JPH0114604Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a yarn breakage detector that detects yarn breakage and running stoppage of yarns in the manufacturing process of anti-spinning yarns or filament yarns.

A conventional thread breakage detector using an optical method is a projection type (Japanese Patent Application Laid-Open No. 49-66925), in which a light emitting element and a light receiving element are mounted facing each other, and a thread is run between them. Yarn breakage is detected by a light amount change signal from a light emitting element corresponding to the presence or absence of a thread. This conventional device had the disadvantage that the thread breakage detector occupied a large area because the light emitting element and the light receiving element were separated.

The purpose of this invention is to provide a small thread breakage detector that occupies a small area.

According to this invention, light from a light emitting element that emits infrared light is irradiated onto a running thread, and the light reflected from the running thread is received by a light receiving element. The light-emitting element and the light-receiving element are arranged as close as possible, and the running yarn is located on the bisector of these elements, so that the angle of light projection from the light-emitting element and the light reception of the light-receiving element with respect to the bisector are The angles match, and in this state both elements are fixed to, for example, the same case and mechanically integrated to form a reflection type photoelectric detector. Furthermore, an infrared filter that blocks visible light is installed in the window of this reflective photoelectric detector, so that the light-receiving element detects minute irregularities (thread irregularities) of the individual vibrating threads of the running thread.
A photocurrent change signal corresponding to the edge deviation, rotation, etc., and thickness of the thread is extracted, and when the photocurrent change signal disappears, a detection output is issued as a thread breakage (or running stoppage).

Embodiments of the yarn breakage detector according to this invention will be described below with reference to the drawings.

As shown in FIG. 1, emitted light 12 from a light emitting element 11 such as a light emitting diode is irradiated onto a running yarn 13, and its reflected light 14 is incident on a light receiving element 15 such as a phototransistor. The angle θ ₁ formed by the emitted light 12 with respect to the bisector 16 between the light emitting element 11 and the light receiving element 15 is made equal to the angle θ ₂ formed by the reflected light 14 entering the light receiving element 15. It is preferable to make the distance d between the light emitting element 11 and the light receiving element 15 as small as possible, and the distance l between these elements 11, 15 and the thread 13 is also preferably small, but if it is too small, the thread 13 will run It becomes difficult to hang threads in the aisle.
For example, l=3.5 mm is selected. Light emitting element 1
The light from the first strand is focused by the projection lens 17 at the position of the yarn 13.

The light emitting element 11 and the light receiving element 15 are attached to a common substrate 18 and have a mechanically integrated structure in order to maintain the above conditions, efficiently detect light reflection, and reduce variations in detection sensitivity. As shown in FIG. 2, such a reflective photoelectric detector 19 is attached to one side of one surface of the case 21, and an alarm lamp 22 is attached to the other side. In order to structurally suppress θ and d, it can also be molded integrally with the case using a mold or the like. The reflective photoelectric detector 19 and the lamp 22 do not need to be on the same plane. In addition, an infrared filter 20 (see Figure 1) that blocks visible light is placed on the window of the reflective photoelectric detector 19 in the case 21.
to avoid the influence of external light.

As shown in FIG.
The film is then wound onto a winding roller 25. Between the roller 23 and the snell guide 24, a yarn breakage detector 26 shown in FIGS. 1 and 2 is installed in a reflective area of the traveling yarn 13 which is vibrating minutely due to traverse or ballooning. FIG. 4 shows an example of the electric circuit of the thread breakage detector. Light emitting diode 11 on the light emitting side of the reflective photoelectric detector 19
A forward current of approximately 30 mA is supplied from the power supply terminal 27 to emit light, and the running yarn 13 is placed within the reflection area of the light emitting diode 11 on the light emitting side and the phototransistor 15 on the light receiving side. , a photoelectric change corresponding to the reflection/absorption rate of infrared light and the frequency of the running yarn is converted into an AC electric signal of several tens of mV (FIG. 5A) by the phototransistor 15 on the light receiving side and output.

This minute alternating current electrical signal is blocked by a capacitor 29 in the alternating current amplifier section 28, and the transistor 31
and is amplified to an AC electrical signal of approximately 2 to 4 V (Fig. 5B). This amplified output is rectified by a diode 33, a capacitor 34, and a resistor 35 in a rectifier 32, and converted into a DC voltage of approximately 1.5 to 3.5V (FIG. 5C).

This rectified output is supplied to the inverting input side of the comparator 37 of the comparator 36, and is compared with the set voltage V _t (FIG. 5D) applied to the non-inverting input side to determine the presence or absence of the running yarn 13. A judgment is made. This judgment result shows that when the running yarn 13 exists, the 0 level is
When the traveling yarn 13 does not exist (after time _t1 in FIG. 5), a binary signal of the power supply voltage level (FIG. 5E) is generated.
is output as

In the setting section 38, a variable resistor 39 sets a set voltage V _t that can determine the presence or absence of running yarn, for example, about 800 mV.
is set and supplied to the comparator 37. The output of the comparator 36 is connected to the switching transistor 4 of the output section 41.
2 and when the running yarn 13 is present, the output of the comparator 37 is at the 0 level, so the switching transistor 42 does not operate, the alarm lamp 22 goes out, and the output of the output terminal 43 reaches the power supply voltage level. Become. Comparator 37 when running yarn 13 does not exist
The output of the switch becomes the power supply voltage level (V _c in Fig. 5E), the switching transistor 42 operates, the alarm lamp 22 inserted in series with the transistor 42 lights up, and the output of the output terminal 43 becomes 0 level. become.

As mentioned above, this invention is a reflection type detector, and the light emitting element and light receiving element are mechanically integrated, so it can be made compact, and therefore there are fewer restrictions on the mounting position. Moreover, the threading work is easy. The thread breakage detector of this invention detects thread breakage both when the thread is cut and when the thread stops running. Therefore, in practice, for example, the operation of the yarn winding machine is also referred to, and it is determined that the yarn breakage detection output when the yarn winding machine is stopped is based on the fact that the yarn has stopped running.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the arrangement relationship among a light emitting element, a light receiving element, and a thread, Fig. 2 is a perspective view showing an example of a thread breakage detector of this invention, and Fig. 3 is a diagram of a thread breakage detector of this invention. Figure 4 is a connection diagram showing an example of the electric circuit in the yarn breakage detector of this invention; Figure 5 is a diagram showing an example of the arrangement;
FIG. 3 is a diagram of electrical signal waveforms at points. 11: Light emitting element, 13: Thread, 15: Light receiving element, 19: Reflective photoelectric detector, 21: Case, 2
2: Thread breakage alarm lamp, 28: AC amplification section, 3
2: Rectifier section, 36: Comparison section, 38: Setting section, 4
1: Output section.

Claims (1)

[Scope of utility model registration request] Reflective photoelectric detection in which a light emitting element that emits infrared light and a light receiving element are arranged so that the light emitting angle and the light receiving angle with respect to the bisector between them almost match, and are mechanically fixed to each other. an infrared filter installed in the window of the reflective photoelectric detector to block visible light; and an infrared filter installed in the window of the reflective photoelectric detector to detect the traveling yarn from the reflected light from the traveling yarn arranged within the light reflection area of the reflective photoelectric detector. A yarn breakage detector comprising means for extracting a photocurrent change signal corresponding to the unique vibration and thickness of the thread, and means for outputting a detection output as a yarn breakage when the photocurrent change signal disappears.