JPS63167274A - Method and device for detecting abnormal rotation of weaving machine - Google Patents

Abstract

PURPOSE:To easily detect the abnormal rotation of the shaft of a weaving machine by detecting a rotating speed before the abnormal rotation and detecting the abrupt variation state of the rotating speed from the quantity of variation in the rotating speed after the unit time of the shaft later. CONSTITUTION:The rotating speed of an object of detection such as the shaft of the weaving machine is converted into an electric signal V proportional to the value of the rotating speed firstly in a rotation-signal converting process. Then this speed signal V is converted into a variation quantity D per unit time by analog or digital differentiating operation in a variation detecting process. In a following comparing process, this variation quantity D is compared with a preset reference permissible value S. When the variation quantity D becomes larger than the reference permissible value S, it is decided the current rotation state is abnormal.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method and apparatus for detecting abnormal rotation of a rotating shaft of a loom, such as a sending beam, a take-up beam, or a crankshaft. It pertains to means for detecting.

Background of the invention For example, li! If the machine's feeding device rotates abnormally, the weaving density will suddenly change, resulting in the fabric being rejected. However, if the warp yarn becomes loose and the dropper operates, or if the overtension device operates due to excessive tension and the loom automatically stops, the number of defective fabrics will be reduced. However, if the above-mentioned abnormalities occur continuously within the range in which these safety devices do not operate, a larger number of defective fabrics than expected will occur.

Prior Art Such abnormal rotation of a loom was reported in Japanese Patent Application Laid-Open No.
It can be detected by the invention of No.-214562. In order to detect rotational irregularities in vlAa, a reference tolerance value is statistically set in advance based on past rotational conditions, this is stored as a reference value for comparison, and this reference value is used for detection. The rotation unevenness is determined by comparing it with the average value at the time.

However, according to the above-mentioned invention, a statistical method is indispensable in advance, a complicated program is required, and the axis to be detected is, for example, the axis of a sending beam or a winding beam, At the same time, when the number of revolutions per unit time changes, past statistical reference values cannot be used as they are, so calculation of complex reference values is periodically required.

If the above-mentioned complicated arithmetic control is performed by the control microcomputer, the time required for the original control of the loom will be correspondingly reduced. Therefore, more sophisticated control is also subject to time constraints.

OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide a method for electrically detecting sudden changes in the rotational speed of an object to be detected without the need for statistical methods, complex programming techniques, or sophisticated electrical circuits. It is to be.

Solution to the Invention Therefore, the present invention measures the rotational speed of the shaft to be detected immediately before detecting the abnormal rotational speed of the shaft to be detected, and detects the rotational speed of the shaft again a short time after the measurement point. However, by comparing the amount of change in the speed difference with a reference allowable value, an abnormal speed increase or deceleration state at that time is electrically detected.

One embodiment of the present invention is configured with an analog circuit, and converts the rotational speed of the shaft to be detected into an electrical signal proportional to the rotational speed using a tacho generator, and differentiates this using a differentiator. The amount of change is determined based on the standard and the amount of change is compared with the standard allowable value.

Another embodiment is configured by a digital circuit, in which the rotational speed of the axis to be detected is converted into a pulse train by a pulse generator, and the amount of change is calculated as the number of pulses per unit time by an up-down counter. ing.

As described above, in the present invention, when detecting abnormal rotation of the shaft of a loom, the immediately preceding rotation speed is detected, and a sudden change in the rotation speed is detected from the amount of change from the rotation speed of the shaft after a unit time. Even if the axis to be detected increases or decreases in speed proportionally over time, sudden changes in rotational speed can be easily detected without using statistical methods or complicated programs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a method for detecting abnormal rotation of a loom according to the present invention over time.

The rotational speed of the object to be detected, such as the shaft of a loom, is first converted into an electrical speed signal V proportional to the value of the rotational speed in a rotation-to-signal conversion process. Next, in the fluctuation detection process, this speed signal ■ is calculated by analog differential operation or digital differential operation to calculate the change fiD per unit time.
is converted to

Then, in the next comparison process, this change measure is compared with a preset standard tolerance value S. When the change iD is smaller than the standard tolerance value S, there is no abnormality in the rotational situation. but,
When the change amount becomes larger than the reference allowable value S, the rotational state at that time is determined to be abnormal. Such a series of processes is performed continuously during operation of the loom or periodically at necessary intervals.

Example 1 Figure 2 shows an abnormal rotation detection device using an analog circuit.
It shows.

The detection target in this example is the sending shaft 2.

That is, the feed shaft 2 is connected to the feed motor 3 at one end, and is connected to the shaft of the feed beam 5 via the reducer 4 at the other end. The rotational speed of the delivery shaft 2 is converted into a speed signal V by a tacho generator 6, which is input to a differentiator 7. Therefore, this differentiator 7 obtains a change fiD by differentiating the speed signal V with respect to time t, and outputs this to each addition point 8.9. Since a positive or negative standard tolerance value S is applied to these addition points 8.9 by the setting device 1O1)1, each of the above-mentioned change scales is calculated by combining the standard tolerance value S and the addition value. and enter the respective comparators 12.13.

Here, the comparator 12.13 generates an alarm signal W as an abnormality on the acceleration side or an abnormality on the deceleration side, depending on whether the output signal of the summing point 8.9 is positive or negative. This alarm signal W is then used as information for controlling the loom.

FIG. 3 shows the above operations on the time axis. The rotational speed of the delivery beam 5 per unit time increases proportionally as the winding diameter decreases. This change is
Since it is almost constant over a short time range, its differential value, that is, the amount of change, is almost constant. but,
In the process of such a proportional change, if the rotational speed suddenly changes, the speed signal (2) also changes, so the time differential amount, that is, the change ID, changes pulsatingly in the positive or negative direction. These changes iD are compared by the respective comparators 12, 13 in accordance with the acceleration or deceleration of the speed signal (2), and an alarm signal W is generated depending on the magnitude relationship. The control device of the loom calculates the number of occurrences of the alarm signal W per unit rotational speed or per unit time, and generates information for controlling the loom.

Furthermore, if noise other than rotational noise appears in this speed signal ■,
This will generate an alarm signal W.

Such malfunctions can be eliminated by interposing a suitable filter between the tacho generator 6 and the differentiator 7.

Embodiment 2 FIG. 4 shows an example in which the abnormal rotation detection device 1 of the present invention is configured by a digital pulse circuit, and the rotational speed of the winding motion is detected.

That is, the rotation of the winding remoter 14 is transmitted to the winding beam 17 via the winding shaft 15 and the reduction gear 16.

The rotational speed of the winding shaft 15 at this time is converted by the pulse generator 18 into a pulse train speed signal (2) proportional to the rotational speed of the winding shaft 15, as shown in FIG.

The speed signal (2) of this pulse train is inputted to the up input terminal or the down input terminal of the up/down counter 21 via switches 19 and 20, respectively. Here, this switch 19.20 and up/down counter 21
For example, the switch 22 on the output side of the program cam 24
This is synchronized with the rotation of the main shaft 25 of the loom and selectively switched at every predetermined cycle. As seen in FIG. 5, one switch 19 is turned on for a certain time T, and the switch 22 is set to be on for the same time T after switch 19 is turned on. be done.

As a result, the up/down counter 21
The number of pulses of the speed signal (2) is added over the on time T of the switch 20, and then the pulse train of the speed signal (2) is subtracted over the on time T of the switch 20. Switch 19.
If the number of pulses of the speed signal V is equal to each other at the time T before and after 2o is turned on, the up/down counter 2
The final count of 1 should always be rOJ. However, if the count value of the up/down counter 21 exceeds a certain value even though these times are equal, the speed signal V will change before and after the period when the switches 19 and 20 are on. This corresponds to a sudden change in the number of pulses on the time axis. in this way,
The up/down counter 21 digitally differentiates the speed signal V by determining the deviation of the number of pulses of the speed signal (2) for a certain period of time T.

In this way, the switches 19.2o are alternately set to be on for a certain period of time T, and then the switch 22 is turned on, so that the count value of the up/down counter 21 is preset via the switch 22. This becomes an input to the counter 23. Since the preset counter 23 has an appropriate numerical value set in advance as the standard tolerance value S, when the switch 22 is turned on, the up/down counter 21
If the count value is larger than the set value, the preset counter 23 immediately generates an alarm signal W to notify the sudden change state of the winding shaft I5. Note that these up/down counters 21 and preset counters 23 are
After the switch 22 is turned on, it is reset by a reset signal R and returned to the initial state.

In addition, in FIG. 4, one preset counter 23
However, in order to monitor abnormalities in both acceleration and deceleration directions as in the first embodiment, another preset counter may be provided on the output side of the switch 22.

Modified Examples of the Invention As seen in the above embodiments, the present invention is not affected by proportional fluctuations over time in the axis to be detected by performing analog or digital differentiation operations. In order to detect the condition, the feed shaft 2 and the winding shaft 1
This is effective in detecting abnormal rotation of No.5. However, even when the axis to be detected always rotates at a constant speed, this invention can
Of course it can be used.

In addition, in the above embodiment, abnormalities on both sides of acceleration and deceleration are monitored, but depending on the detection target, abnormalities may be monitored as necessary.
Only one of acceleration and deceleration may be monitored. Furthermore, in the above embodiment, the standard tolerance value S
It is also possible to set a plurality of values and determine the degree of abnormality in force (1) speed and deceleration.

Note that when the rotation of the shaft to be detected is in a transient rotational state when rotation is started or stopped, the detection operation of the present invention is set to a halted state.

Incidentally, possible causes of abnormal rotation of a loom include wear and misadjustment of bearings and gears, failure of the electrical rotation control system, etc.

Effects of the Invention In the present invention, sudden changes in the rotational speed of the object to be detected can be easily detected using analog or digital differential operations, so statistical methods and complicated calculation programs as in the prior art are not required. Abnormal rotation of the loom shaft can be easily detected.

In particular, each time an abnormal rotation is detected, the abnormal state is identified based on the difference between the previous rotation speed and the rotation speed after a certain period of time, that is, the magnitude relationship between the amount of change and the standard tolerance value. Even if the speed changes proportionally over time, abnormal rotation can be detected without taking the average value of the rotation speed without the influence of the change.

[Brief explanation of the drawing]

Fig. 1 is a process diagram of the method of the present invention, Fig. 2 is a block diagram of an analog abnormal rotation detection device for a loom, and Fig. 3 is a process diagram of the method of the present invention.
Figure 4 is a block diagram of a digital loom abnormal rotation detection device, and Figure 5 is a time chart diagram of the digital loom abnormal rotation detection device.
It is a time chart figure of the thing of the figure. 1. Abnormal rotation detection device of the loom, 2. Delivery shaft, 6
...Tachogenerator, 7..Differentiator, 12.13..
Comparator, 15... Winding shaft, 18... Pulse generator, 19.20... Switch, 21... Up/down counter, 22... Switch, 23... Preset counter. Patent Applicant Tsudakoma Kogyo Co., Ltd. Agent Patent Attorney Kunio Nakagawa Figure 7 Figure 2 + S Figure 3

Claims (3)

[Claims] (1) A rotation-signal conversion process that converts the rotation of the detection target into an electrical signal proportional to the rotation speed, a fluctuation detection process that detects the amount of change in this electrical signal per unit time, and this amount of change and standard tolerance. A method for detecting abnormal rotation of a loom, comprising a comparison process of identifying an abnormal rotation speed of a detection target from a magnitude relationship with a value. (2) A loom shaft to be detected, a tacho generator that converts the rotational speed of this shaft into an analog electrical signal, a differentiator that converts the electrical signal of this tacho generator into a differential signal, and a An abnormal rotation detection device for a loom, comprising a comparator that compares a set reference differential value and identifies an abnormal rotation speed of the shaft from the magnitude relationship thereof. (3) The axis of the loom to be detected, a pulse generator that proportionally converts the rotation speed of this axis into an electrical pulse signal, and the pulse signals from this pulse generator are added over a certain unit time and are different. 1. An abnormal rotation detection device for a loom, comprising an up/down counter that subtracts over a unit time, and a preset counter that compares the counted value of the up/down counter with a preset standard counted value.