EP0999020A2 - Unbalanced mass vibrations generator for a bricks moulding machine - Google Patents

Abstract

A vibrator table (1) is used to compress concrete components, particularly paving blocks, and is equipped with imbalanced shafts (2,3,4,5) driven by motors. A device is provided for control and/or regulation of the speed or the relative phase position of the imbalance shafts, which are the rotor shafts of the motors. The motors are mounted on the vibrator table and are electrical asynchronous machines. The imbalance shafts extend at their two ends out of the motors where they support rectified imbalance weights (6-9).

Description

The invention relates to an unbalance shaker for compacting concrete elements, especially of paving stones during their manufacture for Installation in a stone molding machine. Such an unbalance shaker usually has a vibrating table on which unbalanced shafts are arranged which are driven by at least one motor, one device is provided for controlling and / or regulating the speed or relative phase position of the unbalanced shafts.

Such a device is known for example from DE-U-297 12 242.

With such unbalance shakers, the phase position of several The direction and amplitude of the vibrations are set to each other, whereby a corresponding regulation can lead to the unbalance forces generated at the vibrating table cancel each other out and thus the The vibrating table remains at rest.

Neutralstellung" führt aber bereits zu einem relativ starken unerwünschten Restvibrieren bzw. -schwingen des Rütteltisches, worin ein deutlicher Nachteil gesehen wird.Already a slight angular misalignment with the unbalanced shafts in their

However, the neutral position "already leads to a relatively strong undesirable residual vibration or vibration of the vibrating table, which is seen as a clear disadvantage.

The object of the present invention is accordingly to provide a corresponding To further develop unbalance vibrators in such a way that none of them Residual vibrations occur more.

This object is achieved in that the unbalanced shafts are the rotor shafts of the motors and that the motors on the Vibrating table are mounted.

The invention has the advantage that it uses the conventional cardan shafts with which the unbalanced shafts were previously driven by motors were decoupled from the vibrating table firmly on the bed of a stone molding machine were appropriate. Their bearings are also eliminated. By the The vibration device is eliminated from these mechanical components cheaper and less maintenance. Also required the cardan shafts as well the bearings themselves part of the drive power, so that by their Eliminating the power consumption of the motors is reduced because there are no unnecessary ones Mechanics must be moved. With the cardan shafts mentioned a slight non-uniformity occurs due to the gimbal error between the input and output of such a shaft, which are now bypassed becomes. This eliminates what has been occurring up to now from this non-uniformity resulting acceleration and deceleration of the unbalanced shaft, which caused a load on the motors, so that the motors only accelerates or decelerates when the angle is to be adjusted become.

By eliminating the rotating connecting parts, the regulation the speed of the unbalanced shafts also take place faster, since this Regulation a lower inertia of the total rotating masses has a positive effect.

Basically, it is advantageous if the motors with the unbalanced shafts are provided in pairs on the vibrating table. Each pair can be arranged essentially symmetrically to the center of the vibrating table, it then lies essentially in a horizontal plane.

But it is also possible that each pair of motors essentially in one Vertical plane is arranged.

Due to the paired arrangement, two motors with opposite ones can be used Rotation are provided, so that each of these only a resulting unbalance force in the substantially desired vertical direction is produced. This is due to the symmetrical arrangement this pair is a centric attack of this resulting vibration force guaranteed.

It should also be mentioned that the symmetrically arranged pairs both all can lie in one plane, as well as independently of the other pairs can be arranged in its own horizontal or vertical plane.

To the overall center of gravity of the vibrating table due to the mounted on it Motors with unbalance weights are not too flat remove, in which the resulting vibratory force acts, it is proposed that the unbalanced shafts are the rotor shafts of the motor, and on both ends protrude from the motors, where they each are provided with a rectified unbalance weight. This is external unbalance shafts are no longer necessary, but by eliminating them and the elimination of their bearings, in turn, the power consumption the motors are reduced and the regulation can be carried out more quickly.

The motors are equipped with a rotor position detection for fast control of the imbalance, which immediately delivers their results to the control. This rotor position detection can be, for example Sine-cosine encoder act that have a significantly higher resolution than conventional incremental encoders. For correspondingly demanding control tasks you get such Sine-cosine encoder with resolutions of over 65,000 increments per revolution. This means that even the smallest control deviations can be detected and immediately compensated for due to the good dynamics of the proposed unbalance shaker.

Also a so-called resolver, which is mounted on a shaft end and a voltage dependent on the rotational position with the rotation of the Wave generated sinusoidal shape, can be used with it It is also essential here that the electronics of the controller is able to Evaluation of a resolution of 65,000 increments per revolution and more.

It is also essential that a motor controls the master drive represents, while the other motors are designed as slave drives.

The motors are speed and power controlled via frequency converters, which are also designed as position controllers. A phase angle of 180 ° between the unbalances can be adjusted both motor pairs can be reached by + 90 ° or - 90 °.

It should be mentioned that the motors only have electronic components, Frequency converter coupled with synchronous control are, so that no additional mechanics, such as toothed belts, gears etc. are necessary.

The frequency converters are coupled with each other that angular deviations between the motors due to signal propagation times be avoided. In particular, the leading axis gives its position information directly to the master drive assigned synchronously in a first pair running motor further. The master drive also indicates its position one of the other engines that are related to him from the angle information additionally transmitted to the control is tracked synchronously becomes. This tracked motor provides its position information again to the associated synchronously running motor in it second pair further.

In a preferred embodiment, each motor is a slave drive designed and a virtual master drive is used, the speed setpoint from the higher-level controller. The virtual one Master drive gives the speed of rotation and rotor position to everyone Slave drives continue. This further improves the control properties and also the interchangeability of the electronic controllers.

Figur 1

die schematische Seitenansicht eines Unwuchtrüttlers;

Figur 2

die schematische Unteransicht eines Unwuchtrüttlers.

Figur 3

die schematische Verschaltung der Motoren eines Unwuchtrüttlers.

Figur 4

die schematische Verschaltung der Motoren eines Unwuchtrüttlers gemäß einer weiteren Ausführungsform.

Further advantages and features of the invention result from the following description of an exemplary embodiment. It shows

Figure 1

the schematic side view of an unbalance shaker;

Figure 2

the schematic bottom view of an unbalance shaker.

Figure 3

the schematic connection of the motors of an unbalance vibrator.

Figure 4

the schematic connection of the motors of an unbalance vibrator according to a further embodiment.

In Figure 1 you can see the vibrating table 1 of an unbalance vibrator, which for Compaction of concrete elements in particular of paving stones in one Stone molding machine is used. Be there with this vibrating table concrete elements placed on its top are shaken and thus compacted.

For shaking or for generating vibrations are on the bottom of the Vibrating table 1 four unbalanced shafts 2 to 5 provided on their outer Wear ends of unbalance weights 6 to 9.

As can be seen in FIG. 1, these unbalanced shafts have unbalanced weights each provided in pairs, namely in an outer pair, consisting of unbalanced shafts 2 and 5 or an inner pair from unbalanced shafts 3 and 4. These unbalanced shafts run in pairs each with the same speed by in opposite Directions according to arrows 10. This creates each pair Unbalance shafts 3, 4 and 2, 5 in total only one vibration component in Vertical direction, since each pair revolves in phase synchronization.

The resulting vibratory force, which results from the superposition of the vibratory forces of the individual unbalanced shaft pairs can be between one Maximum value and a minimum value can be varied by the shaking forces of the individual pairs are brought into phase (maximum resulting Vibrating force) or in the opposite phase (minimum resulting vibrating force = 0).

In the example shown in FIG. 1 there is - the same speed for assuming all unbalanced shafts - just the lowest resulting Vibrating power, since the individual vibrating forces just cancel each other out.

It can also be seen that the individual pairs are symmetrical to the median plane 11 of the vibrating table are arranged so that the of each pair of Unbalance shafts generate vibratory force due to the unbalance in this plane attacks.

FIG. 2 shows the bottom view of the vibrating table 1.

It can be seen that the unbalanced shafts 2 to 5 are the rotor shafts of motors 12 to 15 and that the unbalance shafts 2 to 5 at both ends protrude from these motors 12 to 15. One further recognizes that both ends of the unbalance shafts 2 to 5 rectified unbalance weights 6 to 9 are provided so that each individual motor is also symmetrical is with respect to the second central plane running transverse to the central plane 11 16 of the vibrating table 1. This ensures that also with respect to this There is a symmetrical force attack in the median plane and thus the resulting one Vibration force than at the intersection 17 of the two middle planes 11 and 16 can be assaulted.

The motors 12 to 15 themselves have a rotor position detection and are in particular provided with resolvers, not shown, through which these Detection can be done very precisely. The motor 12 acts as Master drive, while motors 13, 14 and 15 are designed as slave drives are.

So the motor 15 always runs in opposite directions synchronously with the motor 12 while motors 13 and 14 are regulated as needed to achieve the to increase or decrease the resulting vibrating force. The engines 13, 14 each run in opposite directions synchronously.

All motors are electrical asynchronous machines that may also be operated in normal operation on the normal power grid can. It is essential that the motors are only electronic Components are connected to each other, while no mechanical, components causing additional weight are present.

This electronic connection is shown in FIG. 3. The engines 12, 13, 14, 15 are frequency converters for their speed and power control 18, 19, 20 and 21 upstream which take the energy out of the normal Take out power supply 22. Here, the frequency converter 18 from one superordinate controller 23 a speed setpoint 24 predetermined.

The resulting rotation speed and position becomes from the frequency converter 18 to be assigned to the master drive 12 Frequency converter 19 and 21 passed on communication lines 25. The frequency converter 21 ensures that the motor 15 with the same speed but in opposite synchronism with the master motor 12 circulates.

In contrast, the frequency converter 19 receives an angle setpoint 26 via the higher-level controller 23, from which the motor 13 results in a phase difference to the master drive 12. The frequency converter 19 gives its rotational speed and rotational position via the Connection line 27 to the frequency converter 20 through which the Motor 14 is operated in synchronism with the motor 13.

This direct coupling of the frequency converters 18, 19, 20 and 21 signal transit times are briefly achieved with one another, so that no angular deviations occur between the motors and the related Motor pairs 12 and 15 or 13 and 14 each rotate synchronously. This decentralized control is in the frequency converters faster than a central interpretation in the parent Controller could be 23.

An alternative electronic connection is shown in FIG. 4. The motors 12, 13, 14, 15 are again for their speed and power control Frequency converter 18, 19, 20 and 21 upstream, which the Take energy from the normal power grid 22. But now from the higher-level controller 23 a speed setpoint 24 a virtual one Master drive 28 specified.

The resulting rotation speed and position becomes from this virtual master drive 28 to the assigned frequency converters 18, 19, 20 and 21 passed on communication lines 25, the thus act as a slave drive to the virtual master drive 28. The virtual master drive 28, which is a correspondingly programmed, an engine simulating control element is now the Motors 12, 13, 14 and 15 via frequency converters 18, 19, 20 and 21 Rotation speed and rotor position. Alternatively, the frequency converter 20 and 21 ensure that motors 14 and 15 are the same Speed, however, in opposite synch with motors 12 and 13 circulate.

With this circuit, there is a further improvement in the control properties achieved and also the interchangeability of the electronic controller and frequency converters 18, 19, 20 and 21 are improved.

With this circuit, the frequency converters 19 and 20 are still on Angle setpoint 26 predetermined by the higher-level controller 23 which is the phase difference for the motors 13 and 14 to the motors 12 or 15 results.

Claims (7)

Unbalance vibrator for compacting concrete elements, in particular paving stones, during their manufacture, with a vibrating table (1), with unbalanced shafts (2, 3, 4, 5) arranged on the vibrating table (1), with the unbalanced shafts (2, 3, 4, 5) assigned motors (12, 13, 14, 15) for driving the unbalanced shafts (2, 3, 4, 5) and with a device for controlling and / or regulating the speed or the relative phase position of the unbalanced shafts (2, 3, 4 , 5),
characterized,
that the unbalanced shafts (2, 3, 4, 5) are the rotor shafts of the motors (12, 13, 14, 15) and that the motors (12, 13, 14, 15) are mounted on the vibrating table (1). Unbalance shaker according to claim 1,
characterized,
that the motors (12, 15; 13, 14) with the unbalanced shafts (2, 5; 3, 4) are each provided in pairs on the vibrating table (1) and each pair is essentially symmetrical to the center (17) of the vibrating table (1) is arranged. Unbalance shaker according to claim 1,
characterized,
that the unbalance shafts (2, 3, 4, 5) protrude at their two ends from the motors (12, 13, 14, 15) and there each carry a rectified unbalance weight (6, 7, 8, 9). Unbalance shaker according to claim 1,
characterized,
that the motors (12, 13, 14, 15) have a rotor position detection. Unbalance shaker according to claim 1,
characterized,
that a motor (12) is the master drive and the other motors (13, 14, 15) are designed as slave drives. Unbalance shaker according to claim 1,
characterized,
that a virtual master drive (28) is provided and the motors (12, 13, 14, 15) are designed as slave drives. Unbalance shaker according to claim 1,
characterized,
that the motors (12, 13, 14, 15) are electrical asynchronous machines.

Images