EP0837829B1 - Optoelectronic sensor and weft yarn measurement and feeding equipment - Google Patents

Description

The invention relates to an optoelectronic sensor device according to the preamble of claim 1 and a Weft thread measuring device according to the preamble of the claim 4th

In an optoelectronic known from GB-C-1 283 528 Sensor device is the cross passage of a spun Fadens detected in a ring spinning machine, the running Thread runs in an opening. The opening is from penetrated by a beam of light, one in an opening wall arranged light source diametrically through the opening onto one opposite receiver throws. In front of the recipient is a Aperture slit provided. The receiver speaks on light variations or the shadow passing through the aperture slit of thread. Interferences such as vibrations, extraneous light and Like. Can cause the receiver to issue an error signal, although the thread has the aperture slit in the scanning zone didn't happen properly.

With weft thread measuring devices, as they are typically for a long time on jet looms to provide the Weft thread is used for control and monitoring exact information of the insertion process of each weft necessary when and that the weft when pulling passes a scan zone. For this purpose there is at least one Trigger sensor provided with one on the illuminated Scanning zone aligned, responsive to light variations Receiver is equipped. Because in practice operational Vibrations, extraneous light and other disturbances affect the receiver also make it respond, is the meaningfulness the signals obtained from the passages of the weft unreliable. In practice, therefore, two closely in the axial direction of the storage body Align arranged receivers to the same scanning zone and from the response of the two receivers in one Differential switching a meaningful signal for the thread passage to derive, which is therefore from interference caused signals can be distinguished because a Interference on both receivers simultaneously and in the same way acts while the thread from the two receivers with one temporal offset is registered. Still works this known scanning sensor with the two receivers from several Reasons not reliable. The recipient area of each The recipient is usually approximately circular. Which with its thread moving relative to the receiver surface Reflection light or its shadow because of the circular shape of the This is because the receiver area is only gradually depicted. In addition is the response sensitivity of the receiver in the peripheral areas the receiver area is weaker than near the center. The signal evaluated in the differential circuit is therefore because of the gradual increase in signals and also gradual signal drop weak and requires considerable Reinforcement effort, but also effective with interference becomes. Furthermore, one is clear in such measurement storage devices aixal back and forth movement of the limit on the trigger side of the thread supply present on the storage body is indispensable, especially when working with thread separation and / or a vivid pattern is woven. This results a thread withdrawal geometry, in which the longitudinal direction of the thread Thread withdrawn from the last turn of the thread supply in the scanning zone between an approximately axial position and one varies approximately in the circumferential direction, each related to the axis of the storage body. At a approximately axial position of the longitudinal direction of the thread in the scanning zone becomes the thread of both receivers at the same time and perceived similarly as to what discrimination also on both receivers simultaneously and in the same way perceived interferences difficult or excluded.

The invention has for its object a simple optoelectronic Sensor device of the type mentioned and to provide a weft measuring storage device in which from the thread passage a strong and meaningful as well easily discriminable against signals from interference Useful signal can be generated. With the measuring storage device the take-off sensor despite varying thread take-off speed, different thread qualities and changing Position of the longitudinal direction of the thread in the scanning zone exact information provide when and that the thread passes the scanning zone.

The term thread generally refers to thread-like ones Substrates such as yarns, threads, threads, threads, wires, Ribbon, film strips and the like

However, complex optoelectronic ones are expressly excluded Sensor devices, the receiver with an illustration or sharpen the object to be scanned and position sensitive detectors, imaging optics with an aperture and high quality circuitry. Such sensor devices are for scanning a thread passage too expensive for itself or in a measurement storage device and expensive and depart from it for other reasons a use from (e.g. WO 89/00215, WO-A-90 06 504, EP-A-0 519 281).

The task is in an optoelectronic sensor device with the features of claim 1 and in a weft measuring memory device with the features of Claim 4 solved.

In the optoelectronic sensor device and in the Weft measuring memory device is a particular advantage when scanning each thread pass an exact, meaningful, powerful and easy from signals useful signal, which can be discriminated from interference, with structurally and in terms of circuit technology low and inexpensive Expenditure. The position of the longitudinal direction of the thread in the scanning zone doesn't matter anymore because the thread is the two aperture slits happens differently in time or geometry, so that the differential evaluation of the response of both Receiver always leads to a clear signal that is clearly different from a signal due to interference, because the interference at both receivers is temporal and is geometrically registered immediately. Furthermore, from a strong modulation in the thread passage in the scanning zone of the signal is achieved because, on the one hand, the less sensitive Edge areas of the receiver surfaces are covered and not come into effect, and on the other hand the thread in each aperture slit (with its reflection light or its shadow) becomes extremely quickly visible at full size. Since the Time taken for the thread to fully image through the slit narrowed area of the receiver surface passes, is extremely short, as is the time to to completely disappear the full figure the signal generated via a differential evaluation strong and frequency components that can be tapped with little amplification, that arise due to interference Signal not present. In summary, it follows from the use of two receivers, two aperture slots and independent of the geometrical arrangement of the diaphragm slots of the position of the longitudinal direction of the thread in the scanning zone, of the strength and frequency of interference, and also largely regardless of dirt, a strong and meaningful Signal from a thread passage that is low circuitry processing can be processed. Simple and inexpensive receivers are used, that respond to light variations. The soft response in itself this receiver is through the aperture slit unexpected when the thread runs properly tightened .. The recipients are close to each other put. This beneficial result is achieved to the highest in modern thread processing systems usual thread speeds guaranteed. There are also more than two recipients conceivable with one aperture slit each.

In the embodiment according to claim 2, the are the response to light variations more responsive Receiver critical peripheral areas of the receiver area covered. But it is also conceivable to make the aperture slit so long how or even longer than the diameter of the receiver surface to train.

In the embodiment according to claim 3, the response of the two receivers in the as a differential circuit designed evaluation circuit generates the useful signal.

In the embodiment according to claim 5, a compact Reach the design of the trigger sensor, the trigger sensor practically independent of the speed variations of the thread moving through the scanning zone and before all regardless of the respective position of the longitudinal direction of the thread is in the scan zone.

The embodiment according to claim is particularly expedient 6. Here it is ensured that the thread from both receivers only in areas restricted by the slits of the receiver surfaces and regardless of the position of the longitudinal direction of the thread temporally and / or geometrically in the scanning zone is perceived differently.

A particularly expedient embodiment is based on claim 7 out. It is useful if the crossbar of the T of the thigh maintains a small distance so that about the geometric configuration of the diaphragm slots Asymmetry in the scanning of the thread results for the Differentiation between useful and interference signal and for a strong useful signal is important.

With the shapes of the aperture slits specified in claim 8 it is ensured that the full light exposure or Shading of the areas of the recipient area very much comes in quickly or stops quickly in order to get you as possible to achieve a strong frequency component for the useful signal.

Diaphragm slots of the same size are advantageous.

The embodiment according to claim 10 is particularly important. With this adjustment of the positions of the diaphragm slots on the possible positions of the longitudinal direction of the thread in the scanning zone it is excluded that the thread of both receivers is geometric or is perceived at the same time.

In the embodiment according to claim 11, a compact, reliable and reliable design of the trigger sensor possible. The holder with its channels, the receivers, the light source and the slit is a simple and component that can be prefabricated inexpensively and with high precision, which can be accommodated cheaply even in tight spaces and can be easily replaced.

In the embodiment according to claim 12, the components summarized in the smallest of spaces.

In the embodiment according to claim 13, the cover plate avoids contamination or dust in the holder arranged components.

The distance dimensioning according to claim 14 has proven to be advantageous proven.

Finally, in the embodiment according to claim 15 respective position of the or the relative position between the Aperture slits adjustable or adjustable.

Fig. 1

eine schematische Draufsicht auf eine Sensorvorrichtung,

Fig. 2A,B

Seitenansichten, teilweise im Schnitt, der Sensorvorrichtung von Fig. 1,

Fig. 3

eine Schemadarstellung einer als Abzugssensor eines Fadenliefergerätes ausgebildeten Sensorvorrichtung,

Fig. 4

eine Auswahl möglicher Formen für die Blendenschlitze, die in den Fig. 1, 3 und 7 benutzt werden können,

Fig. 5A

eine Seitenansicht eines Schußfaden-Meßspeichergeräts,

Fig. 5B

eine zur Fig. 5A gehörige Frontansicht,

Fig. 6

einen Längsschnitt eines Details zu Fig. 5A, und

Fig. 7

eine Druntersicht zu Fig. 6.

Embodiments of the subject matter of the invention are explained with the aid of the drawing. Show it:

Fig. 1

2 shows a schematic top view of a sensor device,

2A, B

Side views, partly in section, of the sensor device of Fig. 1,

Fig. 3

2 shows a schematic representation of a sensor device designed as a take-off sensor of a thread delivery device,

Fig. 4

a selection of possible shapes for the diaphragm slots that can be used in FIGS. 1, 3 and 7,

Figure 5A

2 shows a side view of a weft thread measuring device,

Figure 5B

5A is a front view belonging to FIG. 5A,

Fig. 6

a longitudinal section of a detail of Fig. 5A, and

Fig. 7

a bottom view of Fig. 6.

Fig. 1 illustrates schematically the structure of an optoelectronic Sensor device S for determining the passage one is also transverse to its longitudinal direction D (e.g. in the direction the arrow 1) through a scanning zone 3 moving thread Y. In addition to the movement in the direction of arrow 1 can the thread Y also in the direction of arrow 2, i.e. in its Longitudinal direction D, are moved. The scanning zone S is on spatial area that is at least one light source L is illuminated, and on those in the embodiment shown two receivers R1, R2 with their receiver surfaces 4 and 5 are aligned. Instead of moving towards the receiver R1, R2 offset light source L could either be on the side of the Receiver or on the side opposite the receiver a central light source L 'may be provided. Before the Receiver area 4 or 5 of each receiver R1, R2 is a Aperture slit A1 or A2 is provided in the beam path between the thread Y or the scanning zone 3 and each receiver surface 4 and 5. The two aperture slots A1 and A2 are, for example, of the same size, have the same geometric configuration and a cross-sectional main axis 6 and one each secondary axis 7 lying perpendicular to it. The aperture slots For example, A1, A2 are approximately 1 with a length of approximately 4 mm mm wide. 1 is the aperture slit A2 with its Main axis 6 to that defined by the two receivers R1, R2 Main direction aligned while the aperture slit A1 runs perpendicular to this, with an extension of the aperture slot A2 cuts the aperture slit A1 approximately in the middle. Both aperture slots A1, A2 could be relative to each other also be twisted, but it is important that they are together include an acute angle up to a maximum of 90 °.

2A and 2B illustrate the side views of two Design variants of the sensor device according to FIG. 1. In 2A are the light source L and the two receivers R1, R2 on the same side of the scanning zone 3, under the there is an element 8, either as a reflector or is designed as a light absorber. Between element 8 and an at least partially translucent cover 10 a passage gap is defined for the Y thread. The Light source L and the two receivers R1, R2 are taken into account certain light reflection angle to each other aligned. Both receivers R1, R2 are based on that of the Light source L illuminated scanning zone 3 and aligned reflected by the reflection light. Each receiver R1, R2 is an aperture slit A1, A2, e.g. in an aperture element 9, upstream.

2A works according to the reflection principle, then when the thread Y passes through it light reflected by element 8 according to the outline of the Thread Y shadowed. Each receiver R1, R2 speaks to that Light variation on. Both receivers R1, R2 are connected to an evaluation circuit C (Fig. 2B) connected by the differential principle works and from the difference of photoelectric Response signals of the receiver R1, R2 a useful signal generated.

In contrast, element 8 absorbs the light from the light source L, then the receivers R1, R2 speak to that reflected by the thread Y. Light on.

2B operates according to the Light barrier principle, i.e. the light from the light source L ' passes through the scanning zone 3 and meets the receivers R1, R2, corresponding to the passage of the Y thread the outline of the Y thread.

Assuming that the receivers R1, R2 of Fig. 2A or 2B matched to the light coming from the light source L. are in the absence of the thread Y by the Aperture slots A1, A2 limited area of the receiver surfaces 4, 5 fully loaded with light. In the evaluation circuit C results from the difference of the response signals of both Receiver R1, R2 the value zero or a constant signal value (e.g. a voltage value). The thread Y passes the scanning zone 3 in the direction of arrow 1, then the by the Aperture slit A1 limited area on the receiver surface 4 of the receiver R1 at least partially shadowed, and later also the one limited by the aperture slit A2 Area on the receiver area of the second receiver R2. When the thread Y moves in the direction of the arrow 1 the thread Y has already left the aperture slit A1, while it is still moving over the aperture A2. The Period of time starting with the intersection of the outline of the Thread Y with the aperture slit A1 or A2 until the time on which the outline of the thread Y for the aperture slit A1 or A2 is the largest, is extremely short, what the Advantage of a strong frequency component of the response signal and with a strong modulation. This also applies to that Moving the contour of the thread Y out of the area of the Aperture slit A1 or A2, so that even then a strong Frequency component for an effective modulation arises. That I the thread Y for the two receivers R1, R2 or their limited ones Areas on the receiver areas 4, 5 in time and geometrically different is moved in the evaluation circuit C a difference was found in the thread passage, from which a strong useful signal can be derived. thanks to the strong frequency components and good modulation Useful signal meaningful and with little amplification usable for further processing. Because of the arrangement the aperture slits A1, A2, the sensor device S is insensitive against changes in the position of the thread longitudinal direction D in the scan zone 3 and relative to the direction in which the Receiver R1, R2 lie next to each other.

Arises due to interference (vibrations, extraneous light and the like.) loading of the two receivers R1, R2, then response signals can also result from this. However, as this is applied in terms of time and geometry done immediately, it is possible at any time between real and distinguish faulty useful signals and only the real ones Derive useful signals from the thread passages and process them further.

In Fig. 3, the sensor device S is a trigger sensor Thread delivery device that has a thread supply on a storage area B. 13 of several, preferably axially spaced, Thread turns carries from which the thread Y over a pull-off edge 12 is withdrawn in the direction of an arrow 2, wherein the thread Y rotates in the direction of arrow 1 and the receiver R1, R2 with their front diaphragm slots A1, A2 happens. At 14 is the front in the withdrawal direction Limit of the thread supply 13 indicated. In the operation of such The delivery device varies the axial position of the limit 14 considerable (double arrow 15). The result of this is that the Thread withdrawal also the longitudinal direction D in the area of the receiver R1, R2 between an almost axial position and one Almost circumferentially oriented position can vary. This is indicated by the arrows D. Despite this variation the position of the thread longitudinal direction D in the scanning zone of the sensor device mainly because of the order of the two aligned with each other at an acute angle Aperture slits A1, A2, from one thread passage won a meaningful useful signal as an indication that a Thread turn has been withdrawn and when it was withdrawn has been.

In Fig. 3, the aperture slots A1, A2 are in the form of a T. arranged, the crossbar of the T adjacent the trigger edge 12 and is aligned in the circumferential direction.

The dashed line also indicates that the reverse is also used Arrangement of the aperture slots A1, A2 is possible, or even (indicated on the left and dashed lines) an inclined position of both Aperture slots A1, A2 with respect to the circumferential Deduction margin 12.

In all embodiments, the aperture slits A1 are shorter than the diameter of the circular receiver area each Receiver R1, R2. But it is also conceivable, the aperture slots to train the same length or even longer than that Diameter of the receiver surfaces.

4 schematically illustrates a selection of possible shapes for the aperture slots A1, A2. A rectangular shape is conceivable with the cross-sectional and major axis 6 and the cross-sectional and main axis 7, which are perpendicular to the cross-sectional main axis 6 lies. It is also possible to cover the slits A1, A2 oval, double concave or double convex each in view of the fact that the outline of the to be detected Fadens in its full size as quickly as possible over the Aperture slot is or the aperture slot if possible leaves quickly to get a strong useful signal strong frequency component or a strong modulation.

5A, 5B is a concrete embodiment of a weft measuring memory device F shown. These devices have been around have long been known and are used, for example, to deliver a Weft thread used for a jet loom, the Measurement storage device F in addition to the task, one for the respective pattern of sufficiently large thread supply for pulling off to keep ready with constant pull voltage, too the task accomplished, the respective peelable weft length limit to an adjustable value. In one case 17, a drive shaft 16 is rotatably mounted on the a storage body B, e.g. a bar drum or bar cage 20 from several axially extending and in the circumferential direction spaced rods 21, in turn is rotatably mounted. Of the Storage body B is held stationary by in the housing and arranged in the storage body permanent magnets 25 die relative rotational movement of the storage body B relative to the housing 17 prevent. On the drive shaft 16 is a winder arm 16a attached, which is formed by the hollow Drive shaft 16 fed from the left side in Fig. 5 Thread outwards to the storage area of the storage body B leads where it turns in succession when the drive shaft 16 rotates Windings in the supply 13 shown in FIG. 3 is filed. The free end of the thread runs over the Trigger edge 12 and becomes approximately coaxial with the drive shaft 16 from the textile machine or jet weaving machine, not shown deducted. On a housing bracket 18, below which one Control device 19 for driving the storage device F is provided, a housing 23 is attached in which in addition a stop device with a stop element 24 as a trigger sensor serving optoelectronic sensor device S housed is. The thread is pulled under the housing 23. By one between the housing 23 and the neighboring one Rod 21 formed gap, the stop element 24th extended as soon as no thread may be drawn off. Becomes however, thread is required, then the stop element 24 is withdrawn and the thread pulled off. The sensor device S registers each winding is subtracted and transmits a Representing the point in time and the occurrence of a passage Useful signal to the control device 19 before reaching of the thread length to be withdrawn, the stop element 24 again indent. The distance can be adjusted with an adjusting device V. adjust the rods 21 from the axis of the device, and hence the length of each thread turn.

6 and 7 are components of the sensor device S. indicated by Fig. 5. A block-shaped holder 26, e.g. a Plastic molding, has a storage body B facing lower surface 27. Three channels open into surface 27 28, 29 and 30. The light source L is arranged in the channel 30. The channels R1 and R2 are in the channels 28 and 29 intended. In the mouths of channels 28, 29 in the surface 27, the aperture slots A1, A2 are formed. Furthermore, a translucent cover plate 31 is arranged on the surface 27 be.

In the embodiment shown, all three channels 30 28, 29 arranged in the same axial plane 17 'of the storage body B. The channel 30 is up with respect to a radial plane the drive shaft 16 is set at an angle α3 of approximately -27 °, while the channel 28 with an angle α2 of approximately + 22 ° and the channel 29 inclined at an angle α1 of approximately + 32 ° is. The axes of all three channels are aimed in the scanning zone 3. The trigger sensor S is expedient in the direction of rotation of the thread immediately after pulling off Stop element 24 arranged.

The aperture slots A1, A2 could be in aperture plates (in Fig. 3 indicated), which are in their rotational positions have it adjusted, e.g. depending on the direction of rotation of the Drive shaft or taking into account the respective thread geometry optimal deduction of the relative positions when subtracting the aperture slots A1, A2 relative to each other and in To make reference to the axis of the memory body. Also, both aperture slots A1, A2 could be combined in one for tuning rotatable aperture plates with fixed mutual Assignment should be provided.

Claims (15)

1. Optoelectronic sensor device (S) for detecting a yam (Y) passing through a scanning zone (3) in a direction transverse to the longitudinal direction (D) thereof, comprising a light source (L, L') which illuminates the scanning zone, and at least one receiver (R1, R2) which is responsive to light variations and oriented towards the scanning zone and which is connected to an electronic evaluation circuit (C), and further comprising a slit aperture (A1, A2) which is arranged between said yam (Y) and the receiving surface (4, 5) of said receiver, characterized in that at least two closely adjacent receivers (R1, R2) are oriented towards said scanning zone (3), with the receiving surfaces (4, 5) of said receivers (R1, R2) having each arranged upstream thereof a slit aperture (A1, A2), that each of said slit apertures (A1, A2) has a geometrical configuration with a long cross-sectional main axis (6) and a short cross-sectional secondary axis (7) which is essentially perpendicular to the main axis (6), and that said slit apertures (A1, A2) are arranged with the cross-sectional main axis (6) of said one slit aperture (A1) at an acute angle of 90° or less in a direction transverse to the cross-sectional main axis of the adjacent slit aperture (A2).
2. The sensor device according to claim 1, characterized in that each of said receiving surfaces (4, 5) is approximately circular in the direction of impinging light, and that the length of said cross-sectional main axis of said upstream slit aperture (A1, A2) is shorter than the diameter of said receiving surface.
3. The sensor device according to claims 1 and 2, characterized in that both receivers (R1, R2) are jointly connected to the evaluation circuit (C) which is formed as a differential circuit.
4. A weft-yam measuring and storing device (F) comprising an optoelectronic sensor device (S) as a withdrawal sensor of a weft yam (Y) which is withdrawable in a revolving manner and overhead from a storage body (B), said sensor device comprising at least two optoelectronic receivers (R1, R2) which are arranged one after the other in the axial direction of said storage body (B), at least one light source (L) for illuminating a scanning zone (3) on said storage body, and an electronic evaluation circuit (C) with the aid of which a useful signal can be produced from light variations occurring at said receivers during each passage of said weft yam (Y) through said scanning zone (3), characterized in that a slit aperture (A1, A2) is provided between said scanning zone (3) and each of said receivers (R1, R2), and that said one slit aperture (A1) is arranged relative to the other slit aperture (A2) at an acute angle of 90° or less.
5. The measuring and storing device according to claim 4, characterized in that said one slit aperture (A1) extends in circumferential direction and said other slit aperture (A2) in the axial direction of said storage body (B).
6. The measuring and storing device according to claim 4, characterized in that an imaginary extension of said one slit aperture (A2) intersects said other slit aperture (A1).
7. The measuring and storing device according to claim 5, characterized in that said two slit apertures (A1, A2) are arranged in the form of a T.
8. The measuring and storing device according to at least one of claims 4 to 7, characterized in that both of said slit apertures (A1, A2) have a rectangular, double-concave or double-convex shape.
9. The measuring and storing device according to at least one of claims 4 to 8, characterized in that said two slit apertures (A1, A2) have the same shape.
10. The measuring and storing device according to at least one of claims 4 to 9, characterized in that said slit apertures (A1, A2) are arranged in said scanning zone (3) relative to all orientations of the longitudinal yam direction (D) that are possible during yam withdrawal in such a manner that a movement of said yam (Y) over said two slit apertures (A1, A2) which is identical geometrically or in time is ruled out.
11. The measuring and storing device according to claim 4, characterized in that a reflector (8) is arranged on said storage body (B) below said scanning zone (3), that a housing (23) which is stationarily arranged outside of said storage body (B) has arranged therein a block-shaped holder (26) which has a surface (27) which faces said scanning zone (3) and in which channels (28, 29 30) end which are directed towards said scanning zone (3) and pertain to at least one light source (L) arranged in said holder and to two receivers (R1, R2), preferably photodiodes, which are arranged in said holder, and that the openings of said channels (28, 29) of said receivers (R1, R2) are formed as slit apertures (A1, A2) having an approximately rectangular configuration.
12. The measuring and storing device according to claim 11, characterized in that said channels (28, 29, 30) are positioned in a joint axial plane (16') of said storage body (B), that said channel (30) of said light source (L) is inclined relative to a radial plane (X) of said storage body (B) by about -27°, and that said one channel (28) of said one receiver (R2) is inclined at about +22° and said other channel (29) of said other receiver (R1) at about +32° relative to said radial plane.
13. The measuring and storing device according to claims 11 and 12, characterized in that a transparent cover pane (31) is arranged on the surface (27) of said holder (26).
14. The measuring and storing device according to claim 11, characterized in that the distance seen in axial direction of said storage body (B) between said slit apertures (A1, A2) corresponds approximately to the width of each slit aperture (A1, A2).
15. The measuring and storing device according to at least one of claims 4 to 14, characterized in that each of said slit apertures (A1, A2) or both slit apertures (A1, A2) is/are cut out in a small aperture plate which is held with a selectable, preferably adjustable rotary position in a mount, preferably in the surface (27) of said holder (26), or in an opening of one of said channels (28, 29).

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