JP4314194B2 - Vibration generator for ground compaction equipment - Google Patents

Description

  The present invention relates to a vibration generator for ground compaction equipment of the type described in the superordinate conceptual part of claim 1.

  Such a type of vibration generator is advantageously used mainly in diaphragms and is known, for example, from EP 0358744.

  A similar vibration generator is described in German Offenlegungsschrift 1 0038 206. The vibration generator has two unbalanced shafts that are connected in a shape-connected manner (based on form constraints; formschluessig) so that they can rotate in opposite directions. Both unbalanced shafts each carry a stationary unbalanced mass and an unbalanced mass that is movable relative to this stationary unbalanced mass and thus together with the unbalanced shaft. . The position of the movable unbalanced mass is variable in a relatively large range, actively by the adjusting device.

  When the unbalance shaft rotates, the combined total force is generated by the cooperation of different unbalance masses. This resultant force may be directed forward, backward or in the direction of travel as desired by the operator. Changes in the direction of travel are caused by an adjustment device that controls the movable unbalanced mass. When the operator desires the stationary state of the ground compacting device, the resultant force of the centrifugal weight (flyweight) is adjusted in the vertical direction. This also means that intentional compaction of the ground can be achieved while the machine is stationary.

  However, the operator does not always desire a strong compaction as described above in a locally restricted portion of the ground. In particular, when the diaphragm is reciprocating, the ground may be excessively strong and disadvantageously compacted at a so-called reversal point or reverse point. This is because the force acting on the ground is the maximum at this point, but when the diaphragm moves forward or backward, the resultant force vector turns forward or backward by 45 °, for example. This is because the maximum value is reduced to 1√2.

  Accordingly, even if the device described is well established for compacting earth, sand or gravel, this device may prove problematic for compacting asphalt or composite stone surfaces. obtain. This is because the maximum vertical force prevailing at the reverse point can cause a point-like settlement that can no longer be corrected. Therefore, in the case of asphalt rolling pressure, in order to prevent the roller from entering deeply into the asphalt when reversing the direction, vibration is generally blocked during the reverse operation.

  In order to solve the above problem, in German Patent Application Publication No. 19943391, the phase position of the centrifugal weight is adjustable, and as a result, how the vertical component of the centrifugal force generated by the centrifugal weight is adjusted. A vibration generator is described in which the horizontal component of the centrifugal force is correspondingly directed in the same direction, whereas it can be canceled out even at different rotational positions. This allows the diaphragm to no longer bring vertical vibrations to the ground while at rest, but rather to introduce shear to the ground via the ground contact plate. The shear stress can advantageously compact cracks and pores on, for example, asphalt surfaces.

This device also has an excellent reputation in practice. However, the strong horizontal vibration that dominates during stationary operation of the diaphragm is not always comfortable for the operator and is not always preferred for compaction of the ground surface.
German patent application No. 1095752 is provided with two unbalanced shafts which are parallel to each other so that both unbalanced shafts can rotate relative to a stationary unbalanced mass respectively. An unbalanced vibrator for a ground compactor is described that supports a movable unbalanced mass. With the vibration generator stopped, the relative position of the movable unbalanced mass with respect to the stationary unbalanced mass can be changed and fixed. In this case, once selected adjustments can no longer be changed during operation.

  Therefore, the object of the present invention is to improve the vibration generator of the above type so that the operator or the ground to be compacted is not subjected to the strong horizontal vibration during the opposing tension (Gegenzug), and is stationary based on the strong vertical vibration. It is an object of the present invention to provide a vibration generator adapted to avoid excessively compacting the ground.

  This problem is solved by a vibration generator configured as described in the characterizing part of claim 1. Advantageous embodiments are defined in the dependent claims.

  The vibration generator according to the invention advantageously has two unbalanced axes that are parallel to each other and can be driven in the opposite direction at the same rotational speed, each of these unbalanced axes being a stationary unbalanced mass. And a stationary mass body or an unbalanced mass body movable relative to each unbalanced shaft. An adjusting device is assigned to each unbalanced shaft so that the relative position of each movable unbalanced mass relative to the unbalanced shaft supporting the unbalanced mass can be adjusted. It has become. According to the invention, the relative position of the movable unbalanced mass with respect to the unbalanced shaft that supports the unbalanced mass can be adjusted by the adjusting device, so that the unbalanced mass on rotation of the unbalanced shaft. The centrifugal force generated by the body is totally offset at any rotational position of the unbalanced shaft. This means that although each unbalanced mass itself produces one centrifugal force, these centrifugal forces are adjusted in terms of direction and value to compensate for each other in the aggregate. It is that. Therefore, the vibration generator does not generate vibration in this operating state (rest position) even though the unbalanced shaft is rotated.

  By this, it can be achieved particularly advantageously that the magnitude of the total centrifugal force synthesized, i.e. the vibration strength, can be adjusted depending on the advancing movement / velocity of the diaphragm. If the speed is reduced, the effective centrifugal force is also reduced at a corresponding rate until the machine is at rest. In the stopped state, the synthesized total centrifugal force and thus vibrations no longer occur. Thereby, an energy input to the ground that is very even across the surface to be compacted can be achieved.

  In a special embodiment of the invention, the relative position is adjustable in each individual unbalanced shaft, so that the centrifugal force of the unbalanced mass supported by the unbalanced shaft is Even such rotational positions are offset. This means that, in operation, a relative position can be achieved in which no oscillating action takes place with only one unbalanced shaft.

  In order to achieve the advancing movement of the ground compacting device as in the known devices, in an advantageous embodiment of the invention, the relative position is variable, so that the centrifugal force of the unbalanced mass is not offset The total centrifugal force synthesized has a horizontal component. Thereby, the advancing motion of the diaphragm can be generated as is known based on the known prior art.

  For example, when the direction is changed between the forward traveling direction and the backward traveling direction, the already described stationary position where vibration does not act on the ground can be occupied transiently. Thereby, undesirable vertical vibrations or horizontal vibrations can be avoided when changing the direction at the reverse travel point. In an advantageous embodiment, adjustment of the movable unbalanced mass is sufficient to produce a synthesized centrifugal force with the desired direction and magnitude, for example in DE 100 30 206 A1. It is not required that the mutual phase position of the unbalance axes must be variable as in the case of the vibration generator described in the specification.

  The concept of “unbalanced mass” is considered abstract in the context of this application. The unbalanced mass may of course consist of a plurality of unbalanced elements distributed on the respective unbalance axis.

  The above and further advantages and features of the present invention will be described in detail below with reference to the accompanying drawings.

  As already mentioned, vibration generators are known in a variety of configurations. Similarly, as described, for example, in German Offenlegungsschrift DE 19943391, a so-called “phase adjusting device”, ie to adjust the relative position between the unbalanced mass and the unbalanced axis. Such adjustment devices are known. The present invention does not relate to the detailed and specific configuration of a specific vibration generator or a specific adjusting device, but rather to a relative position (phase position) that is particularly suitable for this, but is not known in the prior art. As such, a detailed description of the vibration generator is not required.

  Nevertheless, we would like to briefly describe the structure of the vibration generator according to the present invention with reference to FIG.

  In the casing 1, two unbalanced shafts 2 and 3 are rotatably supported. In this case, the unbalanced shaft 2 is rotationally driven by a driving device (not shown).

  The unbalance shaft 2 has unbalance elements 4 and 5. These unbalance elements 4, 5 are rigidly connected to the unbalance shaft 2 to form a stationary unbalance mass.

  Further, an unbalanced mass body 6 that is turnably movable is disposed on the unbalanced shaft 2. The unbalanced mass body 6 can be rotated relative to the unbalanced shaft 2 via the hub 7 and the bearing 8.

  The relative position between the movable unbalanced mass 6 and the unbalanced shaft 2 is determined by the adjusting device 9. The principle of operation of such an adjusting device has been known for a long time and is described, for example, in DE 100 03 206 A1. The adjusting device 9 mainly has a piston 10 that can be adjusted in the axial direction under hydraulic action. The piston 10 can reciprocate in the axial direction in the hollow region of the unbalanced shaft 2. The piston 10 supports a lateral pin 11. This transverse pin 11 passes through two longitudinal grooves 12 formed in the wall of the unbalanced shaft 2 and engages in a spiral groove 13. The groove 13 is formed on the inner surface of the hub 7. Accordingly, the hub 7 and the movable unbalanced mass body 6 supported by the hub 7 are rotated relative to the unbalanced shaft 2 when the piston 10 and thus the lateral pin 11 are adjusted in the axial direction.

  The unbalanced shaft 2 further supports a gear 14. The gear 14 meshes with a gear 15 provided on the unbalanced shaft 3. Via these gears 14, 15, the rotational movement of the driven unbalanced shaft 2 is transmitted to the unbalanced shaft 3 in a shape connection manner. This non-parallel shaft 3 therefore rotates in the opposite direction but at the same rotational speed.

  In the same manner as the unbalanced shaft 2, the unbalanced shaft 3 supports two unbalanced elements 16, 17. Both unbalanced elements 16, 17 together form a stationary unbalanced mass. Furthermore, an unbalanced mass body 18 is provided that is movable about the unbalanced shaft 3. The relative position of the unbalanced mass 18 with respect to the unbalance axis 3 can be adjusted via an adjusting device 19. Since the adjusting device 19 has the same structure as the adjusting device 9, detailed description thereof is omitted.

  The position of the unbalanced mass shown in the cross-sectional view of FIG. 1 corresponds to a relative position according to the invention in which the individual centrifugal forces produced by the respective unbalanced mass or unbalanced element are totally offset. (Stationary position). This means that the imbalance effect of the unbalance elements 4, 5; 16, 17 on the one hand and the unbalance action of the movable unbalance masses 6, 18 on the other hand are identical in value. It must be in the opposite direction. The associated mr values (mass m × the radius r of the unbalanced centroid) must be matched to each other accordingly.

  Correspondingly, as a result, the unbalanced shafts 2 and 3 can rotate without causing an effective imbalance outward and thus vibration. However, when adjusting the movable unbalanced mass bodies 6 and 18 by the adjusting devices 9 and 19, the balanced state is eliminated, so that desired vertical vibrations and horizontal vibrations for compacting the ground can be generated.

  The different relative positions and the vibration states obtained from these relative positions are shown in FIG. FIG. 2 shows a highly schematic side view from the right as viewed in FIG.

  For example, as shown in section a) “stationary” in FIG. 2, the hatched semicircle corresponds to a movable or adjustable unbalanced mass 6, 18, to which hatching is applied. The semicircles not applied correspond to the stationary unbalanced masses 4, 5;

  The state shown in FIG. 1 is taken up under the heading “Still” in the row a) of FIG. The direction of rotation of the unbalance axes 2, 3 and thus the unbalanced mass is indicated by curved arrows. Stationary unbalanced masses 4, 5; 16, 17 face the movable unbalanced masses 6, 18, respectively.

  In the rows a) to d), different rotational states of the unbalanced shafts 2 and 3 are shown rotated by 90 °. Of course, the rotational directions of the unbalanced shafts 2 and 3 are the same each time.

  In order to achieve a forward movement of the diaphragm (left column in FIG. 2), the movable unbalanced masses 6, 18 are rotated with respect to the stationary unbalanced masses 4, 5;

  In the example shown, the movable unbalanced mass 6 is rotated relative to the stationary unbalance elements 4, 5 and relative to the unbalanced axis 2 by 90 °. Furthermore, the movable unbalanced mass 18 was rotated by 90 ° in the same direction as the movable unbalanced mass 6 with respect to the stationary unbalanced elements 16, 17 on the unbalanced shaft 3. The corresponding state is shown in the “Forward” column in FIG. Here too, different rotation states of the unbalanced shafts 2 and 3 are shown under a) to d) in the “forward” column.

  The centrifugal force based on the unbalanced mass bodies 4 and 5 and the centrifugal force based on the unbalanced mass body 6 or the centrifugal force based on the unbalanced mass bodies 16 and 17 and the centrifugal force based on the unbalanced mass body 18 are stationary. It can be seen that it no longer compensates as it did during vibration. Rather, the centrifugal forces are superimposed on each other so as to obtain a left-upward resultant force shown in FIG. This corresponds to the forward direction.

  In FIG. 2c), a corresponding reaction in the downward right direction is produced. In this case, the diaphragm is supported by the ground and introduces vibration energy into the ground.

  The backward movement of the diaphragm (rightward as viewed in FIG. 2) is shown in the right column of FIG. For this purpose, the movable unbalanced mass 6, 18 is related to the unbalanced axes 2, 3 that support this unbalanced mass 6, 18, as shown in the “retracted” column in FIG. It is rotated by 90 ° in the opposite direction to the forward direction and relative to the rest position.

  This achieves a reciprocating vibration in the upper right direction or the lower right direction of the diaphragm, as indicated by the straight arrows in FIGS. This results in a reverse run.

  The position of the unbalanced mass shown in FIG. 2 is the extreme position. Depending on the configuration of the adjusting devices 9, 19, any intermediate position, ie an adjusting angle different from 90 °, can be achieved, so that a continuous conversion between forward travel, stationary operation and reverse travel is achieved. Can be done.

  As for the adjusting devices 9 and 19, on the one hand, it is possible to use known means such as a hydraulic control device, an electric motor, an electromechanical adjusting member and the like. As an alternative to this measure, in a simplified embodiment, the control of the movable unbalanced mass is made using a simple tension / push cable that can be controlled by the operator via a common transmitter. It can also be done. This can also save considerable costs in a relatively simple diaphragm.

  In order to achieve a precise conversion between individual operating conditions, the adjustment of the relative position by means of the adjusting devices 9, 19 should be able to be carried out synchronously. However, in some cases it may also be advantageous to achieve individual adjustability of the movable unbalanced mass without forcing synchronization.

  The continuous conversion between forward and reverse travel, where stationary operation without vibration generation can be transiently occupied, the value of the synthesized centrifugal force and thus the effective vibration, It becomes possible to adapt in proportion to the movement and speed of the movement. The slower the travel of the diaphragm, the smaller the combined centrifugal force will be until vibration is no longer introduced into the ground during the stop of the diaphragm, for example at the reverse point. This proportional dependency is obtained from the structure of the vibration generator according to the invention, in which case no expensive adjustment measures need be taken.

  Of course, it is also possible for the vibration generator according to the invention to occupy a relative position different from the relative position illustrated in FIG. If the adjusting devices 9 and 19 are formed accordingly, for example, as is known in German Offenlegungsschrift DE 19943391, vertical vibrations do not occur during the stoppage of the diaphragm, but instead A relative position in which strong horizontal vibrations are to be generated can be achieved.

  The invention has been described with reference to the example of a vibration generator according to FIG. The principle underlying the present invention can of course also be transferred to another vibration generator, for example having a plurality of movable unbalanced masses or another number of unbalanced axes. .

2 is a plan view showing a cross section of a vibration generator according to the invention in a rest position; FIG. FIG. 6 is a cross-sectional view schematically showing two unbalance axes at different rotational positions at respective positions of an unbalance mass.

Claims (10)

A vibration generator for ground compaction equipment, provided with a plurality of unbalanced shafts (2, 3) that are parallel or coaxial with each other and can be driven in the opposite direction at the same rotational speed each unbalance shafts (2,3), said non equilibrium axis (2,3) in the stationary and is unbalanced masses against; and (4,5 16,17), the unbalanced shaft (2, 3) pair and relative times whether capacity imbalance mass (6, 18) and the and support, its Re allows relative rotation, respectively imbalance masses (6, 18), said non equilibrium adjusting device for adjusting the relative position against the mass (6, 18) imbalance shaft supporting the (2,3) (9, 19) is associated arranged in the unbalanced shaft (2, 3) In the form of
(B) a said relative position adjustable during operation of the ground compaction device by the adjusting device (9, 19), upon rotation of the imbalance shafts (2,3), unbalanced masses (4, 5; 16,17; 6,18 centrifugal force which is caused by) the imbalance shafts (2, 3) that are generally offset becomes obtained so that at rotational position of the throat,
Changes in (b) the relative position, imbalance mass value of all the centrifugal forces caused by (4,5; 16,17 6,18) is proportional to the traveling motion and speed of the ground compaction device it can be implemented as
Wherein the vibration generator for ground compaction device. Adjustable, it supported by the front Symbol imbalance axis the unbalanced mass in the relative position that each unbalanced shaft (2, 3); centrifugal force (4,5,6 16,17,18) is not has also become obtained so that offset by any rotational position of the equilibrium axis, the vibration generator according to claim 1. To give rise to progressive movement of the ground compaction device to a horizontal first direction, the relative position is variable as the centrifugal force of the unbalance mass is not canceled, the total synthesized from these centrifugal forces The vibration generator according to claim 1 or 2, wherein the centrifugal force has a horizontal component.   4. The vibration according to claim 3, wherein the relative position defined in claim 1 can be transiently occupied during a change between the first direction and a second direction opposite to the first direction. Generator.   The vibration generator according to claim 1, wherein the change of the relative position can be carried out continuously. 6. The vibration generator as claimed in claim 1, wherein the unbalance shafts (2, 3) are connected in a shape-connected manner so as to be rotatable in opposite directions.   7. The vibration generator according to claim 1, wherein the mutual phase positions of the unbalance axes (2, 3) are not variable. Regulation can be implemented synchronous manner in the relative position by the adjusting device (9, 19) in the unbalanced shaft (2, 3), the vibration generator according to any one of the claims 1 to 7.   9. The vibration generator according to claim 1, wherein the adjusting device (9, 19) can be operated electrically, hydraulically, pneumatically or mechanically.   10. A vibration generator according to claim 1, wherein at least one part of the unbalanced mass is formed from a plurality of unbalanced elements (4, 5; 16, 17).

Images