JP2005042292A - Method for operation of fast running knitting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve regulation of mobile members carried out in operation of a fast running knitting machine. <P>SOLUTION: The method for operation of the fast running knitting machine 1 by at least one driving gear 4, in which the absolute position of an actuating part of the driving gear 4 is detected by an absolute position detector 15 and transmitted to a controller 14, the position of the driving gear 4 is incrementally detected when the actuating part of the driving gear exceeds a predetermined running rate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a method for operating a knitting machine operating at high speed with at least one drive device, wherein the absolute position of the drive device is detected by an absolute position detector and transmitted to a control device. It is related with the operation method of the knitting machine.

  The present invention will be described below by taking a warp knitting machine as an example of a knitting machine. In a warp knitting machine, various knitting elements such as a knitting needle, a guide needle, a sinker and the like cooperate. The individual knitting elements are fixed to the bar for each group. The knitted fabric can be knitted by controlling the movement of the bar. Conventionally, movements of individual knitting elements are performed in a state where they are mechanically connected to each other. All the knitting elements were driven through the main shaft of the warp knitting machine. In order to connect the knitting elements, a relatively complex transmission is required in part. This complex transmission has limited the possibilities when designing the handle, making it difficult to switch the handle.

  Therefore, in recent years, as described in Patent Document 1, there is a tendency to use an electric drive device. In so doing, mechanical connection elements between the different knitting elements are generally unnecessary. However, information on where these knitting elements are located is indispensable for controlling the knitting elements. Said information can most simply be obtained via the position of the operating part of the drive. In the following, the “position of the driving device” means not an installation position of the driving device in the knitting machine, but an output portion that is an operation portion of the driving device with respect to a stationary portion (fixed portion) of the driving device or mechanically therewith. Means the relative position of the combined elements. When a rotary drive device is used as the drive device, the position of this drive device is the angular position of the rotor with respect to the stator.

  The position of the driving device is used in the adjusting device. The control device of the drive device used for this purpose controls the drive device so that the position of the drive device follows a specific set value.

In particular, it is absolutely necessary to know the absolute position of the drive device when starting the warp knitting machine. For this purpose, an absolute position detector that detects the absolute position of the drive device and notifies the control device must be used. This absolute position is detected even when the drive device is moving, and the detected absolute position of the drive device is notified to the control device. Such a configuration can be technically realized without any problem when the operation speed of the warp knitting machine is low. However, various problems appear when the operating speed of the warp knitting machine becomes high (fast). In that case, the amount of data to be transmitted in a short time increases according to the speed. This increase in data volume can certainly be overcome with technically available means today. However, the provision of the available means makes the knitting machine relatively expensive.
JP 2000-328408 A

  An object of the present invention is to improve the control of a movable member during operation of a knitting machine that operates at high speed.

  The problem is that in the method of the type indicated at the outset, when the operating speed of the driving device exceeds a predetermined operating speed, the position of the operating part of the driving device is detected incrementally, i.e. This is solved by detecting the amount of change in the position of the moving part.

  As soon as the operating speed of the driving device of the knitting machine exceeds a predetermined operating speed, the measurement of the absolute value of the operating part is stopped and the change (amount) of the driving device relative to the previously occupied position can be detected. It is carried out. This can significantly reduce the amount of data to be transmitted. In many cases, an analog signal is transferred and then processed in the form of analysis (calculation) for obtaining an increment (increase or change) in the control device. In general, the necessary “intelligence”, that is, processing can be performed without any problem only by using an indispensable computing capacity. The detection of increments (changes) by the control device has the further advantage that an essentially high resolution (accuracy) can be achieved. In other words, in the absolute position detector, only a limited number of positions that can be actually evaluated can be used for space reasons. However, when detecting the increment from the analog signal, the resolution can be increased many times, for example, 10 times to 100 times or more, compared to the case of using the absolute position detector. Thus, an essentially accurate position calculation is possible. This considerably improves the adjustment of the drive. Naturally it is also possible to generate increments (variations) in the absolute position detector so that information on the increments (variations) can be made digitally at its output. In the simplest case, in this case it is sufficient to transmit 1-bit information instead of a value that includes the absolute position of the drive and is generally displayable in only a few bytes. As a result, data transmission is not only simplified. In other words, the processing by the control device is also simplified, and therefore more rapid processing can be realized. Further, the reduction in the amount of information further has the advantage of improving fault tolerance. For example, even if data is lost due to an external failure, it only affects the increment. Such an increment (change amount) is only equivalent to a section of 1/100 mm, for example. On the other hand, the obstacle during transmission when detecting and controlling the absolute position may be related to a relatively large displacement path (displacement). However, such a problem does not originally occur when an analog signal is transmitted from the position detector to the control device. The processing method as described above is preferred at the present time.

  In the driving method, the position of the operating portion of the driving device is absolutely detected when the driving device is stopped, and the absolute detected position, that is, the absolute position is transmitted to the control device, and increments when the driving device operates. It is preferable to configure so that only (change amount) is considered. In such a case, the predetermined operating speed is zero. As the operating speed increases, the position of the operating portion of the drive device, that is, the angular position of the rotor with respect to the stator, for example, is detected only in the amount of change, that is, incrementally. In this case, since it is possible to start from the absolute position of the operating part detected at the time of stopping, the information essential for the adjustment of the drive device is practically available throughout the operation of the drive device.

  Preferably, in the driving method, the absolute position of the drive device is detected when the drive device is stopped, and information (data) relating to the absolute position is stored in the nonvolatile storage device. If comprised in this way, the information of where the position of the drive device was at the time of a stop will be available at each restart of a drive device. With this information, starting can be performed under essentially good control.

  At this time, it is preferable that the absolute position detection described above is performed by supplying the stored auxiliary energy. Thus, it is safe against failures that may occur due to interruptions in energy supply. For example, auxiliary energy can be used to detect the absolute position of the drive when electrical energy for operating the knitting machine is no longer available due to a power outage or other energy interruption. For this reason, auxiliary energy can be stored as electric power in a battery or a storage battery, for example.

  Preferably, the actual absolute position of the operating part of the drive device is detected prior to the occurrence of movement by the drive device, and this absolute position is compared and stored with the absolute position based on the stored actual absolute position data. In other words, the correction is executed in consideration of the difference between the absolute position and the actual absolute position. If the knitting machine is stopped for a certain period of time, for example if it is interrupted at the end of one shift or interrupted over the weekend, the operating part of the drive can be misaligned. In that case, the absolute position no longer coincides with the absolute position based on the stored data at start-up. For this reason, a failure may occur in an inconvenient case. In order to avoid such a failure, the drive device is corrected by the correction so that the risk of failure is reduced. In other words, since the absolute position based on the stored data is known, the difference between the absolute position based on the stored data and the actual position at that time is used as a criterion and corrected. Can do.

  Preferably, a plurality of drive devices are provided, and one of the drive devices drives one main shaft, the other one drive device drives one guide bar, and the drive drives the guide bar. When the actual absolute position of the operating part of the device does not coincide with the absolute position based on the stored data of the driving device that drives the guide bar, the absolute operating part of the driving device that drives the guide bar is stored. It is configured to be moved to a position. In this case, the so-called stored departure state (operation start state) is realized again. Such a configuration is a relatively simple measure (configuration) for assuring a safe start.

  At that time, when the actual absolute position of the main spindle does not coincide with the absolute position of the main spindle based on the stored data, the driving device that drives the guide bar moves to a position corresponding to the absolute position of the actual main spindle. Move part. In so doing, the fact that the main shaft generally has a preferential rotation direction and the drive device that drives the main shaft is generally the first priority drive device in the knitting machine is taken into account. That is, the absolute position of the guide bar is adjusted so as to match the actual absolute position of the main shaft without changing the position of the main shaft. More precisely, the position of the guide bar is attached to each position of the operation portion of the drive unit that drives the main shaft. The relationship between each position of the operation part of the drive device that drives the main shaft and the position of the guide bar is known. As a result, the position of the guide bar can be tracked to the position of the operating portion of the drive device that drives the main shaft. The drive device that drives the main shaft functions as a so-called “master”, while the drive device that drives the guide bar functions as a “slave”.

  Preferably, a cycle-type absolute absolute position detector is used and the drive is configured to be locked when stopped. A cycle-type absolute absolute position detector does not distinguish between individual cycles but only detects the position of the operating part of the drive within one cycle, for example the angular position of the rotor relative to the stator. At this time, whether the rotation is the first rotation, the second rotation, or the N-th rotation is trivial. Such a cycle-type absolute position detector is available at a relatively low cost and is sufficient to detect the position of the drive device before starting operation. By the way, the use of the cycle absolute absolute position detector was memorized by locking the drive during stop to prevent the position of the operating part of the drive during the stop phase from changing significantly. It is also sufficient for the correction required after comparison between the absolute position based on the data and the actually detected absolute position. The lock may not be perfect. Small movements of the operating part during the locking of the drive are quite acceptable. However, these small movements must not exceed one cycle. Also, the locking of the drive device does not necessarily need to be locked inside or on the surface of the drive device itself. In other words, since it is desired to prevent misalignment of the knitting elements driven by the drive device, it is generally sufficient to lock or brake the movement of these elements, for example bars.

  At this time, there is a difference between the actual absolute position and the absolute position based on the stored data, and when correcting the position of the operating portion of the driving device, this difference is determined based on a predetermined cycle ratio (rotation angle). Is smaller, it is preferable to exceed the cycle limit (boundary between the cycle and the next cycle). In other words, when correcting the position of the operating part of the drive device, if this difference is less than a predetermined percentage that is corrected in the direction of advance rather than in the direction of returning in the direction of the cycle, the end of that cycle is exceeded. It is preferable that the correction is made so as to proceed to the cycle. Specifically, it is not necessarily corrected to the stored value within one cycle. For example, an absolute value of 100 per cycle can be detected, and if the stored position is 10 and the actually detected position is 90, the drive is not corrected from 10 to 90 within the same cycle. , Corrected from 10 beyond the cycle limit to 90 in the preceding cycle.

  At that time, the predetermined ratio is preferably 49% at the maximum. In other words, it is sufficient to modify only over half of the cycle.

  Preferably, a sine cosine detector or a resolver is used as the absolute position detector. Both types of absolute position detectors are now available on the market at a reasonable price and are fully available in combination with control devices, drive devices, detectors and electronic processing devices and such absolute position detectors. is there.

  Hereinafter, the present invention will be described in more detail on the basis of preferred embodiments of the present invention with reference to the drawings.

  In FIG. 1, a warp knitting machine 1 has a main shaft 2, and the main shaft 2 is driven to rotate in a direction indicated by an arrow 3. In order to generate a rotational movement in the main shaft 2, a drive device 4, for example, an electric motor is provided, and this drive device 4 is connected to the main shaft 2 via a clutch 5.

  The main shaft 2 is connected to a knitting needle bar 7 through a connecting member 6 shown schematically. The knitting needle bar 7 carries a large number of knitting needles 8 and is capable of reciprocating swinging in the direction indicated by the double arrow 9 and can be moved up and down.

  The guide bar 10 has a large number of guide needles 11. The guide needle 11 is located in a gap between the knitting needles 8 in the illustrated position. The guide bar 10 is connected to a driving device 12, and the driving device 12 enables the guide bar 10 to reciprocate in the direction indicated by a double arrow 13 in the lateral direction (shogging operation). During operation, the movement of the knitting needle 8 (swing movement and lifting movement) and the movement of the guide needle 11 (shogging movement which is a linear displacement) are adjusted to each other so that a knitted fabric is formed by these movements. Naturally, the knitting machine 1 still has other knitting elements such as a slider sinker, a knockover sinker, etc., which can also be fixed to the bar. A plurality of guide bars can be provided. Each such bar can also have its own drive or can be configured to operate in conjunction with the drive of other bars or connected to the main shaft. The configuration of the main knitting machine is represented by a remarkably simplified schematic diagram for easy understanding, and will be described based on the schematic diagram. However, it is easily possible for a specialist in this field to use a configuration using a plurality of driving devices.

  Both said drive units 4, 12 are configured as electric motors in this embodiment. In this case, a servo motor, for example, a permanent magnet excitation synchronous motor is particularly suitable as the electric motor. However, it is also possible to use induction motors, direct current motors or stepping motors as long as they allow a sufficiently accurate positioning of the spindle 2 or the guide bar 10.

  In order to be able to control the positioning, a control device 14 is provided which controls the drive devices 4, 12 by pulses, for example.

  An absolute position detector 15 that detects the absolute position of the driving device 4 is attached to the driving device 4. “Absolute position” refers to the position of the movable element (operating part) relative to the stationary element (fixed element or fixed part) in the driving device 4, for example, the angular position of the rotor relative to the stator. Similarly, an absolute position detector 16 that detects the absolute position of the driving device 12 is also attached to the driving device 12. Both absolute position detectors 15, 16 can be configured as cycle absolute absolute position detectors. That is, they generate absolute values only within one revolution of the drive. This configuration is generally sufficient. As the absolute position detectors 15 and 16, for example, sine / cosine detectors or resolvers can be used. Instead of a cycle-type absolute detector, also called a “single-turn” detector, it is also possible to use a so-called “multi-turn” detector that can actually detect the absolute position over a relatively large rotational range. Of course, it is possible.

  The absolute position detector 15 notifies the control device 14 of the absolute position of the driving device 4 that drives the spindle 2. The absolute position of the main shaft 2 can be detected from the position of the driving device 4, more precisely the movable member in the driving device 4. The display of the absolute position requires a relatively large amount of data, for example several bytes. For the sake of clarity, a thick data line 17 is shown in the figure, via which the absolute position of the drive device 4 can be transmitted to the control device 14.

  Similarly, the absolute position detector 16 notifies the control device 14 of the absolute position via the data line 18.

  This data transmission is not a problem as long as sufficient time is available for that purpose. Such a sufficient time is prepared without any problem both when the spindle 2 is stopped and when the guide bar 10 is stopped. Even when the main shaft 2 and the guide bar 10 move slowly, there is no problem in transmitting the absolute position of the drive device 12 of the guide bar 10 and the drive device 4 of the main shaft 2.

  The situation is different when the warp knitting machine 1 is operated at a high operating speed. In that case, the absolute value could still be transmitted to the control device 14 via the data lines 17, 18. However, if an attempt is made to construct a configuration for transmitting a large amount of data in a short time, a considerable cost is required.

  In order to avoid this problem, the position of the drive device 4, 12 is detected incrementally rather than using the absolute value of the position when the drive device 4, 12 starts to move. That is, the amount of change in the position of the driving devices 4 and 12 is detected. Therefore, binary information, that is, not a digital signal but an analog signal, for example, a sine wave signal and a cosine wave signal of a sine / cosine detector are transmitted to the control device 14. Lines 19 and 20 are shown to show this specifically. These lines 19, 20 need not be physically present. Analog values such as absolute position values can of course be transmitted over the same physical line. These analog values are then evaluated (calculated) in the control device 14 by a correspondingly fast AD converter (analog / digital converter), and increments (changes) are obtained with high resolution. The other position is calculated based on the change amount).

  That is, in order to operate the warp knitting machine 1, the absolute position of the driving devices 4 and 12 is confirmed in a state where the movement of the main shaft 2 or the guide bar 10 by the driving devices 4 and 12 has not yet occurred. Is transmitted to the control device 14.

  When the warp knitting machine 1 is started and the drive units 4 and 12 are operated, that is, when the drive units 4 and 12 drive the main shaft 2 and the guide bar 10, switching is performed, and the absolute position is no longer the absolute position value. Only the change with respect to (change amount), that is, the increment value is used.

  Whether the warp knitting machine 1 stops or whether the warp knitting machine 1 stops, the absolute position of the drive unit 4 of the spindle 2 and the drive unit 12 of the guide bar 10 immediately after the warp knitting machine 1 stops, whether due to the operator's conscious operation or due to a power failure. The absolute position of the driving device 4 of the spindle 2 is stored as data in the storage device 21, and the absolute position of the driving device 12 of the guide bar 10 is stored as data in the storage device 22, respectively. In this embodiment, both storage devices 21 and 22 are constituted by non-volatile storage devices, that is, stored data (data relating to absolute positions) can be stored even if the supply energy to them is stopped due to a failure. . That is, the battery 23 or the capacitor or other energy supplying power to the storage devices 21 and 22 and the absolute position detectors 15 and 16 so that the absolute position can still be detected when the supply energy is stopped due to a failure or the like. A storage means for storing the water is provided.

  When the warp knitting machine 1 is stopped, the brakes 24 and 25 are operated to stop the movement of the main shaft 2 or the guide bar 10. In this case, for example, a small movement of about 3 ° within a range of 1 millimeter or a rotation angle is naturally possible. However, the operation of the brakes 24 and 25 prevents a large change in the position of the drive devices 4 and 12.

Before the warp knitting machine 1 is started again, the absolute position detectors 15 and 16 confirm the actual positions of the driving devices 4 and 12, and the confirmed actual positions are stored in the storage devices 21 and 22. Compare with the location based on the data. If a deviation occurs at this time, the deviation is corrected by the following procedure. That means
If the actual position of the driving device 12 of the guide bar 10 does not coincide with the position based on the stored data, the driving device 12 of the guide bar 10 is operated so as to reach the position based on the stored data.

  If the actual position of the driving device 4 of the main shaft 2 does not coincide with the position based on the stored data, the driving device 4 of the main shaft 2 is left at the actual position (as it is), and instead of this, the guide bar 10 The driving device 12 is operated (to be at its own position corresponding to the actual position of the driving device 4 of the spindle 2). Thereby, the drive device 12 of the guide bar 10 moves the guide bar 10 to a predetermined position corresponding to the actual position of the knitting needle bar 7, that is, the main shaft 2. The operation can be started from such a position. What is important is that the individual knitting elements maintain a predetermined interrelationship.

  By the way, in the absolute absolute position detectors 15 and 16 of the cycle type, the movement of the driving device 4 of the spindle 2 or the driving device 12 of the guide bar 10 that occurs during the stop time of the warp knitting machine 1 It is possible to correct in a direction exceeding the boundary between the cycle and the next cycle. For example, one cycle of the driving device 12 of the guide bar 10 is divided into 100 steps, and immediately after the warp knitting machine 1 is stopped, its position (for example, a numerical value “10” indicating the position) is confirmed, but the actual detected later If the position of the guide bar 10 is, for example, a numerical value “90” indicating the position, the drive device 12 of the guide bar 10 is not returned from 90 to 10 in the same cycle, but from 90 in the actual cycle to the next cycle. To 10. Such movement over a cycle occurs as long as the difference from the stored value is less than half of the cycle in the next cycle or the preceding cycle. Only if the difference is greater than half of the cycle is correction made within the same cycle.

  The method according to the present invention can be used for a knitting machine such as a warp knitting machine.

FIG. 2 is a diagram schematically showing a configuration of a main part of a warp knitting machine.

Explanation of symbols

1 ... Warp knitting machine (knitting machine)
4 ... Drive device 14 ... Control device 15 ... Absolute position detector

Claims (11)

A method for operating a knitting machine operating at high speed with at least one drive device, wherein the absolute position of the operating part of the drive device is detected by an absolute position detector and transmitted to a control device In the operating method of the knitting machine configured as follows:
The method is characterized in that when the operating speed of the driving device exceeds a predetermined operating speed, the amount of change in the position of the operating portion of the driving device is detected.   When the driving device is stopped, the absolute position of the operating part of the driving device is detected, this absolute position is transmitted to the control device, and when the driving device is operated, only the amount of change caused by the operation is considered in the control. The method of claim 1 wherein:   3. The method according to claim 1, wherein an absolute position of the operating part of the drive device is detected when the drive device is stopped, and data relating to the absolute position is stored in a non-volatile storage device.   The method according to claim 3, wherein the absolute position is detected by supplying stored auxiliary energy.   The actual absolute position of the operating part of the drive device is detected prior to the occurrence of movement by the drive device, and this absolute position is compared with the absolute position stored in the data relating to the stored actual absolute position and stored. 5. The method according to claim 3, wherein the correction is performed taking into account the difference between the position and the actual absolute position.   A plurality of the driving devices are provided, and one driving device drives one main shaft, the other driving device drives one guide bar, and the driving device drives the guide bar. When the actual absolute position of the portion does not coincide with the absolute position of the data relating to the drive device that drives the stored guide bar, the operating portion of the drive device that drives the guide bar moves to the stored absolute position. 6. The method of claim 5, wherein the method is moved.   When the actual absolute position of the main spindle does not coincide with the stored absolute position data of the main spindle, the driving device for driving the guide bar guides to a position corresponding to the actual absolute position of the main spindle. 7. The method of claim 6, wherein the bar is moved.   8. The method according to claim 1, wherein a cycle-type absolute absolute position detector is used and the drive is locked when stopped.   When there is a difference between the actual absolute position and the absolute position of the stored absolute position data, when correcting the position of the operating part of the drive unit, this difference is corrected in the direction of returning in the direction of the cycle. 9. The method according to claim 8, wherein if the direction corrected in the direction of advancement is smaller than the predetermined ratio, the correction is made in the direction of advancement to the next cycle beyond the end of the cycle.   10. The method of claim 9, wherein the predetermined percentage is a maximum of 49% of one cycle.   The method according to any one of claims 1 to 10, wherein a sine / cosine detector or a resolver is used as the absolute position detector.

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