EP4382652A1 - Needling machine and method for equipping and operating same - Google Patents

Abstract

A needle machine (2) according to the invention comprises a needle bar (8) with a plurality of needles (10), a hold-down device (22) for holding down and a support device (26) for supporting the fabric (4), and a monitoring device (41, 42) which is designed to monitor the positioning of the plurality of needles (10) relative to the hold-down device (22) and/or the support device (26). Methods according to the invention comprise monitoring a positioning of the plurality of needles (10) relative to the hold-down device (22) and/or the support device (26) by means of a monitoring device (41, 42) after inserting a needle board (12) into the needle machine (2) or during operation of the needle machine (2).

Description

The present invention relates to a needling machine for needling a textile fabric, such as a fibrous web, nonwoven fabric, woven fabric or scrim. The present invention further relates to a method for equipping and a method for operating such a needling machine.

Needle machines are well known and, for example, in Lünenschloss and Albrecht: "Nonwovens", Georg-Thieme-Verlag Stuttgart, 1982, pp. 122 to 129 or also in Albrecht, Fuchs, Kittelmann: "Nonwovens", Wiley-VCH Verlag Weinheim, 2000, p. 270 ff . described.

Usually, a textile fabric, such as a fiber web, nonwoven fabric, woven fabric or scrim, is fed to a needling machine at an inlet and conveyed in the needling machine in a conveying direction to a needling zone. In the area of the needling zone, at least one needle bar with a needle board attached to it is arranged, which is equipped with a large number of needles for consolidating the textile fabric. The needles consolidate the textile fabric by being pierced into the textile fabric at high frequency in a piercing direction and then pulled out again. The expert is familiar with a wide variety of forms of needling machines, including double-needle machines in which needling is carried out from above and below using two needle bars, or needling machines in which the needle bar is also moved in the conveying direction of the textile fabric during the consolidating process.

There are efforts to increase the density of the needles and thus the needling of the textile fabric in order to optimize the properties of the consolidated fleece. However, there are limits to this density of the needles due to shape and position tolerances in the manufacture and assembly of the needles, needle boards, hold-down and stitch plates and the resulting increased risk of collision between the needles and the hold-down or stitch plates. In the event of a collision, the needles could break, which is an unacceptable risk in many applications. In addition, contact between the rapidly moving needles and hold-down and stitch plates can lead to increased wear.

It is an object of the present invention to provide a needle machine and a method for equipping and a method for operating such a needle machine, which enable a high level of operational reliability and at the same time a high needle density.

This object is solved by the subject matter of independent claims 1 and 13 and 14, respectively. Advantageous embodiments are the subject matter of the dependent claims.

A needling machine according to the invention for needling a textile fabric comprises a needle bar with a plurality of needles for compacting the textile fabric in a needling zone of the needling machine, a hold-down device for holding down the textile fabric in the needling zone, wherein the hold-down device has a plurality of through-openings for the plurality of needles, a support device for supporting the textile fabric in the needling zone, wherein the support device has a plurality of through-openings for the plurality of needles, and a monitoring device which is designed to monitor the positioning of the plurality of needles relative to the hold-down device and/or the support device.

In this way, a needle machine is provided in which the positioning of the plurality of needles relative to the hold-down device and/or the support device can be monitored, whereby incorrect positioning of one or more needles can be detected and corrected even when the needle density is high. Incorrect positioning of needles could lead to these needles coming into contact with the hold-down device and/or support device during operation of the needle machine, which in turn could result in increased wear or even needle or wire breakage. The risk increases with increasing needle density. The monitoring device can counteract this and increase operational reliability.

Generally within the scope of the invention, "hold-down device and/or support device" herein means only the hold-down device if the monitoring device is set up to monitor the positioning of the plurality of needles relative to the hold-down device, or only the support device is meant if the monitoring device is set up to monitor the positioning of the plurality of needles relative to the support device, or the hold-down device and the support device are meant when the monitoring device is arranged to monitor the positioning of the plurality of needles relative to the hold-down device and the support device.

A gap can be formed between the holding-down device and the support device for the textile fabric to pass through the needling zone. The textile fabric passes through the needling zone in a conveying direction and is received in the needling zone between the holding-down device and the support device. The holding-down device and the support device are therefore preferably arranged one above the other in a direction perpendicular to the conveying direction.

In all embodiments, the needling zone preferably extends over a range of 20 cm to 200 cm, more preferably 25 cm to 100 cm, in the conveying direction. In all embodiments, the needling zone preferably extends over a range of 200 cm to 500 cm, more preferably 250 cm to 400 cm, transversely to the conveying direction.

The needle bar can perform an oscillating lifting movement that has at least one component in a piercing direction perpendicular to the conveying direction. This allows the plurality of needles to penetrate into the textile fabric and be pulled out of it again. It is also conceivable that the plurality of needles has a movement component in the conveying direction, so that the needles are moved with the textile fabric in the conveying direction while they are in engagement with it. By superimposing the lifting movement in the piercing direction and the movement in the conveying direction, the needle tips of the plurality of needles can describe an elliptical or circular movement path.

The needle machine can in principle also have more than one needle bar, whereby the needle bars can be arranged in a known manner one behind the other in the conveying direction and/or next to one another transversely to the conveying direction and transversely to the piercing direction. The features described here apply analogously to a plurality of needle bars.

To drive the needle bar, the needle machine can comprise a drive device that is designed to set the at least one needle bar into at least one oscillating lifting movement. For example, the drive device comprises a drive shaft on which a connecting rod is eccentrically mounted, which in turn is connected to the at least one needle bar, in particular is connected in an articulated manner.

In order for the plurality of needles to penetrate the textile fabric, at least the holding-down device usually has through-openings for the needles. Furthermore, the support device also has through-openings for the needles, for example if the plurality of needles are to penetrate the textile fabric or the textile fabric is needled from above and below. It is understood that as the needle density increases, the free space of the plurality of needles in the through-openings is reduced and the risk of contact between the needles and the holding-down device and/or the support device increases.

Monitoring the positioning of the plurality of needles relative to the hold-down device and/or the support device can include determining the position of the plurality of needles relative to the hold-down device and/or the support device. However, it can be sufficient to determine whether the plurality of needles has a positioning that is correct or not correct. For example, the positioning of each needle can be correct as long as the needle passes through the through openings in the hold-down device and/or the support device, and not correct as soon as the needle contacts the hold-down device and/or the support device. Determining an exact position of each needle is not necessary for this, so that the monitoring device can be designed simply. In principle, positioning the plurality of needles in a transverse direction perpendicular to the conveying direction and perpendicular to the piercing direction is particularly relevant, since this is where there is usually the least free space.

In one embodiment, the monitoring device can be designed to detect an approach of a needle from the plurality of needles to the hold-down device and/or the support device. In this way, an approach of a needle to the hold-down device and/or the support device can be responded to at an early stage before contact can even occur. The approach can be determined by reducing the distance of a needle from the hold-down device and/or support device or by a distance of a needle from a predetermined position or a deviation from this predetermined position. An approach in the transverse direction is particularly relevant here.

In a preferred embodiment, the monitoring device is designed to detect contact between a needle of the plurality of needles and the hold-down device and/or the support device. Contact between a needle of the plurality of needles and the hold-down device and/or the support device can be detected relatively easily and reliably, so that the monitoring device can be implemented easily and inexpensively while functioning reliably.

Preferably, the monitoring device is designed to output an optical and/or acoustic and/or electrical signal when a needle of the plurality of needles comes into contact with the hold-down device and/or the support device. The electrical signal can be an analogue or digital signal that can be transmitted to a control unit, for example. This allows an operator of the needle machine to be reliably informed of the contact in order to take appropriate measures.

It is also conceivable that in the event of contact, the needle machine, in particular a lifting movement of the needle bar, is stopped, for example by triggering an emergency stop. Consequently, the monitoring device is then set up to cause the needle machine to stop.

The monitoring device can be an optical monitoring device which, for example, comprises at least one camera, light barrier, laser or the like. An optical monitoring device is particularly suitable for detecting a needle which is arranged in an undesirable area or which leaves this area.

Additionally or alternatively, the monitoring device can be an acoustic monitoring device, which includes, for example, a sound transducer, such as a microphone. When a needle comes into contact with the holding-down device and/or the support device, sound waves are generated which can be detected. In particular, a frequency can be recorded. Furthermore, the monitoring device can, additionally or alternatively, be a vibration monitoring device. When a needle comes into contact with the hold-down device and/or the support device, the latter is at least partially set into vibration, which is detectable.

In a particularly preferred embodiment, the monitoring device is an electrical monitoring device which comprises, for example, a resistance detection device, a conductive detection device, an inductive detection device or a capacitive detection device. The electrical monitoring device preferably uses low voltage, in particular a voltage of a maximum of 25 V, more preferably a maximum of 10 V. This makes the monitoring device as safe as possible for the operator. In one embodiment, the hold-down and/or support device can be supplied with a digitally coded signal and the monitoring device is set up to evaluate the signal. For example, the signal can be characteristic of a specific element or a specific section of the hold-down and/or support device.

A conductive detection device and a resistance detection device are particularly suitable for detecting contact of a needle from the plurality of needles with the hold-down device and/or the support device. An inductive or capacitive detection device is particularly suitable for detecting an approach of a needle from the plurality of needles to the hold-down device and/or the support device.

The electrical monitoring device is preferably designed such that when a needle from the plurality of needles comes into contact with the hold-down device and/or the support device, an electrical circuit comprising a voltage source is closed. The plurality of needles and the hold-down device and/or the support device are designed to be at least partially electrically conductive for this purpose. In this way, when a needle comes into contact with the hold-down device and/or the support device, an electrical signal is automatically generated, which can be used for the optical and/or acoustic signal or digitally encoded, for example.

In a first embodiment, each of the needles of the plurality of needles is electrically connected to a ground or the voltage source, in particular to the negative pole of the voltage source. In addition, the holding-down device or the support device be electrically connected to the voltage source. If one of the many needles then contacts the one from the holding-down device and support device that is connected to the voltage source, the circuit is closed and an electric current flows. However, it is also conceivable that, for example, only one needle from a group of needles, for example a needle module, is connected to the voltage source. In this way, it can be concluded from one needle that the entire group is incorrectly positioned.

In the first embodiment, each needle can be individually connected to the voltage source. To do this, the individual needles would have to be stored in the needle board in an electrically insulated manner from one another and individually connected to the voltage source, which is possible, for example, using conductor tracks. However, groups of needles from the plurality of needles are preferably connected to a common electrically conductive contact element, which in turn is electrically conductively connected to the voltage source. Each group of needles comprises a plurality of needles. This reduces the effort and the required installation space.

For example, each needle of the plurality of needles has a tip and a head opposite the tip. At least one electrically conductive contact element is provided on the needle bar or needle board and the plurality of needles is attached to the needle bar or needle board such that the heads of the needles are in contact with the at least one conductive contact element.

In general, the needles are preferably arranged in needle modules, each needle module having a module carrier and a plurality of needles. The plurality of needles is connected to the module carrier in a head-side section, for example injected into it, so that the tips of the plurality of needles protrude in one direction from the module carrier. The module carrier is preferably made of a non-conductor, in particular plastic. Each needle module can have a single longitudinal row of needles or several longitudinal rows of needles. In order to enable electrical contact, the heads of the plurality of needles are preferably also exposed or protrude from the module carrier, which is particularly relevant for the first embodiment of the monitoring device.

The needle modules can in turn be accommodated in recesses or supports of at least one needle board and secured there. Preferably, several needle modules are arranged one behind the other in the transverse direction, with the rows of needles of the needle modules aligned in the conveying direction. The needle modules can be displaced in the recesses or supports and can be fixed in the desired position, e.g. clamped. Each needle board is in turn fixed to the needle bar. In the first embodiment of the monitoring device, the at least one electrically conductive contact element can be inserted into the recess or the support of the needle board or formed integrally with them, so that it is in contact with the needles of inserted needle modules.

The arrangement of the needles in needle modules has several advantages. The needle modules can be arranged so that they can be moved in the needle board, which allows the stitch pattern and the needle board equipment to be designed variably. In addition, the needle modules can be aligned relative to the hold-down device and the support device in order to avoid contact with them. In addition, the needle modules can be arranged so close to one another that there is no space between individual needle modules.

In a second embodiment, the hold-down device and the support device are each at least partially electrically conductive and are electrically connected to the voltage source. Each needle is preferably electrically conductive. In this case, the plurality of needles does not have to be separately connected to the ground or the voltage source. Rather, a needle that contacts the hold-down device and the support device closes the circuit and an electrical current flows. Electrical contact between the hold-down device and the support device and the voltage source is generally easier and more reliable to implement than contact between the plurality of needles.

In order to enable a high needle density, it is preferred that the holding-down device and the support device each comprise, independently of one another, a plurality of wires for holding down or supporting the textile fabric. As a result, the needles of the plurality of needles can be arranged at a small distance from one another, while the wires can extend between the needles in order to fulfill their holding-down or support function. For this purpose, it is also advantageous if the The plurality of wires of the hold-down device are arranged in the needling zone in a plane that is parallel to the conveying direction and the transverse direction. It is also advantageous for the plurality of wires of the support device to be arranged in the needling zone in a plane that is parallel to the conveying direction and the transverse direction or parallel to the plane of the plurality of wires of the hold-down device. Through openings for the plurality of needles are formed between the wires of the hold-down device and through openings for the plurality of needles are also formed between the wires of the support device.

In order to achieve the simplest possible structure, the wires of the plurality of wires are preferably mounted in such a way that they are immobile in the conveying direction of the needle machine. For example, each wire has two ends that are fixed in the needle machine. When the needle machine is in operation, the plurality of wires are preferably arranged in a stationary manner.

To form the electrical monitoring device, each wire of the plurality of wires of the hold-down device and/or the support device can be connected to a voltage source, as described above. This can be one and the same voltage source for all wires of the hold-down device and the support device, a voltage source for the wires of the hold-down device and for the wires of the support device, or several voltage sources for each group of wires of the hold-down device and/or the support device.

In all embodiments, the wires are preferably electrically conductive, preferably as metal wires. The wires can be stretched in such a way that they are electrically insulated from one another.

The plurality of wires are preferably arranged parallel to one another and parallel to the conveying direction of the needle machine in the needling zone and are spaced apart from one another in the transverse direction. Consequently, a passage opening for the needles is formed between every two adjacent wires. By aligning the wires parallel to the conveying direction, the passage openings also extend parallel to the conveying direction, so that the plurality of needles can have a movement component in the conveying direction. The majority of wires can also be aligned at an angle to the conveying direction.

When the plurality of needles oscillate, the needles each pass between two adjacent wires of the plurality of wires. In other words, when the plurality of needles is in a lowered state, each needle is arranged in a passage opening between two wires.

In a preferred embodiment, the needles are arranged in rows, for example in the needle modules described above, wherein the rows of needles are aligned parallel to an extension direction of the plurality of wires. Preferably, each row of needles then enters between two adjacent wires of the plurality of wires. The division of the rows of needles preferably corresponds to the division of the plurality of wires. However, it would also be conceivable, for example, to omit individual rows or modules of needles.

In all embodiments, a pitch of the plurality of wires is preferably between 1.4 mm and 4 mm, more preferably between 1.8 mm and 3.2 mm, even more preferably between 2.2 mm and 2.8 mm.

Preferably, the majority of wires have a diameter of between 0.4 mm and 2 mm, preferably between 0.5 mm and 1.5 mm, more preferably between 0.6 mm and 1.2 mm. The small diameters of the wires promote a high needle density, thus a particularly tight stitch pattern and a particularly uniformly solidified end product.

In a preferred embodiment, the needles are arranged in a density of at least 500 needles/dm ² , preferably at least 1,000 needles/dm ² , more preferably at least 1,500 needles/dm ² . Such high needle densities lead to a particularly uniform stitch pattern in the solidified end product.

The plurality of needles has a diameter at the needle head that is preferably between 1.0 mm and 2.0 mm, more preferably between 1.2 mm and 1.8 mm. The plurality of needles has a diameter at the needle tip or in a working area of the needle that is preferably at most between 0.3 mm and 1 mm, more preferably is between 0.4 mm and 0.6 mm. The working area of the needles is the area that penetrates into the textile fabric or between the support and hold-down device. If the needles in the working area have a cross-sectional shape that is not circular, the diameter can be determined using a circle.

In an embodiment in which the pitch of the wires is 2.4 mm, the diameter of the wires is 0.8 mm and the diameter of the needles is 0.5 mm, a clearance of 0.55 mm remains on each side of the needles to the nearest wire. This illustrates the high risk of contact between the needles and the wires and the resulting importance of positioning the needles as precisely as possible relative to the wires.

In a preferred embodiment, each wire of the plurality of wires is assigned an optical display, in particular an LED, to which the wire is electrically connected in such a way that the optical display outputs the optical signal when a needle of the plurality of needles comes into contact with the wire. This applies to all embodiments of the needle machine that comprise a plurality of wires and whose monitoring device is set up to output an optical signal. If each wire is assigned an optical display, contact between a needle and a wire can be easily located because the affected needle is arranged along the wire whose optical display outputs the optical signal, and thus the affected row of needles can be identified. On the other hand, locating an affected needle without such a display would be difficult due to the high number and density of needles. Of course, it would also be possible to assign an optical display to several wires in order to reduce the complexity of the monitoring device and the required installation space.

The monitoring device can also be set up to maintain the output signal, in particular the optical signal, after contact. This allows the affected row of needles to be identified even if the contact is no longer present, for example due to a lifting movement of the needle bar. The monitoring device can comprise a storage device, such as a capacitor, for this purpose. For example, a contact can be stored by means of a transistor circuit that can be activated and deactivated by a control unit. It is also conceivable that the optical display in Connection to another voltage source that maintains the optical signal. For example, an electrical contact can be maintained using the transistor circuit.

• Einsetzen eines Nadelbretts in die Nadelmaschine;
• Bewegen des Nadelbretts zumindest in eine Einstichrichtung, die senkrecht zu einer Förderrichtung der Nadelmaschine in einer Vernadelungszone ausgerichtet ist, wobei die Mehrzahl von Nadeln durch eine Mehrzahl von Durchtrittsöffnungen in einer Niederhaltereinrichtung und/oder einer Stützeinrichtung der Nadelmaschine hindurchtreten; und
• Überwachen einer Positionierung der Mehrzahl von Nadeln relativ zur Niederhaltereinrichtung und/oder Stützeinrichtung mittels einer Überwachungseinrichtung.

In principle, the needle machine and/or the monitoring device can comprise a control unit, such as a programmable logic controller. The control unit can then also comprise the storage device or carry out the corresponding switching, whereby the optical signal is retained when remanence is activated. Furthermore, detected contacts can be passed on to the control unit in analog and/or digital form, for example in the form of an electrical signal provided by the monitoring device. This enables further signals to be output to the operator, e.g. via a human-machine interface of the needle machine, and further analysis,
A method according to the invention for loading a needle machine comprises the following steps:

• Inserting a needle board into the needle machine;
• Moving the needle board at least in a piercing direction which is aligned perpendicular to a conveying direction of the needle machine in a needling zone, wherein the plurality of needles pass through a plurality of passage openings in a hold-down device and/or a support device of the needle machine; and
• Monitoring a positioning of the plurality of needles relative to the hold-down device and/or support device by means of a monitoring device.

In this way, a method is provided in which the positioning of the plurality of needles relative to the hold-down device and/or the support device can be monitored, whereby incorrect positioning of one or more needles can be detected and corrected even when the needle density is high. Incorrect positioning of needles can lead to contact between these needles and the hold-down device and/or the support device during operation of the needle machine, which in turn can result in increased wear or even needle or wire breakage. The risk increases with higher needle density. Thanks to the monitoring by the monitoring device, this can be counteracted and operational reliability increased.

In principle, the method can be used to equip the needle machine according to the invention described here. All features and advantages described with regard to the needle machine therefore apply analogously to the method and vice versa.

The needle board is preferably equipped with a plurality of needle modules, each of which comprises a plurality of needles. Preferably, the plurality of needle modules is already secured to the needle board when inserted, and the needle board is secured to the needle bar after insertion. In this state, the plurality of needles should be correctly positioned. Before inserting the needle board into the needle machine, the method can include inserting the plurality of needle modules into the needle board. To do this, several needle modules can be inserted one after the other in the transverse direction into a recess or a carrier of the needle board. The needle modules can be inserted into the needle board outside the needle machine.

The needle board can be moved in the direction of penetration as part of the setting up or loading of the needle machine before it is actually operated. In particular, single or a few strokes of the needle bar can be carried out in order to check the alignment of the large number of needles or the majority of needle modules. This allows immediate intervention and, if necessary, the alignment can be corrected before the needle machine starts operating and damage can occur.

• Bewegen eines textilen Flächengebildes in einer Förderrichtung durch eine Vernadelungszone der Nadelmaschine, wobei das textile Flächengebilde in der Vernadelungszone zwischen einer Stützeinrichtung und einer Niederhaltereinrichtung aufgenommen ist;
• Verdichten des textilen Flächengebildes durch oszillierendes Bewegen einer Vielzahl von Nadeln zumindest in eine Einstichrichtung, die senkrecht zu einer Förderrichtung der Nadelmaschine in einer Vernadelungszone ausgerichtet ist, die Vielzahl von Nadeln durch eine Mehrzahl von Durchtrittsöffnungen in der Niederhaltereinrichtung und/oder der Stützeinrichtung hindurchtritt;
• Überwachen einer Positionierung der Vielzahl von Nadeln relativ zur Niederhaltereinrichtung und/oder Stützeinrichtung mittels einer Überwachungseinrichtung.

A method according to the invention for operating a needle machine comprises the following steps:

• Moving a textile fabric in a conveying direction through a needling zone of the needle machine, wherein the textile fabric is received in the needling zone between a support device and a hold-down device;
• Compacting the textile fabric by oscillatingly moving a plurality of needles at least in one piercing direction which is aligned perpendicular to a conveying direction of the needling machine in a needling zone, the plurality of needles passing through a plurality of passage openings in the hold-down device and/or the support device;
• Monitoring a positioning of the plurality of needles relative to the hold-down device and/or support device by means of a monitoring device.

In this way, a method is provided in which the positioning of the plurality of needles relative to the hold-down device and/or the support device can be monitored, whereby incorrect positioning of one or more needles can be detected and corrected even when the needle density is high. Incorrect positioning of needles can lead to contact between these needles and the hold-down device and/or the support device during operation of the needle machine, which in turn can result in increased wear or even needle or wire breakage. The risk increases with higher needle density. Thanks to the monitoring by the monitoring device, this can be counteracted and operational reliability increased.

In principle, the method can be used to operate the needle machine according to the invention described herein. All features and advantages described with regard to the needle machine therefore apply analogously to the method and vice versa.

In both methods, monitoring the positioning of the plurality of needles preferably comprises detecting a contact between a needle of the plurality of needles and the hold-down device and/or the support device. For example, an electrical circuit is closed upon contact. The methods can then further comprise outputting the optical and/or acoustic and/or electrical signal, as described with respect to the electrical monitoring device. The electrical signal can be an analog or digital signal, which can be transmitted to the control unit, for example.

Fig. 1

zeigt eine schematische Seitenansicht der wesentlichen Komponenten einer Nadelmaschine;

Fig. 2

zeigt einen Ausschnitt der Vernadelungszone der Nadelmaschine nach Fig. 1 in perspektivischer Ansicht;

Fig. 3a

zeigt schematisch eine erste Ausführungsform einer Überwachungseinrichtung der Nadelmaschine nach Fig. 1 und 2 in perspektivischer Ansicht;

Fig. 3b

zeigt einen Schaltplan der Überwachungseinrichtung nach Fig. 3a;

Fig. 4a

zeigt schematisch eine zweite Ausführungsform einer Überwachungseinrichtung der Nadelmaschine nach Fig. 1 und 2 in perspektivischer Ansicht;

Fig. 4b

zeigt einen Schaltplan der Überwachungseinrichtung nach Fig. 4a; und

Fig. 5

zeigt eine Detailansicht eines Ausschnitts der Überwachungseinrichtung.

Further features and advantages of the present invention will become apparent from the following description with reference to the drawings.

Fig.1

shows a schematic side view of the essential components of a needle machine;

Fig.2

shows a section of the needling zone of the needle machine after Fig.1 in perspective view;

Fig. 3a

shows schematically a first embodiment of a monitoring device of the needle machine according to Fig.1 and 2 in perspective view;

Fig. 3b

shows a circuit diagram of the monitoring device according to Fig. 3a ;

Fig. 4a

shows schematically a second embodiment of a monitoring device of the needle machine according to Fig.1 and 2 in perspective view;

Fig. 4b

shows a circuit diagram of the monitoring device according to Fig. 4a ; and

Fig.5

shows a detailed view of a section of the monitoring device.

In Fig.1 the essential components of a needling machine 2 are shown schematically in a side view. Basically, in the needling machine 2, a textile fabric 4, such as a fiber web, a nonwoven fabric, a woven fabric or a scrim, is conveyed in a conveying direction F through a needling zone 6 in which the textile fabric 4 is consolidated. For this purpose, the needling machine 2 comprises at least one needle bar 8 with a plurality of needles 10. For example, a needle board 12 can be equipped with the plurality of needles 10 and fixed to the needle bar 8. Optionally, the needling machine 2 can comprise a plurality of needle bars 8a, 8b, 8c, 8d, as shown. The needle bars 8a and 8b are arranged one behind the other in the conveying direction F. In addition, the embodiment shown is a double needle machine in which needling also takes place from below using the needle bars 8c and 8d, which in turn are arranged one behind the other in the conveying direction F. The basic structure of needle machines 2 as well as possible variations thereof are known to the person skilled in the art.

To consolidate the textile fabric 4, the plurality of needles 10 are pierced into the textile fabric 4 at high frequency at least parallel to a piercing direction E and are then pulled out again. For this purpose, the needle bar 8 is set in motion in a known manner by means of a drive device 14. The drive device 14 can comprise a drive shaft 16 on which a connecting rod 18 is eccentrically mounted. The connecting rod 18 in turn is connected to the needle bar 8, preferably connected in an articulated manner. If several needle bars 8a, 8b are provided, these can be connected by means of a bridge 20 to which the connecting rod 18 is connected.

By appropriately designing the drive device 14 and/or guiding the needle bar arrangement 8, 20, a movement path of the plurality of needles 10 can be set during the lifting movement of the needle bar 8. For example, the needles 10 can move up and down exclusively parallel to the piercing direction E. However, it is also possible for this movement to be superimposed with a movement component parallel to the conveying direction F, so that the needles 10 perform an elliptical or circular movement. In particular, the needles 10 then move in the conveying direction F during engagement with the textile fabric 4. Various designs of needle machines that implement the different forms of movement of the needles are known to the person skilled in the art, and the present invention is not limited to a specific one of these designs.

In order to enable the penetration of the plurality of needles 10 into the textile fabric 4 and at the same time to prevent significant amounts of fibers from being pulled out of the textile fabric 4 or the entire textile fabric from being lifted when the needles 10 are pulled out of the fabric 4, the needling machine 2 comprises a holding-down device 22 for holding down the textile fabric 4 in the needling zone 6. The holding-down device 22 has through-openings 24 (see Fig.2 ) through which the needles 10 can pass. A support device 26 for supporting the textile fabric 4 in the needling zone 6 can also have passage openings 28 for the needles 10, for example when the needles 10 of the upper needle bars 8a, 8b completely penetrate the textile fabric 4 or in the case of double-needle machines.

The hold-down device 22 and the support device 26 are described with reference to Fig.2 described in more detail, which shows a section of the needling zone 6 in a detailed view. Basically, the hold-down device 22 and the support device 26 can be designed as hold-down or needle plates with through-openings 24, 28 in the form of round or slot-shaped recesses, as is generally known. In the embodiment shown, the hold-down device 22 comprises a plurality of (upper) wires 30 and the support device 26 comprises a plurality of (lower) wires 32. The plurality of upper wires 30 are preferably arranged in a first plane in the needling zone 6 and the plurality of lower wires 32 are preferably arranged in a second plane in the needling zone 6, which are parallel and spaced apart. is aligned with the first plane. As a result, a gap 34 is formed between the plurality of upper wires 30 and the plurality of lower wires 32, in which the textile fabric 4 is conveyed in the needling zone 6.

The plurality of wires 30, 32 is preferably aligned parallel to the conveying direction F. In a transverse direction Q, the upper wires 30 are spaced apart from one another and the lower wires 32 are spaced apart from one another. As a result, a passage opening 24, 28 for a needle 10 or a row of needles 10 is formed between each two adjacent wires 30, 32 in the transverse direction Q. Due to the extension of the plurality of wires 30, 32 in the conveying direction F, the passage openings 24, 28 allow movement of the needles 10 in the conveying direction F.

The needles 10 are preferably arranged in needle modules 36, each needle module 36 having a module carrier 38 and a plurality of needles 10. The plurality of needles 10 is connected to the module carrier 38 in a head-side section, for example injected into it. The tips 10a of the needles 10 protrude from the module carrier 38 parallel to the piercing direction E. Each needle module 36 preferably has a single row of needles 10, but can also have several longitudinal rows of needles 10. The plurality of needles 10 of all needle modules 36 then form the plurality of needles 10 on the needle bar 8. This applies generally within the scope of the invention.

The needle modules 36 can in turn be accommodated in supports 40 of a needle board 12. Preferably, a plurality of needle modules 36 are arranged one behind the other in the transverse direction Q, so that the rows of needles 10 are aligned in the conveying direction F. The needle modules 36 can be inserted into the support 40 in the transverse direction Q and can be displaced relative to one another there for alignment with respect to the hold-down device 22 and the support device 26. Before the needle machine 2 is operated, the needle modules 36 are fixed in the supports 40. Each needle board 12 can have a plurality of rows of needle modules in supports 40, which are arranged one behind the other in the conveying direction F, as in Fig.1 shown.

The needle machine 2 further comprises a monitoring device 41, 42 which is designed to monitor the positioning of the plurality of needles 10 relative to the hold-down device 22 and/or the support device 26. The monitoring device 41 can be, for example, an optical monitoring device 41 which is designed to optically monitor the positioning of the plurality of needles 10 in the needling zone 6, as in Fig.1 indicated. For this purpose, the monitoring device 41 can comprise a camera, a laser, a light barrier or the like. However, the monitoring device is preferably designed as an electrical monitoring device 42 and is in particular designed to detect contact between a needle 10 of the plurality of needles 10 and the hold-down device 22 and/or the support device 26.

The electrical monitoring device 42 is described below by way of example using a first embodiment according to Fig. 3a, 3b and by means of a second embodiment according to Fig. 4a, 4b described. In the Fig. 3a and 4a For the sake of clarity, only a few wires 30, 32 and a few needle modules 36 are shown as representatives of the previously described structure of the needling machine 2 in the needling zone 6. The principle explained therein can be scaled as desired. It goes without saying that the described features and advantages can also be transferred to embodiments of the needling machine 2 in which the hold-down device 22 and the support device 26 are not formed by wires 30, 32.

In the Fig. 3a and 3b The arrangement shown is equally applicable to the holding-down device 22 and to the support device 26. According to the first embodiment, each needle 10 of the plurality of needles 10 is electrically connected to a voltage source 44. In addition, the holding-down device 22 or the support device 26 is electrically connected to the voltage source 44. If a needle 10 of the plurality of needles 10 contacts the holding-down or support device 22, 26, the circuit is closed and an electric current flows.

More precisely, each wire 30a, 30b, 30c of the hold-down device 22 or each wire 32a, 32b, 32c of the support device 26 is preferably connected to the voltage source 44. In addition, each needle module 36a, 36b, 36c is connected to the voltage source 44. The heads 10b of the needles 10 can be exposed or protrude from the module carrier 38 and touch an electrically conductive contact element 46, which in turn is connected to the voltage source 44. The contact element 46 can, for example, be inserted into the carriers 40 on the needle board 12 or be formed integrally with them. Preferably, for each carrier 40 and thus at least one contact element 46 is provided for each row of needle modules 36. In the case shown, the needle 10c touches the wire 30a, 32a, for example because it is bent, and thereby closes the circuit.

In principle, the monitoring device 41, 42 can be set up to emit an optical and/or acoustic signal when a needle 10 comes into contact with the hold-down device 22 and/or the support device 26. For this purpose, the monitoring device 41, 42 can comprise an optical display 48, for example in the form of an LED. In the embodiment shown, each wire 30a, 30b, 30c or 32a, 32b, 32c is assigned an LED 48a, 48b, 48c. If the circuit is closed on a wire, here on wire 30a, 32a, the corresponding LED 48a lights up and thereby emits the optical signal. The operator of the needle machine 2 can thus determine which wire is in contact with one or more needles 10, for example due to a defective needle 10 or incorrect alignment of the needle 10, and thus locate the corresponding needle(s).

In Fig. 3b the needle modules 36a, 36b, 36c are shown as equivalent resistance. According to the circuit diagram in Fig. 3b Furthermore, each LED 48a, 48b, 48c can be assigned a series resistor 50a, 50b, 50c.

According to the second embodiment, the holding-down device 22 and the support device 26 are each connected to the voltage source 44. In this embodiment, the plurality of needles 10 does not have to be separately connected to the voltage source 44. The heads 10b of the needles 10 can therefore also be completely accommodated in the module carrier 38. If a needle 10 of the plurality of needles 10 contacts the holding-down device 22 and the support device 26, it thereby closes the circuit and an electric current flows.

More specifically, each wire 30a, 30b, 30c of the plurality of wires 30 of the hold-down device 22 and each wire 32a, 32b, 32c of the plurality of wires 32 of the support device 26 is preferably connected to the voltage source 44. In the case shown, the needle 10c, for example, touches the wire 30c and the wire 32c and thereby closes the circuit.

An optical display 48 can also be provided in the second embodiment, whereby here each upper wire 30a, 30b, 30c of the hold-down device 22 is assigned an LED 48a, 48b, 48c and each lower wire 32a, 32b, 32c of the support device 26 is assigned an LED 48d, 48e, 48f. The LEDs 48c and 48f would therefore emit an optical signal. It would also be conceivable that a needle 10c is bent or a needle module 36 is misaligned in such a way that the needle 10c contacts the wire 30c of the hold-down device 22 and the wire 32b of the support device 26. This would also be apparent to the operator through the LEDs 48c and 48e then lighting up.

In the circuit diagram according to Fig. 4b the needle modules 36a, 36b, 36c are represented by equivalent resistors, on both sides of which the upper wires 30 and lower wires 32 extend. Each LED 48a-f can be assigned a series resistor 50a-f.

In Fig.5 is a detailed view of the hold-down device 22 and the support device 26 in the area of an inlet 52 of the textile fabric 4 (see Fig.1 ). The needle machine 2 could be designed analogously at an outlet 54. At the inlet 52 and at the outlet 54, the majority of wires 30 of the hold-down device 22 are deflected upwards and the majority of wires 32 of the support device 26 are deflected downwards. In the area of the inlet 52, the majority of upper wires 30 and the majority of lower wires 32 increasingly approach one another in the conveying direction F in order to form the intermediate space 34 for receiving the textile fabric 4. The majority of wires 30, 32 can be guided essentially arbitrarily outside the inlet 52 and the outlet 54, so that more installation space is available, for example for a tensioning device 56 of the wires 30, 32.

The monitoring device 41, 42 can comprise one or more circuit boards 58, one of which is described by way of example. As shown, several wires 32a-h of the support device 26 can run to a circuit board 58 and can be electrically connected there to an LED 48 each. In addition, the voltage source 44 can be connected to the wires 32a-h via the circuit board 58. It is also conceivable that further control and/or evaluation electronics are arranged on the circuit board 58, for example to count the number of contacts of needles 10 with a wire 32a-h assigned to the respective circuit board 58 or to check for a contact of a needle 10 with one of the Wires 32a-h maintain the optical signal of the respective LED 48, even if the contact is not maintained.

Further embodiments within the scope of the invention will be apparent to those skilled in the art based on the description of preferred embodiments contained herein.

Claims (15)

Needle machine (2) for needling a textile fabric (4), the needle machine (2) comprising: a needle bar (8) with a plurality of needles (10) for compacting the textile fabric (4) in a needling zone (6) of the needling machine (2); a hold-down device (22) for holding down the textile fabric (4) in the needling zone (6), wherein the hold-down device (22) has a plurality of passage openings (24) for the plurality of needles (10); a support device (26) for supporting the textile fabric (4) in the needling zone (6), the support device (22) having a plurality of passage openings (28) for the plurality of needles (10); and a monitoring device (41, 42) which is arranged to monitor the positioning of the plurality of needles (10) relative to the hold-down device (22) and/or the support device (26). Needle machine (2) according to claim 1, characterized in that the monitoring device (41, 42) is designed to detect a contact between a needle (10) of the plurality of needles (10) and the hold-down device (22) and/or the support device (26). Needle machine (2) according to claim 2, characterized in that the monitoring device (41, 42) is designed to output an optical, an acoustic and/or an electrical signal when a contact is detected, wherein the electrical signal is preferably an analogue or digital signal. Needle machine (2) according to one of claims 1 to 3, characterized in that the monitoring device (41, 42) is an electrical monitoring device (42), which preferably comprises a resistance detection device, a conductive Detection device, an inductive detection device or a capacitive detection device. Needle machine (2) according to claim 4, characterized in that the monitoring device (42) is designed such that when a needle (10) of the plurality of needles (10) comes into contact with the hold-down device (22) and/or the support device (26), an electric circuit comprising a voltage source (44) is closed. Needle machine (2) according to claim 5, characterized in that each needle of the plurality of needles (10) is electrically conductively connected to a ground or the voltage source (44). Needle machine (2) according to claim 6, characterized in that a group of needles (10) of the plurality of needles (10) is connected to a common, electrically conductive contact element (46) which is electrically conductively connected to the ground or the voltage source (44). Needle machine (2) according to claim 6, characterized in that the hold-down device (22) and the support device (26) are designed to be electrically conductive and are each electrically conductively connected to the voltage source (44). Needle machine (2) according to one of claims 1 to 3, characterized in that the monitoring device (41, 42) is an optical monitoring device (41). Needle machine (2) according to one of the preceding claims, characterized in that the hold-down device (22) and/or the support device (26) each comprise a plurality of wires (30, 32) for holding down or supporting the textile fabric (4), wherein the passage openings (24, 28) for the plurality of needles (10) are formed between the wires (30, 32) of the plurality of wires (30, 32). Needle machine (2) according to claim 10 in dependence on claim 3, characterized in that each wire (30, 32) of the plurality of wires (30, 32) is assigned an optical display (48), in particular an LED, to which the wire (30, 32) is electrically conductively connected such that the optical display (48) outputs the optical signal when a needle of the plurality of needles (10) comes into contact with the wire (30, 32). Needle machine (2) according to claim 11, characterized in that the monitoring device (41, 42) is arranged to maintain the optical signal after the contact. Method for loading a needle machine (2) comprising the following steps: Inserting a needle board (12) into the needle machine (2); Moving the needle board (12) at least in one piercing direction (E) which is aligned perpendicular to a conveying direction (F) of the needle machine (2) in a needling zone (6), wherein the plurality of needles (10) pass through a plurality of through openings (24) in a hold-down device (22) and/or a plurality of through openings (28) in a support device (26) of the needle machine (2); and Monitoring a positioning of the plurality of needles (10) relative to the hold-down device (22) and/or support device (26) by means of a monitoring device (41, 42). Method for operating a needle machine (2) comprising the following steps: Moving a textile fabric (4) in a conveying direction (F) through a needling zone (6) of the needle machine (2), wherein the textile fabric (4) is received in the needling zone (6) between a support device (26) and a hold-down device (22); Compacting the textile fabric (4) by oscillatingly moving a plurality of needles (10) at least in one piercing direction (E) which is aligned perpendicular to the conveying direction (F) in the needling zone (6), wherein the plurality of needles (10) pass through a plurality of passage openings (24, 28) in the hold-down device (22) and/or in the support device (26); Monitoring a positioning of the plurality of needles (10) relative to the hold-down device (22) and/or to the support device (26) by means of a monitoring device (41, 42). Method according to claim 13 or 14, characterized in that the monitoring comprises detecting a contact between a needle (10) of the plurality of needles (10) and the hold-down device (22) and/or the support device (26) and the method further comprises the following step:
Outputting an acoustic, optical and/or electrical signal by the monitoring device (41, 42) when the monitoring device (41, 42) detects a contact, wherein the electrical signal is preferably an analog or digital signal.

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