JPH05249043A - Illuminating method in compression-bonded terminal image processing inspection - Google Patents

Abstract

PURPOSE:To improve the contrast between a resin part and a metal part and thereby to determine the quality without fail by illuminating a contact-bonded terminal by an irradiating means which makes continuous irradiation in the same direction as the longitudinal direction of the compression-bonded terminal from the same direction as an image-sensing direction. CONSTITUTION:An illuminating means 11 is constructed of a bar-shaped fluorescent lamp making continuous illumination in the same direction as the longitudinal direction of a contact-bonded terminal 2. Besides, a shade is provided so that a light of the means 11 may not enter a means 3 directly. Disposition is made so that the irradiating light of the illuminating means 11 is reflected specularly by the cylindrically formed surfaces of a resin barrel 2a and a conductor barrel 2b of the compression-bonded terminal 2 and that the reflected light enters the means 3. The shape, dimensions, inclination, etc., of the contact-bonded terminal are determined with reference points necessary for an image processing used as references, and the quality of a contact- bonded state of the compression-bonded terminal 2 is determined on the basis of the position of the end part of resin 1a between the barrels 2a and 2b, the length of projection of the conductor 1b between the barrel 2b and the fore end part 2c, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting method for inspecting a crimped state of a crimp terminal at a stripped end of an electric wire by image processing.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 19, a resin barrel 2a in which a resin 1a at a stripped end of an electric wire 1 is held by a cylindrical molding, and an exposed core wire 1b at a stripped end of an electric wire 1 is held by a cylindrical molding. In addition, in the case of inspecting the crimping state of the crimping terminal 2 by image processing, the crimping terminal 2 is provided with the core wire barrel 2b that maintains electrical continuity and the tip 2c that engages with the receiving crimping terminal and becomes conductive. The inspection is performed by the inspection device having the configuration shown in FIG. In addition, in FIG. 19, B is a bell mouth formed at the end of the core barrel 2b for releasing stress during crimping.

That is, a television camera and a two-dimensional CCD
The crimping terminal 2 is imaged by the imaging means 3 such as a camera,
The image by the image pickup means 3 is displayed on a monitor television receiver (hereinafter referred to as monitor) 4, the image is processed by the image processing means 5, and the resin barrel 2a and the core wire barrel 2b of the crimp terminal 2 are processed from the luminance data of each pixel. Resin 1 between
a, presence / absence of the core wire 1b, presence / absence of the core wire 1b between the core wire barrel 2b and the distal end portion 2c, and the condition of the core wire 1b are judged, and the crimped state of the crimp terminal 2 is judged to be good or bad. It is displayed on the printer 6 and the display 7.

Reference numeral 8 is an operation keyboard for inputting program data and the like necessary for image processing.

By the way, in the inspection of the pressure-bonded state by such image processing, the manner of illumination is extremely important, and various illumination methods have been proposed conventionally.

[0006] For example, as disclosed in Japanese Patent Laid-Open No. 57-60249, there is a method of taking a contrast by utilizing a complementary color of a resin. This is a method of irradiating a spot-focused light using a fiber onto a crimp terminal portion to The reflected light is received by the image pickup means through the complementary color filter.

Further, Japanese Patent Laid-Open No. 175942/1982 discloses a method of utilizing polarized light to obtain a contrast between a resin portion and a metal portion, and further, Japanese Laid-Open Patent Publication No. 60-1984.
As described in Japanese Patent Laid-Open No. 73-73, there has been proposed a method of obtaining a contrast between a resin portion and a metal portion by irradiating light having a specific wavelength at which the resin material has a high absorptivity.

[0008]

However, in the case of using the above-mentioned complementary color filter or light having a characteristic wavelength, it is necessary to prepare a complementary color filter and a light source having an appropriate wavelength suitable for each color of the resin. However, it takes a lot of time and labor, and no stable contrast can be obtained by any of the illumination methods, which is insufficient for surely determining the quality of the crimped state of the crimp terminal.

Therefore, the present invention has been made to solve the above-mentioned problems, and aims to improve the contrast between the resin portion and the metal portion so that a stable crimp terminal image can be obtained. With the goal.

[0010]

An illumination method in a crimp terminal image processing inspection according to the present invention is to hold a resin at a stripping end of an electric wire by a resin barrel, hold an exposed core wire by a core barrel, and conduct electrical conduction. A crimping terminal for holding the crimping terminal by an image pickup means from a direction substantially perpendicular to the cylindrical surfaces of the barrels, and an image processing means processes an image of the crimping terminal by the image pickup means. When inspecting the crimped state of the crimp terminal, from the substantially same direction as the imaging direction by the imaging means, to the illumination unit continuous in the substantially same direction as the longitudinal direction of the crimp terminal or in the substantially same direction as the longitudinal direction. It is characterized in that the crimp terminal is illuminated by an illumination means having a plurality of arranged illumination portions.

[0011]

According to the present invention, from a direction substantially the same as the image pick-up direction by the image pick-up means, a lighting unit that is continuous in the same direction as the lengthwise direction of the crimp terminal or has a plurality of lighting units arranged in the same direction. In order to illuminate the crimp terminal by means, a mirror reflection portion in the longitudinal direction of the crimp terminal can be obtained in the resin barrel and the core barrel of the crimp terminal, which is a metal portion, and the core wire is usually provided by a bell mouth at the end of the core barrel. The boundary between the barrel and the core wire becomes clear, and the contrast between the resin part and the metal part is also improved compared to the past,
Images of stable crimp terminals can be obtained.

[0012]

1 to 14 show a first embodiment of an illumination method in a crimp terminal image processing inspection of the present invention.
5 and 16 show the second embodiment, FIG. 17 shows the third embodiment, and FIG. 18 shows the fourth embodiment.

Since the basic structure of the crimping terminal applied to the present invention is the same as that shown in FIG. 19 and the structure of the inspection device is also the same as that of FIG. , FIG. 20.

First, the first embodiment will be described.

As shown in FIG. 1, an illuminating means 11 including a rod-shaped fluorescent lamp having an illuminating part continuous in the same direction as the lengthwise direction of the crimp terminal 2 is arranged.
The crimp terminal 2 is illuminated by being driven by the high frequency power source 12 of about 0 kHz. In addition, the arrow in FIG.
Of the light scattered by the paint on the surface of 1, the crimp terminal 2
Shows the optical path used to illuminate.

At this time, as shown in FIG.
Is arranged so as to illuminate from the image pickup direction of the image pickup means 3, that is, from the direction substantially the same as the direction perpendicular to the cylindrical surfaces of both barrels 2a and 2b, so that the light of the illumination means 11 does not directly enter the image pickup means 3. A light-shielding plate 13 is provided, and the irradiation light of the illuminating means 11 allows the resin barrel 2a of the crimp terminal 2 and the core barrel 2b.
The cylindrically-shaped surface is mirror-reflected so that the reflected light is incident on the image pickup means 3.

An image of the crimp terminal 2 obtained under the above-mentioned illumination is as shown in, for example, FIG. 3, and the hatched portion in FIG. 3 is the specular reflection portion, and the resin barrel 2a and the core wire barrel. Specular reflection is also obtained in the core line portion between 2b and 2b, and only these specular reflection portions are extracted as shown in FIG.

At this time, as described above, the crimp terminal 2
Bell mouths B are usually formed at both ends of the core wire barrel 2b in order to release the stress at the time of crimping, and the bell mouth B makes the boundary between the end of the specular reflection portion of the core wire barrel 2b and the core wire 1b clear. Become.

Next, image processing by the image processing means 5 will be described. Japanese Patent Application No.
The processing by the so-called run length encoding method described in detail in the specification of the application No. 26871 and the accompanying drawings is performed, and the shape of the crimp terminal 2 which is the object from the change of white and black information along one scanning line. Etc. is basically derived.

That is, in order to detect the reference point necessary for image processing, the windows W ₁ and W ₂ formed by straight lines are superimposed on the central portion of the image of the specular reflection portion of the core barrel 2b as shown in FIG. Each set, both windows W ₁ , W ₂
And the boundary line of the specular reflection portion are derived, the inclination of the specular reflection portion is obtained from the inclination of the line segment ab connecting the points a and b, and then the midpoint of the line segment ac or Line segment ac
The window W ₃ is set with an inclination extending from an arbitrary intermediate point of the line and given by the line segment ab, and the change point A of the brightness on the window W ₃ is derived, and this point A is one of the reference points necessary for image processing. Then, the other reference points B, C, D, E, F, G and H shown in FIG. 4 are derived in the same manner.

By the way, in reality, the shape of the mirror-reflecting portion is geometrically unstable due to the fact that the barrels 2a and 2b are not completely cylindrically shaped and the mirror surface is not perfect.
Since it is impossible to obtain the reference point by one processing as shown in FIGS. 5 and 6, the reference point is obtained by the processing of two to three times.

That is, the reference point A'is not located at the end of the specular reflection portion when the window W ₃ is set as shown in FIG. 7 due to the error of the inclination θ based on the line segment ab shown in FIG. As shown in FIG. 8, the windows W ₁ and W ₂ are reset at a position moved by a few pixels from the derived point A ′ and the same operation is repeated to derive a change point of the brightness on the window W _3. It

As described above, the reference point A (see FIG. 6) is accurately derived by repeating the setting of the window W ₃ and the deriving of the change point of the brightness 2-3 times.

When the reference points A to H necessary for image processing are derived by the above procedure, these reference points A to H are derived.
The shape, size, inclination and the like of the crimp terminal 2 are obtained based on H, and the end position of the resin 1a between the resin barrel 2a and the core barrel 2b and the core wire 1b between the core barrel 2b and the tip end 2c are obtained. Depending on the protruding length of the
The quality of the crimped state is determined.

Further, since the reference points A to H are accurately derived in this way, it is not necessary to hold the crimp terminal 2 in the same posture by a mechanical holding means such as a chuck, and the crimp terminal 2 to be inspected. May be rough to some extent, for example, the crimp terminal 2 is parallel to the XY plane, and the width direction perpendicular to the longitudinal direction of the crimp terminal 2 is parallel to the Y-axis direction. Assuming that the case of imaging from the Z-axis direction is the basic arrangement, even if the arrangement of the crimp terminal 2 is deviated in the X-axis and Y-axis directions, it is sufficient if it is within the visual field of the illuminating means 3, and the displacement in the Z-axis direction is This can be dealt with by adjusting the focus of the lighting means 3, and about the so-called yawing in which the crimp terminal 2 rotates about the Z axis, about ± 45 ° from the basic arrangement.
It has been confirmed by experiments that a stable image can be obtained even if there is a displacement within the range of, and a displacement within a range of about ± 45 ° from the basic arrangement is obtained even for so-called rolling that rotates around the Y axis. It was confirmed by experiments that a stable image can be obtained even if there is, and a stable image can be obtained even if there is a displacement of ± 10 to 20 ° from the basic arrangement for so-called pitching that rotates around the X axis. It has been confirmed by experiments.

On the other hand, it is possible to detect the protrusion of the core wire,
For example, as shown in FIG. 9, one core wire L is a core wire barrel 2b.
When crimping is performed while protruding from the
As shown in FIG. 10 which is an enlarged cross-sectional view taken along the line -X ', the projecting core wire L reflects the light from the illuminating means 11 as shown by the arrow, and this reflection is partial with respect to the specular reflection portion of the core wire barrel 2b. Since the diffuse reflection is caused, it can be clearly detected on the image by the binarization process, and therefore, the protrusion of the core wire can be detected by the partial diffuse reflection in the specular reflection portion of the core barrel 2b. Incidentally, FIG.
1 corresponds to a front view when FIG. 9 is a plan view.

Then, as a result of the image processing, as shown in FIG.
As shown in (b), the resin barrel 2a holds the resin 1a with the resin 1a of the electric wire 1 protruding by an appropriate length between the resin barrel 2a of the crimp terminal 2 and the core barrel 2b,
If the core wire 1b is slightly protruded between the core wire barrel 2b and the tip portion 2c and the core wire barrel 2b holds the core wire 1b, the crimped state of the crimp terminal 2 is determined to be good.

As a result of the image processing, as shown in FIG.
As shown in (b), the resin 1a of the electric wire 1 does not project between the resin barrel 2a of the crimp terminal 2 and the core barrel 2b, and the resin barrel 2a grips the end of the resin 1a at the peeling end. If so, it is determined to be a so-called resin portion crimping defect.

Further, as a result of the image processing, as shown in FIG.
As shown in (b), when the end portion of the resin 1a at the stripping end is held by the core wire barrel 2b of the crimp terminal 2 and the core wire 1b cannot be seen between the resin barrel 2a and the core wire barrel 2b, a so-called It is determined that the resin bite is defective.

In addition, as a result of image processing, the above-mentioned core wire protrusion failure, no peeling and crimping failure, and so-called pressing failure in which the resin barrel 2a is open, and the tip of the core wire is the core wire barrel 2.
A core wire breakage defect that does not protrude from b is also detected, and appropriate measures are taken for each detected defect.

Therefore, by illuminating the crimp terminal 2 with the elongated illuminating means 11 parallel to the longitudinal direction of the crimp terminal 2, from substantially the same direction as the imaging direction of the imaging means 3.
In the resin barrel 2a and the core wire barrel 2b of the crimp terminal 2 which is a metal portion, a mirror-reflected portion in the longitudinal direction of the crimp terminal 2 can be obtained, and the bell mouth B allows the boundary portion between the core barrel 2b and the core wire 1b to be formed. Crisp and resin 1
Since the contrast between a and the metal part is also improved, it becomes possible to obtain an extremely stable image of the crimp terminal 2, and it is possible to accurately detect the reference point necessary for image processing and to judge whether the crimp state of the crimp terminal 2 is good or bad. The reliability can be improved.

Next, the second embodiment will be described.

As shown in FIG. 15, two illuminating means 11 in FIG. 1 are provided, and both illuminating means 11 are arranged parallel to the longitudinal direction of the crimp terminal 2 as in the first embodiment. At this time, the light-shielding plate 13 is provided so that the light from both illumination means 11 does not directly enter the imaging means 3.

In this way, when two illuminating means 11 are provided, the mirror reflection on the core barrel 2b is caused by both illuminating means 1.
16 is wide as shown in FIG. 16 (a) when the distance between the two is small, and is large as shown in FIG. 16 (b) when the distance between both lighting means 11 is large. Two each appear in the half and right half.

Therefore, by deriving the reference point based on such an image of the specular reflection portion, it is possible to improve the reliability of the quality judgment of the crimping state of the crimp terminal 2 as in the first embodiment.

Further, as a third embodiment, as shown in FIG. 17, the illumination means 1 comprising the rod-shaped fluorescent lamp in FIG.
Illuminating means 14 including an arc-shaped fluorescent lamp instead of 1.
It is also possible to provide an effect equivalent to that of the first embodiment, and since the bent tip side of the lighting means 14 is closer to the crimp terminal 2 than the root side, the luminous flux It is possible to improve the accuracy of image processing by widening the width of.

Further, as a fourth embodiment, as shown in FIG. 18, an illuminating means 16 having an illuminating section 15 composed of a plurality of light emitting diodes arranged in the same direction as the lengthwise direction of the crimp terminal 2 is provided. It is also possible to provide the same effect as in the first embodiment, and it is possible to reduce the size and cost of the illuminating means 16 by using a light emitting diode or the like.

Of course, both illumination means 11 shown in FIG. 15 may be replaced with the illumination means 16 shown in FIG.

In addition, a plurality of illumination units 15 shown in FIG.
May be arranged in an arc shape as shown in FIG.

Further, the present invention can be applied to the inspection of all crimp terminals made of a resin barrel and a core barrel and applied to wire harnesses for automobiles and the like.

[0041]

As described above, according to the illumination method in the crimp terminal image processing inspection of the present invention, the illumination is continuous from substantially the same direction as the imaging direction by the imaging means to substantially the same direction as the longitudinal direction of the crimp terminal. Part or a lighting means having a plurality of illuminating parts arranged in substantially the same direction, so as to illuminate the crimp terminal, the resin barrel of the crimp terminal, which is a metal part, and the mirror barrel in the longitudinal direction of the crimp terminal in the core barrel. The contrast between the resin part and the metal part can be greatly improved compared to the conventional method, and it becomes possible to obtain a stable image of the crimp terminal, and the crimping is performed by accurately detecting the reference point necessary for image processing. The reliability of the quality judgment of the crimping state of the terminal can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of a first embodiment of an illumination method in a crimp terminal image processing inspection of the present invention.

FIG. 2 is a schematic view of the first embodiment viewed from a different direction.

FIG. 3 is an explanatory diagram of an image according to the first embodiment.

FIG. 4 is an explanatory diagram of image processing according to the first embodiment.

FIG. 5 is an explanatory diagram of image processing according to the first embodiment.

FIG. 6 is an explanatory diagram of image processing according to the first embodiment.

FIG. 7 is an explanatory diagram of image processing according to the first embodiment.

FIG. 8 is an explanatory diagram of image processing according to the first embodiment.

FIG. 9 is an operation explanatory diagram of the first embodiment.

FIG. 10 is an operation explanatory diagram of the first embodiment.

FIG. 11 is an operation explanatory diagram of the first embodiment.

FIG. 12 is an operation explanatory diagram of the first embodiment.

FIG. 13 is an operation explanatory diagram of the first embodiment.

FIG. 14 is an operation explanatory diagram of the first embodiment.

FIG. 15 is a schematic view of the second embodiment of the present invention.

FIG. 16 is an operation explanatory diagram of the second embodiment.

FIG. 17 is a schematic view of the third embodiment of the present invention.

FIG. 18 is a schematic view of the fourth embodiment of the present invention.

FIG. 19 is an external view of a general crimp terminal.

FIG. 20 is a block diagram of a general image processing inspection device used for inspection of crimp terminals.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 electric wire 1a resin 1b core wire 2 crimp terminal 2a resin barrel 2b core wire barrel 3 imaging means 5 image processing means 11, 14, 16 lighting means 15 lighting section

Claims (1)

[Claims] 1. A crimp terminal for holding resin at a stripped end of an electric wire with a resin barrel, holding an exposed core wire by a core wire barrel, and maintaining electrical continuity, wherein the barrel-shaped surfaces of both barrels. When the crimping terminal is inspected in a crimping state by processing the image of the crimping terminal by the image processing means and processing the image of the crimping terminal by the image processing means, the imaging direction by the imaging means The crimp terminal is illuminated by an illuminating unit having an illuminating section that is continuous in substantially the same direction as the longitudinal direction of the crimp terminal or a plurality of illuminating sections that are arranged in the longitudinal direction in substantially the same direction. An illumination method in a crimp terminal image processing inspection, which comprises: