EP1212148B1 - Vibration exciter for ground compacting devices - Google Patents

Description

The invention relates to a vibration exciter, particularly in soil compaction equipment is used.

Soil compactors, especially vibration or vibrating plates, have a movable contact plate above the soil to be compacted, the acted upon by a vibration generated by a vibration exciter becomes. The shaking movement caused by this causes a mutual Moving and moving the soil particles, thereby closing gaps and the desired soil compaction can be achieved.

Numerous solutions are known for such vibration exciters. In the In practice, an arrangement has proven particularly useful in which two are parallel mutually rotating shafts rotating at the same speed are driven. Each of the shafts carries one or more flyweights, so that the centrifugal weights also rotate against each other and an unbalance produce. To achieve a constant phase position via the rotation the gears carry meshing gears. The phase position is chosen that from the rotating flyweights and thus from the The resulting centrifugal force takes a desired direction.

It is particularly advantageous if the phase relationship between the centrifugal weights or unbalanced shafts can be adjusted, whereby the alignment of the resulting Vibration or the resulting force the operator's wishes customizable. For this it is e.g. B. known from DE 30 43 719 C2, that one of the unbalanced shafts can be rotated relative to a gear, which meshes with a gear of the other unbalanced shaft and generally for a fixed coupling of the rotary movement ensures.

Other examples of vibration exciters are in DE 36 09 360 and in DE 35 45 593 C2 described.

5 shows a schematic side view of one from DE 29 09 204 C2 known vibration exciter.

Two unbalanced shafts 1, 2 parallel to each other become counter-rotating and driven at the same speed as indicated by arrows A and B. Each of the unbalanced shafts 1, 2 carries a flyweight 3, 4, which causes the centrifugal forces 5 and 6 shown by arrows. To simplify no repetition of the reference numerals in all other drawings. It is always the same arrangement, but always in different positions.

Fig. 5a) shows the known vibration exciter, in which the phase position by a phase adjustment device, not shown, e.g. B. by that gear that can be rotated relative to one of the unbalanced shafts 1, 2 is set in such a way that the centrifugal forces 5, 6 diagonally upwards in one direction, that is with a Extend vertically and a forward horizontal component. To for this purpose, a force diagram is also shown in FIG. 5a.

The exact course of a 180 ° rotation of the unbalanced shafts 1, 2 with the centrifugal forces 5, 6 is shown in Fig. 6 in 45 ° steps. The rotation of the flyweights 3, 4 in the constant phase position shown causes due to resulting forces that the vibrating plate carrying the vibration exciter moved to the front in FIG. 6 to the left. The vertical component relieves the ground contact plate or even lifts it partially above the ground while the horizontal component provides the desired propulsion.

5b) shows the vibration exciter with changed phase position. Here was the unbalanced shaft 2 or the flyweight 4 relative to the unbalanced shaft 1 the centrifugal weight 3 rotated by an angle of 90 ° by the in FIG. to achieve the phase position shown. 7 shows a 180 ° cycle accordingly in 45 ° steps. From this it can be seen that in the case of FIGS. 7 shows no resulting horizontal forces, while the vertical forces add up to the maximum. At this phase consequently the vibrating plate remains in place and causes a maximum Soil compaction due to maximum vertical vibration.

In addition, Fig. 5c) shows the phase position of the unbalanced shafts 1, 2 for the Reverse travel of the vibrating plate (to the right in the figure).

It is all of the vibration exciters known from the prior art together that in the so-called reversal point, d. H. in the phase position at which the vibrating plate is in place (Fig. 5b), the resulting Centrifugal force vector is directed vertically. The on the to be condensed The force acting on the ground is therefore greatest and reduced in this position when driving forward or backward. Plate and related Swiveling the resulting force vector by, for example, 45 ° forward or backward to 1 / √2 of the maximum value.

The arrangements described have been for soil, sand or gravel compaction Proven excellently, as targeted, with maximum force can be compressed.

Vibrating plates with such vibration exciters prove to be problematic, which are used for asphalt or composite stone compaction should. If here the maximum vertical force acts in the reversing point, selective settlements can occur that can no longer be corrected. at Asphalt rolling is therefore usually the vibration in the reversing area switched off to prevent the roller from penetrating too deeply into the asphalt Avoid reversal of direction.

From US-A-3,736,066 is a soil compacting device with two Vibrators known that are adjustable such that the vertical components the centrifugal forces generated by the centrifugal weights between 0 and a maximum value are adjustable while the horizontal components compensate the centrifugal forces at any time.

The invention has for its object a vibration exciter for soil compaction equipment specify where a strong influence on certain Soils such as asphalt or composite stone when reversing or at a standstill the machine can be avoided.

According to the invention, the task is performed by a vibration exciter with the Features of claim 1 solved. Advantageous further developments of the Invention can be found in the dependent claims.

A vibration exciter according to the invention for soil compaction devices has parallel or coaxial to each other, in opposite directions at the same speed driven unbalanced shafts, each carrying at least one flyweight. It is a special feature of the invention that the phase position of the Flyweights can be adjusted by a phase adjustment device in such a way that the vertical components of the centrifugal forces generated by the centrifugal weights in any rotational position. According to the invention, it is thus possible to set a phase position in which the vertical components of the flyweights cancel so that the force resulting from the flow forces is not a vertical component and has no vertical vibration at all acts on the compacting surface. Despite continuous operation of the vibration exciter and thus rotation of the centrifugal forces can thus further compress of the underground can be avoided.

According to the invention, the horizontal components of the centrifugal forces add up in rectified this phase position. The resulting force vector thus points a maximum horizontal component, which makes it possible to use the ground contact plate a high shear stress z. B. to bring into the asphalt surface, to smooth out small cracks or pores. Because during a 360 ° turn of the centrifugal weights resulting horizontal forces into one and generated in the other direction (forward and backward); emotional the soil compactor practically does not move.

This is a further, particularly advantageous embodiment of the invention characterized in that to cause movement of the soil compacting device the phase position defined for the standstill in a first direction is adjustable by a positive angle while effecting movement the phase position in a second direction opposite to the first direction is adjustable by a negative angle. So it is possible that already in existing vibration exciters known from the prior art Advantages for forward and backward driving of soil compaction equipment exploit.

However, it is particularly advantageous if when switching between forward and reverse travel, d. H. a change between the first and second Direction which, according to the invention, defined for the standpoint or reversing point Phase position can be temporarily occupied. Then if the operator changes between forward and reverse travel, decrease in the reversing point the vertical vibrations automatically zero so that the operator take no further precautions to protect the subsurface to be compacted got to.

An advantageous further development of the invention is that the Phase position is adjustable so that the horizontal components of the Cancel centrifugal forces and add the vertical components in the same direction. This also allows a phase position to be set that has the advantages the vibration exciter already known from the prior art, in particular maximum compaction performance when the machine is at a standstill.

Another advantageous development is that the phase adjuster at least one device for rotating one of each Centrifugal weights overlay relative to an associated other centrifugal weight to the opposite rotation of the unbalanced shafts. The phase adjustment device, their structure and functionality in principle from the above cited publications are known from the prior art, can thus several units can be combined to provide the invention to satisfy versatile adjustment options of the phase position.

Fig. 1

in schematischer Seitenansicht einen Schwingungserreger gemäß der Erfindung in verschiedenen Phasenlagen;

Fig. 2

verschiedene Drehstellungen des Schwingungserregers bei der in Fig. 1b) gezeigten Phasenlage;

Fig. 3

einen Übergang aus der in Fig. 1b) gezeigten Phasenlage in die in Fig. 1a) gezeigte Phasenlage;

Fig. 4

einen Übergang aus der in Fig. 1b) gezeigten Phasenlage in die in Fig. 1c) gezeigte Phasenlage:

Fig. 5

verschiedene Phasenlagen bei einem aus dem Stand der Technik bekannten Schwingungserreger;

Fig. 6

verschiedene Drehstellungen für die in Fig. 5a) gezeigte Phasenlage;

Fig. 7

verschiedene Drehstellungen für die in Fig. 5b) gezeigte Phasenlage.

These and other advantages and features of the invention are explained below with the aid of the accompanying figures. Show it

Fig. 1

a schematic side view of a vibration exciter according to the invention in different phase positions;

Fig. 2

different rotational positions of the vibration exciter in the phase position shown in Fig. 1b);

Fig. 3

a transition from the phase position shown in FIG. 1b) to the phase position shown in FIG. 1a);

Fig. 4

a transition from the phase position shown in FIG. 1b) to the phase position shown in FIG. 1c):

Fig. 5

different phase positions in a vibration exciter known from the prior art;

Fig. 6

different rotational positions for the phase position shown in Fig. 5a);

Fig. 7

different rotational positions for the phase position shown in Fig. 5b).

As already mentioned above, vibration exciters come in a variety of forms known. Likewise, phase adjustment devices - e.g. B. from the cited prior art documents - known, through which the The phase position of the flyweights carried by the unbalanced shafts changed can be. Since the invention is not the detailed and concrete design a certain vibration exciter or a certain phase adjustment device, but rather a particularly suitable one, but so far Concerning unknown phase position is a description of a specific embodiment not mandatory.

However, the person skilled in the art is familiar with the fact that the phase adjustment device does this must be suitable, the relative position of the flyweights on the unbalanced shafts in the superposition of the coupled, counter-rotating movement. For this it is e.g. B. possible that the unbalanced shafts by meshing with each other Gears are coupled, the position of a gear with respect the associated unbalanced shaft can be changed, which also changes the Phase position of the flyweights changes. This principle has proven to be excellent in practice proven and - as already explained - z. B. in DE 29 09 204 C2, which in turn refers to further prior art, to which the present invention can be applied.

In the vibration exciter, it can z. B. a pathogen with two act parallel shafts, each carrying a flyweight, the flyweights of the two unbalanced shafts are arranged opposite one another. On Such vibration exciter is also known from DE 29 09 204 C2.

In another, e.g. B. from DE 30 43 719 C2 known vibration exciter each of the unbalanced shafts carries two flyweights that are coaxially offset are. With another vibration exciter it is possible to change the position the centrifugal weights arranged coaxially on an unbalanced shaft change, for example to cause a steering movement of the vibrating plate.

As already stated, the invention can be used with all of these vibration exciters come into use.

1 shows an overview of the phase positions provided according to the invention, where Fig. 1a) a forward drive of the vibrating plate (in the Fig. After left), Fig. 1b) a phase position in the state or reversing point and Fig. 1c) Phase position for the backward movement of the vibrating plate affects.

An essential aspect of the invention is shown in FIGS. 1b) and 2, respectively concern the phase position in which the vibrating plate is in place. In the 1b) and 2a) are the unbalanced shafts 1, 2 with the centrifugal weights 3, 4 so that the centrifugal forces 5, 6 in Horizontal direction and add up to a maximum value.

On the further rotation indicated by arrows A and B, which in 2a) to 2e) in 45 ° steps, eliminate each of the Vertical components of the centrifugal forces, while the horizontal components add up and thus their direction within a 180 ° cycle to change.

This means that the vibrating plate does not lift off the floor and no vertical vibration in the ground. Rather, the vibrating plate becomes alternate dragged forward and backward without significantly changing their point of view, so that shear forces act in the ground and z. B. pores or seal cracks.

Fig. 3 shows the change in phase position when from the reversing point in Forward position is switched.

3a) the phase position shown in FIG. 1b) for the reversing position on. The phase position is then determined by means of the phase adjustment device, not shown changed in that the unbalanced shaft 2 with the Flyweight 4 relative to the unbalanced shaft 1 with the flyweight 3 by one Angle of -90 ° (according to the mathematical sense of rotation). It was on it pointed out that this twist in addition to the permanent, coupled opposite rotation takes place, i.e. is superimposed.

3c) then shows the position for the in the same phase position as FIG. 3b) Forward travel, with both resulting vertical and horizontal components occur that move the vibrating plate forward in a manner such as it is known from the prior art.

In addition, the switchover from the reversing position (FIG. 4a)) shown in reverse (Fig. 4b)). For this, the phase position becomes like this changed that the second unbalanced shaft 2 compared to the first unbalanced shaft 1 is adjusted by an angle of + 90 °. Here too the overlap Twist by the phase adjuster of the permanently coupled counter-rotation so that the position shown in Fig. 4c) can be reached can.

Of course, it is entirely at the discretion of the specialist, instead of Unbalance shaft 2 also the unbalance shaft 1 simultaneously or exclusively turn to create the desired phase position.

It is essential for the invention that the phase positions mentioned are set can be. The facilities required for this are known in principle, have so far not been used in the manner according to the invention.

In the vibration exciters known from the prior art the phase adjustment device usually consists of a single unit, the enables the desired adjustment of the phase position. Considering the big one Spectrum of phase positions, which is opened by the invention it is advisable to provide several devices in the vibration exciter, which are suitable in each case, the phase position over a certain range to change so that by adding all changes all desired Phase positions are adjustable.

It should be noted that when the phase adjustment device is not operated the phase position is constant over the entire rotation of the unbalanced shafts remains. 1a), 1b) and 1c) therefore show three different phase positions, 2 in the representations a) to e) only one phase position, but shows in different rotational positions.

With the invention it is possible that the unbalance in the reversing point only generate a resulting horizontal force vector that increases with increasing Running speed decreases and when changing the phase position and thereby pivoting the force vector, for example to a value from 45 ° forwards or backwards the value 1 / √2 · C for the horizontal (VH) and vertical (VV) component reached, where C is the maximum achievable force value equivalent.

Claims (6)

1. Vibration plate for ground-compaction, having a vibration exciter which comprises unbalanced shafts (1, 2) which are positioned in parallel with each other, can be driven in opposite directions at the same rotational speed and which each support at least one centrifugal weight (3, 4), wherein the phase position of the centrifugal weights can be adjusted by a phase adjusting device such that the vertical components of the centrifugal forces (5, 6), which are generated by the centrifugal weights, cancel each other out in each rotational position, characterised in that in this phase position the horizontal components of the centrifugal forces (5, 6) are summated in the same direction.
2. Vibration plate as claimed in claim 1, characterised in that in order to effect a progressive movement of the ground-compaction device in a first direction, the phase position defined in claim 1 can be adjusted by a positive angle.
3. Vibration plate as claimed in any one of claims 1 or 2, characterised in that in order to effect a progressive movement of the ground-compaction device in a second direction opposite to the first direction, the phase position defined in claim 1 can be adjusted by a negative angle.
4. Vibration plate as claimed in claims 1 to 3, characterised in that when a change is made between the phase positions defined in claims 2 and 3, the phase position defined in claim 1 can be assumed transitionally.
5. Vibration plate as claimed in claim 1, characterised in that the phase position can be adjusted by the phase adjusting device in such a manner that the horizontal components of the centrifugal forces (5, 6) cancel each other out and the vertical components are summated in the same direction.
6. Vibration plate as claimed in claim 1, characterised in that the phase adjusting device comprises at least one device for twisting a respective one of the centrifugal weights (3) relative to an associated other centrifugal weight (4) in superposition with respect to the counter-rotation of the unbalanced shafts (1, 2).

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