Automotive Construction Machine, As Well As Lifting Column For A Construction Machine

Abstract

Disclosed is an automotive road construction machine, particularly a recycler or a cold stripping machine, comprising an engine frame that is supported by a chassis, a working roller which is stationarily or pivotally mounted on the engine frame and is used for machining a ground surface or road surface. The chassis is provided with wheels or tracked running gears which are connected to the engine frame via lifting column and are vertically adjustable relative to the engine frame. Each individually vertically adjustable lifting column is equipped with a device for measuring the actual vertical state of the lifting column.

Claims

1-36. (canceled)

37. A road construction machine, comprising: a machine frame; a plurality of ground engaging wheels for supporting the construction machine on a ground surface or traffic surface; a plurality of lifting columns, each of the lifting columns including a lifting column support at a lower end of the lifting column, each lifting column support being attached to one of the ground engaging wheels; and at least one distance sensor attached to at least one of the lifting column supports and arranged to detect a change in distance of the at least one of the lifting column supports from the ground surface or traffic surface due to filling pressure, temperature or interaction with the ground surface or traffic surface of the wheel associated with the at least one of the lifting column supports.

38. The road construction machine of claim 37, wherein: the at least one distance sensor is located relative to its associated lifting column support, so that the distance is measured at a pre-determined horizontal position relative to its associated ground engaging wheel.

39. The road construction machine of claim 37, wherein: the at least one distance sensor is a contactless sensor that does not contact the ground surface or traffic surface.

40. A method of operating a road construction machine, the road construction machine including a machine frame, a plurality of ground engaging wheels for supporting the construction machine on a ground surface or traffic surface, and a plurality of lifting columns, each one of the lifting columns being connected between the machine frame and one of the ground engaging wheels, and at least one lifting column support connected to a lower end of at least one of the lifting columns, the at least one lifting column support being attached to at least one of the ground engaging wheels, the method comprising: automatically detecting a change in distance of the at least one lifting column support from the ground surface or traffic surface due to filling pressure, temperature or interaction with the ground surface or traffic surface of the wheel associated with the at least one of the lifting column supports.

41. The method of claim 40, wherein: the automatically measuring step includes measuring the distance with a sensor attached to the at least one lifting column support.

42. The method of claim 40, wherein: the automatically measuring step includes measuring the distance with a sensor mounted on the at least one lifting column support at a pre-determined horizontal position relative to its associated ground engaging wheel.

43. The method of claim 40, wherein: the automatically measuring step includes measuring the distance with a sensor attached to the at least one lifting column support and not contacting the ground surface or traffic surface.

44. The method of claim 40, further comprising: transmitting a signal corresponding to the distance to a controller.

45. The method of claim 40, further comprising: transmitting a signal corresponding to the distance to an indicator device.

46. The method of claim 40, wherein: the automatically measuring step includes generating a signal corresponding to the distance with a sensor attached to the at least one lifting column support.

47. The method of claim 46, further comprising: transmitting the signal to a controller.

48. The method of claim 46, further comprising: transmitting the signal to an indicator device.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0034] In the following, embodiments of the invention are explained in more detail with reference to the drawings. The following is shown:

[0035] FIG. 1 is a side view of the construction machine in accordance with the invention, in which the working drum is in a working position,

[0036] FIG. 2 a top view of the construction machine in accordance with FIG. 1, and

[0037] FIG. 3 a lifting column of the construction machine.

DETAILED DESCRIPTION OF THE INVENTION

[0038] FIG. 1 shows a road construction machine 1 for producing and working carriageways by stabilizing insufficiently stable soils or by recycling road surfaces, with a machine frame 4 supported by a chassis 2, as it is basically known from DE 103 57 074 B3. The chassis 2 is provided with two each rear and front wheels 10, which are attached to lifting columns 14 in a height-adjustable manner and can be raised and lowered independently of one another or also synchronously to one another. It is understood that other drive means like, for instance, crawler track units may also be provided in lieu of the wheels 10. The wheels or crawler track units may also be referred to as ground engaging supports for supporting the construction machine on the ground surface or traffic surface 24. The lifting columns 14 are attached to the machine frame 4.

[0039] Both axles of the chassis, which are formed by the front and rear wheels 10 respectively, may be steerable.

[0040] As can be seen from FIGS. 1 and 2, an operator's platform 12 for a vehicle driver is arranged at the machine frame 4 above the front wheels 10 or in front of the front wheels 10, with a combustion engine 32 for the travel drive and for driving a working drum 6 being arranged behind the driver. In this manner, the operator's platform 12 can be ergonomically optimized for the vehicle driver.

[0041] The working drum 6 which rotates, for instance, in opposition to the direction of travel when seen in the direction of travel, and the axis of which extends transversely to the direction of travel, is mounted to pivot relative to the machine frame 4 in such a manner that it is capable of being pivoted from an idle position to a working position, as depicted in FIG. 1, by means of pivoting arms 42 arranged on both sides. Each pivoting arm 42 is mounted in the machine frame 4 at one end and accommodates the support of the working drum 6 at its other end.

[0042] It is also possible to operate the machine 1 in reversing direction, with the milling operation then taking place synchronously to the direction of travel.

[0043] The working drum 6 is, for instance, equipped with cutting tools that are not depicted in the drawings in order to be able to work a ground surface or traffic surface 24.

[0044] The working drum 6 is surrounded by a hood 28 which, as can be seen from FIG. 1, is capable of being raised together with the working drum 6 by means of the pivoting arms 42.

[0045] In operating position, the hood 28 rests on the ground surface or traffic surface 24 to be worked, as can be seen from FIG. 1, while the working drum 6 is capable of being pivoted further down according to the milling depth.

[0046] It is understood that other embodiments of such a construction machine exist in which the hood 28, or the hood 28 and the working drum 6, are mounted at the machine frame 4 in a rigid manner. In the latter case, the working depth of the working drum 6 is adjusted via the lifting columns 14, in all other cases through an adjustment in height of the working drum 6.

[0047] FIG. 3 shows an individual lifting column 14 comprising two hollow cylinders 13, 15 which are capable of telescoping in a form-fitting manner. The hollow cylinders 13, 15 serve as guiding unit for the height adjustment of the machine frame 4. The upper outer hollow cylinder 13 is attached at the machine frame 4, and the lower inner hollow cylinder 15 is attached at a support 11 which may be coupled with a wheel 10 or a crawler track unit. The lifting column 14 is further provided with a hydraulic piston cylinder unit 16 for the stroke adjustment. The piston cylinder unit 16 acts between the machine frame 4 and the support 11, so that the machine frame 4 is capable of being adjusted in height relative to the support 11 and thus, ultimately, relative to the ground surface or the traffic surface 24 respectively. In the embodiment shown in FIG. 3, the piston element of the piston cylinder unit 16 is attached at the support 11, and the cylinder element of the piston cylinder unit 16 is attached at the upper hollow cylinder 13, which is attached at the machine frame 4.

[0048] It is understood that more than one piston cylinder unit 16 may also be present in the lifting column 14.

[0049] The piston cylinder unit 16 may also be force-coupled hydraulically with a neighbouring lifting column 14, as has been basically described in DE 196 17 442 C1, in order to form a purely hydraulic full-floating axle.

[0050] The lifting column 14 is provided with a measuring device 18 for measuring the current lifting state of the lifting column 14. In the embodiment, the said measuring device 18 includes a wire-rope 22 that is attached at the support 11 or the lower hollow cylinder 15 and is, on the other hand, coupled with a wire-rope sensor 21 that is attached at the cylinder element of the piston cylinder unit 16 or at the upper hollow cylinder 13. The stroke path of the lifting column 14 can be measured by means of the wire-rope sensor 21. The wire-rope sensor 21, and the path signal produced by the same, is ultimately also suitable for being converted into a velocity signal or acceleration signal by including a time measurement.

[0051] The measured path signal of the wire-rope sensor 21 is transmitted to an indicator device 20 and/or a controller 23 by means of a signal line 26. The indicator device 20 and/or the controller 23 receive measured path signals from each lifting column, as indicated in the drawing in FIG. 3. With a total of four existing lifting columns 14, four measured path signals can be displayed in the indicator device 20, so that the vehicle driver is immediately informed about the current lifting state of each lifting column and can alter the lifting position, if required.

[0052] The measured path signals can additionally be supplied to a controller 23, which enables overall control or regulation of the lifting position of the lifting columns 14.

[0053] The controller 23 can, for instance, adjust a desired lifting position of the lifting column 14 without overshooting or with as little overshooting as possible in accordance with the measured path signals of the measuring devices 18 and/or their alteration over time.

[0054] In case of a full-floating axle, floating can be effected purely hydraulically through piston cylinder units 16 which are provided with a piston capable of being loaded from two sides, and the counter-operating cylinder chambers of which are force-coupled with the corresponding cylinder chambers of the piston cylinder unit of a neighbouring wheel 10. Alternatively, a height adjustment in the manner of a full-floating axle may be effected with purely electronic control by means of the measured path signals detected.

[0055] The control or regulation may be such that, for instance, the machine frame 4 is subject to the smallest possible displacement.

[0056] The machine frame 4 may alternatively be regulated by means of the lifting state of the lifting columns 14 in such a manner that a pre-determined transverse inclination of the machine frame 4 transverse to the direction of travel is maintained.

[0057] A further alternative provides that the time sequence of the position of the machine frame 4 such as, for instance, a path-dependent transverse inclination sequence of the machine frame 4, may also be regulated by means of the measured path signals and the piston cylinder units 16 in combination with a path or machine position measurement.

[0058] Ultimately, it is also understandable that a longitudinal inclination or a combination of a transverse and longitudinal inclination can also be regulated by means of the controller 23.

[0059] The measured signals of the measuring device 18 may be calibrated to a unit of length like, for instance, millimetres. In this way, it is possible for the vehicle driver to also alter the lifting state of the lifting columns 14 through entering a specific stroke in millimetres.

[0060] Each lifting column 14 may be provided with a distance sensor 30 each at the supports 11, which measures the distance of the support 11 to the ground surface and traffic surface 24. By means of the measured signal of the distance sensors 30, and in combination with the measured path signals of the measuring device 18, the controller 23 for the lifting columns 14 can also calculate the current distance of the machine frame 4 from the ground surface and traffic surface 24.

[0061] The distance sensor 30 can measure the distance of the support 11 to the ground surface and traffic surface 24 also in a pre-determined distance in front of or next to the wheel 10 or crawler track unit. Measuring in front of the wheel 10 offers the possibility of using the measured signal of the distance sensor 30 for the purpose of controlling the height adjustment of the lifting columns 14 in a manner that allows an immediate reaction to any ground irregularity. Finally, the distance sensors 30 are also capable of supplying measured signals for a regulation of the milling depth, where the measured signals of the distance sensors 30 and the measured path signals of the measuring device 18 are evaluated on a joint basis.

[0062] Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined by the appended claims.