EP1429871B1 - Vibration generator for a soil compacting device - Google Patents

Description

The invention relates to a vibration exciter for a soil compacting device.

For the compaction of soils are designated among other things as "Schleppschwinger" Vibratory plates known. For towing people, there is a vibration exciter off-center on a ground contact plate. The vibration exciter is usually a rotating unbalance shaft. The generated by the imbalance wave Unbalance or centrifugal force tears the ground contact plate - because arranged off-center - up one side and forward, before returning the contact plate pushes down, whereby the compaction energy is introduced into the soil. The very simply constructed vibration exciter is thus able, not only but also to generate the vibration required for soil compaction to move the ground contact plate forward.

Such Schleinger swing plates have excellent running behavior, in particular on difficult soils with high clay content and water content. Especially on such cohesive soils, it can be used in other types of vibratory plates come to difficulties in locomotion. The reason for that favorable behavior of towing plates is on a comparatively large amplitude of the vibrator and the presence of a permanent Reaction torque, the permanent with a suitable direction of rotation of the imbalance shaft a certain friction on the vibration generator opposite End of the ground contact plate causes due.

However, this type of construction has proven to be disadvantageous in that no continuous reversing, So moving back and forth of the vibrating plate, with the possibility of a Point compression, ie a targeted compression at one point without forward movement the vibration plate, with cost-acceptable means is possible.

It is possible, at both opposite ends of the ground contact plate Unbalanced shafts to arrange and for the forward and reverse respectively to drive only one of them. However, the imbalance waves must be for the stand work for point compression and the transition from the flow in the Return with double power and precise speed synchronously operated which requires considerable energy and control effort.

Vibration exciters with two unbalanced shafts are e.g. from DE-4130231 or known from DE-3708922.

The invention is based on the object, a vibration exciter for soil compaction indicate, on the one hand, the advantageous principle of the so-called Schleppschwingers is maintained and on the other hand a pre- and Return of the soil compacting device and a compaction at a standstill allows.

According to the invention the object is achieved by a vibration exciter having the features of claim 1 solved. Advantageous developments of the invention are to be taken from the dependent claims.

An inventive vibration exciter for a soil compacting device has two imbalance shafts rotatably coupled to one another in a form-fitting manner, each carrying a first imbalance mass and a second imbalance mass, which rotatable on the imbalance shaft at least between two extreme positions is. It is thus possible for each unbalanced shaft, carried by it second imbalance mass to adjust so that their imbalance effect either with the effect The firmly attached first imbalance mass coincides and thus strengthens or counteracts the effect of the first imbalance mass and thus largely or completely compensated.

According to the invention, an imbalance adjustment device is provided, which is the second Imbalance masses on the first and the second imbalance shaft positively and rotatably coupled in opposite directions. The unbalance adjustment device makes it possible to adjust the imbalance effects of the first and second imbalance shafts in such a way that - in extreme cases - only one of the unbalanced shafts with the ones carried by it Imbalanced masses produces an imbalance effect, while the imbalance effects compensate the imbalance masses on the other imbalance shaft, so that there is no imbalance. So it is possible, the so-called "mr value", the product of imbalance mass and imbalance radius, on the two Parallel unbalanced shafts installed unbalanced masses so change that at the respective maximum of one imbalance wave the other imbalance wave has a minimum mr value, ideally even zero.

At these respective extreme positions, the pure drag-swinging effect is achieved, as it also occurs in known Schleinger swing plates, the only one Have vibration exciter with a single imbalance wave. This effect can be achieved even though both unbalanced shafts are in rotation, which is of great importance for the bearing life, since the bearings are not punctured by blows loaded statically on one side.

Between the two extreme positions are also any other intermediate positions adjustable for the two second unbalance masses. This allows the the vibration exciter bearing soil compacting device according to the invention comfortably back and forth.

If the unbalance effect of the two imbalance waves is the same, is a punctual Stand work with the soil compacting possible, with one for the Compression particularly effective tilting vibration effect occurs at its maximum. The ground contact plate alternately strikes the front and the back, which a particularly effective soil compaction allows.

In an advantageous further development of the invention, that described above Vibration exciter system provided twice axially side by side. Contributes to this each imbalance shaft two axially displaced first imbalance masses and two associated rotatable second imbalance masses. The two additional (further) second imbalance masses on the first and the second imbalance shaft are by a second Imbalance adjustment in the same way as the two original second Imbalance masses positively coupled with each other.

If the two unbalance adjustment can be controlled separately are, it is possible to the vertical axis of the vibration exciter and thus the Hochachse the soil compacting device to produce a yaw moment, what a steerability of the soil compacting allowed.

Advantageously, a steering device is provided with which the two imbalance adjustment are controllable.

In another particularly advantageous development of the invention is tries to make the center distance between the two unbalanced shafts as large as possible to keep. For this purpose there are two between the two unbalanced shafts positively rotatably coupled intermediate shafts arranged, the rotational movement the driven first unbalance shaft transmitted to the second imbalance shaft. Due to the large distance between the two unbalanced shafts, the Trailing and the compression effect to be strengthened.

Of course, by arranging further pairs of intermediate shafts of Center distance between the two unbalanced shafts can be increased even more.

Fig. 1

eine schematische Schnittdarstellung in der Draufsicht auf einen erfindungsgemäßen Schwingungserreger;

Fig. 2

in schematischer Seitenansicht die durch die einzelnen Unwuchtmassen erzeugten Kraftvektoren und die daraus resultierenden Bewegungsrichtungen;

Fig. 3

eine zweite Ausführungsform der Erfindung mit einem Schwingungserreger zur Lenkbarkeit einer Bodenverdichtungsvorrichtung; und

Fig. 4

eine dritte Ausführungsform der Erfindung mit einem Schwingungserreger mit vergrößertem Achsabstand zwischen den beiden Unwuchtwellen.

These and other advantages and features of the invention are explained in more detail below with reference to several examples with the aid of the accompanying figures. Show it:

Fig. 1

a schematic sectional view in the plan view of a vibration exciter according to the invention;

Fig. 2

a schematic side view of the force vectors generated by the individual imbalance masses and the resulting directions of movement;

Fig. 3

a second embodiment of the invention with a vibration exciter for steerability of a soil compaction device; and

Fig. 4

a third embodiment of the invention with a vibration exciter with increased center distance between the two unbalanced shafts.

1 shows a first embodiment of a vibration exciter according to the invention, with a first imbalance shaft 1 and a second imbalance shaft 2.

The first imbalance shaft 1 is in a known manner by a non-illustrated Drive 3, z. B. a hydraulic motor or a coupling with a not shown Internal combustion engine, driven in rotation.

About two gears 4 and 5, the first imbalance shaft 1 with the second imbalance shaft 2 positively coupled in opposite directions rotatably coupled. That means that the first and the second imbalance shaft 1, 2 rotate against each other.

On the first imbalance shaft 1, a first imbalance mass 6 is arranged while the second imbalance shaft 2 carries a first imbalance mass 7. The first imbalance masses 6, 7 can be integrally connected with the imbalance shaft 1, 2 carrying them become. It is also possible, the first imbalance masses 6, 7 z. B. with Fix screws on the unbalanced shafts 1, 2.

Furthermore, the first and the second imbalance shaft 1, 2 each carry a second imbalance mass 8, 9, however, not firmly connected to the imbalance shaft carrying them is, but is held by this rotatable. The second imbalance masses 8, 9 are each freely rotatably disposed on the first and second imbalance shaft 1, 2. It is also possible to realize only a limited rotation, the but should at least extend over a range of 180 °.

The two second unbalanced masses 8, 9 are by an imbalance adjustment 10 positively coupled in opposite directions rotatable coupled together.

The unbalance adjustment device 10 has two gears 11 and 12, wherein the Gear 11 with the second imbalance mass 8 of the first imbalance shaft 1 firmly connected is, while the meshing with the gear 11 gear 12 with the second Imbalance mass 9 is firmly connected to the second unbalanced shaft 2.

The gear 11 is together with the second imbalance mass 8 on the first imbalance shaft 1 freely rotatable. In contrast, as part of the imbalance adjustment 10 a turning device 13 is provided on the second imbalance shaft 2, with which the relative position between the second imbalance mass 9 or the gear 12 on the one hand and the second unbalance shaft 2 on the other hand precisely can be set.

The twisting device 13 is in its structure and its mode of operation in itself known. It has a hydraulically or pneumatically actuated piston-cylinder unit 14, with an adjusting element 15 in the interior of the second imbalance shaft 2 can be axially moved back and forth.

The actuator 15 carries a pin 16, the grooves 17 in the second imbalance shaft 2 penetrates and in spiral grooves 18, on the inside of a second imbalance mass 9 bearing hub is formed, engages.

This structure results in that in an axial displacement of the actuating element 15th by the piston-cylinder unit 14 by means of the pin 16, a rotation of the second Imbalance mass 9 is effected relative to the second unbalanced shaft 2.

This rotation is by the gears 12 and 11 in the opposite direction transferred to the second imbalance mass 8 on the first imbalance shaft 1.

Thus, it is possible with the help of the imbalance adjustment device 10, the two second Adjust unbalance masses 8, 9 such that they either the first imbalance masses 6, counteract 7 (in Fig. 1 in the lower half of the image through the Position of the imbalance masses 6, 8 shown) or the effect of the first imbalance mass amplify (in Fig. 1 in the upper half of the image by the imbalance masses 7, 9).

However, the adjustment is made - as shown in Fig. 1 - such that always only an imbalance mass pair on an imbalance shaft a maximum unbalance effect reached, while at the same time the imbalance masses on the other unbalanced shaft compensate for their effect. This allows the drag oscillator principle maintained. The imbalance wave, which achieves no imbalance effect, runs simply with, without the effect of the vibration generating imbalance wave to impair. The fact that the so-called "deactivated" unbalance shaft rotates, a one-sided load on the shaft bearings is avoided.

Changing the state by the unbalance adjustment device 10 causes that the initially ineffective imbalance wave generates an imbalance while the imbalance of the other imbalance wave is reduced and finally to zero goes. This makes it possible to achieve a change in direction of the towing vehicle.

Fig. 2 shows different positions for the unbalanced shafts 1, 2 and the imbalance masses 6 to 9.

In picture part a) of Fig. 2, the state is shown already in the plan view of Fig. 1 was visible. While the imbalance masses 7, 9 on the second imbalance wave 2 in their effect, compensate for the effects of imbalance masses 6, 8 on the first unbalance shaft 1. A locomotion of the Vibration bearing ground contact plate 19 to the left is the result. The Imbalance masses 7, 9 cause by their off-center arrangement a one-sided Lifting the ground contact plate 19, so that the soil compaction device in Fig. 2a) moves to the left.

In Fig. 2b) an intermediate position is shown. While the unbalanced shafts 1, 2 and the first unbalanced masses 6, 7 firmly supported by them unchanged from FIG. 2a) remained, with the help of the imbalance adjustment 10 the second unbalanced masses 8, 9 relative to the unbalanced shafts 1, 2 twisted. Both Unbalance shafts 1, 2 now achieve an approximately equal imbalance effect, but is directed alternately up and down. This creates the for the compression in the state very effective tilting vibration effect. A locomotion of Ground contact plate 19 and the entire soil compacting device takes place Not.

Fig. 2c) corresponds to a reversal of the state of Fig. 2a). Here are the imbalance masses 6 and 8 of the first imbalance shaft 1 set so that their Superimposed effect, while the effects of imbalance masses 7, 9 on the compensate for second imbalance shaft 2. A movement in the opposite Direction (in Fig. 2c) to the right) is the result.

Fig. 3 shows in plan view a second embodiment of the invention in a schematic Sectional view.

In principle, the second embodiment corresponds to a doubling, i. H. Juxtaposing the first embodiment of FIG. 1. For simplicity Therefore, for the components already known from Fig. 1, the same reference numerals used.

The first imbalance shaft 1 now carries next to the first imbalance mass 6 another first imbalance mass 20, while the second imbalance shaft 2 next to the first imbalance mass 7 carries another first imbalance mass 21. Likewise, the first bears Unbalanced shaft 1 in addition to the second imbalance mass 8 another second imbalance mass 22 and the second imbalance shaft 2 in addition to the second unbalanced mass 9 another second imbalance mass 23.

As the second unbalanced masses 8, 9 by the imbalance adjustment 10th are positively coupled in opposite directions rotatable, are also the other second imbalance masses 22 and 23 by a second imbalance adjustment device 24 rotatably coupled positively with each other. The functioning of the second unbalance adjustment device 24 corresponds to the first imbalance adjustment 10, so that can be dispensed with a detailed description.

The rotational coupling of the two unbalanced shafts 1 and 2 takes place as in Fig. 1 by means the gears 4, 5.

By a separate controllability of the two imbalance adjustment 10th and 24, it is possible for the respective interacting imbalances different to generate resulting forces. This allows for the vertical axis the vibration exciter (which is perpendicular to the plane of Fig. 3) and thus also around the vertical axis of the soil compaction device a yaw moment generate, with the help of the soil compaction device is steerable.

Advantageously, the interaction of the two imbalance adjustment 10 and 24 coordinated by a steering device, not shown, the can be easily handled by the operator.

Fig. 4 shows a third embodiment of the invention, in which the center distance the two unbalanced shafts 1 and 2 has been increased. Because the two unbalanced shafts 1 and 2 and the imbalance masses 6 to 9 carried by them in principle correspond to the first embodiment of FIG. 1, is based on a repetition of Description omitted.

Between the gears 4 and 5 of the unbalanced shafts 1 and 2 are two intermediate shafts 25 and 26 are used, which in turn carry gears 27, 28 and thus the Rotary movement of the first imbalance shaft 1 transmitted to the second imbalance shaft 2. In the same way are between the gears 11 and 12 of the unbalance adjustment 10 gears 29 and 30 used by the intermediate shafts 25, 26 are worn, but are freely rotatable on this.

This arrangement allows the axial distance between the two imbalance shafts 1 and 2 significantly increase, which allows the distance of the unbalanced shafts 1, 2 from the center also enlarge. This allows the drag effect improve.

Of course, can be for a large towing the second and the third embodiment of the invention according to FIGS. 3 and 4 with each other combine.

Claims (7)

1. Vibration generator for a ground compacting device, having

   a first unbalanced shaft (1), which can be driven in rotation, to which a first unbalanced mass (6) is fixedly connected and on which a second unbalanced mass (8) is held being able to rotate relative to the first unbalanced shaft (1) in such a way that the second unbalanced mass (8) can be rotated at least between two extreme positions in which its imbalance effect increases or decreases that of the first unbalanced mass (6);

   a second unbalanced shaft (2), which is coupled in a positive-locking and oppositely rotatable manner to the first unbalanced shaft (1), to which second unbalanced shaft a further first unbalanced mass (7) is fixedly connected and on which a further second unbalanced mass (9) is held being able to rotate relative to the second unbalanced shaft (2) in such a way that the further second unbalanced mass (9) can be rotated at least between two extreme positions in which its imbalance effect increases or decreases that of the further first unbalanced mass (7); and having

   an imbalance-shifting device (10) which couples the second unbalanced masses (8, 9) of the first and of the second unbalanced shaft (1, 2) in a positive-locking and oppositely rotatable manner;

   wherein the positions of the second unbalanced masses (8, 9) can be set by the imbalance-shifting device (10) in such a way that when the imbalance effects of the first and of the second unbalanced mass (6, 8) on the first unbalanced shaft (1) compensate each other to form a minimal imbalance value, the imbalance effects of the further first and of the further second unbalanced mass (7, 9) on the second unbalanced shaft (2) are combined to form a maximum imbalance value, and vice versa.
2. Vibration generator as claimed in claim 1, characterised in that by means of the imbalance-shifting device (10) any intermediate positions for the second unbalanced masses (8, 9) can be set between the extreme positions defined in claim 1.
3. Vibration generator as claimed in claim 1 or 2, characterised in that the imbalance-shifting device (10) has a hydraulic or pneumatically activatable piston-cylinder unit (14).
4. Vibration generator as claimed in any one of claims 1 to 3, characterised in that when set to the minimal imbalance value virtually no imbalance effect is produced by the unbalanced shaft (1, 2) concerned.
5. Vibration generator as claimed in any one of claims 1 to 4, characterised in that

   the first unbalanced shaft (1) supports a further first unbalanced mass (20), which is disposed axially next to the first unbalanced mass (6), and supports a further rotatable second unbalanced mass (22);

   the second unbalanced shaft (2) supports a further first unbalanced mass (21), which is disposed axially next to the first unbalanced mass (7), and supports a further rotatable second unbalanced mass (23); and that

   a second imbalance-shifting device (24) is provided for positive-locking, oppositely rotatable coupling of the further second unbalanced masses (22; 23).
6. Vibration generator as claimed in claim 5, characterised in that a control device is provided to control the two imbalance-shifting devices (10, 24).
7. Vibration generator as claimed in any one of claims 1 to 6, characterised in that the positive-locking rotational coupling between the first and the second unbalanced shaft (1, 2) and one imbalance-shifting device (10) or both imbalance-shifting devices (10, 24) have two intermediate shafts (25, 26), which are rotatably coupled in a positive-locking manner, for increasing the axial spacing between the first and the second unbalanced shaft (1, 2).

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