JPH0211191U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is an explanatory view showing the state of use of an embodiment of the needle breakage detection device according to the present invention, and FIG. 2 is a block diagram of the same embodiment. A...needle, 1...detector, 3...drive control device, 4...
Drive device, 5... Drum (needle assembly), 6... Foreign matter removal device, 11... Light emitting diode (light emitting element), 1
2...Phototransistor (light receiving element), 22a...
Local maximum value hold circuit, 22b... Local minimum value hold circuit, 13... Optical fiber for light emission, 14... Optical fiber for light reception, 20... Average value circuit (threshold calculation circuit)
, 23...needle judgment comparator (needle judgment circuit), 2
4... First counter, 25... Needle judgment pulse number setter, 27... Second counter, 28... Interval timer, 29... Confirmation number setter, 30... Delay circuit, 31
... Drive control circuit, 61 ... Adhesion judgment comparator (
adhesion determination circuit), a...detection signal, b...local maximum value, b
0...predetermined value, c...local minimum value, d...foreign matter adhesion signal,
e...Average value (threshold signal), f...Needle judgment pulse number,
g...needle presence signal, h...needle breakage detection signal, j...needle breakage confirmation signal, k...stop signal, n...number of confirmations, q...clock pulse, t1...(interval) time, t
2...Delay time.

Claims (1)

[Scope of claim for utility model registration] A drum-shaped, cylinder-shaped, or dial-shaped needle assembly in which needles of a stockinette knitting machine are arranged in rows;
The knitting machine is equipped with a drive device that rotationally drives the needle assembly, and a detector consisting of a light emitting optical fiber and a light receiving optical fiber, and when the detector detects that the needle is broken, the knitting machine is stopped. A needle breakage detection device includes: a detector including a light emitting element connected to a light emitting optical fiber; a light receiving element connected to a light receiving optical fiber and outputting a detection signal; and a maximum peak value of the detection signal. a local maximum value hold circuit that holds the minimum peak value of the detection signal, a local minimum value hold circuit that holds the minimum peak value of the detection signal, and outputs a foreign matter adhesion signal when the local maximum value held by the local maximum value hold circuit exceeds a predetermined value. a foreign matter removal means that blows out air in response to an input of a foreign matter adhesion signal; a threshold calculation circuit that outputs a threshold signal based on the average value of the maximum peak value and the minimum peak value; A needle judgment circuit that compares the signal with the detection signal and outputs a needle presence signal, and a needle judgment circuit in which the number of needle judgment pulses is preset, counts down the clock pulse, outputs a needle breakage detection signal by counting up, and is reset by the needle presence signal. a first counter circuit in which a confirmation number is preset, counts down the needle breakage detection signal, outputs a needle breakage confirmation signal by counting up, and is reset by the output of an interval timer; a delay circuit that receives a confirmation signal and outputs a stop signal delayed by a desired time; and a drive control that receives a stop positioning signal and controls the drive device to stop the needle assembly at a predetermined position. A needle breakage detection device comprising a circuit.