KR20010049797A - Warp knitting machine - Google Patents

Abstract

PURPOSE: A warp knitting machine equipped with at least one bar capable of being shifted as long as a predetermined distance such as a laying bar with guide needles, a controllable motor acting on one side end of the bar and a restoration apparatus acting on another side end of the bar is provided, which is suitable for operation with small tensile force. CONSTITUTION: The warp knitter has at least one bar which can be shifted along a given path. One controlled motor acts on one end of the bar and a restoration apparatus acts on the other end as a second controlled motor. A control unit(18) sets the first motor(4 or 7) to shift the guide bar(1) in one racking direction with a directional force(P1 or P2) and the other motor(7 or 4) to move the guide bar(1) in the opposite direction(P2 or P1). The motors(4,7) apply the directional tension forces(S1,S2) on the bar movement lines. The bar is a strip(1). The control(18) has a proportional-integral(PI) control unit(11) to control the first or the second motor(4,7) and a control(20) which reacts to the force component controls of the other motor(7,4). The control(18) passes the actual and nominal bar position values to the PI control(11) as absolute values. The scale(15) of the actual value transmitter is attached to the bar(1).

Description

Warp knitting machine

The present invention relates to a warp knitting machine having one or more bars, such as a float bar, which can be moved a predetermined distance, a controllable motor acting on one end of the bar, and a restoring device acting on the other end of the bar.

In a known warp knitting machine (DE 29 26 018 C2) of that type the motor is provided with a band which can be shortened by a pressure element whose length can be moved perpendicularly thereto. A spring is used as a restoring device. Such a structure requires a relatively large tensile force to move the bar, and particularly when a large number of bars of that type are placed in the warp knitting machine, a very stable warp knitting machine mount is required. In addition, the work speed is limited.

It is also known that the bars of warp knitting machines are implemented as knitting bands and reinforced by pattern molding (DE 30 06 636 A1).

It is an object of the present invention to provide a warp knitting machine of the type mentioned at the outset which works with small tensile forces and is suitable for high working speeds.

1 shows schematically a bar intended for operation in accordance with the invention in the form of a band with a control device attached;

2 shows another embodiment of a band,

3 shows another embodiment of a band.

<Explanation of symbols for main parts of drawing>

1, 22, 29: band

4, 7, 24, 25, 30, 31: motor

11: PI controller

15: graduation

18: control unit

20: controller responded by P fraction

23: Apostle Elements

32: thread guide hole

P1, P2: Tensile force

S1, S2: Tensile force

Such an object is that a second motor controllable according to the invention serves as a control device, the first motor tensions the bar by one control distance in one direction of movement by the control device, and the second motor extends the bar by a predetermined distance. By tensioning in different directions of movement, each time such tensioning, the other motor is achieved by applying an oppositely directed pull force to the bar.

In such a structure, a considerable amount of force is available for acceleration. Because in the past, the motor must not only provide the tension required for acceleration in one direction of movement, but also overcome the force of the restoring spring of the same magnitude, but now only the tension that can be kept relatively small It's just against the force of movement. Thus, a very significant redundancy of tension is available for rapid acceleration and thus high working speeds. At the same time, since the force generated when the band is moved during operation can be kept smaller than before, a warp knitting machine with low stability can be used.

The bar is preferably formed as a band. The mass of the bar is so small that even a small tensile force is sufficient to realize the acceleration already required for rapid movement. In addition, since the tension is usually only required to keep the band being flexible, the tension can also be kept small.

The control device preferably has a PI controller for controlling the first or second motors and a controller responsive by the P fraction to control each other motor. According to him, the PI controller serves as the main control device, and the controller responded by the P fraction serves as the slave control device. In such a form, a linkage is made between the working modes of the two motors such that the tension is always small compared to the tensile force.

The control device preferably includes a controller supplied with the actual value and the target value of the bar position as absolute values. In that case, since a unique absolute value is assigned to each point, the warp knitting machine can start work from each arbitrary position. That is, zero adjustment is unnecessary.

In that regard, it is advantageous that the scale of the actual detector relative to the position of the bar is assembled in the band. The band has a flat surface on which the scale can be easily mounted.

An additional advantage is given that the total moving distance of the bars reaches more than 150 mm. In practice, one may consider 180 or 200 mm. Such a large total travel distance was not possible because the restoring spring did not permit such a large length change in the past. It is now possible to move the actual travel range, for example 16 mm, within such a large total travel distance without having to change the warp knitting machine.

It is particularly advantageous for the motor to be a linear motor. Such linear motors can be placed directly on the extension of the band, thus eliminating the need for a deflector.

The motor may be a rotating motor instead of a linear motor. Such a rotating motor rotates a disk over which a tow rope guided to the band end is hung over it.

In a preferred embodiment, the band is provided with four dead elements. Such an apostle element may be installed at the point where it is required for inspection reasons.

In another preferred embodiment, the band has a hole for guiding the thread.

Hereinafter, the present invention will be described in more detail based on the preferred embodiments shown in the accompanying drawings.

1 shows a flexible band 1 which can serve as a knitting band of a warp knitting machine. One end 2 of the band 1 is coupled to the slider 3 of the linear motor 4 and the other end 5 of the band 1 is coupled to the slider 6 of the other linear motor 5. Both motors 4 and 7 apply only tensile force to the band 1. If the band 1 should be moved to the left, the motor 4 pulls the band 1 to the left by the corresponding moving distance. At the same time, the motor 7 is controlled to apply a relatively small pulling force such that only the band 1 remains open. If the band is to be moved to the right, this time the motor 7 exerts the tension necessary for the movement and the motor 4 generates the tension to keep the band 1 open.

In order for both motors 4 and 7 to be controlled in the above-described sense, a signal for determining the output of motor 4 via line 9 and motor 7 via line 10 are provided. The control apparatus 8 which gives the signal which determines the output of beforehand is provided. Such a control device 8 has a PI controller 11, which is supplied via the input from the program transmitter 13 in the form of an absolute value of the target of movement. The program transmitter 13 works depending on the spindle speed of the warp knitting machine. In addition, the PI controller 11 is supplied with an actual value of the position of the band 1 via the second input 14, for which a scale 15 which is optically or otherwise scanned by the read head 16 for this purpose. ) Is disposed on the band 1. Output data of the motor, which is tensioned in the movement direction via the first output 17, is transmitted to the switching device 18. The slave controller 20 is sensitive via the second output 19. Such a subordinate controller 20 delivers a signal to the switching 18 device 18 via an output 21 taking into account the fraction of the P component of the PI controller 11, which signal is the minimum possible tension force available. It is the signal corresponding to the motor output that is matched to produce it. The switching device 18 can identify which direction of movement is required from the sign of the signal supplied via the line 17.

Thus, when moved to the left, as indicated by the arrows in FIG. 1, the motor 4 generates a tensile force P1 and the motor 7 generates a significantly smaller pull force S1. On the contrary, when it is to be moved to the right, the motor 7 generates the tension force P2 and the motor 4 generates the tension force S2 as indicated by the dashed arrow in FIG. 1.

In the embodiment according to FIG. 2, a band 22 is provided with a dead end element 23. Such band 22 may be another knitting tool, such as a seat bar, for example. Instead of the motors 4, 7 formed as linear motors in this embodiment, rotary motors 24, 25 that drive rope winches are used, although only schematically shown. It is also shown that the band 22 can be moved on the bolt 27 fixed to the support 28 by the holder device 26.

In the embodiment according to FIG. 3, the band 29 is coupled to the rotary motor 30 at one end and to the rotary motor 31 at the other end. Such a band 29 has a plurality of holes 32 for guiding the thread. Moreover, the guide slit 33 which the support roll 34 engages, respectively is provided.

In the warp knitting machine according to the present invention, a very large force is available for acceleration, since only the tensile force, which can be kept relatively small, opposes the moving force. Thus, a very significant redundancy of tension is available for rapid acceleration and thus high working speeds. At the same time, since the force generated when the band is moved during operation can be kept smaller than before, a warp knitting machine with low stability can be used.

Claims (10)

In a warp knitting machine having one or more bars such as a float bar that can be moved a predetermined distance, a controllable motor acting on one end of the bar, and a restoring device acting on the other end of the bar, A controllable second motor serves as a control device, and the first motor 4, 24, 30 or 7, 25, 31 is one direction of movement (tensile force) of the bar by a predetermined distance by the control device 18. (P1 or P2), the second motor (7, 25, 31 or 4, 24, 30) tensions the bar in a different direction of movement (tensile force) (P2 or P1) by a predetermined distance, and so on Each time the other side of the warp knitting machine, characterized in that to apply the opposite tension (S1 or S2) to the bar. The warp knitting machine according to claim 1, wherein the bar is formed as a band (1, 22, 29). 3. The control device 18 according to claim 1, wherein the control device 18 controls the PI controller 11 and each other of the motors 7 or 4 for controlling the first or second motor 4 or 7. 4. And a controller (20) responsive to the P fraction. The warp knitting machine according to claim 1, characterized in that the control device (18) comprises a controller (11) supplied with an absolute value and an actual value and a target value of the position of the bar. 5. Warp knitting machine according to claim 4, characterized in that the scale of the actual value detector relative to the position of the bar is assembled on the band (1). The warp knitting machine according to claim 1 or 2, wherein the total moving distance of the bar is 150 mm or more. The warp knitting machine according to claim 1 or 2, characterized in that the motor (4, 7) is a linear motor. The warp knitting machine according to claim 1 or 2, characterized in that the motor (24, 25, 30, 31) is a rotating motor. 3. Warp knitting machine according to claim 2, characterized in that the band (22) comprises an apostle element (23). 3. Warp knitting machine according to claim 2, characterized in that the band (29) has a hole (32) for guiding the thread.