EP3252232B2 - Soil compactor and method for operating same - Google Patents

Description

The present invention relates to a soil compactor according to the preamble of patent claim 1 and a method for operating a soil compactor having at least two vibratory compactor rollers according to the preamble of patent claim 9.

Such a soil compactor is from WO 2011/064367 A2 famous. The soil compactor has two compactor rollers which are rotatable about respective roller axes of rotation. The two compactor rollers are arranged one after the other in a longitudinal direction or also in a direction of movement of the soil compactor with roller axes of rotation that are essentially parallel to one another at least when driving straight ahead. At least one of the compactor rollers is a divided compactor roller and has two roller areas that follow one another in the direction of the roller axis of rotation of this compactor roller and can basically rotate independently of one another. A vibration excitation arrangement is assigned to each of these two adjacent roller drives, which can be driven independently of one another for rotation, for example by the roller drives assigned to them. A common flywheel drive is assigned to the two flywheel arrangements of the two compressor roller areas. This drives one of the flywheel assemblies directly and the other of the flywheel assemblies via a planetary gear. The use of the planetary gear ensures that even if the two compactor roller areas rotate at different speeds around the common compactor roller axis of rotation, for example when driving through curves, the two centrifugal mass arrangements of the compactor roller areas work in phase with one another, i.e. if a speed difference occurs, there is no phase shift in the Vibrational movement of the two flywheel mass arrangements and thus no phase shift in the vibrational movement of the compressor roller areas excited by these flywheel mass arrangements to carry out a vibrational movement occurs.

the CN 103603258B discloses a method with which it is intended to ensure that in a soil compactor, which has two compactor rollers that can be excited to carry out an oscillating movement, no beats occur that are caused by superimposition of the oscillating movements. For this purpose, the vibration frequencies of the two compressor rollers that are excited to vibrate are recorded and adjusted in such a way that the occurrence of beats is largely avoided by a difference between these vibration frequencies. The compactor rollers of the soil compactor operated in this way are thus stimulated to carry out oscillating movements with oscillating frequencies that differ from one another.

A soil compactor according to the preamble of claim 1 is from US 2003/0048082 A1 famous.

It is the object of the present invention to provide a soil compactor and a method for operating a soil compactor, with which the occurrence of excessive operating noises when the compactor roller is excited to perform an oscillating movement is avoided without impairing the compaction operation.

• wenigstens zwei um eine jeweilige Walzendrehachse drehbare Schwingungs-Verdichterwalzen,
• in Zuordnung zu jeder Schwingungs-Verdichterwalze, eine Schwingungsanregungsanordnung zur Erzeugung einer Schwingungsbewegung der Schwingungs-Verdichterwalze,
• in Zuordnung zu jeder Schwingungs-Verdichterwalze, eine Schwingungserfassungsanordnung zur Bereitstellung einer die Schwingungsbewegung einer jeweiligen Schwingungs-Verdichterwalze repräsentierenden Schwingungsgröße,
• eine Ansteueranordnung zur Ansteuerung wenigsten einer Schwingungsanregungsanordnung auf Grundlage der in Zuordnung zu den Schwingungs-Verdichterwalzen bereitgestellten Schwingungsgrößen derart, dass die Schwingungsbewegungen der Schwingungs-Verdichterwalzen einen vorbestimmten Phasenversatz zueinander aufweisen.

According to the invention, this object is achieved by a
Soil compactor comprising:

• at least two vibration compactor rollers rotatable about a respective roller axis of rotation,
• in association with each vibrating compactor roller, a vibration excitation arrangement for generating an oscillating movement of the vibrating compactor roller,
• in association with each vibratory compactor roller, a vibration detection arrangement for providing a vibration variable representing the vibratory movement of a respective vibratory compactor roller,
• a control arrangement for controlling at least one vibration excitation arrangement on the basis of the vibration variables provided in association with the vibration compactor rollers in such a way that the vibration movements of the vibration compactor rollers have a predetermined phase offset relative to one another.

Furthermore, a sensor arrangement is provided for detecting vibrations in the area of the soil compactor and for providing a feedback signal which reproduces vibration excitations caused by superimposition of the vibration movements of the vibration compactor rollers. The control arrangement is designed to control the vibration excitation arrangements in such a way that the phase offset is acted upon in order to counteract the vibration excitations caused by superimposition of the vibration movements of the vibration compactor rollers.

The vibrating compactor rollers used in a soil compactor constructed according to the invention can be two compactor rollers that follow one another in a longitudinal direction of the soil compactor, for example provided in a front area and a rear area of the soil compactor, which can therefore rotate about roller axes of rotation that are different from one another but are essentially parallel at least when driving straight ahead but also two towards one compactor roller axis of rotation which follow one another and are therefore rotatable about the same compactor roller axis of rotation.

By monitoring the oscillating movements of these oscillating compactor rollers and operating or controlling the oscillating excitation arrangements of the same in such a way that the phase offset of the oscillating movements relative to one another assumes a predetermined magnitude, this phase offset can be actively influenced so that noise or Oscillations can be counteracted by appropriate setting, possibly also adjustment or shifting of the phase position. In principle, it is not necessary to change the vibration frequency of at least one of the vibration compactor rollers, so that each vibration compactor roller can be excited to oscillate at the optimal frequency for the compaction operation to be carried out, for example all or at least some of the vibration compactor rollers the same frequency can be excited to oscillate or an oscillating movement can be excited with the same frequency but out of phase.

The vibration variable preferably has an essentially periodic curve.

In a configuration that is particularly advantageous for providing the information about the vibratory movements of the vibratory compactor rollers, since it is simple and reliable to set up, it is proposed that at least one vibration detection arrangement comprises at least one acceleration sensor for detecting an acceleration of the associated vibratory compactor roller, preferably for detecting an acceleration of the associated vibration compactor roller in a vertical direction and / or in a circumferential direction.

Each vibration excitation arrangement can include a flywheel mass arrangement and a flywheel mass drive that drives it to move.

Since such soil compactors are generally driven hydraulically, i.e. basically a hydraulic system is available, it is further proposed that each flywheel drive includes a drive motor, preferably a hydraulic motor, and that each flywheel assembly includes at least one flywheel mass that can be driven by the associated drive motor to rotate about a flywheel axis of rotation .

Each drive motor is preferably a hydraulic motor, and more preferably at least one hydraulic pump is provided in order to provide the pressurized fluid required to operate the hydraulic motors or to feed it to the hydraulic motors.

In a design variant that is structurally particularly easy to implement, it is proposed that a hydraulic pump be provided for feeding all hydraulic motors with pressurized fluid, and that at least one hydraulic motor be a variable hydraulic motor. It should be pointed out that, within the meaning of the present invention, a variable hydraulic motor is a hydraulic motor whose speed can be varied by appropriate control of the same, for example by adjusting the displacement of the same.

In an alternative embodiment, it is proposed that a hydraulic pump be provided in association with each hydraulic motor, and that the hydraulic pump and/or the hydraulic motor be variable in at least one, preferably each pair of hydraulic motor and hydraulic pump. This embodiment variant is particularly suitable when the vibratory compactor rollers are provided in different areas, for example in a front area and a rear area of a soil compactor, so that each of the vibratory compactor rollers can be operated with a completely independent system. In order to be able to carry out the phase adjustment, either the hydraulic pump or the hydraulic motor or both is variable in at least one of the vibration compactor rollers or the pair of hydraulic motor and hydraulic pump provided in association with the same. Also in association with a hydraulic pump, the variability means that this hydraulic pump is designed to change the quantity and/or the pressure of the pressure fluid delivered by it, for example by appropriate adjustment of the delivery volume, in order in this way to also achieve a corresponding operational change in the evoke hydraulic motor.

The object specified above is also achieved by a method for operating a soil compactor having at least two vibratory compactor rollers and constructed according to the invention, the vibratory compactor rollers being rotatable about respective roller axes of rotation and being excitable by a respective vibration excitation arrangement to carry out an oscillating movement, with different vibratory compactor rollers associated vibration excitation arrangements are controlled in such a way that the vibratory movements of these vibration compactor rollers have a predetermined, fundamentally changeable phase offset. In this method, a sensor arrangement for detecting vibrations in the area of the soil compactor provides a feedback signal that reproduces vibration excitations caused by superimposition of the vibration movements of the vibration compactor rollers. The vibration excitation arrangements are controlled in such a way that the phase offset is acted upon in order to counteract the vibration excitations caused by superimposition of the vibration movements of the vibration compactor rollers.

On the one hand knowledge about the vibrational state of a respective vibratory compactor roller, and on the other hand to be able to adjust the phase position of the respective vibratory movement based on this, it is further proposed that the acceleration of each vibratory compactor roller is detected and that, based on the acceleration of the vibratory compactor rollers, at least one oscillation excitation arrangement is controlled in this way is that the accelerations of these vibration compactor rollers have the predetermined phase offset to each other.

In order to adjust the phase angles of the vibratory movements of different vibratory compactor rollers and thus the phase offset in relation to one another or to change the phase offset, it can be provided that each vibration excitation arrangement comprises a flywheel mass arrangement with at least one flywheel mass that can be driven to rotate about a flywheel mass axis of rotation and a flywheel mass drive, and that for changing of the phase offset of the oscillating movements of the oscillating compactor rollers with respect to one another in at least one oscillation excitation arrangement at least one centrifugal mass is driven by the associated centrifugal mass drive in a phase matching operating phase for rotation at a rotational speed that has changed with respect to a basic rotational state. With this procedure, if it is first determined that the vibrating compactor rollers vibrating, for example, at the same frequency, have an unfavorable phase offset of the vibrating movements, starting from a basic rotational state of a respective centrifugal mass, i.e. a state in which it is rotating with a Basic rotation state provided basic speed rotates, the speed of one of the flywheels are temporarily changed in a phase adjustment operating phase, for example, this flywheel mass are rotated at a slightly higher speed, which temporarily also leads to a change in the excitation frequency, but essentially a change in the phase offset of the oscillations causes. If the desired or predetermined phase offset is reached, this centrifugal mass is also returned to the basic rotational state, i.e. driven to rotate at the basic speed, so that, for example, both or all vibration compactor rollers vibrate at the same frequency or are excited to vibrate be, but the phase shift of the vibrational movements to each other is in the desired range.

Fig. 1

einen Bodenverdichter mit zwei Schwingungs-Verdichterwalzen in Seitenansicht;

Fig. 2

in ihren Darstellungen a) und b) die beiden Schwingungs-Verdichterwalzen des Bodenverdichters der Fig. 1 mit diesen zugeordneten Schwingungsanregungsanordnungen;

Fig. 3

in schematischer Seitenansicht die beiden Schwingungs-Verdichterwalzen mit diesen zugeordneten Schwungmassen;

Fig. 4

den zeitlichen Verlauf der bei den Schwingungs-Verdichterwalzen des Bodenverdichters der Fig. 1 auftretenden Beschleunigungen der Schwingungs-Verdichterwalzen;

Fig. 5

in prinzipartiger Darstellung zwei nebeneinander liegende und um eine gemeinsame Walzendrehachse drehbare Schwingungs-Verdichterwalzen mit diesen zugeordneten Schwingungsanregungsanordnungen.

The present invention is described in detail below with reference to the attached figures. It shows:

1

a soil compactor with two vibration compactor rollers in side view;

2

in their representations a) and b) the two vibration compactor rollers of the soil compactor 1 with these associated vibration excitation arrangements;

3

in a schematic side view, the two vibrating compactor rollers with these associated centrifugal masses;

4

the time course of the vibratory compactor rollers of the soil compactor 1 occurring accelerations of the vibration compactor rollers;

figure 5

In a schematic representation, two vibrating compactor rolls lying next to one another and rotatable about a common roll axis of rotation with vibration excitation arrangements assigned to them.

In 1 a soil compactor that can be used for compacting a subsoil 10 is generally denoted by 12 . The soil compactor 12 has two vibratory compactor rollers 14, 16 which are arranged one after the other in a longitudinal direction L of the soil compactor and which are rotatable about roller axes of rotation A ₁ , A ₂ which are spaced apart from one another in the longitudinal direction L of the soil compactor. A roller drive can be assigned to at least one of these two vibrating compactor rollers 14, 16, in order to thereby move the soil compactor 12 forward to carry out compacting processes, wherein in the course of this movement the two vibratory compactor rollers 14, 16 rotate about their roller axes of rotation _A1 and Turn A ₂ and roll on the surface 10. To steer the soil compactor 12, the vibration compactor rollers 16, also generally referred to as bandages, can be pivotable on a compactor frame 18, which is denoted by 18 and also has a driver's cab 20, about, for example, substantially horizontally oriented pivot axes.

the 2 shows in its representations a) and b) the two vibratory compactor rollers 14, 16 with a respective vibration excitation arrangement 22 or 24 provided in association therewith 26 with at least one centrifugal mass 28 rotatable about a centrifugal mass axis of rotation.

It is assumed, for example, that the vibration excitation arrangement 22, as well as the vibration excitation arrangement 24, is intended to excite the respectively assigned vibration compactor roller 14, 16 to carry out a vibration movement, i.e. one essentially in a height direction or orthogonal to the subsoil to be compacted oriented direction reciprocating vibrational motion. In this case, the at least one flywheel mass can generally be rotated about an axis of rotation of the flywheel mass, which essentially also corresponds to the axis of rotation of the vibration compactor roller.

In order to set the at least one flywheel mass 28 of the flywheel mass arrangement 26 in motion, i.e. to drive it to rotate about the respective flywheel mass axis of rotation, here for example the roller axis of rotation A ₁ , the vibration excitation arrangement 22 also has a flywheel mass drive 30 . The flywheel drive 30 in turn comprises a drive motor 32, designed as a hydraulic motor in the example shown, and a hydraulic pump 34 that feeds this drive motor 32 or hydraulic motor with pressurized fluid.

The flywheel drive 30 is controlled by a control arrangement, generally designated 36, which controls the hydraulic pump 34, for example, in order to drive it to deliver pressurized fluid with a predetermined delivery quantity or a predetermined pressurized fluid, so that the drive motor 32 or hydraulic motor is also in operation accordingly is offset and drives at least one centrifugal mass 28 to rotate. Wherein is in the in 2 illustrated example, the hydraulic pump 34 is a variable hydraulic pump, ie a hydraulic pump whose flow rate or delivery pressure is adjustable. An increase in the pressure fluid flow rate or the pressure of the pressure fluid delivered by hydraulic pump 34 leads to a corresponding increase in the speed of a motor shaft, not shown, of hydraulic motor or drive motor 32 and correspondingly also a higher speed of the at least one flywheel mass 28, with the result that the resulting vibratory movement offset compactor roller 14 is excited with a correspondingly changed frequency to oscillate or oscillates with a corresponding frequency.

In order to detect this vibrational movement of the vibration compactor roller 14, a vibration detection arrangement, generally designated 38, is provided. This can, for example, comprise at least one acceleration sensor 40, which, for example, detects the acceleration of the compactor roller 14 in the area of the roller axis of rotation A ₁ , for example in the area of a roller bearing, with the acceleration sensor 40 essentially being used for recording in the exemplary embodiment shown of an oscillating compactor roller 14 excited to vibrate an oscillating movement in the direction of movement in which the compactor roller 14 is excited to oscillate, that is to say essentially an up and down direction. The acceleration sensor 40 delivers an acceleration signal, which represents the oscillating movement of the oscillating compactor roller 14 and represents an oscillation quantity, to the activation arrangement 36. The activation arrangement 36 can, in the manner described below, activate the flywheel drive 30, in particular the hydraulic pump 34, based on this acceleration signal, which represents an oscillation quantity. to act on the operation of the flywheel assembly 26 in a corresponding manner.

With reference to the in Figure 2b ) illustrated vibratory compactor roller 16, it should be explained that the vibration excitation arrangement 24 associated with it also comprises a flywheel mass arrangement 42 with at least one flywheel mass 44 that can be rotated about an axis of rotation of the flywheel mass, with the vibration excitation arrangement 24 in this example also being designed to generate a vibration movement of the vibratory compactor roller 16 and consequently the at least one flywheel mass 44 will generally rotate about a flywheel mass axis of rotation corresponding to the roll axis of rotation A ₂ . A flywheel drive 46 with a drive motor 48 embodied as a hydraulic motor and a variable hydraulic pump 50 is assigned to the flywheel arrangement 42 in order to generate this rotational movement. This is under the control of a control arrangement 52. The control arrangement 52 can be configured separately from the control arrangement 36, but can be linked to it for information exchange in order to be able to operate the two vibration excitation arrangements 22, 24 in a coordinated manner. In principle, however, the two control arrangements 36, 52 can also be combined in one and the same control arrangement and can be designed to control both unbalance drives 30, 46.

It should be pointed out that such control arrangements to be used in the context of a soil compactor according to the invention can be provided in a control device or can be designed as such. They can, for example, comprise processors in the form of microprocessors or microcontrollers and can be permanently programmed or rewritable with programs suitable for carrying out the control measures. They can have input connections to which the associated sensors, in particular acceleration sensors, can be connected for feeding in their output signals, and can have output connections to which respective control lines leading to the system areas to be controlled, for example the hydraulic pumps or hydraulic motors, can be connected.

Vibration compactor roller 16 is also assigned a vibration detection arrangement 54 with at least one acceleration sensor 56, which outputs an acceleration signal corresponding to the oscillatory movement of compactor roller 16, which is caused by the at least one centrifugal mass 44 set in rotation, as an oscillation quantity to control arrangement 52. Here too, for example the acceleration sensor 56 detects the acceleration of the compactor roller 16 in the region of a roller bearing of the same. However, it should be pointed out here that acceleration sensors provided, for example, inside the vibrating compactor rollers 14, 16, for example on a roller shell, can be used to detect the acceleration and thus the vibrating movement of the vibrating compactor rollers 14, 16. A plurality of such acceleration sensors can also be provided in association with the vibratory compactor rollers 14, 16 in order to use their output signals to generate a vibration variable representing the vibratory movement of these vibratory compactor rollers 14, 16, for example in the control arrangements 36, 52, and to control the centrifugal mass drives 30, 46 to use.

the 3 shows a basic representation of the two vibration compactor rollers 14, 16 with the flywheel mass arrangements 26 and 42 assigned to them. The _two flywheel masses 28, 44, which can be set in rotation about the respective _compactor roller axes of rotation A1 and A2, are shown in such a way that they have an angular offset α to each other, but basically rotate in the same direction. In association with the centrifugal masses 28, 44 positioned in relation to one another in this way, acceleration signals B ₁ , B ₂ are generated by the acceleration sensors 40, 56 detecting the oscillating movements of the oscillating compactor rollers 14, 16, the course of which is shown in 4 is shown. In particular, when the two vibration excitation arrangements 22, 24 are essentially identical to one another and are basically operated in the same way, i.e. in particular at the same speed of their centrifugal masses 28, 44, the two acceleration signals B ₁ and B ₂ , which indicate the time course of the acceleration of the vibration - Compactor rolls 14, 16 represent the same frequency and also substantially the same amplitude of acceleration. It is recognizable, however, that a phase offset P is present, caused by the offset α of the two flywheel masses 28, 44 (here, for example, reference can be made to the angular position of the centers of mass of the respective flywheel masses 28, 44). The magnitude of this phase offset P can be set according to the principles of the present invention such that the superimposition of the oscillating movements of the two oscillating compactor rollers 14, 16 cannot cause beats or other oscillating excitations, in particular leading to excessive noise. The phase offset P can, for example, be set as a function of the operation of the two vibration excitation arrangements, ie, for example, the speed of the centrifugal masses 28, 44. Alternatively, a sensor arrangement could also be provided on the soil compactor 12, which is designed to detect vibrations, for example sound or body vibrations in the area of the soil compactor 12 itself, and thus supplies a feedback signal about when, during operation of the two vibration excitation arrangements 22, 24, there is a risk that by superimposing the oscillating movements of the two vibratory compactor rollers 14, 16, an excessive vibration excitation of other system areas arises. In this case, the centrifugal mass arrangements 26, 42 can be acted upon in order to act on the phase offset P of the vibration movements caused by them in the two vibration compactor rollers 14, 16 and thus to counteract such an undesired superimposition.

In order to change the phase offset P, the procedure can be such that, starting from a basic rotational state of the two flywheel mass arrangements 26, 42 or the flywheel masses 28, 44 of the same, in at least one of the vibration excitation arrangements 22, 24 by the control arrangement 36 or 52 of the Flywheel drive 30 or 46 is controlled in such a way that it works temporarily, ie in a phase matching operating phase, with a different speed of the respective drive motor 32 or 48. For example, the speed can be increased in order to correspondingly increase the speed of the centrifugal mass 28 or 44 that is set in rotation as a result. An increased speed of one of the two centrifugal masses 28, 44 temporarily leads to an increased excitation frequency, but in particular leads to a change in the in 3 shown angle a. This operation with a changed speed in the phase adjustment phase of operation is continued until the desired phase offset P is reached. If this is the case, the vibration excitation arrangement 22 and/or 24 that was previously operated at a speed that has changed with respect to the basic rotational state, i.e. a basic speed, is controlled again in such a way that the associated flywheel mass arrangement or its flywheel mass is again at the base speed, i.e. rotates in the basic rotational state and consequently both flywheel mass arrangements 26, 42 excite the associated vibration compactor rollers 14, 16 again with the frequency corresponding to the basic rotational state to oscillate, for example with the same frequency to oscillate.

Such an adjustment of the phase offset P of the vibratory movements of the two vibratory compactor rollers 14, 16 can be carried out repeatedly during operation of the soil compactor 12 or, if necessary, continuously, for example as part of a control loop, in order to ensure in this way that with a changing operating condition or operating behavior of the soil compactor 12, for example with increasingly more compacted ground and corresponding change in the vibration behavior of the Vibration compressor rollers 14, 16, the occurrence of unwanted vibration excitations is avoided by vibration superposition.

Although in figure 4 a phase offset P other than zero is shown, depending on the operating state of the soil compactor 12, for example also depending on the respective vibration amplitude of the vibration compactor rollers 14,16, a phase offset P not different from zero can also be advantageous for avoiding an unfavorable superimposition of the vibration movements . A phase offset of this type with the value zero, which can be set by appropriate control of the vibration excitation arrangements 22, 24, but which can also be changed in principle, is a phase offset within the meaning of the present invention. Furthermore, according to the principles of the present invention, a predetermined phase offset can be defined in that a phase offset that is unfavorable with regard to the vibration excitation or vibration superposition is not set or a change away from such an unfavorable phase offset is brought about. If, for example, a phase offset with the value zero, i.e. in-phase vibration excitation of the two vibration compactor rollers, is unfavorable, the setting of any phase offset other than zero can be interpreted as providing a predetermined phase offset within the meaning of the present invention. A predetermined phase offset within the meaning of the present invention can thus also be defined by a value range of the phase offset. It is fundamentally important in the present invention that at least one of the vibration excitation arrangements can be acted upon in order to be able to actively bring about a change in the phase offset.
An alternative embodiment is in figure 5 shown. the figure 5 shows two vibration compactor rollers 14a, 16a which follow one another in the direction of a compactor roller axis of rotation A and are therefore rotatable about the same compactor roller axis of rotation A. Each vibration compactor roller 14a, 16a is assigned a vibration excitation arrangement 22a, 24a, each with a flywheel arrangement 26a, 42a and a flywheel drive 30a, 46a. in the in figure 5 In the example shown, the vibration excitation arrangements 22a, 24a are designed to stimulate the vibratory compactor rollers 14a, 16a to carry out an oscillating movement, i.e. a back and forth rotary movement about the roller axis of rotation A, which corresponds to the continuous rotary movement about this roller axis of rotation A that occurs when a soil compactor moves forward is superimposed. For this purpose, each flywheel mass arrangement 26a, 42a has at least two flywheel masses 28a, 28a' or 44a, 44a', which can be driven to rotate about flywheel mass rotation axes that are eccentric to the roll axis of rotation A, but are parallel thereto. It should be pointed out here that the construction of such flywheel mass arrangements 26a, 42a is known in the prior art, for example from that discussed at the outset WO 2011/064367 A2 .
In association with each of the flywheel arrangements 26a, 42a, the flywheel mass drives 30a, 46a comprise a drive motor 32a, 48a, in turn designed as a hydraulic motor. A common hydraulic pump 34a is assigned to both drive motors 32a, 48a.
In order to be able to provide vibration quantities representing the vibration movement of the two vibration compactor rollers 14a, 16a, a vibration detection arrangement 38a or 54a is provided, for example each comprising one or at least one acceleration sensor 40a or 56a. In the case shown, these are designed to detect a circumferential acceleration of the associated vibrating compactor rollers 14a, 16a and can be provided, for example, on the inner circumference of a respective roller shell or another component or assembly rotating with the vibratory compactor roller about the roller axis of rotation A. Acceleration sensors 40a, 56a feed their acceleration signals into control arrangement 36a. The drive arrangement 36a is basically designed to drive both vibration excitation arrangements 22a, 24a in order to put them into operation. For this purpose, for example, the control arrangement 36a can be in control connection with the hydraulic pump 34a. Furthermore, in the exemplary embodiment shown, the control arrangement 36a is in control connection with the drive motor 32a of the vibration excitation arrangement 22a. For this purpose, the drive motor 32a, which is designed as a variable hydraulic motor in this exemplary embodiment, can have a bypass valve 58a, which is controlled by the control arrangement 36a and is able, depending on the control, to adjust the amount of pressurized fluid used in the hydraulic motor 32a, i.e. its Adjust displacement, so that the speed of a motor shaft of the hydraulic motor 32a is also adjusted accordingly.
To set or adapt the phase offset P, the operation of the flywheel drive 30a can be influenced in the manner described above, while the operation of the flywheel drive 46a of the vibration excitation arrangement 24a, for example, is left unchanged, and in particular the hydraulic pump also remains unchanged in its operation. In principle, however, the hydraulic pump 34a could also be designed with a variable delivery volume in this embodiment, in order to be able to change the speed of the hydraulic motor 48a or to change the speeds of the two hydraulic motors or drive motors 32a, 48a together by appropriately changing the control of the hydraulic pump 34a . Also could the drive motor or hydraulic motor 48a can be designed as a variable motor.

In the figure 5 The illustrated configuration of the vibration excitation arrangements 22a, 24a with a common hydraulic pump 34a acting for both drive motors 32a, 48a is particularly advantageous when the two vibration compactor rollers 14a, 16a are arranged side by side and can therefore be coupled to this hydraulic system in a simple manner . Are the two vibratory compactor rollers to be matched to each other in terms of their phase position as in 1 shown provided on different areas of a soil compactor, hydraulic systems that are decoupled from one another are advantageously used.

The soil compactor 12 of 1 could also be designed in such a way that in one of the end regions thereof the in figure 5 vibrating compactor rollers 14a, 16a illustrated and lying next to one another are provided, while at the other end region a compactor roller which is fundamentally not to be excited to carry out a vibratory movement is provided. In principle, however, a vibratory compactor roller could also be used at this other end area, or two vibratory compactor rollers could be used next to one another, so that more than two vibratory compactor rollers can also be used on one and the same soil compactor and, with regard to the phase position of their vibration excitations, one on the other can be matched.

Claims (11)

1. A soil compactor, comprising:

   - at least two vibrating compactor rollers (14, 16; 14a, 16a) rotatable about a respective roller axis of rotation (A₁, A₂; A),

   - a vibration excitation arrangement (22, 24; 22a, 24a) assigned to each vibrating compactor roller (14, 16; 14a, 16a) for generating a vibrating movement of the vibrating compactor roller (14, 16; 14a, 16a),

   - a vibration detection arrangement (38, 54; 38a, 54a) assigned to each vibrating compactor roller (14, 16; 14a, 16a) for providing a vibration variable (B₁, B₂) representing the vibrating movement of each vibrating compactor roller (14, 16; 14a, 16a),

   - a control unit (36, 52, 36a) for controlling the one vibration excitation arrangement (22, 24; 22a, 24a), based on the vibration variables provided with respect to the vibrating compactor rollers (14, 16; 14a, 16a) in such a way that the vibrating movements of the vibrating compactor rollers (14, 16; 14a, 16a) have a predefined phase offset (P) to one another,

   - a sensor arrangement for detecting vibrations in the region of the soil compactor (12) and for providing a feedback signal representing vibration excitations generated by superimpositions of the vibrating movements of the vibrating compactor rollers (14, 16; 14a, 16a),

   characterized in that
   the control arrangement (36, 52, 36a) is adapted for controlling the vibration excitation arrangements (22, 24; 22a, 24a) in such a way that there is an effect on the phase offset (P) for counteracting the vibration excitations generated by superimpositions of the vibrating movements of the vibrating compactor rollers (14, 16; 14a, 16a).
2. The soil compactor according to Claim 1,
   characterized in that the vibration variable (B₁, B₂) has an essentially periodic curve.
3. The soil compactor according to Claim 1 or 2,
   characterized in that at least one vibration excitation arrangement (38, 54, 38a, 54a) comprises at least one acceleration sensor (40, 56; 40a, 56a) for detecting an acceleration of the assigned vibrating compactor roller (14, 16; 14a, 16a), preferably for detecting an acceleration of the assigned vibrating compactor roller (14, 16; 14a, 16a) in a vertical direction and/or in a circumferential direction.
4. The soil compactor according to one of Claims 1-3,
   characterized in that each vibration excitation arrangement (22, 24; 22a, 24a) comprises an inertial mass arrangement (26, 42; 26a, 42a) and an inertial mass drive (30, 46; 30a, 46a).
5. The soil compactor according to Claim 4,
   characterized in that each inertial mass drive (30, 46; 30a, 46a) comprises a drive motor (32, 48; 32a, 48a), preferably a hydraulic motor (32, 48; 32a, 48a) and that each inertial mass arrangement (26, 42; 26a, 42a) comprises at least one inertial mass (28, 44; 28a, 28a', 44a, 44a') that can be driven by the assigned drive motor (32, 48; 32a, 48a) for rotation about an inertial mass axis of rotation.
6. The soil compactor according to Claim 5,
   characterized in that each drive motor (32, 48; 32a, 48a) is a hydraulic motor (32, 48; 32a, 48a), and at least one hydraulic pump (34, 50; 34a) is provided to provide pressurized fluid for at least one hydraulic motor (32, 48; 32a, 48a).
7. The soil compactor according to Claim 6,
   characterized in that a hydraulic pump (34a) is provided for supplying all hydraulic motors (32a, 48a) with pressurized fluid, and that at least one hydraulic motor (32a) is a variable hydraulic motor (32a).
8. The soil compactor according to Claim 6,
   characterized in that a hydraulic pump (34, 50) is provided assigned to each hydraulic motor (32, 48), and that in at least one, preferably each pair made of a hydraulic motor (32) and a hydraulic pump (34, 50), the hydraulic pump (34, 50) and/or the hydraulic motor (32, 48) is variable.
9. A method for operating a soil compactor (12) having at least two vibrating compactor rollers (14, 16; 14a, 16a) according to one of the preceding claims, wherein the vibrating compactor rollers (14, 16; 14a, 16a) are rotatable about respective roller axes of rotation (A₁, A₂, A) and are excitable to implement a vibrating movement by a respective vibration excitation arrangement (22, 24; 22a, 24a), wherein vibration excitation arrangements (22, 24; 22a, 24a) assigned to different vibrating compactor rollers (14, 16; 14a, 16a) are controlled in such a way that the vibrating movements of these vibrating compactor rollers (14, 16; 14a, 16a) have a predetermined phase offset (P) to one another, wherein in this method, a feedback signal is provided by a sensor arrangement for detecting vibrations in the region of the soil compactor (12), representing excitation vibration excitations generated by superimpositions of the vibrating movements of the vibrating compactor rollers (14, 16; 14a, 16a),
   characterized in that the vibration excitation arrangements (22, 24; 22a, 24a) are controlled in such a way that there is an effect on the phase offset (P) for counteracting the vibration excitations generated by superimpositions of the vibrating movements of the vibrating compactor rollers (14, 16; 14a, 16a).
10. The method according to Claim 9,
    characterized in that the acceleration (B₁, B₂) of each vibrating compactor roller (14, 16; 14a, 16a) is detected, and that, based on the accelerations (B₁, B₂) of the vibrating compactor rollers (14, 16; 14a, 16a), at least one vibration excitation arrangement (22, 24; 22a, 24a) is controlled in such a way that the accelerations (B₁, B₂) of these vibrating compactor rollers (14, 16; 14a, 16a) have the predetermined phase offset (P) to one another.
11. The method according to Claim 9 or 10,
    characterized in that each vibration excitation arrangement (22, 24; 22a, 24a) comprises an inertial mass arrangement (26, 42; 26a, 42a) comprising at least one inertial mass (28, 44; 28a, 28a', 44a, 44a') drivable to rotate about an inertial mass axis of rotation and an inertial mass drive (30, 46; 30a, 46a), and that to change the phase offset (P) of the vibrating movements of the vibrating compactor rollers (14, 16; 14a, 16a) with respect to one another, at least one inertial mass (28, 44; 28a, 28a', 44a, 44a') in at least one vibration excitation arrangement (22, 24; 22a, 24a) is driven by the assigned inertial mass drive (30, 46; 30a, 46a) in a phase matching operational phase to rotate at a speed changed with respect to a base rotational state.

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