DE102004011896B4 - Vibration insulator for machines has spring assembly constructed as air-spring with at least one air volume creating spring action, and elastomer component assembly encloses air-spring assembly on sides - Google Patents

Abstract

The vibration insulator (1) has an elastomer component assembly (10,11) positioned between spaced apart holding elements (30,31) and a spring assembly (20), whereby one holding element (30) is coupled to an object to be insulated. The spring assembly is constructed as an air-spring assembly with at least one air volume creating a spring action. The elastomer component assembly encloses the air-spring assembly on the sides.

Description

The The invention relates to a vibration isolator with an intermediate spaced-apart holding elements positioned, vibration-damping Elastomer body assembly and a spring arrangement, wherein a holding element with a to be insulated Item is coupled.

Such a vibration isolator is in the DE 102 33 023 B3 specified. In this known vibration isolator, between two plate-shaped holding elements, one of which is attachable to an object to be insulated, an insulation assembly of at least one elastomeric body and a cooperating with this steel spring assembly is introduced. The natural frequency of the at least one extending over the distance between the holding elements elastomer body is between 4 Hz and 40 Hz and is reduced by means of steel spring assembly to a range between 1 Hz and 5 Hz. With these measures men results in a compact, easy to handle design with low natural frequencies and advantageous effectiveness in all spatial directions. However, it can also vibration problems, especially in machines to be isolated or similar devices that can not be optimally eliminated with such a vibration isolator.

The DE 41 20 840 C1 shows a vibration isolating engine mount for a motor vehicle, which consists of two spring elements made of rubber, which are arranged between two plate-shaped holding elements. In this case, the externally arranged first spring element projects beyond the spaced apart in its interior second spring element at least partially in the uninstalled state. The second spring element has a centrally arranged outwardly open recess, and at least one annular reinforcing element radially outside the recess, which is connected almost immovably to the second spring element. In the recess, a flowable medium can be fed, with which the second spring element in response to the respective pressure of the flowable medium in the region of the recess is stiffened. The flowable medium can be acted upon by a pressure which exceeds the atmospheric pressure or by a pressure which falls below the atmospheric pressure, as a result of which the second spring element shrinks. With regard to the flowable medium, it is stated that this can be both liquid and gaseous, but it is to be noted in connection with the application of relative overpressure that the incompressibility of the fluid causes the first and the second spring element to be connected in parallel, resulting in a comparatively large amount of fluid hard spring characteristic results. The pressure of the medium in the recess can be reduced by being able to escape via a hydraulic valve. This document makes no statement that the volume of the medium itself is to be formed as an air spring arrangement, but merely serves to change the insulating properties of the second spring element. The engine mount is designed specifically for the needs of a motor vehicle in such a way that relatively high pressure of the flowable medium in the recess higher frequency vibrations are isolated with small amplitudes, while with a relative pressure of the fluid medium low-frequency vibrations are to be damped with large amplitudes In this context, the term attenuation is inaccurate and actually there is a limitation of the large amplitudes. In any case, the natural frequency of this camp depends on the amplitude. Furthermore, in the transition region between high-frequency oscillations with smaller amplitudes and low-frequency oscillations with large amplitudes, there is the risk that an oscillation frequency occurs in which the oscillations are amplified.

Another vibration isolator is in the DE 39 26 696 C3 proposed, which serves in particular for the storage of an internal combustion engine in a motor vehicle and is designed as a rubber bearing with hydraulic damping. The elastic suspension has an inwardly increasing thickness and a substantially triangular profile.

The DE 41 33 037 C2 shows an exposure device with an actively damped storage to reduce vibration.

Also in the US 5,141,201 A For example, a vibration damping system is shown for a transport device to dampen vibrations acting on transported articles.

Of the Invention is based on the object, a vibration isolator to provide, in particular in connection with moving masses containing objects, about machine tools or the like., But also other objects, such as testers or Like., With advantageous coupling possibilities with possible simple measures one achieve optimized vibration isolation.

This object is achieved with the features of claim 1. It is therefore provided that the spring arrangement is designed as an air spring arrangement with at least one air volume generating a spring action, to which at least one air path with a part to change the amount of air a control device is connected controllable valve, that the control device comprises a vibration sensor whose signals are used to actuate the valve and which is always in contact with the object to be insulated facing holding member and that the elastomeric body assembly laterally surrounds the air spring assembly.

With these measures can vertical vibrations with support of the air spring arrangement be isolated while advantageous by means of the elastomeric body also a sufficient one Vibration isolation in the horizontal direction is ensured. For example, are under an object with moving masses arranged a plurality of such vibration isolators, in particular by the air spring assembly also has a different vibration isolation in the range of different vibration isolators causes and thus Overall, the environment of the machine against from this outgoing Vibrations (source isolation) are protected. Conversely, can in a corresponding manner, the object occurring from the outside Vibrations (receiver isolation) be advantageously protected with such a vibration isolator.

With this vibration isolator can the machines mounted on top of the optimally effective vibration isolation automatically adjusted.

The The invention is based on the following considerations: at Vibration isolation should be such that the vibration isolation from a vibration established machine outgoing forces or caused thereby Vibrations are reduced. When designing a vibration isolation is a procedure in practice in that one to insulating machine in the frequency range considered as one rigid body idealized, which is then stored on the elastic elements. In practice, the machine mounted on such elements becomes for the vertical movements as a one-degree-of-freedom oscillator.

In dependence which can be isolated frequencies the isolation element will be designed, because the vibrations will be from the frequency √2 × natural frequency isolated. This means that the degree of isolation with deeper Natural frequency gets better. But since the amplitudes of the elastic stored machine become larger with decreasing natural frequency, these amplitudes should be limited. The size of the amplitude is also from the degree of damping dependent on storage, i.e. with increasing degree of damping the amplitude becomes smaller. But since the degree of damping of an elastic storage not increased arbitrarily can be Amplitudes also not as desired be limited.

It On top of that, many machine tools have a moving mass to have. If the machine is operated, the contact forces will be dependent change the position of the moving mass. This leads to considerable Tilting movements. That means the requirement for interpretation the insulation elements can no longer apply. That so that that Replacement system for the elastically mounted machine no longer has one degree of freedom has, but at least six degrees of freedom, even if the machine considered altogether as a rigid body can be.

In should practice for a vibration isolation on the one hand, the vibrations, which of the Machine go out, be isolated, and on the other the amplitudes the machine itself remain in a predetermined amplitude limit. Otherwise you can the feeder and break cable connections. Furthermore will the quality and productivity the elastically mounted machine considerably limited.

With the present invention, the tilting movements due to moving mass adjusted automatically, so that the above-mentioned disadvantages be avoided at a very low tuning of a machine can.

One advantageous construction for the production and functionality is obtained in that the elastomeric body assembly laterally the air spring assembly surrounds.

For the effectiveness The rules are the measures Cheap, that the vibration sensor facing with the object to be insulated Holding element coupled or always in contact.

Various advantageous design options arise from the fact that the air spring arrangement as the resilient Air volume receiving container a pot with membrane, a bellows or a piston / cylinder arrangement having.

is provided that the volume of air to change the amount of air at least An airway connected to a valve can be further advantageously influence the mode of operation of the air spring arrangement, in particular if the embodiment is such that the valve controllable or regulated as part of a control device.

An advantageous construction for the regulation of a single vibration isolator or several vibration isolators in the composite is to the control device has a vibration sensor whose signals are used to actuate the valve. In combination, the air spring arrangements of the various vibration isolators can be influenced differently by evaluating the signals supplied by the various vibration isolators of a common control device or control device, so that the vibration transmission can be suppressed even more differentiated and the amplitudes of the vibration-isolated mounted machine in the predetermined amplitude range stay.

to Influencing the air volume is a further advantageous measure in that the air volume over the valve is connected to an air supply.

One for the Use cheaper Construction is that the holding elements parallel to each other are spaced and at least one, the object to be isolated facing holding element plate-shaped is formed and provided with fastening means for the article.

The Vibration isolation is further supported by the fact that the diaphragm, bellows or piston with the one to be isolated Object facing the retaining element is coupled.

With the specified inventive measures is an effective isolation of the emanating from a machine personnel or acting on a machine floor vibrations and damping of Vibrations and shocks in all spatial directions achieved at the same time. In addition to insulation and damping can the object is automatically adjusted by the air spring arrangement become. The air spring assembly and insulating packages in the form of the elastomeric body are received between the holding elements, in particular a top and bottom plate, which are screwed together accordingly. The air to be supplied can be generated by a compressor of the air supply. With the vibration isolator it is possible a relatively low vote and a high degree of damping at low contact surfaces realize.

The inventive measures can be particularly advantageous in an elastic and damping Storage of forming machines, machine tools and equipment, such as e.g. milling machines, Lathes, Grinders, Presses, Punching, Hammering, and other aggregates and to isolate them. Further are the vibration isolators advantageously usable for the insulation of test benches, measuring instruments, laser microscopes, Laser welding systems.

The achievable by using elastomers for vibration isolation vertical storage natural frequency is generally more than 10 Hz. Insulating packages can be formed by layering elastomers be achieved with which a vertical natural frequency of 5 Hz is, so that such Isolierpakete not only for the elastic storage of Machines but also for the elastic storage of a building can be used. elastomers have spring and damping properties simultaneously. By suitable mixing, the damping of the Elastomers increased up to 20% be, with the dimensional stability the elastomers can be ensured by mixing.

With the structure of the invention The vibration isolator can be tuned to low frequencies e.g. in the range between 3 and 5 Hz with a relatively high degree of damping to about 20% for a building, a press or other machine are allowed. This can be huge loads with small contact surfaces be recorded.

at the design of the vibration isolators by elastic and damping Elements that are passive elements are the focus of the to be protected Object to consider. Taking into account the dimensions, the weight and the location of the Center of gravity of the protected Object can the static bearing forces be determined. With the measures according to the invention, the insulation elements for each Bearing point can be chosen differently in a relatively simple way, so that the object, statically speaking, stands straight. For this would have to predetermined insulation elements, for example, exclusively Elastomers the bearing surfaces be different.

The measures according to the invention can be used particularly advantageously for objects or machines with movable mass (in particular machine tools, machining centers, transfer lines, machines with concatenation, pressing machines, grinding machines). The moving masses can amount to up to a third of the total weight of the object and move at significantly higher speeds or accelerations and jerks. This leads to significant tilting movements of the bearing on the vibration isolators machine, whereby the functioning of the machine disturbed and in particular a rapid traverse can be limited. With the vibration isolator of the above structure, however, these disadvantages can be counteracted advantageous. In particular, the decay of the elastically mounted machine is significantly reduced. The amplitude of this machine is kept in the predetermined amplitude limit, especially if in addition a regulation of Luftfedera is provided for. The required horizontal vibration isolation is achieved by the suitably designed and stored elastomer body. By the elastomeric body and damage to the air spring assembly is prevented by horizontal vibrations. Furthermore, a sufficient damping in the horizontal direction is ensured by the elastomer body assembly. In addition, insulation is already ensured during a Ausregelverzögerung in cooperation between the elastomeric body assembly and the air spring assembly. In summary, the following advantages of the vibration isolator with the above structure are listed: automatic adjustment, short reaction time, relatively high damping, low natural frequency, very low tilting movements in spite of moving masses, no limitation of the functionality of the vibration-isolated mounted machine due to vibrations, increased productivity of the vibration-isolated Machine.

The Invention will now be described with reference to an embodiment with reference closer to the drawings explained. Show it:

1 a vibration isolator around cross-section,

2A the horizontal speed of vibration over time in a combination of elastomeric body and air spring assembly over a structure without elastomeric body,

2 B an amplitude spectrum of the horizontal vibration speed in a combination of elastomeric body and air spring assembly with respect to a structure without an elastomeric body,

3A the vertical vibration velocity over time in a combination of elastomeric body and air spring assembly over a structure without elastomeric body and

3B an amplitude spectrum of the vertical vibration velocity in a combination of elastomeric body and air spring assembly over a structure without elastomeric body.

An in 1 illustrated vibration isolator 1 points between a holding element in the form of a base plate 31 and another holding member in the form of a top plate spaced parallel from the base plate 30 an insulation device made of elastomeric bodies 10 . 11 . 12 and an air spring assembly 20 on. The air spring arrangement 20 is from the elastomeric bodies 10 . 11 . 12 surrounded, which may for example also be integrally formed and in plan view, for example, have an annular or rectangular or square outer contour and for receiving the air spring 20 have a round or square or rectangular recess in the central region. The elastomeric body 10 . 11 . 12 may be composed as elastomeric packets of different elastomeric material, for example in parallel layers between the top plate 30 and the base plate 31 , wherein the individual layers can be oriented vertically or horizontally. The top plate 30 and the base plate 31 are advantageously secured by means of several cohesive elements, such as threaded rods and nested rings or other coupling elements against falling apart, the insulation of the insulating device is ensured unhindered. Furthermore, the top plate 30 and / or the base plate 31 with arranged on the outside fasteners, such as screws 32 . 33 be provided to the vibration isolator 1 in a simple way on the one hand with the top plate 30 on an object and on the other hand with the base plate 31 to attach to a substructure.

The air spring arrangement 20 For example, it consists of a pot with a membrane attached to the top plate 30 is coupled, with the pot between the base plate 31 and the top plate 30 but there is enough room for vibration. The volume of air formed in the pot is above an air line 22 with an air supply 21 in connection, from which for example by means of a compressor air can be conveyed into the pot. In the air line 22 can be arranged a controllable or controllable valve to regulate the amount of air suitable. Further, from the air volume of the pot, air may be released to the environment via the valve or other valve to reduce the amount of air.

The amount of air in the pot is advantageously adjusted by means of a control device to the given requirements for a suitable control algorithm. The controller has a responsive to the vibrations or applied forces transducer 23 from which signals to a control unit for controlling the amount of air in the pot 20 be delivered. The control device is programmed so that the best possible vibration isolation is achieved in all directions. In this case, the control may be limited to a respective vibration isolator or it may be several vibration isolators of the insulated object as a function of each other for optimum vibration isolation of the object can be controlled.

As 2A shows, is the combination of the insulating body with the air spring assembly the horizontal vibration velocity suppressed in a much shorter time than without elastomer body. 2 B shows that also significantly lower amplitudes of the horizontal vibration velocity arise in the combination of the elastomeric body assembly and the air spring assembly as in the case without elastomeric body.

The 3A and 3B show corresponding improvements in the vibration velocity and the amplitude spectrum of the vertical vibration velocity of the mounted on the insulators machine.

Claims (5)

Vibration isolator ( 1 ) with a holding element between spaced apart ( 30 . 31 ), vibration-damping elastomeric body assembly ( 10 . 11 . 12 ) and a spring arrangement, wherein a holding element ( 30 ) is coupled with an object to be isolated, characterized in that the spring arrangement as an air spring arrangement ( 20 ) is formed with at least one air volume generating a spring action, to which at least one air path is connected to a valve that is controllable as part of a control device in order to change the air volume, that the control device comprises a vibration sensor ( 23 ), whose signals are used to actuate the valve and with the object to be insulated facing the holding element ( 30 ) and that the elastomeric body assembly ( 10 . 11 . 12 ) the air spring arrangement ( 20 ) surrounds laterally. Vibration isolator according to claim 1, characterized in that the air spring arrangement ( 20 ) As the resilient air volume receiving container having a pot with membrane, a bellows or a piston / cylinder assembly. Vibration isolator according to claim 1 or 2, characterized in that the volume of air via the valve to an air supply ( 21 ) connected. Vibration isolator according to one of the preceding claims, characterized in that the retaining elements ( 30 . 31 ) are spaced parallel to each other and at least one, the object to be insulated facing holding element ( 30 ) plate-shaped and with fastening means ( 32 ) is provided for the object. Vibration isolator according to one of claims 2 to 4, characterized in that the membrane, the bellows or the piston with the object to be isolated facing holding element ( 30 ) is coupled.