Method for working ground pavements, as well as self-propelled construction machine

Abstract

In a self-propelled construction machine for working ground pavements comprising at least one machine frame, at least one height-adjustable milling drum for working the ground pavement in a working operation, driven by at least one drive unit, at least one control device for monitoring and controlling the milling depth of the milling drum and the speed of the construction machine,
it is provided for the following features to be achieved: that a monitoring device detects an interruption of the working operation, and when detecting the interruption of the working operation emits a signal to interrupt the drive of the milling drum.

Claims

1. A self-propelled construction machine for working ground pavement, comprising: at least one machine frame; at least one height-adjustable milling drum configured to work the ground pavement in a working operation, driven by at least one drive unit; at least one control device configured to monitor and control a milling depth of the milling drum and a speed of the construction machine; and a monitoring device configured to monitor adjustments to at least one nominal operating parameter of the construction machine, said nominal operating parameter effectively corresponding to an actual operating parameter of the construction machine, to detect an interruption of the working operation, and upon detection of the interruption of the working operation, to emit a signal to interrupt the drive of the milling drum via the drive unit.

2. The self-propelled construction machine of claim 1, wherein the monitoring device is configured to detect an interruption of the working operation by comparing the at least one monitored nominal operating parameter with at least one specified limit value.

3. The self-propelled construction machine of claim 2, wherein the at least one nominal operating parameter comprises a nominal advance speed, and an interruption of the working operation is detected when the nominal advance speed becomes zero.

4. The self-propelled construction machine of claim 2, wherein the at least one nominal operating parameter comprises a nominal milling depth, and an interruption of the working operation is detected when the nominal milling depth becomes negative.

5. The self-propelled construction machine of claim 1, comprising a power transmission device configured to transmit a driving power from the drive unit to the milling drum, and further configured responsive to the emitted signal from the monitoring device interrupt the drive of the milling drum.

6. The self-propelled construction machine of claim 1, wherein the monitoring device is configured to detect an interruption of the working operation and to emit the signal to interrupt the drive of the milling drum only after a specified time delay.

7. The self-propelled construction machine of claim 1, wherein the monitoring device is configured, following the interruption of the drive of the milling drum, to detect whether the working operation is to be continued, and upon detecting the intended continuation of the working operation to emit a second signal for the renewed driving of the milling drum.

8. The self-propelled construction machine of claim 7, wherein the monitoring device is configured to detect the intended continuation of the working operation by: querying at least one operating parameter of the construction machine from the control device, and comparing the at least one operating parameter with at least one specified limit value.

9. The self-propelled construction machine of claim 1, wherein the control device is configured to delay one or more of the movement of the construction machine and a lowering of the milling drum until the milling drum has reached a specified operating speed of revolution.

10. A method for working ground pavements with a construction machine that is self-propelled via one or more travelling devices, and in which a milling drum is driven by a drive unit, wherein the milling drum works the ground pavement in a working operation, the method comprising: monitoring adjustments to at least one nominal operating parameter of the construction machine, said nominal operating parameter effectively corresponding to an actual operating parameter of the construction machine, to automatically detect an interruption of the working operation; and upon detecting an interruption of the working operation, automatically interrupting the drive of the milling drum.

11. The method of claim 10, wherein detecting an interruption of the working operation comprises comparing the at least one monitored nominal operating parameter with at least one specified limit value.

12. The method of claim 11, wherein the at least one nominal operating parameter comprises a nominal advance speed, and an interruption of the working operation is detected when the nominal advance speed becomes zero.

13. The method of claim 11, wherein the at least one nominal operating parameter comprises a nominal milling depth, and an interruption of the working operation is detected when the nominal milling depth becomes negative.

14. The method of claim 10, wherein the drive of the milling drum is interrupted by one or more of decoupling the milling drum from the drive unit and switching off the drive unit.

15. The method of claim 14, wherein the drive of the milling drum is interrupted only after a specified time delay.

16. The method of claim 10, further comprising automatically detecting whether the working operation is to be continued, and upon detecting the intended continuation of the working operation to automatically resume driving of the milling drum.

17. The method of claim 16, wherein detecting an intended continuation of the working operation comprises: querying at least one operating parameter of the construction machine, and comparing the at least one operating parameter with at least one specified limit value.

18. The method of claim 10, further comprising delaying one or more of the movement of the construction machine and a lowering of the milling drum until the milling drum has reached a specified operating speed of revolution.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Hereinafter, embodiments of the invention are illustrated in more detail with reference to the drawings.

(2) The following is shown schematically:

(3) FIG. 1 shows a self-propelled construction machine for working ground pavements,

(4) FIG. 2 shows the construction machine according to FIG. 1 with raised milling drum,

(5) FIG. 3 shows a power train of the construction machine,

(6) FIG. 4 shows an illustration showing the control device and monitoring device,

(7) FIG. 5 shows an alternative illustration,

(8) FIG. 6 shows a flow diagram for detecting the interruption and the intended continuation of the working operation,

(9) FIG. 7 shows a further self-propelled construction machine.

DETAILED DESCRIPTION OF THE INVENTION

(10) FIG. 1 shows a self-propelled construction machine 1 for working ground pavements 2. The construction machine 1 comprises, as a minimum, a machine frame 4. Furthermore, the construction machine comprises a height-adjustable milling drum 12 for working the ground pavement 2 where, in a working operation, the milling drum 12 works the ground pavement 2. The milling drum 12 may be accommodated in a milling drum housing. The milling drum housing may comprise a left and a right edge protector 24 at the end sides, a hold-down device at the front side and a scraper 22 at the rear side, where the same close the working chamber of the milling drum 12 towards the outside.

(11) Furthermore, the construction machine 1 comprises a control device 14 for monitoring and controlling the milling depth of the milling drum 12 and the speed of the construction machine 1. The milling drum 12 is driven by a drive unit 6. The drive unit 6 is preferably a drive motor, specifically, a combustion engine. Alternatively, the drive unit may also be an electric or hydraulic motor. The construction machine 1 furthermore comprises front and rear travelling devices 8, 9. Said travelling devices 8, 9 may be wheels or tracked ground-engaging units. The rear travelling devices 9 are connected to the machine frame 4 in a height-adjustable fashion via lifting columns 20 by means of, for example, piston-cylinder units. The front travelling device 8 is also connected to the machine frame 4. The front travelling devices 8 may, in a different fashion than depicted, also be connected to the machine frame via lifting columns. The construction machine 1 or the machine frame 4, respectively, can be adjusted in height relative to the ground pavement by means of the lifting columns 20. The machine frame 4 is adjusted in height by adjusting the lifting columns 20, and as a result, the milling drum 12 mounted in the machine frame 4 is adjusted in height as well. In FIG. 2, the construction machine 1 is depicted with the milling drum 12 raised. Alternatively or additionally, the milling drum may be adjustable in height relative to the machine frame.

(12) In a method for working the ground pavement 2, an interruption of the working operation is detected, and the drive of the milling drum 12 is interrupted in the event of a detected interruption of the working operation. In this arrangement, the monitoring device 15 detects an interruption of the working operation, and when detecting the interruption of the working operation, the monitoring device 15 emits a signal to interrupt the drive of the milling drum 12.

(13) The monitoring device 15 monitors operating parameters of the construction machine 1 to detect the interruption of the working operation. The operating parameters are compared with specified limit values which may be stored in the monitoring device.

(14) The operating parameters which are monitored to detect the interruption of the working operation may specifically be the actual speed of the construction machine 1 and/or the actual milling depth.

(15) Provided that the actual speed of the construction machine 1 is zero, the working operation is interrupted. Furthermore, the working operation is also interrupted when the milling drum 12 is no longer engaged with the ground pavement 2. This is the case, for example, in FIG. 2. There, the milling drum 12 is no longer engaged with the ground pavement 2. In this case, the working operation is interrupted.

(16) When detecting the interruption of the working operation, the drive of the milling drum 12 is interrupted.

(17) The power train of the construction machine 1 is depicted in FIG. 3. In this arrangement, the driving power is transmitted, via a drive unit 6 which is preferably a drive motor, specifically a combustion engine, to the milling drum 12 via a power transmission device 13. The power transmission device comprises a coupling 7 and a drum drive 10. The drum drive 10 drives the milling drum 12 by means of a belt drive 11.

(18) In case of an interrupted working operation, a signal is emitted to the power transmission device which interrupts the drive of the milling drum 12. In the process, the drive unit 6 is decoupled from the milling drum 12 by means of the coupling 7.

(19) In FIG. 4, an illustration is depicted which depicts the signal paths between the control device 14, monitoring device 15, operating device 16, travel drive, height adjustment, drive unit 6 and milling drum 12. The monitoring device 15 monitors operating parameters of the construction machine to detect the interruption of the working operation.

(20) It is depicted in FIG. 4 that the monitoring device queries the operating parameters from the control device 14. In the embodiment depicted, the operating parameters which can be queried from the control device 14 are, among other things, the actual speed, the nominal speed, the nominal milling depth and the actual milling depth.

(21) The monitoring device 15 compares the operating parameters queried with specified limit values. The actual operating parameters are queried specifically to detect the interruption of the working operation. The actual speed, which is referred to as actual advance rate, and/or the actual milling depth are thus specifically queried by the monitoring device 15 and compared with specified limit values.

(22) The control unit receives measuring data from sensors about the actual speed and the actual milling depth. The sensors for determining the actual speed may be arranged at parts of the travel drive. The travel drive comprises the travelling devices and running gear motors for driving the travelling devices, where one running gear motor is preferably assigned to each travelling device. The running gear motors may be hydraulic motors and may be driven by a common hydraulic variable displacement pump.

(23) Sensors of any other kind may also be used, however, which are able to determine the actual speed of the construction machine 1.

(24) The actual milling depth is detected by sensors which are arranged at the height adjustment feature, for example, at the lifting columns or at the piston-cylinder units. The sensors may also be arranged in any other position, however, provided that the same are able to determine the actual milling depth. They may be arranged, for example, at the scraper blade 22 and/or at the side plates 24. Further sensors for determining the milling depth, such as ultrasonic sensors, are known to the person skilled in the art. The exact procedure to determine the milling depth is not relevant to the invention; it must merely be ensured that one can be detected reliably when the milling drum is disengaged from the ground surface in order to detect an interruption of the working operation.

(25) Provided that the monitoring device determines, by comparison of the operating parameters with specified limit values, that the working operation is interrupted, the monitoring device emits a signal to the power transmission device 13. The power transmission device 13 comprises means for interrupting the flux of power.

(26) The means for interrupting the flux of power is preferably a coupling as it is depicted in FIG. 3.

(27) The drive of the milling drum is interrupted with the aid of the means for interrupting the flux of power. Provided that the means for interrupting the flux of power is a coupling 7, the milling drum 12 is decoupled from the drive unit 6 in case of an interrupted working operation.

(28) After the drive of the milling drum 12 has been interrupted, it is detected as to whether the working operation is to be continued. When detecting the intended continuation of the working operation, the milling drum 12 is driven again. To this effect, the monitoring device 15, following the interruption of the drive of the milling drum 12, detects as to whether the working operation is to be continued, and when detecting the intended continuation of the working operation, emits a second signal for the renewed driving of the milling drum 12. In this process, the monitoring device 15 emits the second signal for the renewed driving of the milling drum 12 specifically to the power transmission device 13.

(29) In order to detect the intended continuation of the working operation, the monitoring device 15 queries operating parameters from the control device 14 and compares the queried operating parameters with specified limit values which may be stored in the monitoring device 15. In this arrangement, the nominal operating parameters are specifically queried to detect the intended continuation of the working operation. The nominal speed and the nominal milling depth are preferably queried in this process. These may be queried from the control device and/or the operating device.

(30) It is depicted in FIG. 5 that the monitoring device 15 may also query the operating parameters directly from the sensors or directly from the operating device 16, respectively.

(31) The monitoring device 15 may detect an interruption of the working operation and emit the signal to interrupt the drive of the milling drum only after a specified time delay.

(32) The monitoring device 15 may also delay the movement of the construction machine 1 and/or a lowering of the milling drum 12 until the milling drum 12 has reached a specified operating speed of revolution again. It is further depicted in FIG. 5 that sensors may also be arranged at the milling drum 12 which measure the speed of revolution of the milling drum 12. To this effect, the monitoring device 15 may query the operating speed of revolution determined by a sensor from the control unit or directly from the sensors.

(33) The milling drum 12 may also be raised after detection of an interruption of the working operation.

(34) After detection of the intended continuation of the working operation, the milling drum 12 may then be driven again and then be lowered. In this way, it is ensured that the milling drum 12 is in contact with the ground pavement 2 only when the milling drum 12 has reached an operating speed of revolution.

(35) FIG. 6 shows a flow diagram for detecting the interruption of the working operation and the intended continuation of the working operation.

(36) In order to detect the interruption of the working operation, the nominal speed of the milling machine queried from the control device 14 or from sensors is compared with a limit value in block 100 specifically to determine as to whether the advance rate, that is, the speed of the construction machine 1 is greater than 0.

(37) If the speed is greater than zero, the actual milling depth determined from the control device 14 or from sensors is compared with a limit value in a subsequent step in block 110, it being specifically determined as to whether the milling drum 12 is engaged with the ground at the adjusted milling depth.

(38) If it is determined in block 100 that the actual speed is zero, an interruption of the working operation is detected. Following detection of the interruption of the working operation, the milling drum may be raised by a specified amount as depicted in block 101. The drive of the milling drum is then interrupted in block 102.

(39) In the following, the nominal milling depth, which may also be queried from the control unit 14 or from the operating unit 16, is monitored in block 103, where it is monitored as to whether the same falls below a preadjusted limit value. It is thus monitored as to whether, in addition to the standstill of the machine, the milling drum 12 is also disengaged from the ground. If the nominal milling depth continues to be greater than the limit value, it is monitored in the next step in block 104 as to whether a nominal speed greater than zero has been adjusted again, that is, whether the machine operator wishes to resume the working operation by increasing the speed. The steps 103 and 104 are performed continuously during the standstill of the machine until either the milling depth is changed, or the advance rate is increased again.

(40) In addition, it may also be monitored in step 104 as to whether the nominal milling depth was increased by the machine operator, meaning whether the milling depth is to be increased while the machine is stationary.

(41) If it is detected in block 104 that the nominal speed has now reached a value greater than zero again or that the nominal milling depth was increased, meaning that the machine operator wishes to move the construction machine forward again and/or to increase the milling depth, an intended continuation of the working operation is detected and the milling drum driven again in block 120. After the specified milling drum speed of revolution has been reached, the milling drum is lowered to the adjusted nominal milling depth in block 121, and the machine is driven via the travelling devices 8, 9 in block 122 until the actual speed corresponds to the nominal speed adjusted. Subsequently, monitoring is performed according to blocks 101 and 110 again as to whether the actual speed and/or actual milling depth change beyond the specified limit values.

(42) If it is determined in block 110 that the milling depth is reduced below a specified limit value, an interruption of the working operation is also detected.

(43) The drive of the milling drum is therefore interrupted in block 112. In the following, it is monitored in block 113 as to whether a nominal milling depth has been adjusted again which is greater than the specified limit value.

(44) During this monitoring process, the actual and nominal speeds are not relevant as the road milling machine can be moved freely, for example, in manoeuvring mode while the milling drum is disengaged from the ground. If it was detected in the previously described block 103 that, with the drive of the milling drum already interrupted, the milling depth was reduced below the limit value and, as a consequence, the milling drum was disengaged from the ground, a jump is made to block 113 as the nominal and actual speeds do, in this case, also not have an influence on the detection of the continuation of the working operation.

(45) If it is detected in block 113 that a nominal milling depth above the limit value has been adjusted, that is, the milling drum is to be engaged with the ground again, it is monitored in block 114 as to whether the machine is in reverse travel. If the machine is not in reverse travel, an intended continuation of the working operation has been detected, and the steps of blocks 120, 121, 122 are performed in accordance with the aforementioned description. If a reverse travel of the machine is detected in block 114, the steps 120-122 are not performed until a reverse travel of the machine can no longer be determined.

(46) FIG. 7 shows a construction machine 1 as a so-called large milling machine which is different from the construction machine according to FIG. 1 in that, among other things, the front and rear travelling devices 40 are tracked ground-engaging units and the front as well as the rear travelling devices 40 are connected to the machine frame 4 via lifting columns. The detection of the interruption of the working operation or of the intended continuation of the working operation, respectively, is effected in an analogous fashion by means of monitoring the operating parameters.

(47) The terms control device 14 and monitoring device 15 may be or comprise a multipurpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic circuits, discrete gate or transistor logic, discrete hardware components, or a combination of the same, or may be part thereof, provided that they are programmable in order to perform the features described above.

(48) A multipurpose processor may be a microprocessor, microcontroller, state machine, or a combination of computer devices, for example, a combination of a DSP and a microprocessor, a multitude of microprocessors, or any other type of known configuration.

(49) The procedural steps of the method described above may be implemented directly through hardware components, or through a software module that is executed by a processor, or a combination thereof. The software module may be located on a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable hard disk, a CD-ROM, or any other type of computer-readable storage medium.

(50) The computer-readable storage medium may be coupled with the control device and/or monitoring device so that the control device and/or the monitoring device can retrieve the information from the computer-readable storage medium and save information on the computer-readable storage medium. The computer-readable storage medium may alternatively also be an integral part of the control device and/or monitoring device. The control device and/or monitoring device and the computer-readable storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Alternatively, the control device and/or monitoring device and/or the computer-readable storage medium may be located in a user terminal as discrete components.