DE102006052848B4 - Device for shaping and compacting mixtures - Google Patents

Abstract

The invention relates to a device for shaping and compression of compactable mixture, preferably of concrete amount. The device consists of a vibrating table (1) with form elements, bearing elements and a vibration exciter system, wherein the vibration exciter system excites vibrations in a horizontal with a frequency between 3 Hz and 10 Hz. In such a device, the bearing elements couple a horizontal oscillatory motion with a vertical oscillatory motion with a frequency doubling for the vertical oscillatory motion relative to the horizontal oscillatory motion.

Description

The invention relates to a device for shaping and compaction of compressible mixture, consisting of a vibration table with form elements, bearing elements and vibration exciter system, wherein the vibration excitation system excites vibrations in a horizontal direction with a frequency between 3 Hz and 10 Hz. As a mixture is preferred to concrete amount addressed.

The currently widely used vibration compression with shape excitation is carried out by external vibrators and with exciter frequencies between 50 Hz and 200 Hz in the normal to high frequency range. This creates a high level of noise pollution. One approach to reducing noise in vibration compression is to work in the low frequency range because the threshold of hearing is very frequency dependent for humans.

These considerations led to the so-called "shaking", whereby low-frequency mechanical vibrations are mainly entered in the horizontal direction over the mold in the concrete amount. This shaking technique has the disadvantage that the compaction effect is inadequate for precast concrete components of large thickness. In these methods occur even at lower precast concrete unevenness of concrete compaction.

Solutions are known in which the compression takes place with a compression system in the horizontal direction and a further compression system in the vertical direction.

A practiced solution in the DE 43 35 944 A1 is the combined vibration excitation at Vibrierstationen in pallet circulation systems. First shake horizontally at low frequencies and then vibrate vertically normal frequency. The combined excitation is also used in tilting tables, as in the DE 41 43 469 C2 described, the horizontal and vertical excitation can be done sequentially but also simultaneously. The horizontal path amplitudes are larger than the vertical ones.

Another method with simultaneous action of horizontally and vertically directed vibrations is in the SU 1189683 A described and is characterized by constantly changing in the direction of horizontal vibrations.

Disadvantage of the method with a normal frequency vertical vibration is the noise. Another disadvantage of the known methods is that the large-area forms in the normal frequency excitation frequency range are flexible and thus distribution differences of the acceleration amplitude occur. These often lead to uneven concrete compaction. Furthermore, the vibration excitation with two separate exciter systems for horizontal and vertical vibration with an increased drive and control effort is connected.

In the DE 43 41 387 A1 Finally, a method and apparatus for compacting concrete with low frequency vibration will be described. Vibrations are possible in X- and / or Y-direction, design-induced unavoidable vertical vibrations are suppressed as well as possible. For this purpose, various measures are taken to suppress in particular vertical bending vibrations with frequencies in the vicinity of the natural bending frequencies of the vibrating table.

The invention has for its object to maintain the noise reduction associated with the low-frequency shaking and at the same time to improve the compaction even with precast concrete parts with a large thickness.

This object is achieved by a device having the features of claim 1. Advantageous embodiments can be found in the dependent claims.

The invention will be explained in more detail below with reference to drawings.

The device according to the invention consists, as in 1 shown from a compaction system with a vibrating table 1 , several storage elements, here the storage units 2 , a horizontal vibration exciter 3 and a shape 4 with the concrete amount. In this compression system, a horizontal and a vertical vibration is coupled. This coupling takes place by means of the bearing elements so that a vertical movement takes place with twice the frequency of the horizontal oscillation. The exclusively horizontal excitation is low-frequency in the frequency range between 3 Hz and 10 Hz. The resulting from the coupling vertical vibration is thus in the range between 6 Hz and 20 Hz.

The invention offers the advantage that the combined horizontal and vertical vibration is achieved with a horizontal excitation system. Since both horizontal excitation and vertical excitation are low-frequency, low noise emission is achieved.

Since the oscillation frequency of the vertical oscillation is twice as high due to the coupling, sufficient acceleration amplitudes for the concrete compaction are achieved even with small oscillation paths.

By the storage of the horizontally rigid vibration table on many bearings a uniform expression of the vertical vibration and thus a uniform concrete compaction is achieved.

A possible embodiment shows 2 , The vibration table 1 is on a sufficient number of as an eccentric 5 designed bearing elements against the ground 6 supported. The length of the eccentric 5 is chosen so that a favorable ratio between horizontal and vertical vibration path is achieved. The deflection of the eccentric 5 during operation is between 20 ° and 85 °. The drive of the vibration table 1 takes place with conventional unbalance exciters or also hydraulically, pneumatically or by mechanical transmission.

Another embodiment shows 3 , The storage of the vibration table 1 takes place on designed as a bearing assemblies bearing elements with a defined curved path 8th , which produces the desired coupling between horizontal and vertical vibration travel, and on a cam follower 7 , This bearing assembly is provided by a return device 9 complements the coupling between curved track 8th and cam follower 7 ensures. Due to the geometry of the curved path, the ratio between the horizontal and vertical vibration travel can be adapted to the requirements. The vibration excitation in the horizontal direction is carried out with conventional unbalance exciters or hydraulically, pneumatically or by mechanical transmission.

Another embodiment shows 4 , The storage of the vibration table 1 takes place on designed as a bearing assemblies bearing elements consisting of layers of elastic rubber 10 and curved shells 11 consist. The layering creates a bearing unit which is flexible in the direction of the curvature and has a high rigidity in the transverse direction. The curvature of the steel shells produces the desired coupling between the horizontal and vertical vibration paths. By changing the curvature, the ratio between horizontal and vertical vibration amplitude can be adapted to the requirements. The vibration excitation in the horizontal direction is carried out with conventional unbalance exciters or hydraulically, pneumatically or by mechanical transmission.

In a further embodiment variant, the coupling bearings and the vibration excitation are integrated in the vibrating station of a pallet circulation system.

LIST OF REFERENCE NUMBERS

1

vibration table

2

storage unit

3

vibratory exciter

4

shape

5

eccentric

6

underground

7

cam follower

8th

cam track

9

retractor

10

rubber layer

11

curved shell

Claims (5)

Device for shaping and compacting compressible mixture, consisting of a vibrating table ( 1 ), wherein the vibration exciter system excites vibrations in a horizontal direction with a frequency between 3 Hz and 10 Hz, characterized in that the bearing elements a horizontal oscillatory motion with a vertical oscillatory motion with a frequency doubling for the vertical oscillatory movement relative to the horizontal Couple oscillation movement. Apparatus according to claim 1, characterized in that the bearing elements as an eccentric ( 5 ) are executed, which are deflected in the operating state between 20 and 85 °. Apparatus according to claim 1, characterized in that the bearing elements as bearing assemblies with a defined curved path ( 8th ) are carried out, wherein the coupling between horizontal and vertical vibration takes place through the curved path. Apparatus according to claim 3, characterized in that the bearing assemblies each have a cam follower ( 7 ), and a return device ( 9 ) for coupling between curved paths ( 8th ) and cam follower ( 7 ) is provided. Apparatus according to claim 1, characterized in that the bearing elements as bearing assemblies consisting of layers of elastic rubber ( 10 ) and curved shells ( 11 ), are executed.

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