EP0705930B1 - Guide bar device for a warp knitting machine - Google Patents

Description

The invention relates to a bar arrangement for a warp knitting machine, in which the laying bar by means of an offset device axially displaceable and under Interposition of a compensation device from an axially fixed, preferably on one Swivel shaft-attached holding device is worn.

In a known bar arrangement of this type (DE-GM 18 57 100) the offset device consists of a by a cam rod controlled push rod, against which held the bar by means of a return spring becomes. As a compensation device, which the offset of the Laying bar opposite attached to the swivel shaft Allows levering, serves a variety of guide bolts, those in thrust bearings that are equipped with ball bearing bushings are, are held. To the warp knitting machine To be able to operate at high speed the guidance in the axial bearings is as free of play as possible be. This leads to increased wear, one corresponding energy consumption, which is converted into heat becomes, and thus to an unwanted expansion the laying rail. Due to the high frictional forces also the transmission elements of the offset device heavily loaded and exposed to wear. At high effective speed, large deceleration and acceleration forces.

The invention has for its object a bar arrangement of the type described in the introduction, which is a much simpler structure and only insignificant Has friction losses.

This object is achieved in that Compensation device and offset device by bending transducers are formed, which have one end on the holding device are attached to the other end of the Bear laying bar and get under the influence of a control signal deform by bending.

A separate offset device is not required in this construction (Sample disc, sample chain, servomotor and the like). All axial bearings of the compensating device are also dispensed with. Rather, the functions of Offset device and compensation device by the Bending transducer taken over. The number of required Bending converter depends on the machine performance or the expected operating conditions. Already two Bending transducers form together with the holding device and the parallel bar a parallelogram that the linear bar even with deformed bending transducers parallel to themselves holds. The height change of the bar is common with them occurring displacement paths so small that one can neglect them. In practice, however used a larger number of bending transducers to a high one around the bar despite the axial movement Giving stability, on the other hand, due to the bending deformation to achieve a sufficiently large offset force. It should be noted here that the offset forces can be kept much lower than before, because no return spring to generate one non-positive connection between the offset device and laying bar is needed. After all, that's additional mass of bending transducers moved to the bar much less than that in addition to the bar moving mass of the thrust bearing, so that higher working speeds are achievable.

It is particularly favorable that the holding device on the pivot shaft attached levers and one of these has supported mounting rail and that the bending transducer arranged along the length of the bar are. By using the holding rail can be the bending transducers or bending transducer groups with proportional Arrange a short distance from each other so that the stops of the laying bar are relatively tight are neighboring. This allows the bar to be one smaller cross section and thus a lower mass give, which in turn increase the rate of action allowed.

It also offers advantages that the bending transducers too Groups are grouped, each one common Head rail for attachment to the holding device and a common baseboard for attachment to the Have laying bar. In this way, the Bending transducers in groups, what kind of the assembly and repair is cheap.

The bending transducers are preferably piezoelectric Bending converter, each a strip-shaped, one or with an active layer of piezoelectric on both sides Have material coated carrier. Such bending transducers can be controlled by a control voltage operate and speak very quickly to this control voltage on. One can therefore with the currently usual high effective speeds or even higher effective speeds work. The invention includes also the use of other bending transducers, for example electromagnetic or magnetostrictive or operated in other ways.

The strip-shaped carrier preferably has on its An end extending beyond the active layer on. This non-bending active layer is enlarged the relocation of the bar, so that displacement paths of several millimeters can be achieved.

It is recommended that the strip-shaped carrier be made of Carbon fiber composite consists of one with Carbon fiber reinforced plastic. This gives one particularly light yet stable construction of the Bending transducer.

It is particularly favorable that the bending transducer from one Rest position by appropriately creating one Control voltage can be deflected either left or right are. If you put the same control voltage that one with a positive effect, the other with a negative one Effect on the bending transducer, there are three equidistant positions of the bar, so that for example a jersey can work. Using different voltages can also be different Achieve offset movements.

In a preferred embodiment, it is ensured that that the strip-shaped carrier made of electrical insulating material and on both sides one layer each of inner electrode, more active Layer and outer electrode, the inner Electrodes each have a control voltage and the outer electrodes are grounded. Such a bending transducer has the further advantage that it is safe to touch is because the external electrodes are grounded.

It is also favorable that an offset control device is provided, which is to be fed to the bending transducers Control voltage in terms of both size and shape program-guided. In this way, the Offset movement should be carried out so that none large accelerations and decelerations occur. Further details can be found in the earlier patent application P 44 11 528.8 of the applicant.

Furthermore, limit stops are recommended the offset movement of the bar. You can be very quick Achieve offset movements. Nevertheless, the end position is precisely defined.

In addition, these stops can be controlled by an actuator be relocatable. You can therefore use the laying bar very much operate different offset steps.

In a further embodiment of the invention, the laying needles with the interposition of piezoelectric Bending transducers carried by the bar and individually shiftable under the influence of control voltages. On this results in a displaceable by bending transducers and jacquard-controlled laying bar by bending transducers.

Fig. 1

einen Schnitt durch den Arbeitsbereich einer Kettenwirkmaschine mit erfindungsgemäß ausgebildeten Legebarrenanordnungen,

Fig. 2

einen Querschnitt durch eine der beiden rechten Legebarrenanordnungen der Fig. 1,

Fig. 3

eine Vorderansicht dieser Legebarrenanordnung,

Fig. 4

einen Querschnitt durch die linke Legebarrenanordnung der Fig. 1,

Fig. 5

eine für den Einbau vorbereitete Gruppe der Biegewandler,

Fig. 6

die obere Einspannstelle eines Biegewandlers,

Fig. 7

den Verlauf der Steuerspannung und

Fig. 8

einen abgewandelten Biegewandler.

The invention is explained in more detail below with reference to preferred exemplary embodiments illustrated in the drawing. Show it:

Fig. 1

3 shows a section through the working area of a warp knitting machine with laying bar arrangements designed according to the invention,

Fig. 2

2 shows a cross section through one of the two right-hand laying bar arrangements of FIG. 1,

Fig. 3

a front view of this bar arrangement,

Fig. 4

2 shows a cross section through the left laying bar arrangement of FIG. 1,

Fig. 5

a group of bending transducers prepared for installation,

Fig. 6

the upper clamping point of a bending transducer,

Fig. 7

the course of the control voltage and

Fig. 8

a modified bending transducer.

1 shows the work area 1 of a warp knitting machine with a knitting needle bar 2 carrying knitting needles, a slide bar carrying the associated slide 3, a piercing bar 4 and a bar 5, the knitted fabric 6 is drawn off over the upper edge thereof becomes. Two laying bars 7 and 8 with their laying needles 9 and 10 serve to manufacture the goods base. A Laying bar 11 with jacquard-controlled laying needles 12 is used for patterning. All laying bars are under Interposition of bending transducers 13, 14 and 15 of a holding device carried by holding rails 16, 17 and 18 and pivot lever 19 is formed. The latter are firmly connected to a pivot shaft 20 and can therefore be pivoted back and forth in the direction of arrow 21 can be, whereby the laying needles 9, 10th and 12 from the illustrated position in FIG the underlying position and back can be moved.

The term "bending transducer" primarily includes such elements that consist of a bendable material and under the influence of an external stimulus, which is mostly electrical or magnetic, by Deform the bend. Have for the present purpose these elements are preferably striped.

From a synopsis of FIGS. 2 and 3, in which the Arrangement with the right laying bar 8 is shown, can be seen that the holding rail 18 over the same length as the laying bar 8. Each eight piezoelectric bending transducers 15 are one Group 22, 22a summarized, the top of a header 23, 23a and below a baseboard 24, 24a. The Piezoelectric bending transducers 15 are fixed with a header 23 and baseboard 24 connected. Screws 25, which reach through holes 26 are used for attachment the header 23 on the holding rail 18. screws 27, which reach through holes 28 serve to attach the Skirting board 24 on the bar 8. The latter carries in the usual way Wise lead 29, which with the help of screws 30 are attached and in each of several laying needles 10 are cast.

A control device 31 has two signal lines 32 and 33, via which the bending transducers 15 have an electrical one Voltage can be applied in conjunction with this 5 and 6 will be explained while the support rail 18 is grounded at 34. By applying a control voltage shift the lower ones Ends of the bending transducers 15 in one or the other Direction, so that the bar 8, for example one Offset X1 experiences. Stops 35 and 36 serve the limitation the offset movement and thus the exact setting the laying needles 10 when swinging through the Needles of knitting needles.

A total offset X is set in FIG. 3. The attacks 35 and 36 can, however, by servomotors 37, 38 are shifted for what purpose the servomotors via signal lines 39 and 40 to the control device 31 are connected.

4 and 5 show the left bar arrangement 1 with the laying bar 11 and the holding rail 16. Again groups 41 of bending transducers 13 are at the top End with a header 42 and at the bottom with a baseboard 43 connected in a similar manner as in Figs. 2 and 3 by screws, for example the screws 44, with the holding rail 16 or the laying bar 11 are connected. The bending transducer 13 is 6, from a strip-shaped carrier 45 made of electrically insulating material, for example glass fiber reinforced plastic on one side a layer of inner electrode 46, piezoelectric active layer 47 and outer electrode 48 and on the other side a layering of an inner electrode 49, piezoelectrically active layer 50 and outer Electrode 51 carries. The two inner electrodes 46 and 49 are connected to signal lines 32 and 33, respectively. The two outer electrodes 48 and 51 are about machine parts connected to ground potential, here the header 42 and the support rail 16, grounded. To for this purpose, the header 42 is comb-like with grooves 52 formed in which the upper end of the bending transducer 13 inserted and jammed there or by others Means is attached. The strip-shaped carrier 45 has one that extends beyond the active layers 47 and 50 Extension 53, the lower end of which in Slots of the baseboard 43 is inserted.

Starting from a rest position of the bending transducer 13 the skirting board 43 shifts when creating one Control voltage to the left inner electrode 46 after left and when applying a control voltage to the right inner electrode 49 to the right. The deflection is about the charge applied to the bending transducer and thus proportional to the applied voltage VDC. At equally large voltage result in equal displacement paths, the same as the simple without difficulty or multiples of a needle pitch can be selected. In this way, the offset can be patterned Taxes.

In addition, as shown in FIG. 7, within one Duty cycle A the control voltage VDC after a curve K run in section a the deliberate misalignment corresponds. This is done in section b Swing through to the underlay position. In the section c the backing offset results. In the section d the laying bar 11 swings back into the consideration position. The individual sections can be straight run, but expediently show gradual Transitions between themselves. That way initially a gradual change in acceleration the laying bar 11 and at the end a gradual one Delay achieved. Therefore, there are no excessive effects Opposing forces, so that perfect operation results.

The laying needles 12 are on carrier strips 54 of piezoelectric Bending transducers 55 attached, which in turn are attached to a header 56. This is attached to the bar 11 with the aid of screws 57. Electrical leads 58 are connected to the control device 31 connected. This way the laying needles 12 individually in the sense of a jacquard control offset. Because of further details of such Jacquard control with piezoelectric bending transducer be on the older German patent applications P 42 26 899, P 43 16 396, P 44 14 876 and P 44 18 714 referred to the applicant.

The structure of the piezoelectric described in these applications Bending transducer can also be in the appropriate Use way for the bending transducers 13 to 15. This applies, for example, to the attachment of a second one Bending converter in the area of extension 43, the bends opposite to the first bending transducer. The lower one is moved by the second bending transducer End of the strip-shaped support during bending deformation parallel to itself. The strain on the wearer is therefore low at the clamping point on the laying bar side.

8 is the upper part of a modified bending transducer 59 illustrates. A stripe-shaped carrier 60, which is made of carbon fiber reinforced plastic, that is, it is electrically conductive Side a layering of a piezoelectrically active Layer 61 with an outer electrode 62 and on the on the other hand a layering of a piezoelectric active layer 63 and an outer electrode 64. Die outer electrode 62 is connected to the control signal line 32, the outer electrode 64 with the control signal line 33 and the electrically conductive support 60 is connected to ground 34. Such a bending transducer can be extremely light Weight, but still manufactured with high stability will.

In many cases it is sufficient if the holding device consists only of the pivot levers 19, the holding rails 16, 17, 18 are therefore eliminated.

Claims (12)

1. Guide bar arrangement for a warp knitting machine, in which the guide bar can be racked axially by means of a racking device and, with a compensating device being interposed, is carried by an axially fixed holding device fastened preferably to a pivoting shaft, characterized in that the compensating device and the racking device are formed by bend transducers (13, 14, 15) which are fastened at one end to the holding device, at the other end carry the guide bar (7, 8, 11) and experience bending deformation under the influence of a control signal (VDC).
2. Arrangement according to Claim 1, characterized in that the holding device has levers (19) fastened to the pivoting shaft (20) and a holding rail (16, 17, 18) carried by the said lever, and in that the bend transducers (13, 14, 15) are arranged, distributed, over the length of the guide bar (7, 8, 11).
3. Arrangement according to Claim 1 or 2, characterized in that the bend transducers (13, 14, 15) are combined to form groups (22, 22a; 41) which have in each case a common head batten (23; 42) for fastening to the holding device and a common foot batten (24; 43) for fastening to the guide bar (8, 11).
4. Arrangement according to one of Claims 1 to 3, characterized in that the bend transducers (13, 14, 15) are piezoelectric bend transducers which have in each case a strip-like carrier (45; 60) coated on one side or on both sides with an active layer (47, 50; 61, 63) consisting of piezoelectric material.
5. Arrangement according to Claim 4, characterized in that the strip-like carrier (45) has, at its foot end, an extension (53) going beyond the active layer (47, 50).
6. Arrangement according to Claim 4 or 5, characterized in that the strip-like carrier (60) consists of composite carbon-fibre material.
7. Arrangement according to one of Claims 4 to 6, characterized in that the bend transducers (13, 14, 15) can be deflected out of a position of rest selectively to the left or to the right by the corresponding application of a control voltage (VDC).
8. Arrangement according to one of Claims 4 to 7, characterized in that the strip-like carrier (45) consists of electrically insulating material and carries, on each of the two sides, a layering consisting of an inner electrode (46, 49), of an active layer (47, 50) and of an outer electrode (48, 51), a control voltage (VDC) being capable of being supplied in each case to the inner electrodes, and the outer electrodes being earthed.
9. Arrangement according to one of Claims 4 to 8, characterized in that a racking control device (31) is provided, which emits the control voltage (VDC) to be supplied to the bend transducers, both the magnitude and the profile of the said control voltage being program-controlled.
10. Arrangement according to one of Claims 1 to 9, characterized by stops (35, 36) for limiting the racking movement of the guide bar (8).
11. Arrangement according to Claim 10, characterized in that the stops (35, 36) can be racked by means of a servo-motor (37, 38).
12. Arrangement according to one of Claims 1 to 11, characterized in that the guide needles (12) are carried by the guide bar (11), with piezoelectric bend transducers (55) being interposed, and can be displaced individually under the influence of control voltages.

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