Patent Application
20230129064
The present application claims priority to German Patent Application no: 10 2021 005 293.5, filed Oct. 25, 2021, which is incorporated herein by reference in its entirety.
The invention relates to a device for introducing a running material web into a tenter machine, which comprises at least one tiltable cheek. The latter receives the material web and guides it into the tenter machine. In this case, the location of a web edge of the material web is recorded and the tiltable cheek is aligned with the web edge of the material web so that the latter can run directly onto the cheek. For this purpose, a regulator which regulates the position of the cheek to the material web edge location under the influence of an actuator is provided. In order to initiate the desired tilting movement of this at least one cheek, it can be tilted by at least one control element with at least one actuator. This at least one control element engages on the one hand on a fixed frame and on the other hand on the at least one cheek. Measuring means for recording a tilt angle of the at least one cheek are furthermore provided, particularly in order to handle hazardous operating states of the device.
DE 20 2010 014 335 U1 discloses a device of the generic type for introducing a running material web into a tenter machine. This device comprises two tiltable cheeks, which can each be tilted by a control element respectively by means of an actuator. For this purpose, the control element engages on the one hand with a pinion on a rack held on a frame, while an opposite end is respectively connected to one of the cheeks. In this way, the cheeks can be adjusted with a corresponding actuation force while being accurately positioned in their angular location. Limit switches are furthermore provided on the cheeks in order to detect extreme cheek setting angles. These limit switches are actively connected to web running regulation. One of the limit switches is used, for example, for the emergency stop signal generation, in order to shut down the entire tenter machine before the cheek angle enters an unallowed range which could cause damage to the device. This device has widely proven useful in practice and forms the starting point of the present invention.
The object of the invention is to provide a device of the type mentioned in the introduction, which is distinguished by a simpler structure and a reduced mounting and set-up time, with the further possibility of straightforwardly carrying out other adaptations as required during operation in order to make the device more efficient overall.
This object is achieved according to the invention by the following features.
A device according to the invention is used to introduce a running material web into a tenter machine. A running material web is in this case intended to mean a two-dimensional product which is transported in a running direction, particularly in order to be subjected to a processing operation. The running material web may consist of any desired materials, a textile material web preferably being envisaged. A tenter machine, which is not to be regarded as part of the subject matter of the invention, is a machine which receives the running material web at its edge regions and draws it through itself. Such tenter machines have different working widths transversely to the running direction of the running material web, which necessitates the introduction of the running material web into the tenter machine. For this purpose, the device comprises at least one tiltable cheek which receives the material web and correspondingly delivers it to the tenter machine. The reception of the material web itself may in this case be carried out in various ways, pins or clamps being envisaged in particular. This list is only exemplary, however, and should not be regarded as exhaustive. The effect achieved by the tiltability of this cheek by means of the at least one control element with at least one actuator is that the edge of the running material web can be matched to the width of the tenter machine during its running. In this way, the running material web is delivered correctly to the subsequent tenter machine. Since the running material web may under certain circumstances exert a corresponding counter-force on the cheeks due to resilient forces, it is held in or tilted against the desired position by the at least one control element with at least one actuator, which applies the corresponding actuation force for this purpose. The actuator in this case engages on the one hand on a fixed frame of the device and on the other hand on the at least one cheek, in order to be able to support the resilient restoring force of the running material web. Depending on the material properties of the running material web and the delivery thereof, as a function of its web width, and position to the device, the tilt angle of the at least one cheek is tilted by correspondingly driving the at least one actuator. It may in this case occur that the at least one cheek enters an impermissible tilt angle range. This may cause damage to the running material web or damage to the device, or the subsequent tenter machine. For this reason, such operating states must be reliably prevented. For this purpose, the device comprises measuring means for recording the tilt angle of the at least one cheek, with which the angular location of the at least one cheek is recorded. In this case, it is entirely sufficient for the measuring means to record a relative tilt angle of the at least one cheek. Although an absolute angle value therefore cannot be determined, a relative angle, that is to say in particular an angle change, can be determined in this way and converted by suitable calculation operations into corresponding signals. The evaluation of these signals, however, becomes simpler when the measuring means determine an absolute angle so that certain calculation steps can be omitted. In order to shorten the mounting and set-up time and for further adaptation possibilities during ongoing operation of this device, the measuring means comprise angle sensors which record on the one hand an angle between the at least one cheek and the at least one control element, and on the other hand the angle between the frame and the at least one control element. Since the two angle sensors respectively take the at least one control element as a reference for the angle measurement, they may be provided in the region of the at least one control element, preferably on or inside the latter. Additionally provided calculation means then calculate the difference of the two recorded angles, which then corresponds to the cheek angle relative to the frame. In this way, the mounting and set-up of the device are substantially shortened and simplified. Furthermore, the device therefore becomes more compact and costs may be saved. It is, in particular, also possible to adapt the angle monitoring further in relation to extreme cheek setting angles of the cheek during ongoing operation, without the material web having to be stopped for this, or other adaptations being necessary. Since the adaptation of the device to different operating requirements is then carried out substantially more simply, adaptation is thus possible even during operation, in particular when changing the type of material web. The effect achieved in this way is that the tilting range of the at least one cheek can be utilised even better, if the physical properties of the material web allow this. Nevertheless, it is also possible to run more critical material webs, for which the corresponding angle threshold values are then adapted accordingly.
Preferably, at least one of the angle sensors is configured as an analogue sensor. This at least one angle sensor therefore has the potential option of recording the respective angle with a high resolution, so that different operating states of the at least one cheek may readily be detected and assigned.
It is furthermore conceivable to configure at least one of the angle sensors as a digital sensor which can output more than two different angle values. A digital sensor has the advantage that numerical post-processing of the sensor data is possible, which in particular simplifies the calculation means in terms of their structure.
Preferably, the at least one angle sensor can output more than four different angle values, so as to thus allow sensitive angle recording which can be adapted to different operating states.
In order to determine the current operating state of the device from the angle values, or the calculated output value of the calculation means, it is advantageous for the calculated difference to be compared with at least one first threshold value. If this is exceeded, further tilting of the at least one cheek is prevented. This prevents the at least one cheek from being tilted too far and therefore being damaged.
It is furthermore advantageous for the difference calculated by the calculation means to be compared with at least one second threshold value, the at least one cheek being tilted into a location which lies closer to a neutral location when this is exceeded, so that the angle between the cheek and the web running direction is reduced. This is intended to prevent the at least one cheek from being tilted further, for example by a width setting of the tenter machine, and therefore entering a state in which it could be damaged.
Furthermore, it is advantageous for the difference calculated by the calculation means to be compared with at least one third threshold value, an alarm signal being transmitted to the tenter machine when this is exceeded. This generally achieves the effect that the tenter machine is turned off. This may in particular be necessary, for example, if the tenter machine is set further in its width and the cheek cannot be tilted according to a second threshold value in the direction of a neutral location. An advantage of the subject matter of the invention is in this case that the said extraordinary operating states can be recorded by the two angle sensors without a separate sensor being required for each individual operating state.
The said threshold values are compared with the result of the angle measurement so as to generate corresponding signals. Preferably, at least one comparator and/or at least one window comparator is used for the comparison.
In order to increase the operational reliability, it is furthermore advantageous for the device to comprise at least one further sensor, which records the angle between the at least one cheek, on the one hand, and the frame on the other hand. Using this further sensor, the angle sensors together with the calculation means can be double-checked, for example in order to identify failure of the angle sensors or of the calculation means and to react accordingly thereto.
In the simplest case, this further sensor is used for plausibility checking, so that its recorded sensor value is not in general used for determining the operating state.
Lastly, it is advantageous for the angle sensors together with the at least one control element to be accommodated in a common housing. In particular, this simplifies the structure of the device. Lastly, this measure achieves the effect that the entire device becomes less sensitive to interference since long cabled lines outside the housing, through which interference signals can readily be coupled in, are avoided.
Naturally the configurations of the functional components described above can also be combined in any manner in order to fulfil several functions simultaneously.
Other advantages and characteristics of this invention will be explained in the detailed description below with reference to the associated figures that contain several embodiments of this invention. It should however be understood, that the figure is just used to illustrate the invention and does not limit the scope of protection of the invention.
A device 1 according to
Immediately after the splaying devices 5, the running material web 3 is delivered to chains 8 which are guided around deflecting rollers 9. These chains may, in contrast to the representation according to
The location of the cheeks 12 is regulated in such a way that the respective edge 7 of the material web 3 is aligned with the chain 8. For this purpose, edge sensors 52 which record the edge length of the material web 3 and deliver it to a regulator (not represented) are provided. These edge sensors 52 are firmly connected to the cheeks 12, so that they record the edge 7 of the material web 3 relative to the cheek position. In this way, the edge sensors 52 immediately indicate a feed error of the edge 7 relative to the cheeks 12. This feed error is adjusted to the setpoint value 0 by the regulator in order to achieve optimal feed, in particular without distortion, of the material web 2 to the cheeks 12 in the stabilised regulating state.
In order to set each of the cheeks 12, a control element 13 is respectively provided, which is tiltably supported by means of a tilting bearing 14 on the respective cheek 12 and is tiltably supported by means of a tilting bearing on a frame 17. An actuator, the pinion 15 of which meshes with a rack 16 that is fitted on the frame 17 fixed to the machine, is provided in this control element 13. By rotation of the pinion 15, it rolls along the rack 16 so that a pinion shaft is displaced transversely with respect to the web running direction 2. Because of the coupling of the control element 13 to the cheek 12, the latter is thereby tilted in order to adapt an angle of attack of the chain 8 to the web running direction 2.
The specific structure of the control element 13 will be explained in more detail with the aid of
Magnetic strips 30, which cooperate with magnetic sensors 31 that are firmly connected to the housing 18 of the control element 13 and together form angle sensors 32, are arranged on the tilting bearing 14 and on the plate 23. As an alternative, optical sensors may also be used. In this case, the magnetic strips 30 are alternately poled so that, when the control element 13 is tilted, the magnetic sensors 31 supply an AC voltage signal from which the current angular location can be determined by counting the zero crossings. In order to be able to establish the direction of rotation as well, the magnetic strips 30 and/or the magnetic sensors 31 are duplicated, so that the direction of rotation can also be determined with the aid of the phase angle of the zero crossing. Hall sensors are preferably used as magnetic sensors 31.
The signals of the magnetic sensors 31 are delivered via signal paths 43 to an evaluation unit 40, which is likewise located inside the housing 18 of the control element 13 and can be seen in
The evaluation unit 40 will be explained in more detail with the aid of the outline circuit diagram according to
Provided between the regulator 50 and the actuator 19, purely for the purpose of increasing the operational reliability, is an adder 54 which can subtract a constant but adjustable value from the output signal of the regulator 50. In general, that is to say in normal operating states, the adder 54 receives a zero signal at its non-inverting input 55 so that the entire adder 54 is inactive in this operating state and the signal at the output 53 of the regulator 50 is forwarded unchanged via the signal path 41 to the actuator 19.
The magnetic sensors 31 are actively connected via signal amplifiers 60 to a phase detector 61. This phase detector 61 records zero crossings at its inputs 62, including the phase angle of these zero crossings. Depending on which of the two inputs 62 the zero crossing with a positive flank occurs at first, a clock signal is output either on its plus output 63 or on its minus output 64. This indicates that the magnetic sensors 31 have moved forwards by one polarity period either in the plus direction or in the minus direction. In this way, the rotation angle on the one hand of the tilting bearing 14 and on the other hand of the tiltable plate 23 is recorded with a high accuracy. In order to be able to determine the actual rotation angle, the plus output 63 and the minus output 64 are connected to a bidirectional counter 65. This bidirectional counter 65 counts only the flanks of the plus output 63 upwards and of the minus output 64 downwards, so that its counter state is proportional to the angle actually present.
The described circuit parts of the magnetic sensors 31 up to the bidirectional counter 65 are duplicated in order to record on the one hand the rotation angle of the tilting bearing 14 and on the other hand the rotation angle of the tiltable plate 23. They are in principle constructed identically and will therefore not additionally be described in detail. The outputs of the two bidirectional counters are delivered to an adder 66, which records the difference of the two counter states and forms calculation means 66′. This differential angle corresponds to the actual cheek angle to within an additive correction value, which is not important in what follows. It is in principle also conceivable to omit the adder 66 by replacing the two bidirectional counters 65 with a single bidirectional counter 65, which then has two upward counting inputs and two downward counting inputs that are connected to the corresponding phase detectors 61. It has been found that although this measure saves on resources, it entails the risk of counting pulses being lost. This is, in particular, because the counting pulses occur entirely asynchronously and may therefore even occur virtually simultaneously. This leads to undefined states in the counter circuit, which then causes counting pulse losses. Since this is a safety-relevant component which is intended to record the respective angular location of the control element 13 exactly at any instant, this simplification is generally not acceptable.
An output 67 of the adder 66 is compared by means of a comparator 68, 69, 70 with threshold values of threshold value generators 71, 72, 73. The threshold value generators 71, 72, 73 may in the simplest case be potentiometers which output analogue voltages. As the threshold value generators 71, 72, 73, it is however also conceivable to provide a numerical keypad or a communication link via which the data entry to the threshold value generators 71, 72, 73 is made possible by means of a terminal (not represented). In this case, the comparison is carried out insofar as an active signal is output when the value at the output 67 is greater than the respective threshold value. In this way, critical operating states of the cheek 12 are established.
If the value at the output 67 is not greater than each of the threshold values of the threshold value generators 71, 72, 73, the operating state is a normal operating state so that the regulation by means of the regulator 50 can operate by any desired setting of the cheek 12. In this operating state, a zero value is delivered to the adder 54 so that the signal of the regulator at its output 53 is delivered unchanged to the actuator 19 via the signal path 41.
If the signal at the output 67 exceeds the threshold value of the threshold value generator 71, the comparator 68 transmits a signal to the regulator 50, by which the output value of the regulator 50 is kept. If regulation deviations which travel via the signal path 42 to the regulator 50 subsequently occur, the latter will no longer react to these regulation deviations and also the cheek 12 will therefore not be set further by means of the actuator 19. This effect then takes place in such a way that although the regulator 50 can set the cheek 12 in the direction of its neutral position lying parallel to the web running direction 2, it cannot do so in the opposite direction. This avoids the cheek 12, the material web 3 or the subsequent tenter machine from being damaged by excessive tilting of the cheek 12. If the fault which has triggered this exceptional situation is intended to be eliminated by itself, the regulator 50 will reduce its signal at the output 53 so that the limiting action of the comparator 68 is removed. The evaluation unit 40 therefore returns automatically into the normal operating state with self-eliminating faults.
It may occur that the cheeks are tilted further despite the aforementioned limitation, so that the operating state of the entire device 1 may become critical. This occurs particularly if a width setting of the tenter machine is carried out and the limiting effect of the comparator 68 is thereby removed.
For this purpose, the second comparator 69 is provided, which compares the signal at the output 67 with a somewhat higher threshold value. At its output 75, this comparator 69 outputs a signal which is zero in the normal but inactive state, although when the threshold value of the threshold value generator 72 is exceeded it supplies a value predeterminable by a generator 56 to the adder 54. In this way, the output signal of the regulator 50 is reduced by this predetermined value so that the cheek 12 is forced to be tilted back by this value in the direction of the neutral setting. The generator 56 may be produced in a similar way to the threshold value generators 71, 72, 73 or else differently.
In this way, the situation is alleviated after the cheek 12 has been forced to be tilted back in the direction of the neutral location under the effect of the comparator 69.
If the measures—due to the comparator 69—do not also show the required effect, it may be assumed that there is a particularly serious fault which makes it impossible to operate the equipment as a whole. For this purpose, the signal at the output 67 of the adder 66 is compared with a third threshold value in the comparator 70, which, if this threshold value is exceeded, then transmits a highly prioritised signal via the output 75 to the subsequent tenter machine so that the latter is turned off. This state may be removed only by means of the reset 74.
Preferably, the evaluation unit 40 as a whole or parts thereof are produced in the form of a microcontroller. This simplifies the structure of the evaluation unit 40.
Since some of the embodiments of this invention are not shown or described, it should be understood that a great number of changes and modifications of these embodiments is conceivable without departing from the rationale and scope of protection of the invention as defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| DE102021005293 | Oct 2021 | DE | national |
