JPH0756474B2 - Wire surface defect detector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wire surface defect detector. Furthermore, in more detail, the present invention relates to a wire rod surface defect detector capable of detecting an irregularity defect generated in a coating layer formed on a conductor such as an enameled wire.

[Prior Art] Enameled wire is an insulated wire with the thinnest insulating layer. Nevertheless, the various characteristics required for the enameled wire are high. That is, enamel wire is flexible and wear-resistant to withstand harsh machine windings, solvent-resistant to withstand varnish treatment containing highly erosive organic solvent, heat-resistant to use under high temperatures, and refrigerant. Refrigerant resistance that can be used even in an atmosphere and excellent electrical characteristics that do not cause dielectric breakdown even after long-term operation are required.

Therefore, it is strongly required that the enameled wire has no abnormal appearance, for example, no particles or dents.

Application of enameled wire to meet such strict requirements,
The baking work is done with the enamel paint on the conductor several times to several dozen times. That is, the enamel wire is manufactured by repeating the steps of applying the enamel coating on the conducting wire, squeezing it uniformly with a die, and then passing it through a baking oven at high temperature 5 to 15 times.

However, even if the die is squeezed or the divided coating is performed in this way, a few particles or dents may occur every several thousand meters to tens of thousands of meters.

When such a coating film defect occurs, it is necessary for the enamel wire manufacturer to automatically detect it in-line, immediately remove defective products, and immediately take preventive measures.

Now, the wire rod surface defect detector is classified into a contact type and a non-contact type.

As the contact type wire rod surface defect detector, a die wire rod surface defect detector, a holding resistance sensing wire rod surface defect detector, a roller sensing wire rod surface defect detector, and the like have been proposed.

As a die type wire rod surface defect detector
No. 53-92669, JP-A-54-87883, S55-1
Devices such as 48608, 57-134608, 57-166115, and 58-184717 have been proposed.

As shown in FIG. 8, the die-type wire rod surface defect detector uses a limit switch 4 or the like to act so as to raise the die 3 upward when the particles 2 in the coating film of the wire rod 1 pass through the die 3. It is to be detected through.

As a pinch resistance detection type wire rod surface defect detector
No. 3284 is proposed. In this method, as shown in FIG. 9, the wire rod 5 is passed through the pinch resistance sensing type wire rod surface defect detector so that the wire rod 5 is held by the resistor 6, and the resistance received when there are particles is detected by the spring 7, the limit switch 8 and the like. It is a device that does.

As shown in FIG. 10, the roller-sensitive wire rod surface defect detector is a device for passing a wire rod 9 having particles 10 between a pair of contact rollers 11 and detecting a displacement by the particles 10 by a displacement detection mechanism 12. .

On the other hand, non-contact type wire rod surface defect detectors include a transmitted light type, a laser light type, and a diffuse reflection light type.

As a transmitted light type wire rod surface defect detector
Methods such as 488 and JP-A-59-109808 are available. As shown in FIG. 11, this transmitted light type wire rod surface defect detector irradiates the wire rod 13 with detection light from the light source 16 through the lens 17 and the slit 15, and the detector 14 detects unevenness of the coating film. is there.

As a laser beam type wire rod surface defect detector, a laser beam is irradiated from a laser oscillator 19 onto a rotating mirror 18 as shown in FIG. 12, the reflected light is applied to a wire rod 21 through a lens 20, and a particle 22 is a light receiving element. It is a device to detect at 23.

As a diffuse reflection type wire rod surface defect detector
No. 43281 is proposed. As shown in FIG. 13, this detector irradiates the wire 24 with light from the light source 17 through the lens 28 and reflects the light in a plane perpendicular to the axis of the wire 24 and the optical axis of the light source and the wire 24. This is a method of detecting the surface defect 25 of the coating film from the light receiving element 27 provided in the deep hole in which the intersection point of the surface of the is seen obliquely.

In order to improve such a defect of the diffuse reflection type wire rod surface defect detector, a diffuse reflection light condensing type wire rod surface defect detector using an elliptical concave mirror as shown in FIG. 14 has been put into practical use. As the diffused light condensing type wire rod surface defect detector, Japanese Patent Publication No. 55-25788, Japanese Patent Publication No. 56-29776, and Japanese Patent Laid-Open No. 53-6
3084, JP-A-53-63084, JP-A-53-63085, Shoukaisho
No. 58-119753 and No. 58-120952 are proposed.

In FIG. 14, 30 is a wire rod, 31 is an elliptical concave mirror, 32 is a lens, 33 is a light source, 34 is a light receiving element, 35 is a specular reflection mirror, and 36 is a diffuse reflection mirror.

That is, this irregular reflection light condensing type wire rod surface defect detector irradiates the wire rod 30 with the light emitted from the light source 33 through the lens 32,
The specularly reflected light from the minute portion of the wire 30 is escaped, and the irregularly reflected light 36 is reflected and condensed by at least a pair of elliptical concave mirrors 31 arranged with the minute portions as respective focal positions.
Is received by the light receiving element 34 and converted into a signal, and the surface defect of the wire 30 is detected by the signal.

[Problems to be Solved by the Invention] However, since the contact type wire rod surface defect detector as shown in FIGS. 8 to 10 is a system in which a die, a resistor, a roller and the like are in contact, the traveling wire rod 1, 5, 9, 13,
The vibrations of the detectors 21 and 24 and the vibrations of the detectors themselves are likely to be overlapped with each other to cause malfunction, and there is a problem that the wire rod is scratched by the sensing material die, resistor, roller or the like.

In addition, in the die type wire rod surface defect detector as shown in FIG. 8, it is necessary to replace the die each time the wire diameter of the wire to be detected changes, and the setup work is troublesome.
Further, in the holding resistance sensing type wire rod surface defect detector as shown in FIG. 9, the resistance material 6 is worn and deteriorated, and accordingly, the holding force must be constantly adjusted. The roller-sensitive wire rod surface defect detector as shown in FIG. 10 needs to constantly control the wear and pressing of the roller, which is also a maintenance difficulty.

On the other hand, the non-contact type wire rod surface defect detector as shown in Figs. 11 to 13 does not have a concern of causing scratches on the wire rod, but the conventional one has a complicated structure and is considerably expensive. There is.

That is, in the transmitted light type wire rod surface defect detector as shown in FIG. 11, it is necessary to use parallel rays, and a complicated optical mechanism capable of irradiating the parallel rays is required. Further, in order to improve the detection accuracy of the transmitted light type wire surface defect detector, it is necessary to install a powerful light source and a special light receiving element. Moreover, this transmitted light type wire rod surface defect detector can only detect defects on one surface side of the wire rod, so it is necessary to install a plurality of devices to detect defects on the entire circumference of the wire rod, which makes the device large and complicated. In addition, price increase is inevitable.

The laser beam type wire rod surface defect detector as shown in FIG. 12 has the same drawbacks as the transmitted light type wire rod surface defect detector. Since it is detected by scanning, it is not suitable for detecting minute unevenness.

In the diffuse reflection type wire rod surface defect detector as shown in Fig. 13, since the reflected light is scattered in every direction and becomes weak, it becomes large, complicated and expensive with many light sources and many light receiving elements. Inevitable.

Further, in the irregular reflection light condensing type wire rod surface defect detector using the elliptical concave mirror as shown in FIG. 14, the elliptical concave mirror is a special product with extremely high precision, which is a disadvantage. Furthermore, in the irregular reflection light condensing type wire rod surface defect detector using such an elliptical concave mirror, since the surface defects are condensed and detected by the two light receiving elements 34, a special amplifier with improved frequency response is used. There is a need to. Of course, special amplifiers are expensive.

The present invention has been made in view of such a point, and the purpose thereof is to eliminate the above-mentioned drawbacks of the prior art,
Detecting surface defects No need to replace or adjust parts depending on the wire diameter, you can reliably detect surface defects without contact,
Moreover, it is to provide a wire rod surface defect detector that is small, lightweight and inexpensive.

[Means for Solving the Problems] The gist of the present invention is to detect a surface defect of a wire by irradiating the surface of the wire with light from a light source and receiving and amplifying diffusely reflected light from the wire to amplify the light. And a plurality of detection plates having the light source and a plurality of light receiving elements arranged around the light source fixed on a mounting plate, the three detection plates being the light source and the plurality of detection plates. In the wire rod surface defect detector, the light receiving element and the light receiving element are formed in a triangular tube shape so as to be inside.

The reason why the triangular tubular body is used in the present invention is that it has the advantages that the structure is simple and the manufacturing is easy, and the influence of unnecessary light can be most effectively eliminated.

In the present invention, as the light source, in addition to the conventional lamp, a light emitting diode, a semiconductor laser, or the like, which has been conventionally impractical due to its weak illuminance, can be used.

Here, as the light emitting diode, a high brightness light emitting diode having a light amount of 5 mw or more is suitable. This is because the detection accuracy is slightly reduced at 5 mw or less.

In the present invention, a photoelectric conversion element is used to convert the light received by the light receiving element into a signal. A photodiode, a phototransistor, a solar cell, a CCD, or the like can be used as the photoelectric conversion element, but a silicon photodetection diode having a large photoelectromotive force and good signal response is suitable.

In the present invention, the use of a plurality of light receiving elements is to receive any diffused reflected light, to detect surface defects with high accuracy, and to significantly reduce the manufacturing cost of the light source. That is, if one light receiving element is used as in the diffused light condensing type wire rod surface defect detector, it is necessary to form an extremely special shape such as an elliptical shape from the viewpoint of light condensing property. It was inevitable that the skyrocketing and maintenance costs would rise. On the other hand, in the present invention, an inexpensive general-purpose light receiving element can be used by using a plurality of light receiving elements in combination.

[Operation] Since the wire rod surface defect detector of the present invention is configured as described above, the structure can be simplified and the manufacturing cost can be significantly reduced.
In addition, maintenance management such as disassembly, cleaning, assembly, and adjustment can be greatly improved. Moreover, specular reflection light can be effectively reduced and diffuse reflection light generated from the surface defect portion can be reliably received to increase the surface defect of the wire rod. It can be detected accurately.

[Embodiment] Next, an embodiment of a wire rod surface defect detector of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of a wire rod surface defect detector of the present invention, FIG. 2 is an explanatory view of its detection principle, and FIGS. 3 to 6 are explanations of advantages of a triangular irregular reflecting mirror. FIG.

In FIG. 1, 37 is a wire rod, 38 is a high brightness emitting diode, 39 is a light receiving element, 40 is a mounting plate, and 41 is an outer frame.

That is, in one embodiment of the wire rod surface defect detector of the present invention, four light receiving elements 39 are mounted on the inner side surface at appropriate intervals, and the light emitting diodes 38 are attached to the four light receiving elements 39 at substantially the central positions. 3 mounting plates 40 are formed, and the three mounting plates 40 are assembled in a triangular tube shape so that the mounting surfaces of the light receiving element 39 and the light emitting diode 38 are the inner surfaces, and the outer frame 41 is provided on the outer periphery thereof. It consists of That is, an embodiment of the wire rod surface defect detector of the present invention comprises a total of three light emitting diodes 38 and twelve light receiving elements 39.

In this case, since the upper surface side of the three mounting plates 40 can be opened and closed, inspection, cleaning, and adjustment work can be easily performed.

The mounting plate 40 is a metal plate or a hard polymer plate on which a black polystyrene foam sheet is laminated with an adhesive.

FIG. 7 shows an example of this particle detection control circuit, in which 38 is a light source, 39 is a light receiving element, 59 is a voltage conversion resistor, and 60 is a voltage conversion resistor.
Is an oscillation prevention capacitor, 61 is an amplifier, 62 is a recorder,
63 is an adjusting resistor.

In one embodiment of this particle detection control circuit, the light emitted from the three light sources 38 is applied to the surface defects of the wire rod 37, and the irregular reflection light generated there is received by the 12 light receiving elements 39.
By connecting the two light receiving elements 39 in parallel, a light receiving effect equivalent to that of one large light receiving area light receiving element can be obtained. Moreover, since there are a plurality of light receiving elements on the mounting plate 40, one large light receiving area light receiving element is provided. It is possible to effectively eliminate the light receiving error of diffused reflection light far from the fixed position of the light receiving element, which tends to occur when used.

Next, the detection principle of an embodiment of the wire rod surface defect detector of the present invention will be described.

Now, when the wire 47 having no surface defect is irradiated with infrared light from the light emitting diode 43, the specularly reflected light 45 is reflected vertically as shown in FIG. 2, so that an electric signal is generated in the light receiving elements 42 and 44. Absent.

On the other hand, when the wire 47 having a defect such as a granular projection 48 on the surface is irradiated with infrared light from the light emitting diode 43, irregularly reflected light 46 is reflected obliquely as shown in FIG. , 44 to produce an electrical signal. The generated electric signal is amplified by a signal amplifier circuit, and a surface defect number counter, an automatic recorder, etc. are operated to automatically record the number of surface defects of the wire 37 and the generation position in the longitudinal direction.

The shape of the wire surface defect detector of the present invention is a triangular tubular body, but a square tubular body, a pentagonal tubular body, a hexagonal tubular body and the like can also be used. It is also possible to have a shape that can improve the S / N ratio, such as a donut ring shape.

On the other hand, since the wire rod surface defect detector detects surface defects by detecting diffused reflected light from defects on the surface of the wire rod, ideally, it is desirable that the specular reflected light is zero. However, in practice, it is impossible to irradiate the light from the light source to make the specular reflection light zero.

Therefore, with respect to an example of the wire rod surface defect detector of the present invention in the shape of a triangular tube and an example of the wire rod surface defect detector in the shape of a rectangular tube, the relationship between the specular reflection light and the attenuating property of irregular reflection light will be described. To do.

First, in one embodiment of the wire rod surface defect detector of the present invention in the shape of a triangular tube as shown in FIG. 3, when light is emitted from the light source 50, specular reflection light 53 is generated at least twice as shown in FIG. As described above, it is possible to effectively attenuate the light while repeating the surface reflection, and as a result, it is possible to remarkably improve the detection ability of the diffuse reflection light generated when there is a surface defect.

On the other hand, in an example of the wire rod surface defect detector in the shape of a rectangular tube as shown in FIG. 5, when light is emitted from the light source 57, specularly reflected light 58 directly enters the light receiving element 56 as in the sixth embodiment. The noise becomes slightly large (reflectance becomes 0.5 or more), and as a result, the detection capability of irregularly reflected light generated when there is a surface defect is slightly reduced. Therefore, the shape of the wire rod surface defect detector is preferably a triangular cylinder, but of course other shapes can be used.

Further, in order to improve the S / N ratio in the mounting plate 40, it is appropriate to use a colored plate having a reflectance of 0.4 or less, such as a black porous plate.

[Advantages of the Invention] The wire rod surface defect detector of the present invention can exert the following excellent effects and is extremely useful industrially.

(1) Surface defects of the wire can be detected with high accuracy.

(2) The structure is simple, the manufacturing is easy, and the disassembling and assembling are easy, so that maintenance, inspection and adjustment, cleaning work, etc. are extremely easy.

(3) Manufacturing cost is low.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a wire rod surface defect detector of the present invention, FIG. 2 is an explanatory view of its detection principle, and FIGS. 3 to 6 are shapes and positive shapes of the wire rod surface defect detector. FIG. 7 is an explanatory view for explaining attenuation of reflected light and diffused light, FIG. 7 is a circuit diagram showing an example of a particle detection control circuit in an embodiment of a wire rod surface defect detector of the present invention, and FIG. Fig. 9 is an explanatory view of a die type wire rod surface defect detector, Fig. 9 is an explanatory diagram of a conventional holding resistance sensing type wire rod surface defect detector, and Fig. 10 is an explanatory diagram of a conventional roller sensing type wire rod surface defect detector, FIG. 11 is an explanatory view of a conventional transmitted light type wire rod surface defect detector, FIG. 12 is an explanatory view of a conventional laser light type wire rod surface defect detector, and FIG. 13 is a conventional diffuse reflection light type wire rod surface defect detector. Illustration,
FIG. 14 is an explanatory view of a diffuse reflection light condensing type wire rod surface defect detector using a conventional elliptical concave mirror. 1,5,9,21,24,30,37,47,49,54: Wire rod, 2,10,22,25,48: Surface defect, 3: Die, 4,8: Limit switch, 6: Holding resistance Body, 7: Spring, 11: Contact roller, 12: Displacement detection mechanism, 14: Detection element, 15: Slit, 16,26,33,50,52,55,5
7: Light source, 17, 20, 26, 28, 32: Lens, 18: Rotating mirror, 19:
Laser oscillator, 23,27,34,39,42,44,51,56: Photodetector,
29: concave mirror, 31: elliptical concave mirror, 35, 45, 53, 58: specular reflection light, 3
6,46: Diffuse reflection light, 38,43: Light emitting diode, 40: Mounting plate, 4
1: Outer frame, 59: Voltage conversion resistor, 60: Oscillation prevention capacitor, 61: Amplifier, 62: Recorder, 63: Adjustment resistor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shuichi Takano 1500 Kawajiri-cho, Hitachi-shi, Ibaraki Hitachi Cable Co., Ltd.Toyoura factory (72) Inventor Misao Matsuzawa 1500 Kawajiri-cho, Hitachi-shi, Ibaraki Hitachi Cable Co., Ltd. Inside the Toyoura Plant (72) Inventor Akio Mitsuoka 1500 Kawajiri-cho, Hitachi City, Ibaraki Hitachi Cable Co., Ltd.Toyoura Plant (72) Inventor Shuji Tobita 1500 Kawajiri-cho, Hitachi City, Ibaraki Hitachi Cable Co., Ltd.Toyoura Plant ( 72) Inventor Nobuyuki Shinohara 983, Teramae, Tajiri-cho, Hitachi, Ibaraki Prefecture 6 Within Wako Engineering Co., Ltd. (72) Inventor, Ryo Kajiyama 983, Taeji-machi, Taemachi, Hitachi, Ibaraki 6 Within Koko Engineering Co., Ltd. (56) References Actually open 3-30854 (JP, U) Actually open 54-143281 (JP, U)

Claims (3)

[Claims] 1. A wire surface defect detector for irradiating the surface of a wire with light from a light source and receiving and amplifying diffusely reflected light from the wire to detect a surface defect, wherein the light source and the light source are mounted on a mounting plate. There are three detection plates to which a plurality of light receiving elements arranged around the light source are fixed, and the three detection plates are formed in a triangular tube shape so that the light source and the plurality of light receiving elements are inside. A wire rod surface defect detector characterized by being formed. 2. The wire rod surface defect detector according to claim 1, wherein the mounting plate is a black plate which is a colored porous plate. 3. The wire rod surface defect detector according to claim 1, wherein the mounting plate is a black plate having a reflectance of 0.4 or less.