JPS61105442A - Method for resonating filament by self-excitation with basic wave - Google Patents

Abstract

PURPOSE:To satisfy resonance conditions between a filament and a driving force and to secure even self-excitation oscillation with a basic wave by incorporating an integration circuit in a feedback path. CONSTITUTION:One terminal of the filament 5 which is tensed with a weight 7 is suspended from a grounded metallic support 1, and the length of the vibra tion section of the filament 5 is set from said terminal by using a wedge 2. Vibrations of the filament 5 are detected by a photoelectric converter 3 and an obtained electric signal is passed through the integration circuit 8 and an amplifier 9, whose output voltage is applied to an electrode 4 placed nearby the filament 5 to constitute the feedback circuit. Consequently, the phase shift of photoelectric conversion can be ignored and the electrostatic driving force applied from the electrode 4 to the filament 5 is in phase with the output signal of the amplifier 9. Two points of the filament 5 are fixed, so a phase difference that vibrations need to have so as to resonance with the driving force is logi cally a fixed value, i.e. 90 deg.. This is given by the integration circuit in the feed back path, so the filament 5 oscillates itself while meeting resonance requirements.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Industrial Application Field The present invention is applicable to, for example, when measuring the linear density of thin a-fibers by the vibration method, the vibration of the fibers is detected and the method of excitation oscillation is used. Apply to.

(,21 To measure the IM density r of l short tan using the conventional technical vibration method,
When a fa male stretched over a length section with a tension T creates a standing wave with a Jic main frequency f and a small amplitude c, the following formula is calculated for this by the inventor in an earlier application (Japanese Patent Publication No. 37-18535, The method of self-excited oscillation is that one end of the vibrating section of the filament is set as y + < oscillator, a DC amplifier is used as a feedback circuit to promote self-oscillation, and a continuous By attaching a variable phase adjuster, we made the self-excited oscillation of the resonance at X to become a standing wave at this frequency.

(3) Problems to be Solved by the Invention In the following cases, (1) Since the drive chip vibrates, there remains uncertainty in the length of the vibration section of the row. In addition, (2) since the driver itself always has resonance characteristics, it gives shape to the resonance frequency fo of the fiber itself, and for this reason (3) the resonance phase adjustment also differs from sample to sample. Due to these reasons, it is not possible to compensate for pressure using redundant calculation formulas, and when using formula (1), there is no choice but to treat it as an error.

(≠) Means for solving the problem This invention is based on the inventor's paper (P%1 Textile Society Journal 38゜4
07 (1982)), the oscillating electric field generated by an electrode placed close to the charged filament is the driving force of the filament, so for example, this can be used to solve the previous problem (1) +
It becomes possible to implement by solving (2). In other words, by incorporating an integrating circuit into the feedback circuit, the problem (
The present invention is characterized in that it solves the problem of 3) and can even guarantee self-sustained oscillation due to the fundamental wave.

(5) Example J An overview of the example is shown. Tensioned n in minutes @7
One end of the filament j is suspended from a grounded support metal fitting/, and the length of the vibrating section of the filament is set using a flag 2 from this end. The vibration of the fibers is detected by the same photoelectric conversion 3 as in the previous application, and the obtained electrical signal is sent to the extenuating integration circuit! and an intensifier with negligible phase shift 9
The feedback circuit is spared by applying the output voltage of this wire to the open flood 1iIi≠ near the strip 88.

(6) In an operational example, the (1γ phase shift in photoelectric conversion is negligible, and the phase of the static force applied to the single line charged by the electrode, qi P) is similar to that of many other I11 !The movement method is the phase itself of the amplifier blade signal. Also, since the two points of the filament are fixed, the phase difference necessary for the vibration to resonate with the driving force is 1 !The constant value becomes 90 degrees.Since this is given by the integration circuit of the feedback path mentioned earlier, the fiber will perform self-lrm oscillation that satisfies the resonance condition.

Moreover, since this integrating circuit has the effect of the following formula % formula %, the amplifier output is the frequency Tll of the sine wave signal.
! It shows a large amplification degree at lower wave numbers. Therefore, it is guaranteed that the standing wave caused by the resonance of the filaments will be the lowest frequency fundamental wave B.

(7) Effect of the invention When using the above implementation date to calculate the linear density of aaa+, 91! of tJ(1)! Set the condition to 1 as much as possible.
．． In order to add j, the amplitude of the standing wave is made so small that it cannot be seen in bare III. Even in this case, according to the present invention, the fundamental standing wave can be reliably obtained by automatic oscillation due to resonance.
The number of palm motions is measured using an electrical signal, and without any doubt, f in equation (1) is used. Using the predetermined tension T and vibration length on the glass, the kneaded Ma- is determined as an accurate product. You can ask for more.

[Brief explanation of the drawing]

The accompanying drawing is a principle diagram showing one embodiment of the present invention. /...Grounded support metal fittings, 2...1 ship 3
......Light converter, l...Electrode plate (2 pieces), j...Filament, Otsu...M at the fundamental wave of the fiber Dynamic pattern (standing wave), 7... Weight, t...
...Integrator circuit, 9...Amplifier

Claims (1)

[Claims] In order to cause self-oscillation of the fundamental wave in a filament of a predetermined length using feedback, two points on the filament are fixed, and on the return path, the vibration of the filament, its detection, and the detection signal and the vibration of the filament are detected. If the configuration is such that the phase shift between each driving force can be ignored, an integral operator is incorporated in the middle of this return path to satisfy the resonance condition between the fiber and the driving force, and at the same time A self-excited oscillation method for fibers that ensures that self-excited oscillation becomes a standing wave of the fundamental wave.