WO1997022424A2

WO1997022424A2 - Device and process for machining away hard surfaces, in particular road surfaces

Info

Publication number: WO1997022424A2
Application number: PCT/EP1996/005700
Authority: WO
Inventors: Günter HÄHN
Original assignee: Wirtgen Gmbh
Priority date: 1995-12-20
Filing date: 1996-12-19
Publication date: 1997-06-26
Also published as: ZA9610806B; DE19547698A1; AU1302697A; WO1997022424A3; DE19547698C2

Abstract

A device and process are proposed for machining away hard surfaces, in particular road surfaces. The device comprises a housing (2) and a milling roller (4) mounted in the housing (2) and provided at its surface with machining tools (8) which are made to vibrate by a vibrator unit. The vibrator unit applies a torsional vibration to the milling roller (4).

Description

Device and method for milling hard surfaces, in particular road surfaces

The invention relates to a device for milling hard surfaces, in particular road surfaces, with a chassis and a milling drum arranged in the chassis, with processing tools arranged on the surface of the milling drum, which are subjected to vibration by means of a vibration exciter. and a method for milling hard surfaces according to the preamble of claim 33.

A road milling machine is known from DE 29 48 540 A. In this road milling machine, the milling process is to be overlaid with a vibration movement known from compaction devices in the form of a linear vibration. It is provided that the vibration exciter is arranged on the chassis. This has the disadvantage that the entire road milling machine is set in vibration. Alternatively, provision is also made for the vibration exciter to be provided in the milling drum. With such a linear vibration

ORIGINAL DOCUMENTS However, the vibration is carried out vertically in the radial direction of the milling drums.

This has the disadvantage that the vibration is not excited in the cutting direction, so that the vibrations cannot be used efficiently. Furthermore, the linear vibration in the vertical direction leads to high loads on the bearings.

The invention has for its object to provide a device and a method for milling hard surfaces, with which the tool load can be reduced and the removal rate can be increased with reduced energy consumption.

According to the invention, the features of claims 1, 12, 13, 33 and 41, 42, 46, 49 and 62 serve to achieve this object.

In the solution according to the invention it is advantageously provided that the vibration exciter applies a torsional vibration to the milling drum. This has the advantage that the oscillation takes place in the direction of the cutting forces arising during milling, so that an increase in output with a lower energy requirement is made possible with reduced tool loading. Ultimately, the improved removal rate also makes it possible to reduce the weight of the milling machine, which results in further energy savings. Due to the improved efficiency, very hard materials such as Concrete, can be processed economically.

The milling, which is subjected to torsional vibrations, also allows the use of standing processing tools conventional milling machines cannot be used due to the high wear rate. Because standing tools can now be used, other tools can be used, for example with a linear cutting edge, which have advantages when processing the road surface.

In a preferred exemplary embodiment it is provided that the milling drum has masses oscillating in opposite phase, which compensate for the reaction forces of the torsional vibrations of the milling drum. By compensating the reaction forces of the torsional vibrations of the milling drum, vibration transmission to the chassis can be largely avoided. This is particularly important for road milling machines that are operated by a driver. Furthermore, the load on the bearing of the milling drum is reduced. A further reduction in the transmission of vibrations to the chassis can be achieved by decoupling the milling drum drive from the milling drum.

The milling drum can also be subdivided in the direction of its longitudinal axis, sections of the milling drum vibrating in phase opposition to compensate for the torsional vibrations.

For example, the milling drum can be formed in the direction of the axis of rotation divided from two halves with the same moment of inertia.

In the case of a one-piece milling drum, the masses vibrating in opposite phases can also be stored within the milling drum.

The section of the milling drum which is excited to vibrate can be coupled to the masses vibrating in opposite phases via a torsion spring. In one exemplary embodiment it is provided that the mass oscillating in opposite phase consists of an inner drum which is coaxial with the milling drum and which is connected to the milling drum via the torsion spring. This embodiment has the advantage that no two-part milling drum is required.

In a particularly preferred exemplary embodiment it is provided that the frequency of the torsional vibrations is set to the resonance frequency of the milling drum. The operation of the milling drum at the natural frequency leads to a reduction in the energy expenditure.

A damping element is preferably arranged between the masses vibrating in opposite phase, which protects the vibrating system from overstressing in the event of resonance and further allows the effect of the natural frequency to be used in a wider frequency band.

The vibration exciter can consist of two imbalances rotating in the same direction, 180 ° out of phase, which transmit torsional vibrations to the milling drum. The frequency and amplitude of the vibrations can be set with the aid of the rotational speed of the unbalances. The amplitude can also be influenced by measuring the unbalance weight.

The imbalances are preferably stored in the interior of the milling drum.

In an alternative solution it is provided that the vibration exciter applies a linear vibration to the milling drum which has a direction which produces a counter torque essentially parallel to that. resulting reaction force of all processing tools that are in engagement. In the case of such a vibration exciter, the vibration vector runs in the direction of the average cutting forces of the processing tools in engagement. The direction of oscillation is therefore essentially the same as the working direction of the processing tools.

In a further alternative solution to the problem, it is provided that the individual processing tools or groups of processing tools oscillate in the longitudinal axis running in the working direction. The tools consequently perform a linear oscillation in their holders on the milling drum. It can be provided that only the processing tools which are in engagement are excited to linear vibrations. The processing tools can oscillate in phase, the milling drum then also being excited to produce torsional vibrations. If the linear vibrations of the individual processing tools are generated out of phase, the vibrations can be compensated for in the engaged area of the milling drum.

The axis of rotation of the milling drum normally runs parallel to the desired profile of the surface.

Alternatively, however, it can also be provided that the axis of rotation of the milling drum is orthogonal to the surface. The oscillation of the milling drum or the processing tool can be adjustable in terms of frequency and / or amplitude. The direction of advance of the milling drum is preferably parallel to the surface.

The peripheral speed of the processing Tools must be aligned with the direction of advance (synchronization) or run opposite to the direction of advance (counter-rotation).

The milling which is subjected to torsional vibrations advantageously makes it possible to mill hard surfaces even in counter-rotating operation, it being possible to determine the grain size. The average size of the fragments of the road surface processed by the milling drum is determined by the operating parameters of the milling process, e.g. Cutting speed, feed speed, frequency and amplitude of the vibration and weight loading of the milling drum. The setting of suitable operating parameters enables the grain size distribution of the fragments to be optimized. The grain size distribution is of essential importance for the recyclability of the fragments and their installation in a new road surface.

The processing tools protrude from the roller surface at an angle that is determined by the forces that arise during milling. The main factors influencing this are the machine weight and the forces arising due to the torque.

In a preferred embodiment, the vibration exciter generates the vibrations with dynamic excitation.

The vibration exciter is preferably driven hydraulically.

The vibration exciter can also be coupled to the drive of the milling drum via a gear. The dynamic excitation of the vibrations can alternatively take place hydraulically, pneumatically, electrically and / or electromagnetically.

In the case of all alternative possible solutions, it can be provided that the milling is carried out with the milling drum stationary, rotating intermittently or preferably with the milling drum rotating continuously.

It is thus also possible to operate the milling drum at standstill or in intermittent operation with torsional vibrations or with a directed linear vibration. It is furthermore possible to use the milling drum at a standstill or in intermittent operation with vibrating processing tools. It can also be provided that only the machining tools in engagement are subjected to linear vibrations.

The preferred oscillation frequency is in the range between 60 and 100 Hertz.

The milling drum drive can be connected to the milling drum drive shaft by means of a coupling, which decouples the milling drum drive from torsional vibrations of the drive shaft. In this way it is reliably avoided that torsional vibrations of the milling drum can have a negative effect on the milling drum drive.

The processing tools are preferably mounted on the circumference of the milling drum in interchangeable holders. This enables not only a quick replacement of the processing tools in the event of damage, but also replacement by other types of tools. So it is For example, it is possible to operate the milling drum in a conventional manner, ie without superimposed torsional vibrations, and to use the rotating tools which are more advantageous for this purpose.

The milling drum mounted in the housing can be part of an attachment that can be coupled to a vehicle.

In a preferred exemplary embodiment of the invention, the housing of the milling drum is arranged in a self-propelled chassis.

In a further alternative embodiment it is provided that the processing device is attached to a free end of a torsion bar which can be excited to torsion vibrations by the vibration exciter acting on the other end of the torsion bar. In this exemplary embodiment, the processing device vibrates in a plane running orthogonally to the torsion bar, the processing device being able to have fixed processing tools or rotating moving processing tools in the form of a milling drum.

For example, the milling drum can be rotatably mounted about an axis running orthogonally to the torsion bar.

The vibration exciter is connected eccentrically to the torsion bar via a lever arm and vibrates in phase opposition to the processing device.

The vibration exciter consists of two imbalances rotating in opposite directions with a phase shift of 180 °. In the case of such a vibration exciter, reciprocating, Forces running orthogonal to the lever arm connected to the torsion bar, which exert a changing torsion moment on the torsion bar and excite it to torsion vibrations.

The torsion bar can be mounted in the middle between its ends in a pivotable arm, secured against twisting and against linear displacement.

The torsion bar can be held in the bearing with a limited play so that the torsional vibrations are not damped.

In this exemplary embodiment, work devices can be overlaid at one end of the torsion bar with a vibration that lies in a plane that is orthogonal to the torsion bar. In particular, the rotary movement of a milling drum can be overlaid with an oscillating pivoting movement of the milling drum axis.

The pivot axis of the torsion bar orthogonal to the axis of rotation of the milling drum crosses the milling drum axis outside the area of engagement of the processing tools.

This embodiment is particularly suitable as an attachment, e.g. on an excavator arm.

Further advantageous refinements of the device can be found in the further subclaims.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Show it -

1 a road milling machine according to the invention,

Fig. 2a a dynamic vibration exciter for generating up to 2d against torsional vibrations in four phase positions,

3 shows a period of the torsional vibration,

4 shows an alternative exemplary embodiment of a dynamic vibration exciter,

Fig. 5 shows a section through a divided milling roller.

6 different configurations of the milling cutter,

9 shows sections through an embodiment of one and 10 undivided milling rollers,

11 shows sections through a further exemplary embodiment and 12 of a divided milling roller,

13 shows an alternative embodiment with a torsion bar,

14 shows a further embodiment with a torsion bar, and

15 shows a cross section through the bearing of the torsion bar

The embodiment shown in FIG. 1 shows a road milling machine 1 with a chassis 12, m dem a separately drawn milling drum 4 is mounted in a housing 2 and is used to mill a surface 3, for example a street surface. A vehicle driver can operate and steer the road milling machine in a driver's seat. At the rear end, the road milling machine has a conveyor device 6 with which the removed material can be transported, for example, onto the loading area of a truck.

The processing tools 8 consist of milling chisels which are arranged at the same mutual distance on the circumference of the milling drum 4. In the direction of the longitudinal axis of the milling drum 4, the milling bits 8 are arranged next to one another offset. The torque of the milling drum 4 is transmitted to the milling chisels 8, which are interchangeably and fixedly or rotatably mounted in chisel holders 9. The torque exerted by the milling drum 4 generates cutting forces running in the direction of the cutting movement.

6 to 8 show different designs of the milling chisel 8. FIG. 6 shows a round shank chisel with a conical cutting edge geometry, which is rotatably mounted in the chisel holder 9. The rotatability of the milling cutter 8 leads to a self-sharpening of the tool. Rotating milling chisels have been used in conventional milling without applying vibrations in order to reduce wear. Such processing tools have the disadvantage, however, that there is inevitably a play in the chisel holder 9 that influences the power transmission.

When milling with a milling drum exposed to vibrations, it is now possible to use stationary processing tools point or line-shaped attack surface to use.

7 and 8 show a processing tool 8 held in the chisel holder 9 in the form of a round shank chisel with a conical cutting edge geometry or in the form of a flat chisel. The advantage of such a fixed processing tool 8 is that better power and momentum transmission can take place since there is no play between the processing tool 8 and the chisel holder 9 and therefore no relative movement is possible.

The use of a flat chisel as a processing tool 8 has the advantage of producing a better processing surface, the tool producing a strip-shaped joint instead of a groove-shaped joint.

The figures 2a to 2d explain schematically a dynamic excitation of the milling drum 4 in order to excite the milling drum to a rotational oscillation with which the milling drum 4 can be acted on when it is at a standstill, in intermittently rotating operation or in continuously rotating operation. The dynamic excitation of the milling drum 4 is brought about with the aid of a vibration exciter 10, which in the case of FIGS. 2a to 2d embodiment shown consists of two imbalance weights 14 which rotate in the same direction and are 180 ° out of phase with each other. The synchronous drive can, for example, as shown in FIGS. 2a to 2d shown, take place by means of a drive pinion 19 which is arranged between the unbalanced shafts 17 and which engages with pinions 27 on the unbalanced shafts 17. Alternatively, as shown in FIG. 4, the synchronous drive can take place via a toothed belt 20 wrapping around both unbalanced shafts 17, one of the unbalanced shafts 17 being driven. A period of the torsional vibration as a torque curve over time is shown graphically in FIG. 3 in a diagram. The corresponding phase positions are shown in FIGS. 2a to 2d reproduced. 2a, both unbalance weights 14 are in their radially outer position. Due to their symmetrical position relative to the pivot point of the milling drum 4, the forces of the unbalance weights 14 compensate each other, so that no torque is generated at a phase angle of 0 °.

2b shows the position of the unbalance weights 14 at a phase angle of 90 °. The forces generated by the unbalance weights do not compensate for the rotational point of the milling drum 4, rather they each generate a torque with respect to the axis of rotation of the milling drum 4 that corresponds to the maximum amplitude of the milling drum shown in FIG. 3 4 applied torque at 90 °.

In the phase position 180 ° according to FIG. 2c, the force vectors of the unbalance weights 14 are directed towards the axis of rotation of the milling drum 4, as in the embodiment of FIG. 2a, and therefore cannot generate any torque with respect to this axis of rotation. Since the forces of the unbalance weights compensate each other, the curve of the torque curve according to FIG. 3 has a zero crossing again at 180 °.

2d shows the position of the unbalance weights 14 at a phase position of 270 °, in which the forces generated by the unbalance weights 14 in turn generate a torque with respect to the axis of rotation 7. In comparison to FIG. 2b, however, this torque is directed in the opposite direction, so that the sinusoidal torsional vibration according to FIG. 3 has its maximum negative amplitude in this phase position. reached the value.

The desired frequency and amplitude of the vibration can be set via the speed of the unbalanced shafts 17. An additional possibility of influencing the amplitude value is to provide replaceable or addable unbalance weights 14. A vibration exciter 10 can also be used, in which additional weights are switched on depending on the direction of rotation of the unbalanced shafts. In such vibration exciters, two unbalance weights of different sizes are provided on each unbalanced shaft 17, which partially compensate each other in one direction of rotation and add up in the other direction of rotation.

5 shows a section through a preferred exemplary embodiment of a milling drum 4, which is rotatably mounted in the housing 2. A milling drum drive 16 is coupled to the drive shaft 24 of the milling drum 4 via a vibration-damped coupling 22. The milling drum is divided into two parts and consists of two halves 4a, 4b with preferably the same moment of inertia. A sealing strip 26 is provided between the halves 4a, 4b of the milling drum 4, which seals the gap between the halves, but allows a relative rotational movement between the halves 4a, 4b. The sealing strip 26 made of soft rubber material also has the task of damping the oscillatory movement between the milling drum halves 4a, 4b in the event of resonance. The sealing strip 26 has the additional function of damping in order to protect the oscillating system in the event of resonance and to be able to use the effect of the natural frequency in a wider frequency band.

The drive shaft 24 drives the milling drum half 4b, furthermore the two milling drum halves 4a, 4b are connected via a shaft designed as a torsion spring 15. The milling drum half 4a contains the vibration exciter 10, which essentially corresponds to the schematic diagrams of FIGS. 2a corresponds to 2d. The unbalanced shafts 17 are supported at their ends in the lateral end faces of the milling drum half 4a. They each have a pinion 27 which meshes with the drive pinion 19 for the unbalanced shafts 17. The drive pinion 19 is mounted on an axle stub 21 running coaxially to the axis of rotation 7 of the milling drum 4 and is driven via a coupling 23 and a hydraulic motor 25 flanged to the housing 2.

The division of the milling drum 4 into two halves 4a, 4b has the advantage that, with the aid of the torsion spring 15, the two milling drum halves 4a, 4b can oscillate in phase opposition to one another, so that no reaction forces of the torsional vibrations act on the drive shaft 24. This is done by compensating the vibrating masses and by decoupling the milling drum drive 16 from the milling drum 4. With regard to the decoupling of the milling drum drive from the milling drum drive shaft 24, there are, for example, the following options, namely the decoupling via a rotary coupling or the decoupling via a positive coupling with play. Through these measures, the transmission of vibrations to the housing 2 and thus to the chassis 12 is almost eliminated and the load on the bearing of the milling drum 4 is reduced.

An oscillation frequency in the range between 60 and 100 Hertz has proven to be particularly advantageous.

The torsional vibrations are preferably set to the natural frequency of the milling drum 4. The torsional vibrations can then be carried out with a minimized expenditure of energy with maximum efficiency of the milling process.

The torsional vibrations are damped in the resonance range with the aid of a damping element in order to be able to use the resonance effect in a wider frequency band.

By dynamizing the cutting forces of the milling cutter 8, it is possible to reduce the jacket thickness of the milling drum 4. The mass inertia of the milling drum can thus be reduced and thus also the activation energy required for the excitation of vibrations. At the same time, the stress on the drive train is reduced.

The unbalanced shafts are preferably mounted as far radially as possible inside the milling drum 4 in order to generate the highest possible torque with relatively low unbalanced weights 14.

As an alternative to the application of a rotary vibration to the milling drum 4, provision can also be made for the milling drum 4 to be subjected to a linear vibration which occurs in a direction which corresponds to the mean value of the direction vectors of all milling bits 8 in engagement. As can be seen from FIG. 4, depending on the milling drum diameter and the milling depth, for example, less than a quarter of all milling chisels 8 are engaged during milling. The linear oscillation is vor¬ preferably in direction of the resultant cutting force of all cutting teeth 8. A oscillations ^¬ in engagement supply pathogen for linear vibrations consists beispielεweise of two contra-rotating eccentric shafts, which are adjustable to one another in their phase position, the Rich¬ processing of the vibration to change . The unbalanced shafts 17 are fixed in such a vibration exciter.

A further alternative solution is to apply a vibration directly to the milling bits, the milling bits 8 being able to vibrate linearly, for example, in the bit holder 9. Alternatively, it can also be provided that the chisel holder 9 is excited to vibrate. Preferably, only the milling bits 8 in engagement are excited to vibrate.

The figures 9 and 10 show an exemplary embodiment with a one-piece milling drum 4, in which an inner drum 30 is provided as a mass oscillating in opposite phase, which is connected to the milling drum 4 and the drive shaft 24 via a torsion spring 15. The inner drum 30 is rotatably mounted on a tube 34 which is coaxial with the torsion spring 15, so that the inner drum 30 can execute a torsional vibration relative to the milling drum 4. The tube 34 and the torsion spring 15 coaxial with the milling drum 4 are attached to the end wall of the milling drum 4 connected to the drive shaft 24 in a rotationally fixed manner.

The inside of the inner drum accommodates the unbalances 14, which are rotatably supported in the end walls of the inner drum 30 with diametrically opposite shafts 17. As in the exemplary embodiment in FIG. 5, the unbalances 14 are driven via spur gears 19, 27. In each case one spur gear 27 is rotationally fixed on an unbalance shaft 17 and meshes a drive pinion 19 which is rotatably mounted in the milling drum 4 and in the housing 2 and is driven via a clutch 23 and a hydraulic motor 25. As in the exemplary embodiment in FIG. 5, the oscillation is generated by rotating in the same direction of the unbalanced shafts 17 with unbalanced weights 14 arranged out of phase with the phase. The shaft 29 of the drive pinion 19 is mounted in the hub 32 of the milling drum 4, which is mounted on the side opposite the housing 2. The hub 32 and the clutch 23 are protected with a housing 36 to which the hydraulic motor 25 is flanged.

The figures 11 and 12 show a further embodiment of a two-part milling drum 4a, 4b, the halves of which are connected to one another via a torsion spring 15 and between which an annular sealing strip 26 made of rubber-elastic material is arranged on the outer circumference, which at the same time also acts as a damping means between the opposite phases mutually vibrating milling drum halves 4a, 4b is used. A hydraulic vibration exciter 50 is arranged in the milling drum half 4a and is acted upon by a hydraulic slide valve 42 and a rotary feedthrough 46 with pulsating hydraulic pressure. The hydraulic vibration exciter 50 has two arms 55, 56 protruding diametrically from the axis of rotation of the milling drum half 4a, in which a hydraulic channel 48 runs. The hydraulic vibration exciter 50 is firmly connected to the milling drum half 4a. At the free ends of the arms 55, 56, piston cylinder units 52 are provided which act orthogonally to the axis of rotation and relatively in the opposite direction to one another, the pistons 54 of which are acted upon in accordance with the pulsating hydraulic pressure and act on bars 58 which are fixed with the other milling drum half 4b are connected and protrude from this. For this purpose, the end wall of the milling drum half 4a facing the torsion spring 15 has two recesses 60 through which a bar 58 of the milling drum 4b passes. The recess 60 is larger than the cross-sectional area of the beam 58, so that the milling drum halves 4a, 4b can swing relative to each other. The direction of the piston oscillation and the orientation of the beam 58 are matched to the orientation of the milling cutter 8, so that the impact force resulting from the excessive torque is induced in the milling cutter 8 without loss. For this purpose, the piston-cylinder unit 52 in the illustration according to FIG. 11 can also have an angle of inclination deviating from 90 ° to an axis parallel to the pressure channel 48.

By setting suitable operating parameters for the operation of the milling drum, namely the speed (cutting speed), direction of rotation, feed speed, oscillation frequency and oscillation amplitude, as well as the weight load of the milling drum 4, the size of the worn fragments of the road surface 3 and their grain size distribution can be determined become. The average grain size and the associated grain size distribution are of essential importance for the reusability of the removed road surface 3, since, for example, fragments that are too large cannot be incorporated into a new road surface.

13 shows a further exemplary embodiment, in which torsional vibrations on a processing tool 66, for example a milling bar, as can be seen in FIG. 13, or a milling drum 4, with the aid of a torsion bar 68, which is mounted, for example, in an excavator arm 72 14, as can be seen from FIG. The processing tools 66 are fastened or mounted on a free end of the torsion bar 68, while the vibration exciter 10 is arranged on the other free end of the torsion bar 68 which is mounted in its center in the excavator arm 72. The vibration exciter 10 is connected to the lever arm 70 with the Torsion bar 68 connected so that the forces generated in the vibration exciter 10 in an orthogonal to the drawing plane of FIGS. direction in combination with the lever arm 70 can transmit a torsional moment to the torsion bar 68. The vibration exciter 10 has imbalances 14 which, as shown in FIGS. 16 to 19 can be seen, rotate in opposite directions and out of phase by 180 °. One of the unbalanced shafts 17 is driven by a hydraulic motor 25, the force being transmitted from the driven unbalanced shaft 17 via spur gears 27 to the other unbalanced shaft. In the cases of FIGS. 16 and 17, the forces of the unbalances 14 are compensated for while they are shown in FIGS. Add 18 and 19 cases shown. The processing tools 4, 66 then execute a torsional vibration in the opposite phase. The processing tools 66 swing in a plane orthogonal to the torsion bar 68.

The milling drum 4 is rotatably mounted in a holder at the end opposite the vibration exciter 10 orthogonal to the torsion bar 68 and driven by a hydraulic motor 76. The torsional vibration of the milling drum 4 is thus superimposed on the rotational movement of the milling drum.

15 shows a cross section through the mounting of the torsion bar 68 in the excavator arm 72. The torsion bar 78 is rotatably mounted in the excavator arm 72 but with play. The torsion bar 68 designed as a hollow shaft is also secured against displacement in the direction of its longitudinal axis.

Claims

claims

1. Device for milling hard surfaces (3), in particular road surfaces, with a housing (2) and a milling drum (4) mounted in the housing (2), with processing tools distributed on the surface of the milling drum (4) (8), which are subjected to vibration with the aid of a vibration exciter (10), characterized in that the vibration exciter (10) acts on the milling drum (4) with a rotary vibration.

2. Device according to claim 1, characterized in that the milling drum (4) has opposite-phase oscillating Maεεen, the reaction forces of the torsional vibrations of the milling drum (4) compensate.

3. Apparatus according to claim 2, characterized in that the milling drum (4) is divided iεt, and that Ab¬ sections (4a, 4b) of the milling drum swing in phase opposition to compensate for the torsional vibrations.

4. Apparatus according to claim 2 or 3, characterized gekenn¬ characterized in that the milling drum (4) in the direction of the axis of rotation divided from two halves (4a, 4b) is formed with the same moment of inertia.

5. Apparatus according to claim 2 or 3, characterized gekenn¬ characterized in that the phase oscillating masses (30) εind stored within the milling drum (4).

6. Device according to one of claims 2 to 5, characterized in that the vibration excited cut the milling drum (4) via a torsion spring (15) is coupled to the masses oscillating in opposite phases.

7. Apparatus according to claim 5 or 6, characterized gekenn¬ characterized in that the phase oscillating mass consists of a to the milling drum (4) coaxial inner drum (30) which is connected via the torsion spring (15) with the milling drum.

8. Device according to one of claims 1 to 7, characterized in that the frequency of the torsional vibration is set to the resonance frequency of the milling drum (4).

9. Device according to one of claims 2 to 8, characterized in that a damping element (26) is arranged between the masses oscillating in opposite phase.

10. Device according to one of claims 1 to 9, characterized in that the vibration exciter (10) consists of two imbalances rotating in the same direction by 180 ° out of phase (14), which transmit torsional vibrations to the milling drum (4).

11. The device according to claim 10, characterized in that the unbalances (14) in the interior of the milling drum (4) are mounted.

12. Device for milling hard surfaces (3), in particular road surfaces, with a housing (2) and a milling drum (4) mounted in the housing (2), with the surface of the milling drum (4) divides arranged processing tools (8) which are subjected to a vibration with the aid of a vibration exciter (10), characterized in that the vibration exciter applies a linear vibration to the milling drum (4) which has a direction which is essentially parallel to the one Resulting reaction forces of all processing tools (8) in engagement which generate counter torque are.

13. Device for milling hard surfaces (3), in particular road surfaces, with a housing (2) and a milling drum (4) mounted in the housing (2), with processing tools arranged on the surface of the milling drum (4) (8), which are subjected to a vibration by means of a vibration exciter (10), characterized in that the individual processing tools (8) or groups of processing tools (8) vibrate in the direction of the cutting force.

14. Device according to one of claims 1 to 13, characterized in that the milling is carried out with a stationary, intermittently rotating or continuously rotating milling drum (4).

15. The device according to one of claims 1 to 14, da¬ characterized in that the axis of rotation of the milling drum (4) runs parallel to the desired profile of the surface.

16. The device according to one of claims 1 to 14, characterized in that the axis of rotation of the milling drum (4) is orthogonal to the surface.

17. The device according to one of claims 1 biε 16, da¬ characterized in that the vibration with respect to frequency and / or amplitude is adjustable.

18. Device according to one of claims 1 to 17, characterized in that the direction of advance of the milling drum (4) is parallel to the surface.

19. Device according to one of claims 1 to 18, characterized in that the peripheral speed of the processing tools (8) is aligned with the direction of advance.

20. Device according to one of claims 1 to 18, characterized in that the peripheral speed of the processing tools (8) is opposite to the direction of advance.

21. Device according to one of claims 1 to 20, characterized in that the vibration exciter generates the vibrations with dynamic excitation.

22. The device according to one of claims 1 to 21, da¬ characterized in that the vibration exciter is hydraulically driven iεt.

23. The device according to claim 1 to 21, characterized gekenn¬ characterized in that the drive deε Schwingεerregerε (10) with the drive (16) of the milling drum (4) coupled iεt.

24. The device according to claim 21, characterized in that the dynamic excitation of the oscillation takes place hydraulically, pneumatically, electrically and / or electromagnetically.

25. The device according to claim 22, characterized in that the dynamic excitation of the vibration by hydraulic, with pressure pulses controlled piston-cylinder units (52) takes place, which transmit a torque to the milling drum (4).

26. Device according to one of claims 1 to 25, characterized in that the milling drum drive (16) by means of a coupling (22) with the drive shaft

(24) of the milling drum (4), which decouples the milling drum drive (16) from torsional vibrations of the drive shaft (24).

27. The device according to one of claims 1 to 26, characterized in that the processing tools (8) on the circumference of the milling drum (4) are mounted in interchangeable holders (9).

28. Device according to one of claims 1 to 27, characterized in that the fixed Abarbei¬ processing tools (8) are milling cutters with point or line cutting geometry.

29. Device according to one of claims 1 to 27, characterized in that the processing tools

(8) are rotatably mounted about the longitudinal axis running in the working direction.

30. Device according to one of claims 1 to 29, characterized in that the oscillation frequency is in the range between 60 and 100 Hertz.

31. Device according to one of claims 1 to 30, characterized in that the housing (2) with the milling drum

(4) is part of an attachment that can be coupled to a vehicle.

32. Device according to one of claims 1 to 30, characterized in that the housing (2) with the milling drum (4) is arranged in a chassis (12).

33. Device for milling hard surfaces (3), in particular of road coverings, with a housing (2) and with at least one processing device (66) with a plurality of processing tools (8), which with

With the help of a vibration exciter (10), vibration is applied, characterized in that the processing device (66) is attached to a free end of a torsion bar (68) which is acted upon by the vibration exciter (68) acting on the other end of the torsion bar (68). 10) excitable to torsional vibrations.

34. Device according to claim 33, characterized in that the processing device (66) consists of a milling drum (4) which is rotatably mounted about an axis running orthogonally to the torsion bar (68).

35. Device according to claim 33 or 34, characterized in that the exciter (10) is eccentric to the torsion bar (68) is connected to the torsion bar (68) via a lever arm (70).

36. Apparatus according to claim 35, characterized in that the vibration exciter (10) oscillates in phase opposition to the processing device (66).

37. Device according to claim 33 to 36, characterized in that the vibration exciter (10) consists of two imbalances (14) rotating in opposite directions by 180 ° phase shift.

38. Device according to one of claims 33 to 37, characterized in that the vibration exciter (10) generates reciprocating forces which, in conjunction with the lever arm (70), exert an alternating torsional moment on the torsion bar (68) and thereby Induce torsional vibrations in the torsion bar (68).

39. Device according to one of claims 33 to 38, characterized by the fact that the torsion bar (68) is mounted in a pivotable arm (72), secured against twisting.

40. Device according to claim 39, characterized in that the torsion bar (68) mounted in the arm (72) is held in the bearing (74) with a limited play.

41. Method for working off hard surfaces, in particular road surfaces, by milling subjected to vibrations, characterized by superimposing the rotary motion of the milling process with a torsional vibration.

42. Method for working off hard surfaces, in particular road surfaces, by means of milling subjected to vibrations, and the use of a non-rotating or intermittently turned milling drum which is subjected to a torsional vibration.

43. The method according to claim 41 or 42, characterized gekenn¬ characterized in that antiphase oscillating masses are used to compensate for reaction forces of the torsional vibrations.

44. The method according to any one of claims 41 to 42, characterized in that a milling drum (4) divided in the longitudinal axis, the halves (4a, 4b) of which are in phase opposition, is used.

45. The method according to any one of claims 41 to 42, characterized in that an undivided milling drum (4) is used with masses oscillating in opposite directions, which are mounted in the interior of the milling drum (4).

46. A method for processing of hard surfaces (3), in particular of road surfacings, by εchwingungε- beaufεchlagteε Abfräεen, characterized by daε applying a Fräεwalze (4) with a Li ^¬ near vibration aufweiεt a direction perpendicular to the generating a counter torque in weεentlichen parallel resulting reaction forces of all im Interacting processing tools (8) iεt.

47. The method according to claim 46, characterized in that the linear oscillation is generated with two counter-rotating εyn- chronically rotating imbalances (14).

48. The method according to claim 47, characterized in that the phase position of the unbalance (14) is adjustable for setting the direction of the linear vibration.

49. Method for working off hard surfaces, in particular road surfaces, by milling subjected to vibrations, characterized by the application of the processing tools (8) or groups of processing tools (8) distributed on a cylindrical outer surface of a milling drum (4) ) with a linear vibration, the direction of which coincides essentially with the direction of the cutting force of the machining tools (8) in engagement.

50. Method according to claim 49, characterized in that only the processing tools (8) which are in engagement are acted upon with the linear vibration.

51. The method according to any one of claims 46 to 50, characterized in that the milling drum (4) is operated at a standstill or with intermittent rotary movement or with continuous rotary movement.

52. Method according to one of claims 41 to 51, characterized in that the frequency and / or amplitude of the Vibration is variably adjustable.

53. The method according to any one of claims 41 to 52, characterized in that the direction of advance is parallel to the surface.

54. The method according to any one of claims 41 to 53, characterized in that the milling is carried out in synchronism.

55. The method according to any one of claims 41 to 53, characterized in that the milling is carried out in the opposite direction.

56. The method according to claim 55, characterized in that the grain size and the grain size distribution of the processed fragments of the milling drum via the operating parameters of the milling drum operation, namely, for example, speed, direction of rotation, feed rate, vibration frequency, vibration amplitude and weight loading of the milling drum (4) Road surface (3) can be set.

57. The method according to any one of claims 41 to 56, characterized in that the milling drum (4) is operated with a torsional vibration frequency in the resonance range which corresponds to the natural frequency of the milling drum (4).

58. The method according to claim 57, characterized in that the rotary vibration is damped in the resonance range in order to use the effect of the natural frequency in a broader frequency band.

59. The method according to one of claims 41 to 58, characterized in that the milling drum drive (16) is decoupled from torsional vibrations of the milling drum (4).

60. The method according to any one of claims 41 to 59, characterized in that the vibrations are generated dynamically.

61. The method according to any one of claims 41 to 60, characterized in that an oscillation frequency in the range between 60 and 100 Hertz is used.

62. Method for milling hard surfaces (3), in particular road surfaces, by vibration-loaded surfaces, characterized by superimposing the rotary movement of the milling process with a swinging pivoting movement of the axis of rotation of the processing device (66) about an orthogonal to the axis of rotation extending swivel axis.

63. The method according to claim 62, characterized in that the swivel axis crosses the axis of rotation outside the engagement areas of the processing device (66).