ROAD CONSTRUCTION MACHINE AND METHOD FOR OPERATING A SELF-PROPELLED ROAD CONSTRUCTION MACHINE

Abstract

A method for operating a self-propelled road construction machine as well as a road construction machine with which an adjustment of the traction of the wheeled undercarriage can be performed in a quick and easy manner by monitoring and actively regulating the traction of the tires in dependence on the operating mode of the road construction machine. Pavers and feeders for the making of road covers have a wheeled undercarriage, especially with pneumatic tires. For a uniform production process of the road cover, adequate traction of the tires is needed. For this, prior to the start of the production process the tire air pressure of the tires is decreased, and it is increased once again for travel on the road, and the manual adjustment of the tire air pressure to the installation conditions and/or to the operating mode of the road construction machine is time consuming and cost intensive.

Claims

1. A method for operating a self-propelled road construction machine, especially a paver (10) or a feeder for producing a road cover with an undercarriage (12) having driven tires (15), comprising monitoring and actively regulating the traction of the tires (15) of the undercarriage (12) in dependence on the operating mode of the road construction machine.

2. The method as claimed in claim 1, wherein the monitoring and active regulating of the traction during the operation of the road construction machine are done automatically or manually and independently of each other for each tire (15).

3. The method as claimed in claim 1, wherein the active regulating of the traction of the tires (15) is done by changing the tire air pressure, wherein tire air pressure is increased during travel on the road or during transport and the tire air pressure is decreased during an installation process of the road cover.

4. The method as claimed in claim 1, wherein the active regulating of the traction of the tires (15) is done by changing the load relief on a screed of a paving screed (20) of the road construction machine, especially the paver (10), preferably in that the load relief of the paving screed (20) is increased in order to increase the traction.

5. The method as claimed in claim 4, wherein the active regulating of the traction of the tires (15) is done by changing the load relief of the screed and by changing tire air pressure, in particular in that the regulating of the traction may be done by the load relief of the screed in addition to a changing of the tire air pressure.

6. The method as claimed in claim 1, wherein the tire air pressure is determined, preferably permanently, by a tire pressure monitoring unit for the monitoring and active regulating of the tire air pressure of all tires (15) during the operation of the road construction machine, wherein an air pressure loss of the tires (15) is determined by the tire pressure monitoring unit.

7. The method as claimed in claim 1, wherein the traction of the tires (15) of the undercarriage (12) is monitored and actively regulated in dependence on a ground base (25) on which the road construction material is being installed, and/or on a thickness of the layer of the road construction material and/or an installation width of the road construction material.

8. The method as claimed in claim 1, wherein the speed of the road construction machine is changed, in particular reduced, preferably automatically, in the event of a changing, especially decreasing tire air pressure and/or in the event of a changed, especially decreased screed load relief.

9. The method as claimed in claim 1, wherein reference values of tire air pressure are recalibrated for the monitoring and regulating of the traction in the event of a change of tires, especially in the event of a change of tire manufacturers.

10. The method as claimed in claim 1, wherein the active regulating of the traction of the tires (15) is performed through additional weights or through compound disk wheels or through filling air into tires (15) having at least two separate air chambers.

11. A road construction machine, especially a paver (10) or feeder, having an undercarriage (12) with driven tires (15), comprising an automatic or manually activatable traction control device (26) for the active traction control of the tires (15) with a tire pressure monitoring unit, wherein the traction of the driven tires (15) is adaptable accordingly during the running of the operating mode by a measurement of the tire pressure.

12. The road construction machine as claimed in claim 11, wherein the traction control device (26) further comprises at least one compressor (27) with which an air tank (28) can be filled with compressed air, a tank pressure switch (29), a tank pressure manometer (30) and a preselect pressure manometer (32), for regulating the air pressure, a preselect unit (31), a tire pressure monitoring unit and a regulating unit (34), pressurized air lines (34) and connection points (35) for the compressed air on the tires (15).

13. The road construction machine as claimed in claim 11, wherein the traction control device (26) further comprises at least one sensor for determining the operating mode and/or one sensor, preferably one sensor for each tire (15), for determining the traction, especially the slippage.

14. The road construction machine as claimed in claim 11, wherein the traction of the tires (15) is regulatable through the traction control device (26) by changing a screed load relief of a paving screed (20).

15. The road construction machine as claimed in claim 12, wherein the compressor (27) is hydraulically, electrically, or mechanically drivable or has its own drive unit.

16. The road construction machine as claimed in claim 12, wherein the traction control device (26) and/or the compressor (27) are/is permanently connected to the tires (15), especially to the tire inside or outside or the wheel hub, or in that the traction control device (26) and/or the compressor (27) are/is not permanently connected to the tires (15).

17. The road construction machine as claimed in claim 11, further comprising at least one of (a) the tires (15) have weights for the traction control, (b) the tires (15) are composed of a compound disk wheel, consisting of at least one wheel disk and an outer rim ring, and (c) the tires (15) each have two separate air chambers.

18. The method as claimed in claim 1, wherein the monitoring and active regulating of the traction during the operation of the road construction machine are done automatically or manually and independently of each other for each for each rear tire (15), looking in the production direction (13).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] A preferred exemplary embodiment of a road construction machine according to the invention shall be explained more closely below with the aid of the drawing. This shows:

[0029] FIG. 1 is a schematic side view of a construction machine, namely, a paver, and

[0030] FIG. 2 is a block diagram of a traction control device.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0031] A paver 10 shown schematically in FIG. 1 serves for the production of road covers. These can be a road cover of any given kind.

[0032] The paver 10 has a self-propelled design. For this, it comprises a central drive unit 11, which is formed for example by an internal combustion engine, the hydraulic pumps for the powering of hydraulic motors, and optionally a generator for creating energy for electric drives and compressors.

[0033] The paver 10 has an undercarriage 12, which in the exemplary embodiment shown in FIG. 1 is designed as a wheeled undercarriage. The undercarriage 12 is driven by the drive unit 11 such that the paver 10 can be moved forward in the production direction 13. The undercarriage 12 has wheels 14 at a front part of the paver 10, looking in the production direction 13, which are formed as all-rubber wheels in the exemplary embodiment depicted here. A pair of tires 15 is associated with the rear part of the paver 10, looking in the production direction 13. These tires 15 serve as drive tires and are air-filled.

[0034] Looking in the production direction 13, a tub or trough-shaped reservoir tank 14 is arranged in front of the drive unit 11. The reservoir tank 14 holds a supply of the material serving for the production of the road cover, such as asphalt. Optionally, several reservoir tanks may also be provided. The road construction material may either be loaded into the reservoir tank 16 by a truck, not shown, having driven up to the front end 17 of the paver. However, it is also conceivable for the road construction material to be loaded into the reservoir tank 16 via a feeder, not shown, which is likewise arranged at the front end 17 of the paver 10.

[0035] By delivery members, not shown, the road construction material is transported from the reservoir tank 14 beneath the drive unit 11 through to the rear end 18 of the paver 10, in the production direction 13. From a distributing worm 19 arranged behind the undercarriage 12, the road construction material is distributed over the entire working width of the paver 10. In this process, a supply of the road construction material ends up in front of a paving screed 20, suspended from the undercarriage 12 and able to move up and down behind the distributing worm 19.

[0036] Furthermore, the paver 10 shown in FIG. 1 has an operator's station 21, from which the paver 10 can be controlled by an operator, not shown.

[0037] In order to produce the road cover, the still hot road construction material is deposited by the distributing worm 19 in front of the paving screed 20 and compacted by the paving screed 20. For this, the paving screed 20 suspended from the support arms 22 is set down on the road construction material and pulled by the paver 10 across the material. The support arms 20 are moved up and down in this process by lifting cylinders 23 and leveling cylinders 24. During the installing of the road construction material, the paving screed 20 floats on the road construction material. To relieve the load on the paving screed 20, the support arms 22 or the paving screed 20 may be raised by the lifting cylinder 23 or leveling cylinder 24.

[0038] For a uniform installing of the road cover and thus for the production of a trouble-free cover, it is important for the tires 15 to have adequate traction on the ground base 25.

[0039] FIG. 2 shows, highly schematized, a block diagram of a traction control device 26. This traction control device 26 shown in FIG. 2 stands in direct connection with the two drive tires 15. However, it is precisely provided, according to the invention, that the traction control device 26 regulates the screed load relief of the paving screed 20. For this, the traction control device 26 actuates the lifting cylinder 23 or the leveling cylinder 24.

[0040] The traction control device 26 shown in FIG. 2 has a compressor 27. This compressor generates compressed air and is driven either through its own drive or through the drive unit 11 or auxiliaries. The compressor 27 is assigned an air tank 28, in which compressed air can be stored. In order to always store an adequate quantity of compressed air in the tank 28, the air tank 28 is assigned a tank pressure switch 29 and a tank pressure manometer 30. Furthermore, the traction control device 26 has a preselect unit 31 with a preselect pressure manometer 32 and a regulating unit 33. In order to be able to actuate the tires 15 accordingly, a pressurized air line 34 leads from the compressor 27 to the tires 15. This pressurized air line 34 is connected across connection points 35 to the tires 15. These connection points 35 may be, for example, the wheel hub of the tires 15.

[0041] Furthermore, the tires 15 are connected at least to the regulating unit 33 by pressure sensor means, not shown. These sensor means determine the pressure in both tires 15 continually or in a timed manner or according to a manual input and transmit this value to the regulating unit 33. Then, depending on the predetermined operating mode, the air pressure in the tires 15 is regulated. For this, the tire air pressure can be increased by means of air from the air tank 28 or the compressor 27 or the pressure in the tires 15 can be reduced by bleeding or extracting of the compressed air. Furthermore, the regulating unit 33 is connected directly to a traction measuring device for both tires 15. Once this traction measuring device ascertains a lack of traction, the tire air pressure is changed accordingly. The tire air pressure will be changed until the traction is optimal, and at the same time a minimal consumption is achieved for the drive unit 11.

[0042] Besides the traction control and regulating of the tires 15 via the tire air pressure, the traction regulation can also be done by variation of the screed load relief of the paving screed 20. For this, the regulating unit 33 in the case of a determined lack of traction relays a corresponding signal to the lifting cylinder 23 or to the leveling cylinder 24. The regulating unit 33 ascertains for this an optimal interconnection of the traction regulation by altering the tire air pressure and the screed load relief.

[0043] Likewise, the traction for a feeder is regulated by measuring the tire air pressure of the drivable tires and regulating and increasing or reducing the tire air pressure of the drive tires according to the operating mode or the measured and required traction.

LIST OF REFERENCE NUMBERS

[0044] 10 Paver [0045] 11 Drive unit [0046] 12 Undercarriage [0047] 13 Production direction [0048] 14 Wheel [0049] 15 Tire [0050] 16 Reservoir tank [0051] 17 Front end [0052] 18 Rear end [0053] 19 Distributing worm [0054] 20 Paving screed [0055] 21 Operator's station [0056] 22 Support arm [0057] 23 Lifting cylinder [0058] 24 Leveling cylinder [0059] 25 Ground base [0060] 26 Traction control device [0061] 27 Compressor [0062] 28 Air tank [0063] 29 Tank pressure switch [0064] 30 Tank pressure manometer [0065] 31 Preselect unit [0066] 32 Preselect pressure manometer [0067] 33 Regulating unit [0068] 34 Pressurized air line [0069] 35 Connection point