655B1 - Rubber wheel roller for compacting soil and method for controlling an irrigation system of a rubber wheel - Google Patents

Description

The invention relates to a pneumatic tire roller for compacting a soil, in particular for compacting asphalt. The invention also relates to a method for controlling a sprinkler system for a pneumatic tire roller.

Generic rubber-tyred rollers are typically used for soil compaction and, in particular, in road construction for asphalt compaction. These are self-propelled construction machines, which usually have a machine frame, a drive motor and a chassis driven by the drive motor with a front chassis part and a rear chassis part. Typically, at least one chassis part comprises at least two wheels with treads arranged next to one another. The wheels are usually made of an elastic material such as a rubber material. When driving over the ground, the elastic properties of the wheels result in a kneading or flexing effect, which results in a particularly good pore closure on the surface of the layer to be compacted when using generic rubber-tyred rollers.

In road construction in particular, it is customary to drive over the asphalt material to be compacted with the rubber-tyred rollers while the asphalt material is still hot. Due to the increased temperature, the viscosity of the binder components of the asphalt layer, for example the bitumen, is still low enough so that adequate compaction can be achieved. On the other hand, as the temperature of the asphalt falls, it becomes more viscous and therefore more difficult to compact. A known problem with asphalt compaction with pneumatic tire rollers is that the hot asphalt material adheres to the cold wheels of the pneumatic tire rollers due to the property described above. Especially at the beginning of the work, when the wheels are significantly colder than the asphalt material, It is therefore always the case that asphalt material sticks to the rubber wheels, which can cause unevenness in the finished asphalt layer. In the course of the work, the wheels then heat up until the temperature difference between the wheels and the asphalt material is so small that the material no longer sticks to the wheels.

In order to counteract the adhesion of asphalt material to the wheels, it is known, on the one hand, to provide scrapers on the rubber wheels which mechanically remove adhering asphalt material. In addition, it is known to use a sprinkler system for the wheels which is designed to apply a liquid release agent, for example a solvent-free, water-dilutable release agent, to the running surfaces of the wheels. Typically, there is also a control unit for controlling the sprinkler system. Such sprinkler systems are for example from the EP 3 181 753 A1 and the post-published EP 3 258 013 A1 known. By wetting the wheels with the release agent, sticking of the asphalt material can be prevented from the outset. For this, however, large amounts of the release agent have to be carried along on the rubber-tyred roller. In addition, the release agent must be refilled as soon as the supply carried on the rubber-tyred roller is used up. Attempts are therefore made to apply the release agent to the running surfaces of the wheels as sparingly as possible and only when this is actually necessary.

In order to minimize the consumption of release agent in practice, the operator of the pneumatic tire roller must assess or observe when the asphalt material no longer threatens to adhere to the wheels. As soon as the wheels are sufficiently heated, the sprinkler system can then be switched off. If this is done too early, there is a risk of damaging the asphalt layer by loosening pieces adhering to the wheels. However, if the operator switches off the sprinkler system too late, too much release agent is used unnecessarily. In order to give the operator an indication of how to control the sprinkler system, it is known in the prior art to determine the temperature of the floor, for example from the EP 3 181 753 A1 known. In this way, the operator can better estimate how long he will have to work the ground before the wheels have warmed up sufficiently. Even with the measurement of the ground temperature, the operator's decision to switch off the sprinkler system is still very subjective, so that on the one hand there is a risk of damage to the asphalt layer and on the other hand too much release agent is used.

It is therefore the object of the present invention to reduce the consumption of release agent and at the same time to reduce the risk of damage to the soil layer to be compacted. In particular, it is the object of the invention to provide a possibility of how the decision about whether to switch a sprinkler system on or off during work can be made more objectively. At the same time, the solution should be as inexpensive as possible.

This object is achieved with the pneumatic tire roller and the method according to the independent claims. Preferred developments are given in the dependent claims.

Specifically, the solution is achieved in a rubber-tyred roller mentioned at the outset in that there is an optical temperature sensor with a measuring field with at least two measuring points, which is designed and arranged in such a way that it determines the temperature of at least one wheel, in particular the tread of the wheel, and the floor . A basic idea of the present invention is therefore to directly determine the temperature of the wheel and, in particular, of the contact surface of the wheel with the ground, i.e. the tread. This means that the temperature is now determined directly at the point where the asphalt material threatens to stick. Contactless optical temperature sensors are particularly suitable for use with the invention. These can be arranged in the vicinity of the wheels, for example in the wheel arch of the rubber tire roller, and from there they can be aligned with the running surface of the wheel. The arrangement does not have to be in the immediate vicinity of the wheel; it is only important that the temperature sensor is arranged in such a way that the wheel to be measured is in its measurement field. In other words, at least one measuring point of the temperature sensor must be on the wheel, in particular on the running surface of the wheel. The temperature of the tread of the wheel is a variable that is more directly related to the adhesion of asphalt material than just the temperature of the ground, since the latter does not provide any information about the heating state of the rubber wheel itself. The measured temperature of the wheel, in particular of the tread of the wheel, can be displayed to the operator of the rubber-tyred roller, which means that the operator can estimate with greater precision whether or not asphalt material is currently still likely to stick. The operator can therefore adapt the switching on and / or off of the sprinkling system much more precisely to the actual need for sprinkling, which saves release agent overall. It is just as conceivable and encompassed by the scope of the invention that, in addition or as an alternative, the sprinkler system is controlled fully automatically by a control unit which uses the temperature value of at least the temperature sensor to control the sprinkler system, in particular to switch the sprinkler on and / or off.

According to the invention, the temperature sensor is an optical temperature sensor with a measuring field. For example, the temperature sensor can be designed as a thermal imaging or infrared camera. In a particularly preferred embodiment, the temperature sensor comprises an infrared sensor array, or the temperature sensor is designed as an infrared sensor array. An infrared sensor array is a measuring device with which the temperature of several measuring points can be determined at the same time. An infrared sensor array can be viewed, for example, as an infrared camera with only a few image points or pixels that represent the measurement points. For example, an infrared sensor array can have 16 × 4 pixels or measuring points. However, other resolutions are also possible and can be used according to the invention. In addition or as an alternative, a temperature scanner can also be used. This essentially has only a single measuring point, but directs it alternately to at least two points on a rubber wheel and / or at least one point in each case on at least two rubber wheels.

Rubber-tyred rollers usually have several wheels arranged next to one another. Depending on the operating situation of the rubber-tyred roller, the wheels can have different temperatures. For example, the rubber-tyred roller can drive partly on an asphalt strip that has already cooled down and partly on a still hot asphalt strip, so that the wheels that come into contact with the hot or cold asphalt have different temperatures. In order to also obtain information about such different temperature conditions, it is preferred that the optical temperature sensor is designed and arranged such that the measuring field comprises at least one measuring point on at least two wheels, in particular on the tread of the respective wheel. The at least two wheels can, for example, be arranged next to one another. In addition, it can be, for example, two wheels lying next to one another which are arranged transversely to the working direction of the rubber-tyred roller on the left or right outer side of the chassis part. In particular, the wheels arranged on the very outside transversely to the working direction often have a different temperature than the wheels arranged further inside next to the outer wheels. This is because the wheels further inside are already shielded from the environment by the outer wheels. A temperature difference must therefore be expected, especially between these wheels.

It is particularly preferred if the optical temperature sensor is designed and arranged in such a way that the measuring field comprises at least one measuring point on each wheel of the respective chassis part, in particular on the running surface of the respective wheel. In this way, the temperature of each individual wheel of the chassis part is determined by the temperature sensor. These Information can then, for example, be displayed to the operator or used directly to control the sprinkler system, as will be described in more detail below. If the temperature data for each individual wheel is known, a particularly efficient decision can be made as to whether the sprinkler system needs to be activated or deactivated, depending on which wheel is driving on the hot asphalt material at which temperature. In this embodiment, the advantage of using an infrared sensor array also comes into its own. An infrared sensor array can be arranged on the rubber tire roller, for example in the wheel arch of the chassis part or on a thermal apron provided for this chassis part or its holder, so that the temperature of each individual wheel of the chassis part can be measured by the temperature sensor. At least one pixel of the measurement field is therefore on each of the wheels. In this way, the temperature of all the wheels of the chassis part can be determined with just a single temperature sensor. The solution according to the invention is therefore particularly cost-effective since, for example, a separate temperature sensor does not have to be used for each individual wheel to be measured.

The invention can also be used advantageously in rubber-tyred rollers in which both the front chassis part and the rear chassis part have wheels. In this case it is preferred that a total of two optical temperature sensors are present, one optical temperature sensor determining the temperature of at least one wheel of the front chassis part and the other optical temperature sensor determining the temperature of at least one wheel of the rear chassis part. In particular, the two temperature sensors each determine the temperature of all the wheels arranged in the respective chassis part. Overall, the use of only two temperature sensors on the rubber-tyred roller ensures that the temperature of all the wheels can be determined. The operator of the pneumatic tire roller, to whom the corresponding measurement results are displayed, can use this information to implement particularly efficient control of the sprinkler system. Both temperature sensors are particularly preferably designed as infrared sensor arrays or temperature scanners.

As already indicated, it can be provided that a display device is present by means of which the temperatures of the wheels, which are determined by the temperature sensor, can be displayed to the operator. The operator can therefore decide on the basis of the wheel temperature whether sprinkling with release agent by the sprinkling system is necessary in order to prevent asphalt from sticking to the wheels. According to a preferred embodiment, however, it is provided that the control unit is designed to independently control the sprinkler system based on the measured values of the temperature sensor, in particular to at least activate and / or deactivate it. This can be done in addition to or as an alternative to the presence of a display device. It is therefore provided that the control unit automatically controls the sprinkling system directly on the basis of the temperatures of the wheels measured by the temperature sensor or the temperature sensors, without the operator having to take any additional action. In this way, the last subjective influence in the control of the sprinkler system is eliminated and at the same time the operator of the pneumatic tire roller is relieved so that he can concentrate on other activities of the compaction process. For example, the control unit activates the sprinkler system when the temperature of the at least one wheel is below a predetermined threshold value. In addition, the control unit can deactivate the sprinkler system if the temperature of the wheel is above or above a predetermined threshold value. Depending on the asphalt material used, different threshold values can be preset here. Typical threshold values are, for example, in the range from 60 ° C to 110 ° C, in particular at 80 ° C. The specific suitable threshold value depends on the softening point of the bitumen type used in the asphalt mix. It is further preferably provided here that the rubber-tyred roller or the above-mentioned control unit can optionally be switched into a "rolling mode" and / or "sprinkling mode", in particular to prevent the normal driving operation outside of the rolling operation, ie when the ground and the The wheels are cold, the sprinkler system is automatically activated by the control unit.

In particular when the temperature of more than one wheel within a chassis part is determined by the temperature sensor, it is preferred that this additional information is then also used to control the sprinkler system. For example, it is preferred that more than two wheels arranged side by side are arranged in the front undercarriage part and / or in the rear undercarriage part, and that the control unit is designed to separate the irrigation of the wheels arranged transversely to a working direction separately from the one or those between them Wheels to control lying wheels. At the same time, the sprinkling system is expediently designed in such a way that it can sprinkle the wheels arranged on the outside transversely to the working direction independently of the other wheels of a chassis part. As already indicated, it happens that the wheels of a chassis part that are on the outside transversely to the working direction are colder than those that are between these wheels. This is due to the fact that the wheels arranged on the outside are cooled to a greater extent from the outside environment. While the inner wheels have already reached the necessary temperature so that irrigation of these wheels can be dispensed with, this must be continued with the outer wheels. So that the already hot inner wheels are not sprinkled in vain, the control unit provides the sprinkler the wheels on the inside, while the wheels of the undercarriage part lying on the outside transversely to the working direction continue to be sprinkled until they too have reached the required temperature.

In particular in the case in which the temperatures of all wheels of the rubber-tyred roller are determined via the temperature sensor (s), it is preferred that the control unit is designed in such a way that it controls the irrigation of each individual wheel independently of the remaining wheels. Accordingly, the sprinkling system is of course also designed in such a way that the sprinkling of each individual wheel can be activated or deactivated independently of the other wheels. For example, the sprinkler system has a spray bar which has its own spray nozzle for each wheel, each spray nozzle having its own valve which can be individually controlled by the control unit. In this way, the control unit can respond individually to any asymmetry in the temperatures of the wheels. Regardless of how the temperature of the wheels is distributed among each other, the control unit activates the irrigation of those wheels whose temperature is below a predetermined threshold value, while the control unit deactivates the irrigation of those wheels whose temperature is above a predetermined threshold value. The threshold values already mentioned above can also be used here. Because the sprinkling of each individual wheel is controlled independently of the other wheels, the sprinkling with release agent is actually only carried out on those wheels and in that temperature range in which the asphalt material can adhere to the wheels. The release agent is used particularly efficiently and the consumption of the release agent is greatly reduced.

Basically, based on the measured temperature of the wheels, it is already possible to increase the accuracy of the control of the sprinkler system and thus the efficiency of the release agent consumption. As explained at the beginning, the asphalt material adheres to the wheels when the hot asphalt material is cooled by the cold wheels and the viscosity is thus increased. An essential factor for the adhesion of the asphalt material is therefore the temperature difference between the ground or the asphalt material and the wheels of the rubber-tyred roller. The temperature sensor is therefore designed and arranged in such a way that, in addition to the temperature of the at least one wheel, the temperature of the floor can also be determined. In other words, at least one measuring point of the measuring field of the temperature sensor lies on the floor, so that its temperature can be measured by the temperature sensor. This, too, can advantageously be achieved, for example, by means of an infrared sensor array that has sufficient pixels or measuring points to cover all the wheels of a chassis part as well as the ground and the to determine the respective temperatures. It is particularly preferred if, in addition to the temperature of each wheel, the temperature of that floor section is also determined over which this wheel is traveling. For each wheel of the rubber-tyred roller, two temperatures are measured, which correspond to the tread of the wheel and to the ground surface that comes into contact with this tread.

The temperature of the ground can then also be taken into account by the control unit when controlling the sprinkler system. For example, it is preferred that the control unit is designed to activate sprinkling by the sprinkler system when the temperature of the ground is above a threshold value, and to deactivate the sprinkler system when the temperature difference between the ground and the wheel falls below a predetermined threshold value. This procedure is preferably carried out hierarchically, specifically in such a way that only when the sprinkler system is activated, ie "warm floor", which would trigger an activation of the sprinkler system in terms of temperature, the determined temperature difference for deactivation due to the determined temperature of the soil above a threshold value is being used. The threshold value for the temperature of the ground or the asphalt layer, above which the sprinkler system is activated by the control unit, is between 40 ° C. and 80 ° C., for example 55 ° C. The temperature difference between the ground or asphalt layer and the wheel, below which the irrigation is deactivated by the control unit, is between 10 ° C and 50 ° C, for example 20 ° C. These values can also vary depending on the asphalt material used and depend on the prevailing soil temperature. At a temperature that is only slightly above the switch-on temperature of the sprinkler system, the tire temperature must not be significantly lower than the floor temperature. At very high asphalt temperatures, e.g. 130 ° C, a tire temperature of 80 ° C may be sufficient to avoid buildup. The automatic activation and deactivation of the sprinkler system, in particular for each individual wheel and taking into account the temperature of that section of the ground over which this wheel drives, prevents the sprinkler from being switched on too late and asphalt material from adhering to the wheels is. In addition, irrigation emulsion is prevented from being used unnecessarily, although there is no risk of adhesion.

In addition or as an alternative, provision can also be made for a device for, in particular optical, detection of the outer surface of at least one rubber wheel, for example a digital camera, to be provided. With this, with the aid of suitable image processing software, it can also be determined whether or not adhesions actually occur. This information too can be displayed to the operator of the rubber-tyred roller and / or used to control the control unit of the sprinkler system, for example when at least one threshold value is set manually by the driver.

In order to further improve the control of the sprinkler system, it is preferred that the control unit is designed to automatically switch off the previously activated sprinkler system by the sprinkler system when the determined temperature of the soil is below a threshold value. If the asphalt material has already cooled down to such an extent that there is no longer any risk of sticking to the wheels of the rubber-tyred roller, the previously activated sprinkler system is automatically deactivated, thus preventing unnecessary consumption of release agent. This switch-off also preferably relates to the irrigation of each individual wheel individually on the basis of the temperature of that floor section over which the corresponding wheel is traveling.

In addition, it can also be provided that the control unit is designed to switch off the sprinkling by the activated sprinkling system when the temperature difference between the ground and the wheel falls below a predetermined threshold value. In this way, too, release agent is saved if there is no longer any risk of the asphalt material sticking to the wheel due to the material cooling down due to contact with the wheel.

In particular, the above-described control of the sprinkling system takes place for each individual wheel of the rubber-tyred roller individually and independently of the other wheels or of the sprinkling of the other wheels of the rubber-tyred roller. The irrigation of a wheel depends only on the temperature of this wheel and the temperature of the floor, in particular that floor section over which this wheel travels, as well as the temperature difference between the wheel and the floor or this floor section. The decision as to whether a wheel is to be sprinkled with release agent is made by the control unit based on the measured values of the temperature sensor, which measures the temperature of the wheel concerned. The operator of the rubber-tyred roller does not have to issue any control commands for this. The sprinkling is therefore automatically controlled by the control unit depending on the objectively determined need of the individual wheel.

As already mentioned, the temperature sensor must be arranged in such a way that at least the wheels to be measured and the floor are in its measuring field. For example, the temperature sensor can be arranged in the wheel arch of the rubber tire roller. In addition, however, it must be noted that the temperature sensor should be arranged in such a way that it is affected by the rough Working conditions within the wheel arch is spared as much as possible. It is therefore preferred that the temperature sensor is arranged in the upper half, preferably in the upper third, particularly preferably in the upper quarter, very particularly preferably in the upper fifth and at best at the upper vertex of a wheel arch. In addition, it is also possible, for example, to place the temperature sensor set back in a shaft or a sensor viewing shaft which opens into the wheel arch and from which the temperature sensor has a clear field of view of the wheels to be measured and possibly the floor. By offsetting the temperature sensor in a shaft, it is also protected from negative environmental influences. A blowing-out device can be provided as a support, which prevents the temperature sensor, in particular the infrared temperature sensor, from becoming soiled.

The object set at the beginning is also achieved with a method for controlling the sprinkling system of a rubber-tyred roller described above, comprising the steps of: determining the temperature of at least one wheel, in particular the tread of the wheel, and determining the temperature of the ground by a temperature sensor and controlling the sprinkling of the at least one wheel by the sprinkler system based on the measured values of the temperature sensor by a control unit. All of the features, advantages and effects mentioned above for the pneumatic tire roller also apply in a figurative sense to the method according to the invention. The corresponding threshold values also correspond to the values mentioned above. Reference is therefore made to the above explanations only to avoid repetition.

In particular, the method comprises at least one of the following steps: determining the temperature of at least two wheels, in particular the tread of the respective wheel, by means of a temperature sensor; Determining the temperature of all wheels of the respective chassis part, in particular the running surface of the respective wheel, by means of a temperature sensor; Determining the temperature of all the wheels of the front and rear undercarriage parts, in particular the tread of the respective wheel, by means of a temperature sensor for the front undercarriage part and the rear undercarriage part; Controlling the sprinkling of wheels arranged outside transversely to a working direction separately from the wheel or wheels lying between these wheels; Controlling the irrigation of each individual wheel independently of the remaining wheels; Activating the sprinkling by the sprinkler system when the temperature of the ground is above a threshold value and / or the temperature difference between the ground and the wheel exceeds a predetermined threshold value; and deactivating sprinkling by the sprinkler system when the temperature of the soil is below a threshold value; and / or deactivating the irrigation by the sprinkler system when the temperature difference between the ground and the wheel falls below a specified threshold value.

Figur 1:

eine Seitenansicht einer Gummiradwalze;

Figur 2:

eine Frontansicht einer Gummiradwalze;

Figur 3:

eine Draufsicht auf Teile des Maschinenrahmens, des Fahrwerks und der Berieselungsanlage;

Figur 4:

eine Seitenansicht eines Rades mit Berieselungsanlage und Temperatursensor;

Figur 5:

einen Temperatursensor und dessen Messfeld; und

Figur 6:

ein Ablaufdiagramm des Verfahrens.

The invention will now be explained in more detail with reference to the exemplary embodiments shown in the figures. They show schematically:

Figure 1:

a side view of a pneumatic tire roller;

Figure 2:

a front view of a pneumatic tire roller;

Figure 3:

a plan view of parts of the machine frame, the chassis and the sprinkler system;

Figure 4:

a side view of a wheel with sprinkler system and temperature sensor;

Figure 5:

a temperature sensor and its measuring field; and

Figure 6:

a flow chart of the process.

Identical or identically acting components are numbered with the same reference numerals. Repetitive components are not identified separately in all figures.

The Figures 1 and 2 show a pneumatic tire roller 1. Figure 1 shows the pneumatic tire roller 1 in side view and Figure 2 in front view. The rubber-tyred roller 1 comprises a driver's cab 2 and a machine frame 3, which is supported by a chassis with a front chassis part 5 and a rear chassis part 6. The chassis parts 5, 6 each have wheels 7 arranged in wheel housings 9, with which the rubber-tyred roller 1 travels over the soil 8 to be compacted. The energy required for this is provided by a drive motor 4, for example a diesel internal combustion engine. In the present case, the forward direction of travel of the rubber-tyred roller 1 is referred to as the working direction a, although the rubber-tyred roller 1 can also compact the soil 8 while driving backwards. In addition, the Figures 1 and 2 One temperature sensor 11 each arranged on the front chassis part 5 and the rear chassis part 6, the measuring field of which - as will be explained in more detail below - the wheels 7, in particular their running surfaces 16 ( Figure 2 ), and the bottom 8 includes. There is also a sprinkler system 10 with a spray bar 25, which extends transversely to working direction a and is designed in such a way that all wheels 7 of the respective chassis part 5, 6 can be sprayed with a separating agent, on the front chassis part 5 and rear chassis part 6. The sprinkler systems 10 are controlled by the control unit 12 on the basis of the measured values from the temperature sensors 11.

Figure 3 shows the components of the pneumatic tire roller 1 that are essential to the invention in a plan view. For reasons of clarity, parts of the machine frame 3, the driver's cab 2 and the drive motor 4 and other components of the rubber-tyred roller 1 are not shown. The rubber-tyred roller 1 of the exemplary embodiment has four wheels 7 arranged next to one another in the front chassis part 5 and also four wheels 7 in the rear chassis part 6, each of which is arranged in a wheel arch 9. The wheels 7 of the front chassis part 5 are offset transversely to the working direction a with respect to the wheels 7 of the rear chassis part 6 in order to ensure uniform compaction of the soil 8 when the rubber-tyred roller 1 is passed over. Both the front chassis 5 and the rear chassis 6 have a sprinkler system 10. The sprinkler system 10 comprises a spray bar 25 which extends transversely to the working direction a and on which at least one sprinkler nozzle 14 is arranged for each wheel 7. Via the sprinkler nozzles 14, as in the Figure 3 indicated, a liquid release agent, applied to the running surface 16 of the respective wheel 7. To store the release agent, a tank 17 is provided on the rubber-tyred roller 1, which is connected to the sprinkler system 10 and supplies it with release agent. The connection of the sprinkler system 10 to the tank 17 is shown in FIG Figure 3 illustrated only for the sprinkler system 10 of the rear chassis part 6. The sprinkling system 10 of the front chassis part 5 is, however, connected to a tank 17 for separating agent. This can be the same tank 17, which is also connected to the sprinkler system 10 of the rear chassis part 6, or a separate tank 17.

It is important in the sprinkler system 10 that the control unit 12 is provided to control the sprinkling of the running surfaces 16 of the wheels 7 by the individual sprinkler nozzles 14. For this purpose, on the one hand, the control unit 12 is connected to the sprinkler system 10 in terms of control technology, as in FIG Figure 3 indicated. In addition, each sprinkling nozzle 14 of the spray bar 25 has its own controllable valve which can be opened or closed by the control unit 12. Each individual valve of a sprinkling nozzle 14 can be activated and opened or closed individually and individually, that is to say independently of all other valves, by the control unit 12. The control unit 12 therefore decides for each individual wheel 7 whether this wheel 7 has to be sprinkled with release agent in the current working mode or not. In order to make this decision, the control unit 12 uses the measurement results of the temperature sensors 11. As in Figure 3 As shown, a temperature sensor 11 is located on the front chassis part 5 and a further temperature sensor 11 is located on the rear chassis part 6. Both temperature sensors 11 are connected to the control unit 12 in terms of control technology. The temperature sensor 11 for the front chassis part 5 is arranged in the wheel arch 9 of the front chassis part 5. He can be arranged either on the machine frame 3 or on a holder for a thermal apron of the chassis part (not shown) or on the thermal apron itself. The temperature sensor 11 of the rear chassis part 6 is offset towards the inside of the rubber-tyred roller 1, as seen from the wheel housing 9. In particular, the temperature sensor 11 is arranged in a shaft 26 which is designed to be optically open to the rear chassis part 6. This means in particular that the temperature sensor 11 has a clear field of vision out of the shaft 26, in particular in the infrared range, onto the wheels 7 of the chassis part and the floor 8. The offset of the temperature sensor 11 towards the center of the machine ensures, on the one hand, that the measurement angle that is required to span a sufficiently large measurement field 13 of the temperature sensor 11 becomes smaller. On the other hand, the temperature sensor 11 is protected by the shaft 26 and is not damaged, for example, by chunks of asphalt possibly thrown around in the wheel arch 9. The arrangement of the temperature sensors 11 in Figure 3 is only exemplary. Thus, both temperature sensors 11 can also be arranged in the wheel arch 9 or in a shaft 26, as indicated by way of example for the two chassis parts 5, 6.

The function of the temperature sensors 11 and the shape of the measurement field 13 or field of view of the temperature sensors 11, which is also already shown in FIG Figure 3 is indicated, goes in particular from an additional consideration of the Figures 4 and 5 in front. As in particular in Figure 5 As shown, the measuring field 13 of the temperature sensor 11 comprises a plurality of measuring points 15 or pixels. In the illustrated embodiment of the Figure 5 the temperature sensor 11, which is designed as an infrared sensor array, has a measuring field 13 of 16 × 4 measuring points 15. Similar to a thermal imaging camera, the temperature sensor 11 thus determines or measures the temperature of an object on which the respective measuring point 15 is located. The measurement field 13 is, so to speak, the field of view of the temperature sensor 11. The extent of the measurement field 13 is based in particular on a synopsis of the Figures 3 and 4th emerged. How out Figure 3 As can be seen, the temperature sensor 11 is designed and arranged in such a way that the measuring field 13 detects all the wheels 7 of the respective chassis part 5, 6. In particular, at least one measuring point 15 lies completely on the running surface 16 of each individual wheel 7 of this chassis part 5, 6. The measuring field 13 of the temperature sensor 11 thus extends transversely to the working direction a at least over all the running surfaces 16 of the wheels 7. This ensures that the temperature sensor 11 can assign the respective wheel 7 to at least one measuring point 15, so that the temperature of each wheel 7 can be determined.

Figure 4 shows a side view of a wheel 7 of the front chassis part 5. Also shown are the temperature sensor 11 and the extent of the measurement field seen from this perspective 13th Figure 4 illustrates that the measuring field 13 of the temperature sensor 11 includes both the wheel 7 and the floor 8. In other words, the temperature sensor 11 is designed and arranged in such a way that within its measuring field 13 at least one measuring point 15 is completely on the running surface 16 of at least one individual wheel 7 and in particular each individual wheel 7 of the corresponding chassis part 5, 6 (in Figure 4 for example the front chassis part 5), as well as at least one measuring point 15 lies completely on the ground 8, i.e. on the asphalt layer to be compacted. Overall, the temperatures of all the wheels 7 of the rubber-tyred roller 1 and of the floor 8 can be determined via the two temperature sensors 11. In addition, due to the shape of the measurement field 13, it is shown in FIG Figure 5 possible that the temperature sensor 11 determines the temperature of the floor 8 for each wheel 7 individually. For example, each measuring point 15 located on a wheel 7, in particular on the running surface 16 of the wheel 7, can be assigned a measuring point 15 on the floor 8, the measuring point 15 for the floor 8 and the measuring point 15 for the wheel 7 lie in a common vertical plane which is aligned parallel to the working direction a. In other words, the temperature sensor 11 determines both the temperature of the wheel 7 and the temperature of the floor 8 or that floor section over which this wheel 7 travels. In this way, a temperature difference to the ground 8 can be measured or determined individually for each wheel 7. It is therefore optimal if the temperature sensor 11 for each wheel 7 determines both the temperature of the wheel 7 itself and the temperature of the floor 8 or floor section over which this wheel 7 travels.

This information is used by the control unit 12 to control the sprinkler systems 10. In particular, the control unit 12 is designed to carry out the method 18, the flowchart of which is shown in FIG Figure 6 is shown. In step 19 of method 18, the wheel temperatures are determined. In particular, the temperature of all the wheels 7 of the rubber-tyred roller 1 is determined via a single temperature sensor 11 for each chassis part 5, 6. In addition, in step 21, the temperature of the floor 8 is also determined by at least one of the temperature sensors 11. In addition, each temperature of a wheel 7 measured by the temperature sensor 11 can be assigned a temperature of the floor 8 over which this wheel 7 is traveling. In step 20, the sprinkler system 10 is then controlled by the control unit 12. The control can include different control commands. If, for example, it is determined that the temperature of the floor 8 is above a previously determined threshold value, for example above 55 ° C, and it is determined, for example, that the temperature difference between the floor 8 and the wheel 7, in particular that floor section over which the wheel 7 travels, and this wheel 7 itself exceeds a predetermined threshold value, for example a threshold value of 10 ° C, the control unit 12 activates the sprinkling of this wheel 7 via the sprinkler nozzle 14 according to step 22. If, on the other hand, it is determined, for example, that the temperature of the floor 8 is below a predetermined threshold value, for example below 5 ° C, then the control unit 12 deactivates the sprinkler system 10, and in particular the sprinkling of that wheel 7 that is driving over that section of the ground whose temperature is below the threshold value, according to step 23. Even if it is determined that that the temperature difference between floor 8 and wheel 7 falls below a predetermined threshold value, for example a threshold value of 10 ° C, the irrigation is deactivated according to step 24, in particular the irrigation of that wheel 7 that no longer has a sufficient temperature difference to that soil section that is run over by this wheel 7.

All in all, in this way an efficient and objective control of the sprinkler systems 10 is provided by the control unit 12 on the basis of the measured values of the temperature sensors 11, which removes all subjective influences from the control of the sprinkler systems 10. The invention therefore leads to a particularly precise control of the sprinkler system 10, which on the one hand guarantees that the soil layers to be compacted are not damaged by the adherence of material to the wheels 7 of the rubber-tyred roller 1, and on the other hand to a particularly economical and effective use of the Release agent leads. Overall, therefore, less release agent is used, which means, for example, that less time has to be expended to refill the storage container for release agents. The invention therefore increases the economy of the pneumatic tire roller 1 overall.

Claims (15)

1. A rubber-tired roller (1) for compacting a ground (8), in particular for asphalt compaction, with

   - a machine frame (3);

   - a drive engine (4);

   - a chassis driven by said drive engine (4) with a front chassis part (5) and a rear chassis part (6), at least one chassis part (5, 6) comprising at least two tires (7) with running surfaces (16), which are arranged next to each other;

   - at least one sprinkler system (10) for the tires (7) of the chassis part (5, 6), which is configured to apply a liquid separating agent to the running surfaces of the tires (7); and

   - a control unit (12) for controlling the sprinkler system (10);
   characterized in that
   an optical temperature sensor (11) with a measuring area (13) and at least two measuring points is provided where the temperature sensor (11) is configured and arranged such that one mesuring point (15) of the temperature sensor (11) is located on at least one tire and one mesuring point (15) of the temperature sensor (11) is located on the ground so that the temperature of the at least one tire (7) and the temperature of the ground (8) can be determined, by means of the temperature sensor (11).
2. The rubber-tired roller (1) according to claim 1,
   characterized in that
   the optical temperature sensor (11) comprises an infrared sensor array.
3. The rubber-tired roller (1) according to any one of the preceding claims,
   characterized in that
   the optical temperature sensor (11) is configured and arranged such that the measuring area (13) comprises at least one respective measuring point (15) on at least two tires (7), in particular on the running surface (16) of the respective tire (7).
4. The rubber-tired roller (1) according to any one of the preceding claims,
   characterized in that
   the optical temperature sensor (11) is configured and arranged such that the measuring area (13) comprises at least one measuring point (15) on each tire (7) of the respective chassis part (5, 6), in particular on the running surface (16) of the respective tire (7).
5. The rubber-tired roller (1) according to any one of the preceding claims,
   characterized in that
   each of the front chassis part (5) and the rear chassis part (6) includes tires (7), and that a total of two optical temperature sensors (11) is provided, wherein one optical temperature sensor (11) determines the temperature of at least one tire (7) of the front chassis part (5) and the other optical temperature sensor (11) determines the temperature of at least one tire (7) of the rear chassis part (6).
6. The rubber-tired roller (1) according to any one of the preceding claims,
   characterized in that
   the control unit (12) is configured to control the sprinkler system (10) based on the measured values of the temperature sensor (11).
7. The rubber-tired roller (1) according to claim 6,
   characterized in that
   more than two tires (7) are arranged next to one another in the front chassis part (5) and/or in the rear chassis part (6), and that the control unit (12) is configured to control the sprinkling of the tires (7) arranged at external positions transversely to a working direction (a) separately from the tire (7) or tires (7) arranged between these tires (7).
8. The rubber-tired roller (1) according to any one of claims 6 or 7,
   characterized in that
   the control unit (12) is configured to control the sprinkling of every single tire (7) independently of the remaining tires (7).
9. The rubber-tired roller (1) according to any one of the preceding claims,
   characterized in that
   the control unit (12) is configured to activate the sprinkling performed by the sprinkler system (10) when the temperature of the ground (8) is above a threshold value and the temperature difference between the ground (8) and the tire (7) exceeds a specified threshold value, and/or to deactivate the sprinkling performed by the sprinkler system (10) when the temperature of the ground (8) is below a threshold value.
10. The rubber-tired roller (1) according to any one of the preceding claims,
    characterized in that
    the control unit (12) is configured to turn the sprinkling performed by the sprinkler system (10) off when the temperature difference between the ground (8) and the tire (7) falls below a specified threshold value.
11. The rubber-tired roller (1) according to any one of the preceding claims,
    characterized in that
    the temperature sensor (11) is arranged in the upper half, preferably in the upper third, more preferably in the upper quarter, even more preferably in the upper fifth, and ideally at the upper apex of a wheel box (9).
12. A method (18) for controlling the sprinkler system (10) of a rubber-tired roller (1) according to any one of the preceding claims, comprising the steps of:

    - determining (19) the temperature of at least one tire (7), in particular the running surface (16) of said tire (7), by means of the optical temperature sensor (11); and

    - determining (21) the temperature of the ground (8), by means of the optical temperature sensor (11); and

    - controlling (20) the sprinkling of said at least one tire (7) performed by the sprinkler system (10) based on the measured values of the temperature sensor (11) by means of a control unit (12).
13. The method (18) according to claim 12,
    characterized by at least one of the following steps:

    - determining (19) the temperature of at least two tires (7), in particular the running surface (16) of the respective tire (7), by means of a temperature sensor (11);

    - determining (19) the temperature of all tires (7) of the respective chassis part (5, 6), in particular the running surface (16) of the respective tire (7), by means of a temperature sensor (11);

    - determining (19) the temperature of all tires (7) of the front and rear chassis parts (5, 6), in particular the running surface (16) of the respective tire (7), by means of a respective temperature sensor (11) for each of the front chassis part (5) and the rear chassis part (6).
14. The method (18) according to any one of claims 12 or 13,
    characterized by at least one of the following steps:

    - controlling (20) the sprinkling of tires (7) arranged at external positions transversely to a working direction (a) separately from the tire (7) or tires (7) located between said tires (7);

    - controlling (20) the sprinkling of every single tire (7) independently of the remaining tires (7).
15. The method (18) according to any one of claims 12 to 14,
    characterized by at least one of the following steps:

    - activating (22) the sprinkling performed by the sprinkler system (10) when the temperature of the ground (8) is above a threshold value and the temperature difference between the ground (8) and the tire (7) exceeds a specified threshold value;

    - deactivating (23) the sprinkling performed by the sprinkler system (10) when the temperature of the ground (8) is below a threshold value; and/or

    - deactivating (24) the sprinkling performed by the sprinkler system (10) when the temperature difference between the ground (8) and the tire (7) falls below a specified threshold value.

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