EP2119818A1 - Needling machine and method for operating same - Google Patents

Abstract

An industrial sewing machine has a sub-frame supporting a number of component groups, one of which is an oscillating needle beam that causes oscillation of the sub-frame. A further oscillation actuator is attached to one part of the sub-frame and modifies the sub-frame's own natural oscillation characteristics within critical ranges. The assembly has a control unit (17) coupled to an oscillation actuator (17) and oscillation sensor (19) coupled to the chassis (1). The control unit incorporates a microprocessor (18) in which chassis vibration characteristics are stored and generates control commands. Further claimed is an operating process for the sewing machine.

Description

The invention relates to a needle machine for needling a fiber web according to the preamble of claim 1 and a method for operating such a needle machine according to the preamble of claim 12.

A generic needle machine is for example from the DE 197 30 532 A1 known. In the known needle machine, the individual modules for guiding a fiber web and for needling the fiber web are arranged in a multi-part machine frame. Here, especially when needling the fiber web very high process forces are introduced via the modules in the machine frame. Thus, at least one of the assemblies on an oscillating driven needle bar, which holds a plurality of needles on an underside and is driven to oscillate at high speed. The assemblies are held in the known needle machine by an upper carrier and a sub-carrier, which are arranged by a plurality of support beams to a distance. In the space formed between the upper carrier and the sub-carrier of the machine frame, a pad for guiding and receiving the fiber web to be needled and a cooperating with the pad needle bar is arranged, which is connected via a plurality of connecting rods with a crank drive.

In the known needle machine, considerable mass and process forces must be absorbed by the frame parts of the machine frame, especially at high production speeds. Since these forces occur periodically, the machine frame parts are excited to frame vibrations. Here, in particular, the suggestions of the machine frame are critical, which are in the range of natural frequencies of the machine frame. In order to avoid critical vibration conditions, the machine frames are usually made very rigid, so that the machine frame has the highest possible natural frequencies. Thus, complex and complex machine frame structures are required to achieve higher production speeds with correspondingly high operating speeds of the drives.

Basically, it is also known in the prior art, the dynamic forces, which usually occur periodically with the puncturing movement of the needle bar, compensate by a plurality of the crank mechanisms associated with balancing masses. Such a needle machine is for example from the DE 199 10 945 A1 known. In this case, balancing weights are attached to the crankshaft, which lie opposite the eccentric areas of the crankshaft. However, these balancing weights only act directly as mass balance on the crankshaft. Thus, the puncturing forces and pull-out forces occurring on the needle bar can not be influenced. The dynamic forces occurring periodically with the puncturing movement can therefore not be compensated by balancing masses. In addition, it is common practice to move the needle bar through multiple engines both in the vertical direction and in the horizontal direction. This results in mass forces also in the horizontal direction. To avoid resonance phenomena in the machine frame, therefore, correspondingly heavy and large machine frames are required in order to securely hold the assemblies for needling a fiber web, even at higher production speeds.

Furthermore, if the machine frame is subjected to a high dynamic load, there is a risk that deflections will occur between the machine frames, which will have an immediate effect on different penetration depths of the needles over the entire working width of the fiber web. Such deflections can be avoided only by increasing the rigidity of the machine frames. So steel sheets are known in the range up to 120 mm thickness, in order to achieve high stiffnesses. However, such rigid machine frames have the disadvantage, in particular in the connection points, that there is no sufficient stretchability, so that loosening of the screw connections can occur due to the changing loads within the machine frame.

It is an object of the invention to develop a needle machine of the generic type such that uniform needling on the fiber web are certainly possible even at higher production speeds and operating frequencies.

Another object of the invention is to provide a generic needle machine as possible in a lightweight construction, in which the machine frame is changeable as a vibration system.

It is also an object of the invention to provide a method for operating a needle machine of the generic type, with which an active influencing of the vibration system formed by the machine frame is possible.

This object is achieved by a needle machine with the features of claim 1 and by a method for operating such a needle machine according to the features of claim 12.

Advantageous developments of the invention are defined by the features and feature combinations of the respective subclaims.

The invention is characterized in that the vibration system formed by the frame parts of the machine frame and the assemblies held therein is actively changeable. This makes it possible in particular to carry out critical rotational speed ranges and the critical operating frequencies associated therewith, without resulting in resonance phenomena. In order to be able to actively intervene in the vibration system of the machine frame, a separate vibration actuator is provided, which acts on one of the frame parts to change the frame vibrations of the frame parts during operation. By means of the oscillation actuator, counter-excitations can be initiated in at least one of the frame parts, which counteracts the oscillation excitation from the operation of the assemblies. Thus, operating frequencies in the range of the natural frequency of the machine frame can be traversed without risk of resonance phenomena.

Since the critical areas of the vibration system of the operating frequency and the associated vibration excitation in the machine frame are dependent, provides the development of the invention, in which the vibration actuator is controlled by a control device and in which the control device is coupled to a vibration sensor, which for detecting the Frame vibrations associated with one of the frame parts, the particular advantage that only in case of need an active change of the vibration system of the machine frame is initiated by the vibration actuator. Thus, for example, shortly before reaching a resonant frequency, the oscillation actuator can be activated so that excitation in the region of the natural frequency of the machine frame is avoided by the counter-excitation.

Particularly advantageous here is the use of a microprocessor within the control device, which compares the measured values of the frame vibrations with stored natural frequencies of the frame parts and generates corresponding control commands as a function of the comparison in order to activate or deactivate the oscillation capacitor. Thus, the vibration actuator can be activated and deactivated depending on the operating frequency. As measured values of the frame oscillations, for example, the motion quantities such as travel, speed or acceleration are measured which, given ideal behavior, show a different frequency dependence. Preferably, the acceleration is detected directly or indirectly by a force measurement. Thus, the temporal course of the frame vibrations can be determined in order to initiate targeted forces for suppressing the vibrations.

As vibration actuators, it is possible to use all known means which have a controllable actuator and which, by activating the actuator, enables a detuning of the vibration system formed by the machine frame.
According to an advantageous development of the vibration actuator is formed by at least one force transmitter, which is arranged within one of the frame parts or between a plurality of frame parts to produce a compressive force and / or a tensile force. Here, the force transmitter can be used both dynamically and statically to influence the vibration system. In dynamic mode of operation alternately a pressure and a pulling force on the force generator generated so that a counter-excitation is generated within the frame part. In a static mode of operation, either a tensile or compressive force is generated to create tension within one of the frame members or between multiple frame members. This can be the rigidity of the machine frame influence to change the natural frequency. In that regard, force transmitters are particularly flexible as vibration actuators. Depending on the mode of operation, piezoelectric actuators (piezo stacks) or hydraulic and pneumatic piston-cylinder units can be used as force transmitters.

In order to take into account as far as possible the time course of the dynamic forces in the operation of the needle machine in generating the counter-excitation, the development of the invention is particularly advantageous, in which the vibration actuator is formed by at least one mass oscillator. The mass oscillator in this case acts on one of the frame parts in order to generate a vibration excitation acting on the frame parts. By dimensioning the counterweight periodically occurring opposing forces can be generated by the mass oscillator and be introduced directly into the machine frame.

In order to be able to adapt the frequency of the counter-excitation to the requirements or the operating conditions, the development of the invention is preferred in which the mass oscillator has a movable countermass and a drive means acting on the counterweight, the drive means oscillating the counterweight in a reciprocating motion drives. Thus, the movement of the counterweight both in frequency and in their amplitude can be adapted to the respective operating conditions.

However, it is also possible to form the mass oscillator with a passively guided countermass. In this case, the movable counterweight is supported by a spring relative to the frame part. The counter-excitation by the movement of the counterweight is in this case generated directly by the frame vibrations of the frame parts. On the one hand to avoid the changed by the mass oscillator resonant frequency in the excitation and on the other hand to perform only a needs-based vibration control, according to a further development of the invention, the mass oscillator is designed with a blocking agent acting on the counterweight. Thus, the movement of the counterweight can be selectively blocked by controlling the blocking agent.

The effectiveness of the counter-excitation by the vibration actuator to avoid resonance phenomena is particularly effective in the event that the vibration actuator is arranged on the frame part on which the assembly is held with the needle bar. Thus, the counter-excitation is generated directly to each frame part on which the excitation from the assembly out.

For guiding and holding the assemblies within the needle machine, the frame parts of the machine frame are preferably assembled into a machine frame. Thus, the frame parts are preferably formed by a sub-carrier, an upper carrier and a plurality of support beams, wherein the support beams hold the upper carrier with a distance above the sub-carrier and are arranged on two opposite support ends of the upper carrier.

In order to obtain as far as possible vibration isolation with respect to the site of the needle machine, is preferably at an underside of Subcarrier several elastic support means arranged by which the machine frame is held opposite a hall floor. Thus, the frame vibrations of the frame parts remain substantially isolated from the hall floor within the needle machine.

The inventive method for operating such a needle machine is particularly advantageous to safely control critical operating conditions within the needle machine. Thus, defined vibration excitations can be generated by the vibration actuator, which counteracts the frame vibrations of the machine frames caused by the operating frequencies.

In order to enable a controllable intervention in the vibration system as a function of the operating frequencies, the frame vibrations are measured at least on one of the frame parts, so that the vibration actuator is controlled as a function of the respective measured values of the frame vibrations. Thus, the acceleration of the frame vibrations is preferably measured by means of acceleration sensors. This allows the temporal course of the frame vibrations as well as critical frequencies of the vibrations to be determined.

This method variant can be further improved by comparing a frequency of the frame oscillations with at least one natural frequency of the frame parts and that the oscillation actuator is controlled as a function of a difference value between the frequency of the frame vibrations and the natural frequency of the frame parts. This targeted resonance phenomena can be avoided in the machine frame. Critical speed ranges when guiding the needle bar can thus be passed through without resonance.

Depending on the application, the vibration system of the machine frame can be influenced. Thus, the vibration actuator as a force transmitter within one of the frame parts or between a plurality of frame parts generate a compressive force and / or a tensile force.

Alternatively, however, there is also the possibility that the vibration actuator generates as a mass oscillator on one of the frame parts an acting on the frame parts vibration excitation.

The vibration excitation can be generated both by an actively guided counterweight of the mass oscillator and by a passively guided mass of the mass oscillator.

The invention can be used in principle for all needle machines. Particularly great advantages result with wide machines, high stroke frequencies and unfavorable process parameters, which lead to high-frequency needle penetration forces. In this case, relatively lightweight and low-stiffness machine frames can be realized, which are also suitable for higher production speeds by actively influencing the vibration system.

The needle machine according to the invention and the method according to the invention for operating such a needle machine are explained in more detail below with reference to some embodiments with reference to the accompanying figures.

They show:

Fig. 1

schematically a front view of a first embodiment of the needle machine according to the invention

Fig. 2

schematically a side view of the embodiment of Fig. 1

Fig. 3

schematically a front view of another embodiment of the needle machine according to the invention

Fig. 4

schematically a front view of another embodiment of the needle machine according to the invention

Fig. 5

schematically a plan view of a machine frame part with multiple acting as a vibration actuator force generators

In the Fig. 1 and 2 a first embodiment of the needle machine according to the invention is shown in several views. In Fig. 1 is the needle machine in a front view and in Fig. 2 shown in a side view. The following description applies to both figures, insofar as no explicit reference is made to one of the figures.

The needle machine has a machine frame 1, which is designed in the shape of a frame to accommodate a plurality of assemblies for guiding and needling a fiber web. The machine frame 1 is for this purpose formed of a plurality of frame parts. The frame part which is arranged in the upper region of the needle machine is formed by a top carrier 2 which extends like a bar between two support ends ( Fig. 1 ). Below the upper support 2, a further frame part is provided at a distance, which forms the bottom of a needle machine as a parallel aligned sub-carrier 3. The sub-carrier 3 extends parallel to the upper carrier 2. Between the upper carrier 2 and the sub-carrier 3 are more frame parts arranged as a support beam 4.1 and 4.2. The upper carrier 2, the sub-carrier 3 and the support beams 4.1 and 4.2 together form the frame-shaped machine frame. 1

In the machine frame 1, a plurality of assemblies and drives are integrated to needling a fiber web. As an example, an assembly 5.2 is shown which has a bed plate 9 which is held on the sub-carrier 3 via a holder 10. The bed plate 9 serves to receive a fibrous web, which is continuously fed to the bed plate 9 via supply means (not shown here). One of the bed plate 9 associated conveyor is also held by the machine frame 1. As another example, the assembly 5.1 is shown having a bed plate 9 associated with the needle bar 6. The needle bar 6 extends over the entire working width of a fibrous web. The needle bar 6 is connected via a plurality of connecting rods 11 with at least one crank drive 7 and is held by the upper carrier 2. At the bottom of the needle bar 6, a needle board with a plurality of needles is attached (not shown here), so that in an oscillating up and down movement of the needle bar 6, the needles penetrate the nonwoven fabric on the bed plate 9. The needle bar 6 is shown in this example as a double bar, such double bars are usually held by a beam support.

At high process speeds 6 high dynamic inertia forces and process forces are generated in particular by the drive and the movement of the needle bar, which leads to a periodic excitation of the machine frame 1. The dynamic forces occurring during needling of a fibrous web thus cause frame vibrations in both frame parts 2 and 3.

In order to change the vibration system of the machine frame 1, the machine frame 1 is assigned a vibration actuator 12. In this embodiment, the vibration actuator 12 is formed by a plurality of force transmitters 13.1 to 13.4. The force transmitter 13.1 to 13.4 are assigned to the support beams 4.1 and 4.2.

As in Fig. 2 is shown, the force transmitter 13.1 to 13.4 are connected to a control device 17. The control device 17 is associated with a vibration sensor 19, which is arranged on the upper support 2 of the machine frame 1. The vibration sensor 19, for example, a piezoelectric accelerometer is preferably arranged in the central region of the machine, where the swing amplitude are greatest. The control device 17 has a microprocessor 18, by means of which a measured value evaluation as well as the generation of control commands and output signals for activation or deactivation of the force transmitters 13.1 to 13.4 takes place.

As from the representations in the FIGS. 1 and 2 shows, the support beams 4.1 and 4.2 are formed in two parts, wherein the parts of the support beams 4.1 and 4.2 respectively associated with the support ends of the frame parts 2 and 3. Each of the frame parts of the support beams 4.1 and 4.2 is assigned in each case one of the force transmitter 13.1 to 13.4. Thus, a total of four force transmitters are provided to initiate a symmetrical tensile and compressive load in the support beams 4.1 and 4.2, whose forces are introduced directly into the upper beam 2 and sub-carrier 3. Thus, the force transmitter 13.1 and 13.3 the support beam 4.1 and the force transmitter 13.2 and 13.4 assigned to the support beam 4.2. In the Fig. 1 and 2 however, the force transmitter 13.4 is not shown.

The machine frame 1 is supported against a hall floor by a plurality of support means 23. The support means 23 are elastically formed as a vibration damper and arranged on the underside of the sub-carrier 3.

At the in Fig. 1 and 2 illustrated embodiment, the needle bar 6 is guided by the crank drives 7 in an oscillating up and down movement during operation during needling a fiber web. In this case, an excitation of the frame vibrations by unbalanced mass forces higher order and by the Nadeleinstichkräfte. In particular, the Nadeleinstichkräfte act gegengleich on the upper carrier 2 and the sub-carrier 3. Parallel effect between the upper carrier 2 and the sub-carrier 3, the force transmitter 13.1 to 13.4. About the force transmitter 13.1 to 13.4 now equal forces are initiated on the upper carrier 2 and the sub-carrier 3. The magnitude of the opposing force generated by the force generator and the time course of the occurrence of the opposing force can be selected so that they initiate a constant line load on the upper beam 2, together with the Nadeleinstichkräften the needle bar. The forces acting on the upper carrier 2 Nadeleinstichkräfte thus no longer lead to a bending, but the up and down movement of the needle bar is received as a rigid body, so that excitation of it is upper carrier 2 excluded in its resonance frequency. The forces introduced into the sub-carriers 3 via the force transmitters 13.1 to 13.2 likewise lead to a vibration excitation, which, however, is absorbed directly by the supporting elements 23. Due to the relatively large masses of the frame parts 2 and 3, only small movement amplitudes occur, but the occurring movement is the same size over the entire machine width.

In the event that the vibration sensor 19 detects the frame vibrations of the upper carrier 2 and thus the operating frequency of the needle bar 6, a Control circuit can be constructed, which can suppress the frame vibrations of the machine frame 1 for any suggestions. Thus, the tension / compression force can be changed in terms of their time occurrence and their size on the force transmitter 13.1 to 13.4.

This in Fig. 1 and 2 illustrated embodiment of the needle machine according to the invention, however, can alternatively also operate such that on the force transmitter 13.1 to 13.4 a constant compressive or tensile force is initiated, so that the upper carrier 2 and the sub-carrier 3 are braced against each other. It is understood that the support beams between the upper and lower beams are connected to each other, so that larger actuator forces can be generated. By the force transmitter 13.1 to 13.4 can be produced in the machine frame, a high compressive residual stress. Thus, the tensile stresses acting on the machine frame 1, in particular in the connection point between the upper support 2 and the support beam 4.1, can be counteracted by the mass and process forces, so that a swelling load prevails in the operating state in the area of the compressive stress. Thus, the strengths of the materials of the machine frame can be optimally utilized. Tensile loads in the joints within the machine frame are avoided, resulting in a significant life extension. In addition, the rigidity of the machine frame 1 is influenced by generating tensile and compressive stresses, as the machine frame as a whole has a higher natural frequency. This also advantageous resonance phenomena in the operation of the needle machine can be avoided.

In Fig. 3 a further embodiment of a needle machine according to the invention is shown schematically in a front view. The embodiment according to Fig. 3 is essentially identical to the embodiment according to Fig. 1 and 2 , so that reference is made to the above description and only the differences will be explained at this point.

At the in Fig. 3 illustrated embodiment of the needle machine is provided as a vibration actuator 12, a mass oscillator 14. The mass oscillator 14 is arranged on an upper side of the upper carrier 2. The mass oscillator 14 is formed in this embodiment by a movable counterweight 15 and a counterweight 15 associated drive means 16. Here, the counterweight 15 is reciprocated by the drive means 16 oscillating in the vertical direction and forth. As drive means 16, for example, hydraulic cylinders, electric linear drives or piezo stacks can be used.

The drive means 16 is connected to a control device 17. The control device 17 is coupled to a vibration sensor 19, which is arranged on the upper carrier 2. Within the control device 17, a microprocessor 18 is provided for measured value evaluation.

The drive means 16 is activated via the control device 17 and guides the counterweights 15 in an oscillating up and down movement. In this case, a counter force is generated, which is introduced directly into the upper carrier 2 of the machine frame 1. The size of the counterweight 15 and the drive frequency and the drive amplitude of the counterweight 15 are selected such that counteracts an appropriate counterforce to acting on the upper carrier 2 periodic Nadeleinstichkräfte and inertial forces and thus in particular excitation in the natural frequency of the upper carrier 2 is prevented. In order to obtain a matched to the excitation of the upper carrier 2 counter-excitation by the mass oscillator 14, the frame vibration at the Oberträger 2 measured by the sensor 19 in particular the acceleration of the vibration and fed to the control device 17. Within the control device 17, a measured value evaluation, in particular a frequency determination and comparison with stored natural frequencies is carried out via the microprocessor 18, so that an activation or deactivation of the drive means 16 for generating a counter-excitation can take place. By the vibration sensor 19 can be detected in addition to the acceleration and the time course of the frame vibration, so that on the drive means 16 settings of the frequency and the amplitude for moving the counterweight 15 is possible. This can suppress any suggestions from the assembly 5.1 in the machine frame 1.

It should be expressly mentioned at this point that each of the previously shown embodiments or subsequent embodiments may simultaneously comprise a plurality of vibration actuators. That's how it works in Fig. 3 illustrated embodiment also run with multiple parallel mass oscillators. Thus, relatively large opposing forces can be generated by the majority of mass oscillators with relatively small countermeasures. The vibration actuators or the mass oscillators would advantageously be controlled synchronously.

In Fig. 4 a further embodiment of a needle machine according to the invention is shown schematically in a front view. The embodiment according to Fig. 4 is essentially identical to the embodiment according to Fig. 1 and 2 , so that reference is made to the above description and only the differences will be explained at this point.

At the in Fig. 4 illustrated embodiment of the needle machine is also provided as a vibration actuator 12, a mass oscillator 14, which, however, has a passively guided countermass. The mass oscillator 14 is arranged on the upper side of the upper carrier 2. The mass oscillator 14 has in this embodiment, a guide block 21, in which a movable counterweight 15 is guided vertically. The counterweight 15 is associated with a spring 20, through which the counterweight 15 is supported relative to the guide block 16 and thus relative to the upper carrier 2. On the guide block 21, a blocking means 22 is held, which acts on the movable counterweight 12. The blocking means 22 can be controlled via the control device 17, wherein in the activated state the blocking means 20 fixes the counterweight 15 in the guide block 21. In the deactivated state of the blocking means 22, the counterweight 15 is released into the guide block 21.

The control device 17 is connected to a vibration sensor 19, which is arranged to measure the frame vibrations on the upper support 2, in particular at the location of the greatest vibration. Within the control device 17, a microprocessor is provided to perform a measured value evaluation. In this case, for example, the measured values can be adjusted with given natural frequencies of the machine frame in order to activate the mass oscillator 14 before reaching critical operating states. Here, the counterweight 15 is coupled via the spring 20 on the upper carrier 2. In extreme cases, this means that the excitation generated via the assembly 5.1 to the upper carrier 2 can be completely eliminated by the counter-excitation of the mass oscillator 14, so that the upper carrier 2 does not perform any frame vibrations. The amplitude of the countermovement of the counterweight 15 is so great that the spring force of the spring 20 corresponds to the exciting dynamic force resulting from the assembly 5.1 and the resulting force on the upper carrier 2 disappears. The movement of Counterweight 15 is dependent on spring force and on the frame vibrations of the machine frame 1 and not actively changed.

The mass oscillator 14 is activated in this case depending on the measured frame vibration or the working frequency by releasing the blocking of the counterweight or deactivated by blocking the counterweight. Thus, the natural frequencies resulting from the overall system consisting of frame part 2 and mass oscillator 14 remain without any effect. Thus, the mass oscillator 14 is activated only in critical operating conditions.

In Fig. 5 an embodiment of a frame part of the machine frame is shown on the needle machine, which advantageously as the upper carrier, for example in the embodiment according to Fig. 1 could be used. This in Fig. 5 shown frame part 2 is shown schematically in a plan view.

The frame part 2 is designed as a box profile 24, which have on the longitudinal sides of the machine, the side members 25.1 and 25.2. In the box section 24, a vibration actuator 12 is integrated, which consists of a plurality of force generators. The force transmitter 13.1 are integrated into several at a distance in the longitudinal member 25.1. The force transmitter 13.2 are integrated into several in the opposite side member 25.2. Each of the force transmitters 13.1 and 13.2 is controlled via a control device 17 in order to introduce pressure or tensile forces in the respective side members 25.1 and 25.2. Thus, by a periodic control of the force transmitter each of the longitudinal members 25.1 and 25.2 to stimulate counter-vibrations. Now, if the frame part 2 excited by periodic inertial forces and Nadeleinstichskräfte in its natural frequency, can via the activation of the Force transmitter 13.1 and 13.2 a counter-excitation can be applied. This allows frame vibrations in the resonance region of the frame part 2 can be avoided.

Due to the relatively low amplitudes of motion, which are initiated by the force transmitter 13.1 and 13.2 in the longitudinal members 25.1 and 25.2 for generating the counter-excitation, piezoelectric elements, for example in the form of piezo stacks, are particularly suitable as force transmitters. These are preferably biased to pressure to generate periodic compressive forces.

This in Fig. 5 illustrated embodiment can alternatively be used to obtain by static compressive or tensile forces a strain in the frame part 2 to increase the rigidity. Thus, the force transmitters can be activated shortly before reaching a critical operating state via the control device 17 in order to generate a tension in the frame part 2. This increases the rigidity of the frame part 2, so that at the same time the range of the resonance frequency is shifted. The critical operating state can thus be passed through without major frame vibrations in the frame part 2.

In the in the Fig. 1 to 5 Illustrated embodiments is assigned for active vibration control of the machine frame 1 of the needle machine by way of example a vibration actuator as a force transmitter or as a mass oscillator. In principle, other vibration actuators can also be used which can controllably change into the vibration system of the machine frame. In addition, several vibration actuators can also advantageously be arranged simultaneously on one or more frame parts of the machine frame. In this case, the vibration actuators are preferably operated synchronously.

Furthermore, the arrangement of the modules, in particular the assembly with the needle bar within the machine frame is exemplary. Thus, the assembly 5.1 can also be advantageously arranged in a sub-carrier. The vibration actuators shown can also be used advantageously in needle machines in which an oscillatingly driven needle bar is guided both on the upper carrier and an oscillatingly driven second needle bar on the lower carrier.

Likewise, the arrangement and position of the vibration sensors in the exemplary embodiments is exemplary. The vibration sensors are usually arranged in areas of the machines in which the vibration amplitudes are greatest. In the embodiments shown, these areas are likely to be in the middle of the machine.

LIST OF REFERENCE NUMBERS

1

machine frame

2

top carrier

3

subcarrier

4.1,4.2

support beam

5.1, 5.2

module

6

needle beam

7

crank drive

8th

stripper

9

bedplate

10

holder

11

connecting rod

12

Schwingungsaktor

13.1, 13.2, 13.3

force transmitter

14

mass oscillator

15

to ground

16

drive means

17

control device

18

microprocessor

19

vibration sensor

20

feather

21

guide block

22

blocking agent

23

proppant

24

box section

25.1, 25.2

longitudinal beams

Claims (17)

Needle machine for needling a fibrous web with a machine frame (1) composed of several frame parts (2, 3, 4.1, 4.2) for receiving a plurality of assemblies (5.1, 5.2), one of the assemblies (5.1) having at least one oscillatingly driven needle bar (6) and wherein the frame parts (2, 3, 4.1, 4.2) in operation by the assembly (5.1) are excitable to frame vibrations,
characterized in that
at least one separate vibration actuator (12) is provided which acts on one of the frame parts (2, 3, 4.1, 4.2) in order to change the frame vibrations of the frame parts (2, 3, 4.1, 4.2) during operation. Needle machine according to claim 1,
characterized in that
the vibration actuator (12) is controllable by a control device (17) and that the control device (17) is coupled to a vibration sensor (19), which vibration sensor (19) detects the frame vibrations of one of the frame parts (2, 3, 4.1, 4.2) assigned. Needle machine according to claim 2,
characterized in that
the control device (17) has a microprocessor (18), by which measured values of the frame vibrations with stored natural frequencies of the frame parts (2, 3, 4.1, 4.2) are comparable and by which control commands can be generated. Needle machine according to one of claims 1 to 3,
characterized in that
the oscillation actuator (12) is formed by at least one force transmitter (13.1) which is arranged inside one of the frame parts (2, 3, 4.1, 4.2) or between a plurality of frame parts (2, 3, 4.1, 4.2) in order to produce a compressive force and / or or to generate a tensile force. Needle machine according to one of claims 1 to 3,
characterized in that
the oscillation actuator (12) is formed by at least one mass oscillator (14) which is arranged on one of the frame parts (2, 3, 4.1, 4.2) in order to generate vibration excitation acting on the frame parts (2, 3, 4.1, 4.2). Needle machine according to claim 5,
characterized in that
the mass oscillator (14) has a movable countermass (15) and a drive means (16) acting on the counterweight (15), which drive means (16) oscillates the counterweight (15) in a reciprocating motion. Needle machine according to claim 5,
characterized in that
the mass oscillator (14) has a movable countermass (15) and a spring (20), which spring (20) the counterweight (15) relative to the frame part (2) is supported. Needle machine according to claim 6,
characterized in that
the mass oscillator (14) has a blocking means (22) acting on the countermass (15) in order to block the movement of the counterweight (15). Needle machine according to one of claims 1 to 8,
characterized in that
the vibration actuator (12) is arranged on the frame part (2) on which the assembly (5.1) is held with the needle bar (6). Needle machine according to one of claims 1 to 9,
characterized in that
the frame parts by a sub-carrier (3), an upper carrier (2) and a plurality of support beams (4.1, 4.2) is formed, wherein the support beams (4.1, 4.2) hold the upper carrier (29 with a distance above the sub-carrier (3) and to two opposite support ends of the upper carrier (2) are arranged. Needle machine according to claim 10,
characterized in that
the sub-carrier (3) has on a lower side a plurality of elastic support means (23), by which the machine frame (1) is held opposite a hall floor. Method for operating a needle machine, in which a plurality of assemblies are held by a plurality of frame parts of a machine frame, in which at least one needle bar is driven to oscillate in one of the assemblies and in which the frame parts are excited by the assembly to frame vibrations,
characterized in that
at least one separate vibration actuator acts on one of the frame parts and that the active vibration actuator generates a change of the frame vibrations of the frame parts. Method according to claim 12,
characterized in that
the frame vibrations are measured at least on one of the frame parts and that the oscillation actuator is controlled as a function of measured values of the frame vibrations. Method according to one of claims 12 or 13,
characterized in that
the vibration actuator generates a compressive force and / or a tensile force as a force transmitter within one of the frame parts or between a plurality of frame parts. Method according to one of claims 12 or 13,
characterized in that
the vibration actuator generates as a mass oscillator on one of the frame parts an acting on the frame parts vibration excitation. Method according to claim 15,
characterized in that
a counterweight of the mass oscillator is actively guided, wherein a frequency and an amplitude of the movement of the counterweight is adjusted. Method according to claim 15,
characterized in that
a counterweight of the mass oscillator is passively guided, wherein a frequency and an amplitude of the movement of the counterweight is determined by a spring.

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