Roller For Asphalt Compaction, In Particular A Rubber Tire Roller, And Method For Spraying A Rubber Tire Of A Roller For Asphalt Compaction

Abstract

The present invention proposes a roller for asphalt compaction, in particular a rubber tire roller, comprising: a rubber tire, a spray device for spraying a rubber tire with a separation agent mixture composed of a first liquid and a second liquid, a first tank for the first liquid and a second tank for the second liquid, characterized in that the rubber tire roller, in order to form the separation agent mixture, comprises a mixing device for mixing the first liquid supplied by the first tank and the second liquid supplied by the second tank. Further, the present invention relates to a method for spraying a rubber tire of a roller for asphalt compaction with a separation agent mixture.

Claims

1. A rubber tire roller for asphalt compaction, comprising: at least one rubber tire; a spray device for spraying the rubber tire with a separation agent mixture composed of a first liquid and a second liquid, wherein the roller comprises a first tank for the first liquid and a second tank for the second liquid, and in that the roller comprises a mixing device for mixing the first liquid provided by the first tank and the second liquid provided by the second tank for producing the separation agent mixture, that the roller comprises a first pump for conveying the first liquid from the first tank to the mixing device and/or a second pump for conveying the second liquid from the second tank to the mixing device, that the mixing device comprises a regulating device for adjusting a mixing ratio of the first liquid and the second liquid in the separation agent mixture with the regulating device comprising a control device that controls the first pump and/or second pump.

2. The roller according to claim 1, wherein the control device for controlling the regulating device is connected to a first actuating element and/or to a second actuating element for setting an operating mode of the spray device.

3. The roller according to claim 1, wherein the roller comprises a first supply line connecting the first tank with the mixing device for providing the first liquid and/or comprises a second supply line connecting the second tank with the mixing device for providing the second liquid.

4. The roller according to claim 1, wherein the first pump and/or the second pump is a hose pump, a gear pump or a diaphragm pump.

5. The roller according to claim 1, wherein the second tank and the roller are detachably connected to one another via a coupling device or in that the second tank comprises a drain for discharging the second liquid.

6. The roller according to claim 1, wherein the second tank is arranged within a covering of the roller or on an outer covering of the roller so as to be accessible from the outside.

7. The roller according to claim 1, wherein the mixing device comprises a water jet pump or a static mixer.

8. The roller according to claim 7, wherein the mixing device comprises a static mixer, and wherein the static mixer is connected to a drain for discharging the separation agent mixture from the static mixer.

9. The roller according to claim 1, wherein the mixing device provides the separation agent mixture to a plurality of spray devices for different rubber tires.

10. The roller according to claim 1, wherein the roller comprises a measuring device for determining at least one of the following characteristics: viscosity of the second liquid, temperature of the second liquid, fill level of the first tank, of the second tank and/or of the static mixer, temperature of the external environment, temperature of one or more of the rubber tires or their surface, and/or temperature of the asphalt to be compacted.

11. A method for spraying a rubber tire of a roller for asphalt compaction with a separation agent mixture, comprising the following steps: providing a first liquid in a first tank and a second liquid in a second tank, delivering the first liquid with a first pump and/or the second liquid with a second pump to a mixing device, wherein the mixing ratio of first liquid to second liquid in the mixed liquid is set via a control device of a regulating device, said control device controlling the first pump and the second pump, mixing the first liquid and the second liquid in the mixing device in order to form a separation agent mixture during an operation of the roller, and spraying the rubber tire with the separation agent mixture provided by the mixing device.

12. The method according to claim 11, wherein the regulating device and/or the spray device is actuated during the operation of the roller as a function of a viscosity or temperature of the second liquid and/or as a function of a temperature of at least one rubber tire of the roller or a surface of the at least one rubber tire and/or as a function of a temperature of the asphalt to be compacted and/or a temperature of the external environment.

13. The method according to claim 11, wherein the second liquid is drained from the second tank or the second tank is detached from the roller after operation of the roller has ended.

14. The roller according to claim 1, wherein the roller comprises a rubber tire roller.

15. The roller according to claim 2, wherein the first actuating element and/or the second actuating element is arranged in a driver's cabin of the roller.

16. The roller according to claim 10, wherein the measuring device is connected to the control device.

17. The method according to claim 11, wherein the mixing ratio of first liquid to second liquid in the mixed liquid is set during operation of the roller.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention is described in greater detail below by means of the illustrative embodiments indicated in the figures, which show schematically:

[0035] FIG. 1 is a side view of a roller for asphalt compaction, specifically a rubber tire roller;

[0036] FIG. 2 is a system for spraying a rubber tire of a roller for asphalt compaction according to a first illustrative embodiment of the present invention;

[0037] FIG. 3 is a system for spraying a rubber tire of a roller for asphalt compaction according to a second illustrative embodiment of the present invention;

[0038] FIG. 4 is a system for spraying a rubber tire of a roller for asphalt compaction according to a third illustrative embodiment of the present invention;

[0039] FIG. 5 is an arrangement of a second tank on a rubber tire roller;

[0040] FIG. 6 is an alternative arrangement of a second tank on a rubber tire roller;

[0041] FIG. 7 is a further alternative arrangement of a second tank for a rubber tire roller; and

[0042] FIG. 8 is a flowchart pertaining to a method for spraying a rubber tire.

[0043] Identical elements are indicated by the same reference numbers in all figures. Repetitive elements may not be separately designated in each figure.

DETAILED DESCRIPTION OF THE INVENTION

[0044] FIG. 1 shows a side view of generic roller 1, specifically a rubber tire roller 1, in particular a self-propelled rubber tire roller 1, with a chassis 52, an operating platform or driver's cabin 50, rubber tires 2 and a motor 51. The rubber tire rollers 1 depicted in FIG. 1 and in the other figures are to be understood as representative for rollers 1 for asphalt compaction in general, in particular for so-called combined rollers. Of the said rubber tires 2, only the wheels facing the viewer are discernable. Specifically, four rubber tires 2 are respectively arranged next to one another both in the front and in the rear, the front rubber tires being arranged relative to the rear rubber tires 2 in the gaps in the direction of travel in a manner known in the prior art. Such rubber tire rollers 1 are typically provided for compacting work in road construction, wherein they operate by travelling over a surface to be compacted. Here, a rolling and kneading effect emanating from the rubber tires 2 results in a homogeneous compaction and pore sealing on a surface layer of the surface material to be compacted. During operation, i.e., during the compaction of the surface material, it regularly occurs that the surface material to be compacted adheres to the rubber tires 2 and is thus carried along, this tendency of the rubber tire 2 to pick up material depending primarily on the temperature of the rubber tire 2. An adhesion of the surface material occurs, in particular, at low temperatures of the rubber tires, which, for example, predominate immediately after the rubber tire roller 2 has been started up. In order to prevent this, a separation agent mixture 10 is used, which is sprayed onto the rubber tire 2 or all of the rubber tires 2 present by means of a spray device 70. In particular, such a separation agent mixture 10 is composed of at least one first liquid 11, preferably water, and at least one second liquid 12, preferably a separation agent concentrate. FIGS. 2 to 4 show embodiments of systems for mixing the two liquids and for spraying the rubber tires 2.

[0045] FIG. 2 shows a system for spraying a rubber tire 2 for a rubber tire roller 1 in accordance with a first illustrative embodiment of the present invention. A first tank 21 for the first liquid 11, a second tank 22 for the second liquid 12, and a mixing device are provided. As a result, a common tank provided for the separation agent mixture 10 can advantageously be omitted and the separation agent mixture can be prepared from the two liquids on the machine during operation. By means of the mixing device, the first liquid 11 and the second liquid 12 are mixed in order to form the separation agent mixture 10 and then passed as the separation agent mixture to a spray device 70 via a common supply line. For example, the spray device 70 is a spraying bar 71 extending horizontally across the front or rear rubber tires and transversely to the working direction, on which spray nozzles 72, preferably individually adjustable spray nozzles 72, are arranged at regular intervals. These spray nozzles 72 are preferably pointed at the rubber tire 2 or are oriented in such a way that their spray cones hit the rubber tire 2. However, other spraying devices 70, e.g., those comprising simple outlet openings instead of spray nozzles 72, are possible and within the scope of the present invention.

[0046] In the embodiment illustrated in FIG. 2, a water jet pump 5 is the mixing device, which enables the first liquid 11 and the second liquid 12 to be mixed with each other as needed. The first tank 21 containing the first liquid 11 is connected to the mixing device via a first supply line and the second tank 22 containing the second liquid 12 is connected to the mixing device via a second supply line. The water jet pump 5 here comprises, in particular, two inlets and one outlet. During operation of the water jet pump, a jet comprising the first liquid 11 is introduced at a first inlet from a nozzle into a tube with a larger diameter under the greatest possible line pressure. Via a second inlet, the second liquid 12 gains access to the tube with the larger diameter from the second supply line, in particular because of the negative pressure prevailing in the tube. Between the fast-flowing jet of the first liquid 11 and the medium comprising the second liquid 12, turbulence is caused in the tube by friction so that a mixing of the first liquid 11 and the second liquid 12 occurs. An advantage of using a water jet pump 5 is that no residues from the composite separation agent mixture 5 remain in the system or mixing device.

[0047] Furthermore, the second supply line has a regulating device in the form of a valve 3 and a fine-regulating valve 4. As a result, the quantity of the second liquid 12 supplied to the mixing device can be influenced in an advantageous manner, in particular in a situation-dependent manner. This proves particularly advantageous in that a change in the mixing ratio caused by changes in temperature after the start-up of the rubber tire roller or in the event of temperature variations in the environment of the rubber tire roller 1 can be counteracted. Such a change in the mixing ratio is to be expected, for example, when the first liquid 11 and the second liquid 12 have different temperature dependencies with regard to their viscosity and the quantity of the first liquid 11 and the second liquid 12 respectively delivered to the mixing device varies differently so that the mixing ratio is unintentionally modified. In addition, it is conceivable that the mixing ratio can be adjusted via the regulating device during operation of the rubber tire roller to the current need for the second liquid 12, depending on the situation or particular application of the rubber tire roller 1.

[0048] Furthermore, the first supply line, i.e., usually the water supply line, comprises a valve 3 as well as a filter 7 as part of a regulating device. By means of the filter 7, the first liquid 11 supplied to the mixing device can advantageously be cleared of unwanted impurities. Furthermore, integrated in the first supply line is a first pump 13′, in particular a water pump, with which the pressure required for the water jet pump can be obtained in the first line. In the embodiment shown in FIG. 2, the filter 7 is arranged between the valve 3 and the water pump 5. In order to be able to provide a desired target pressure at the spray device 70, preferably between 1.5 and 2 bar, a pressure regulating device is also provided, which is realized in the illustrated embodiment by a bypass circumventing the pump 13′, the bypass comprising a check valve with a spring 6′. In this manner, the system pressure is regulated exclusively within the water circuit. Both the valves 3 as well as the pump 13′ are controlled by the control device 60 via suitable control lines. Via these lines, the control device 60 controls, e.g., the opened/closed position of the vales 3 and/or the operation of the pump 13′, e.g., with regard to the intervals during which it is turned on/off and/or with regard to the conveyed volume. The entirety of valves 3, pump 13′, control device 60 and control lines constitutes the regulating device. This receives operational commands from the operator via corresponding actuating means, as illustrated, e.g., in FIG. 4.

[0049] FIG. 3 shows a system for spraying a rubber tire 2 for a rubber tire roller 1 according to a second illustrative embodiment of the present invention. In particular, the second tank 22 here is designed as a pressure tank 22′. The tank 22 can thus be overpressurized in relation to the external environment. According to the second illustrative embodiment, in order to transport the second liquid 12, the second liquid 21 in the second tank 22 is pressurized by means of compressed air from a compressed air reservoir 31, thus causing the transport of the second liquid 12 to the mixing device. A preferred pressure, for example, between 1.5 and 2 bar, can be set by means of a pressure-reducing valve 32 controlled by the control device 60, said pressure-reducing valve 32 being inserted between the compressed air reservoir 31 and the pressure tank 22′. The second supply line, which connects the second tank 22 to the mixing device, furthermore preferably comprises, as part of the regulating device, a 2/2-way valve 8, in particular an electrically actuable 2/2-way valve, and a fine-adjustment valve 3, in order to set or adjust the mixing ratio of the first liquid 11 and the second liquid 12 in the separation agent mixture 10 depending on the situation and need. Furthermore, the second supply line between the 2/2-way valve 8 and the mixing device includes a check valve without a spring 6″ which, in a closed state, prevents the first liquid 11 from entering the second supply line.

[0050] As is known from the first embodiment, the first liquid 11, driven by a first pump 13′, reaches the mixing device via a first supply line with a filter 7. In order to be able to provide a desired target pressure at the spray device 70, preferably between 1.5 and 2 bar, a bypass circumventing the pump 13′ is also connected as a pressure-regulating device to the first line, the bypass comprising a check valve with a spring 6″.

[0051] The adjustment of the aforementioned valves 3, 4 and/or 8 can be controlled manually or, in particular, also by means of a suitable control device which transmits corresponding control signals to the valves 3, 4 and/or 8, for example, depending on determined parameters such as, e.g., temperature, viscosity, etc.

[0052] In the embodiment illustrated in FIG. 3, a static mixer 15 is provided as the mixing device. The person skilled in the art understands a static mixer 15 to be, in particular, a device for mixing fluids in which the flow movement of the fluids, in the present case the first and the second liquid, alone effects the mixing and which does not have any moving elements. The static mixer 15 preferably consists of flow-influencing elements arranged in a chamber or a mixing tube. These flow-influencing elements alternately divide the material stream and then bring it together again, whereby mixing is achieved. Flow-influencing elements are, for example, a helical mixer or a grid mixer.

[0053] FIG. 4 shows a system for spraying a rubber tire 2 for a rubber tire roller 1 according to a third illustrative embodiment of the present invention. The third embodiment, like the second embodiment, comprises a static mixer 15 as a mixing device. Moreover, as in the second embodiment, the first liquid 11 is led to the mixing device via a supply line with a first pump 13′, in particular a water pump, and a filter 7. Furthermore, the first supply line comprises a valve 3 between the filter 7 and the first tank 21.

[0054] In order to provide the second liquid 12, the third embodiment provides, in particular, a second tank 22 comprising a drain 25. This drain 25 advantageously allows the second liquid 12 to be discharged from the tank 22 after the operation of the rubber tire roller 1. If the second liquid 12 has, in particular, a comparatively low freezing point temperature, the freezing of the second liquid 12 in the second tank 22 can thus be avoided. For the same purpose, the common supply line between the static mixer 15 and the spray device 70, additionally, or alternatively, preferably comprises a drain 25 which allows the separation agent mixture 10 to be drained or removed from the common supply line and/or the static mixer 15. In order to assist the draining of the second liquid, the bottom side of the second tank 22 preferably tapers in a funnel-shaped manner towards the drain 25 or the common supply line between the static mixer 15 and the spray device 70 preferably slopes, i.e., in the direction of a ground surface on which the rubber tire roller is standing.

[0055] Furthermore, the second liquid 12 is preferably conveyed to the static mixer 15 by means of a second pump 13″, in particular an adjustable variable displacement pump, controlled separately from the first pump 13′. For this purpose, a second pump 13″ is integrated in the second supply line. It is conceivable that the second pump 13″ is an electrically adjustable variable displacement pump with the aid of which the quantity of the second liquid 12 fed to the static mixer 15 per time unit is regulated by way of an electrical input voltage. In other words, the variable displacement pump controlled by the control device is preferably part of the regulating device. For its control, the variable displacement pump is connected to the control device 60. Via a first actuating element 61, which is preferably arranged in the driver's cabin 50 and connected to the control device 60, a roller operator can preferably set and/or adjust the mixing ratio in the separation agent mixture 10 by adjusting, e.g., an input voltage at the variable displacement pump in such a way that the desired quantity of second liquid 12 is provided to the static mixer 15.

[0056] Moreover, the first pump 13′ integrated in the first supply line is linked with a second actuating element 62 via the control device 60. By means of the second actuating element 62, an operating mode of the spray device 70 can preferably be set by the roller operator. For example, the spray device 70 can be turned off or on or operated in an interval mode, in particular during the operation of the rubber tire roller 1, via the second actuating element 61. For this purpose, the control device 60 preferably turns the first pump 13′ in the first supply line on and/or off again. Furthermore, a bypass line 57 is provided around the pump 13′ and a further check valve 6 is provided in the line portion downstream of the bypass line 57 in order to prevent an unintentional conveying of separation agent into the water path.

[0057] For the above variants, it is also possible that a corresponding arrangement is provided for the front and rear rubber tires, respectively. It is preferred, however, if the front and rear rubber tires are collectively sprinkled by a system for spraying the rubber tires with separation agent mixture.

[0058] Furthermore, a ventilation bypass 57′ is provided, which connects the line section downstream from the pump 13″ to the second tank 12 via a valve 3′ (a 2/2-way valve in the present case). Via this bypass, it is possible for the pump 13″ to convey in a first step, e.g., after the filling and/or installation of the second tank 12, without pressure into the tank 12 for ventilation purposes. Once the pump 13″ has been ventilated, a blocking of the ventilation bypass 27′ occurs by means of the valve.

[0059] In the embodiment in accordance with FIG. 4 with two pumps 13′ and 13″ controlled separately from one another and according to which the mixing ratio is thus adjusted by means of the control of both pumps 13′ and 13″, it is further provided that the tank is monitored with the help of the control device 60. Specifically, the energy consumption of the pumps 13′ and 13″ is monitored. If the latter sinks suddenly, this is a sign that the tank 11 or 12 is empty. This information is relayed to the operator by means of a suitable display device.

[0060] FIGS. 5 to 7 show various arrangements of the second tank 22. In this case, the second tank 12 is arranged in a recess 55 in the arrangement illustrated in FIG. 4, in particular in the region of the wheel housing 56. For this purpose, the frame or outer covering is partly faded out in this figure. Such an arrangement proves advantageous inasmuch as it permits free access to the second tank 22, for example, for draining the second liquid 12 via the clearance between the rubber tire 2 and the wheel housing 56, while the second tank 22 is simultaneously protected against external environmental influences by the casing of the rubber tire roller 1. In addition, the second tank 22 is arranged comparatively close to the spray device 70 so that installation space and costs for supply lines that would be necessary otherwise can be saved.

[0061] In contrast, the second tank 22 in the arrangement shown in FIG. 6 is arranged on an outer side of the outer covering of the rubber tire roller 1 from the outside. In particular, the second tank 22 is arranged in a mounted state on or adjacent to a covering hood of the rubber tire roller 1. In the mounted state, the second tank 22 preferably sits flush with at least one of its sides with the general profile of the outer covering. Furthermore, the second tank 22 is preferably temporarily mountable on the rubber tire roller via a coupling device. For example, the coupling device is a latching or tensioning device by means of which the coupling device is temporarily or reversibly mountable on the outer covering. This advantageously permits a removal and temporary storage of the second tank 22 when the rubber tire roller 1 is not being operated. Furthermore, it is conceivable that the second tank 22 comprises a viewing window, which advantageously directly conveys information about the fill level of the second tank 22 to the roller operator.

[0062] In the arrangement shown in FIG. 7, the second tank 22 is arranged in a recess near the wheel housing or below/adjacent to the water tank and/or near the water tank and the driver's cabin 50 or beneath the driver's cabin. In such an arrangement, the second tank 22 is protected from external environmental influences.

[0063] FIG. 8 schematically shows a method for spraying a rubber tire 2 in accordance with an illustrative embodiment of the present invention. With one of the rubber tire rollers 1 according to any one of the embodiments described above, for example, the following steps are performed: [0064] providing 41 a first liquid 11 in a first tank 21 and a second liquid 12 in a second tank 22, [0065] delivering 42 the first liquid 11 with a first pump (13′) and/or the second liquid 12 with a second pump (13″) to a mixing device, wherein the mixing ratio of first liquid (11) to second liquid (12) in the mixed liquid is set, in particular during an operation of the roller (1), by means of a control device (60) of a regulating device, said control device (60) controlling the first pump (13′) and the second pump (13″), [0066] mixing the first liquid 11 and the second liquid 12 in the mixing device during the operation of the rubber tire roller, and [0067] spraying the rubber tire 2 with the separation agent mixture 10 provided by the mixing device. Furthermore, it is provided that the first tank 21 is filled with the first liquid 11 and the second tank 22 is filled with the second liquid 12 in order to provide the first liquid 11 and the second liquid 12. It is particularly preferred that the operation of the spray device and/or of the mixing device occurs as a function of the detected temperature values, in particular the temperature of at least one of the rubber tires or the surface of a rubber tire, the outer environment and/or the asphalt to be compacted. In this context, the illustrated method can, in particular, be carried out in such a way that the illustrated steps are executed automatically by a control unit when the temperature falls below a predetermined temperature threshold value and stopped when the temperature exceeds a predetermined temperature threshold value. Furthermore, when supplying the first and second liquids, a further preferred embodiment lies in the modification of the mixing ratio of the first and the second liquid as a function of at least one of the temperature values described above. Specifically, an increase in the proportion of the second liquid in the separation agent mixture occurs at low or decreasing temperatures, and vice versa.

[0068] While the present invention has been illustrated by description of various embodiments and while those embodiments have been described in considerable detail, it is not the intention of Applicants to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will readily appear to those skilled in the art. The present invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of Applicants' invention.