JPH10227745A - Method and device for inspecting side of top of rivet-shaped part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inspect surface defects on the sides of tops of plural rivet-shaped parts at once, by irradiating the sides of tops of the barts which are inserted into through holes in translucent pallet using light from down side of the pallet, and by photographing the reflected light. SOLUTION: A light-shielding cylinder 6 is attached to a lens 2 fixed to a camera 3 to eliminate effect from disturbance light, and a pallet 1 made of translucent material is shined by a surface lighting halogen lamp 5 on its down side. The light radiates the side of top parts of the rivet-shaped parts which are inserted into through holes in the pallet 1, and a camera 3 photograph its reflected light. An image processing device 4 processes the photographed image, and judges whether surface detects are on the side of top parts. By arranging the through holes with same intervals, orderly inserting the components, and radiating light them from downside, light which scatters in a pallet 1 irradiates the side of top of each part circumferencially and uniformly and causes surface defects to generate their shadows. Thus, surface defects on the sides of tops of plural rivet-shaped barts are inspected at once.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method and apparatus for selecting a surface defect on a side surface of a head of a rivet-shaped component such as an electrical contact by highlighting the defect with illumination light.

[0002]

2. Description of the Related Art In selecting a defective product by inspecting a surface defect on a side surface of a head of a rivet-shaped component, for example, an electric contact, the rivet-shaped component is irradiated with soft scattered light reflected by paper or the like from above. In reality, the rivet-shaped part is rolled on a table with tweezers or the like to inspect for surface defects.

[0003] Inspection of such surface defects is carried out exclusively by visual inspection of an operator. Therefore, the visual inspection does not increase the work efficiency, and the inspection accuracy varies due to individual errors and errors. I will. In order to solve this problem, in recent years, introduction of an automatic inspection device using optical means has been attempted.

[0004]

When performing a surface defect inspection on the side surface of the head of the rivet-shaped part, the head of the part is changed from a flat posture to a vertical posture and rotated along the side surface. This method is actually used in surface defect inspection of a circular flat article such as a medicine tablet. However, it is difficult to rotate the article having a foot shape such as a rivet-like part along the side face, and there is a disadvantage that the whole head side inspection apparatus becomes very complicated. Furthermore, when the parts are rotated, an image processing system for obtaining a high-speed and high-resolution image is required, and a method of inspecting the side of the head from multiple directions using several cameras is also conceivable. The equipment is complicated and not suitable for automatic inspection equipment.

As described above, in the inspection method according to the prior art, the surface defect on the side surface of the head of the rivet-shaped part is hardly emphasized and the oversight rate is high. There is also a disadvantage that the inspection takes a long time to perform the inspection.

The present invention effectively solves the above-mentioned problems of the prior art. In the present invention, rivet-shaped parts are placed and aligned in through holes or slots provided in a translucent pallet, and illumination is provided below the pallet. By installing the apparatus and detecting the light reflected from the side of the head of the part above the pallet, there is no need for rotation or the like, and if necessary,
It is an object of the present invention to provide an inspection method capable of inspecting a surface defect on a side surface of a head of a plurality of rivet-shaped components at a time, thereby greatly reducing an inspection time. Another object of the present invention is to provide an apparatus for inspecting a surface of a rivet-shaped part on a side surface of a head which can be easily constructed and can be automated by using the above method.

[0007]

The inventor of the present invention detects a light reflected on a side surface of the head of the rivet-shaped component, thereby emphasizing a surface defect on the side surface of the head as if it were raised as if it were a shadow. I found that I can do it.

That is, in order to emphasize the surface defect on the side surface of the head of the rivet-shaped part, it has been considered that the surface defect on the side surface of the head is shaded by illuminating the part directly beside the part. Since it is difficult to shine light from all sides, the transmitted light was used with the aim of shining light obliquely from below. Here, in order to supply uniform soft light, through holes or slots are provided at regular intervals to accommodate the rivet-shaped parts, and a pallet made of a translucent material having a predetermined thickness is formed. Or, by aligning the rivet-shaped parts in the slots and shining light from below, the soft light scattered in the translucent pallet uniformly illuminates the side of the head of the part from the surroundings, Defects can be emphasized as shadows.

Therefore, in order to achieve the above object, a first embodiment of the present invention is a method for inspecting a surface defect on a side surface of a head portion of a rivet-like component, the method comprising at least one through hole or a hole for accommodating the component. Put the parts in a translucent pallet provided with a slot, apply light from below the pallet, this light passes through the pallet and illuminates the head side of the part, and A method for inspecting a head side surface of a rivet-shaped component in which reflected light is imaged by a camera provided above a pallet, wherein a plurality of through holes or slots provided in the pallet is provided with the rivet-shaped component. It is preferable that the images captured by the camera are further processed by an image processing device.

In order to achieve the above object, a second embodiment of the present invention provides a translucent pallet having at least one through hole or slot for accommodating a rivet-like component, and irradiates light from below the pallet. An apparatus for inspecting a head side surface of a rivet-shaped part comprising an illuminating means and a camera provided above the pallet, further comprising a plurality of through holes or slots provided in the pallet. It is preferable that the parts can be housed in an aligned state at equal intervals, and the distance between the through-holes or slots is set such that the distance from the side of the head of each rivet-like part housed in the hole is increased. It is characterized by further comprising an image processing device for setting the distance so as not to be influenced by the reflected light mutually, or for performing image processing of the image picked up by the camera.

[0011]

FIG. 1 is a block diagram showing an embodiment of a head side inspection apparatus according to the present invention, FIG. 2 is a perspective view showing surface defects on the side of the head in electrical contacts, and FIG. FIG. 2 is a diagram showing an electric contact as a rivet-shaped article that is the subject of
(A) is a cross-sectional view of an electrical contact having a thick silver layer and a gentle head side inclination, (b) is a cross-sectional view of an electrical contact having a thin silver layer and a steep head inclination, and FIG. 4 is used in the present invention. 3A is a partial plan view of the electrical contact pallet shown in FIG. 3A, FIG. 3B is a cross-sectional view taken along line AA of FIG.
(C) is a partial plan view of the electrical contact pallet shown in FIG. 3 (b), (d) is a cross-sectional view taken along the line BB of (c), and FIG. 5 is when illuminated by a surface illumination halogen lamp from below the pallet. FIG. 3A is a diagram schematically showing the direction of light by arrows, and FIG.
FIG. 6A is a diagram showing a state in which the electrical contacts are housed, FIG. 6B is a diagram showing a state in which the electrical contacts are housed shown in FIG.
1 is a diagram showing a state when an electrical contact is actually imaged by the device shown in FIG. 1, 1 is a pallet, 2 is a lens, 3 is a camera, 4 is an image processing device, 5 is a surface illumination halogen lamp,
Reference numeral 6 denotes a light shielding tube.

The pallet 1 made of a translucent material is illuminated from below by a surface illumination halogen lamp 5, and a lens 2 attached to the camera 3 is provided with a light-shielding tube 6 in order to eliminate the influence of disturbance light. . On the other hand, the light of the surface illumination halogen lamp 5 applied from below the pallet 1 illuminates the side surface of the head of the electrical contact as an example of a rivet-shaped part contained in a through hole or a slot provided in the pallet 1, The light reflected by the side of the head is captured by the camera 3, and the image captured by the camera is subjected to image processing by the image processing device 4 to determine the presence or absence of a surface defect on the side of the head.

As shown in FIGS. 2 and 3, the electrical contact as an example of a rivet-shaped part targeted by the automatic inspection apparatus is as follows. Defective products (surface defects 9 on the side of the head) made of copper and identified
As shown in FIG. 2, it occurs in the form of cracks or scratches in the silver portion.

The electric contact which is an example of the rivet-shaped part which is the object of the present invention can be roughly divided into an electric contact having a thick silver layer of the upper part 7 of the head and a gentle side inclination as shown in FIG. As shown in FIG. 3 (b), there is an electrical contact where the silver layer on the upper part 7 of the head is thin and the side surface slope is steep. The dimensions of the electrical contacts shown in FIG. 3 are merely examples, and are not limited to these dimensions. However, the specular defect on the side of the head of the electrical contacts is so small that it is difficult to visually inspect it. This is shown in this figure.

FIG. 4 shows the details of the pallet 1 in FIG. The material of the pallet 1 used for this inspection is, for example, a translucent material made of milk-white acrylic, and the electric contacts are provided in the through holes 1-1 or the slots 1-2 provided at equal intervals in the pallet 1. It is set and set so that the foot 8 enters. Here, the interval between the through holes 1-1 or the slots 1-2 was 7 mm, which is the shortest distance not affected by the reflected light from the adjacent electrical contact. The difference between the shape of the through hole 1-1 and the shape of the slot 1-2 of the pallet 1 is that
The through hole 1-1 is used for an electrical contact having a thick silver layer.
No. -2 is for an electrical contact with a thin silver layer. The counterbore portion 1-3 is provided on the pallet 1 for the electrical contact with a thin silver layer, because the light passing through the pallet 1 is sufficiently applied to the steeply inclined side of the head to emphasize shadows due to cracks and scratches. To make it.

Further, in FIG. 5, the directions of light passing through the pallet 1 are schematically shown by arrows, each of which is divided into electrical contacts having a thick silver layer and electrical contacts having a thin silver layer. By illuminating the surface illumination halogen lamp 5 from below the pallet 1, light is diffused inside the translucent pallet 1. The diffused light is uniformly illuminated from obliquely below the electrical contact as shown in FIG. 5A, or from the side by the spot facing portion 1-3 as shown in FIG. 5B. here,
The reason for providing the spot facing portion 1-3 is that light can be sufficiently applied from the spot facing portion 1-3 of the inspection pallet for the electrical contact having a thin silver layer to the steeply inclined side surface of the electrical contact. The light illuminating the inclined portion on the side of the head of the electric contact is reflected toward the camera 3 installed above. At this time, if there is a crack or a scratch on the side of the head, the light is not reflected in the direction of the camera 3 but is scattered in another direction, so that a shadow due to a surface defect is generated.

Next, FIG. 6 shows an example of a picked-up image of an electric contact having no surface defect and an electric contact having a surface defect. The shade 10 due to electrical contacts without surface defects looks round. But,
In the case of cracks or scratches on the side of the head of the electrical contact, the light is scattered instead of being reflected toward the upper camera, and is emphasized as a shadow. That is, when a surface defect such as a crack or a scratch on the side surface of the head crawls up to the upper part, it appears as a shadow 11 having a projection around a round shadow formed by electrical contacts. When the surface defect does not crawl to the upper part, it appears as a shadow 12 separated from a round shadow by the electric contact. The shadows 11 and 12 due to the surface defects on the side of the head of the electrical contacts highlighted by this method are photographed by the camera 3 and the image signals are processed by the image processing device 4.
Determine defective products.

[0018]

According to the present invention, when inspecting surface defects on the side surface of the head of a rivet-shaped component such as an electric contact,
Without missing a defective product with cracks or scratches on the side of the head of the electrical contact, it can be distinguished under clear criteria, and there is no trouble such as rotating the electrical contact,
Defects can be easily identified by imaging from above,
The time required for the inspection can be significantly reduced.

Further, by providing a mechanism for transferring the contact points to the pallet and a mechanism for moving the pitch of the pallet, a device for automatically inspecting the surface defects on the side surface of the head of the rivet-shaped component can be provided, and the inspection by unmanned operation can be performed. Become like

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a head side inspection apparatus according to the present invention.

FIG. 2 is a perspective view showing a surface defect on a side surface of a head in an electric contact.

3A and 3B are diagrams showing an electric contact as a rivet-shaped article which is an object of the present invention, wherein FIG. 3A is a cross-sectional view of an electric contact having a thick silver layer and a gentle inclination to the side of the head, and FIG. It is sectional drawing of the electrical contact which is thin and the head side inclination is steep.

4A and 4B are diagrams showing a pallet used in the present invention, wherein FIG. 4A is a partial plan view of the pallet for electrical contacts shown in FIG.
FIG. 3B is a cross-sectional view taken along line AA of FIG. 3A, and FIG.
Partial plan view of the electrical contact pallet shown in (b), (d)
FIG. 7C is a cross-sectional view taken along line BB of FIG.

5A and 5B are diagrams schematically showing directions of light when illuminated by a surface illumination halogen lamp from below the pallet with arrows, and FIG.
FIG. 3A is a diagram showing a state where the electrical contacts shown in FIG.
FIG. 3B is a diagram showing a state where the electrical contacts shown in FIG.

FIG. 6 is a diagram showing a state when an electric contact is actually imaged by the device shown in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pallet 1-1 Through hole 1-2 Slot hole 1-3 Counterbore part 2 Lens 3 Camera 4 Image processing device 5 Surface illumination halogen lamp 6 Shielding cylinder 7 Upper head part 8 Foot part 9 Surface defect 10, 11, 12 Shadow

Claims (7)

[Claims] 1. A method for inspecting a surface defect on a side surface of a head of a rivet-shaped part, comprising:
Placing the part in a translucent pallet provided with two through holes or slots, irradiating light from below the pallet, this light passes through the pallet and illuminates the side of the head of the part,
A method for inspecting a head side surface of a rivet-shaped component, wherein the light reflected on the head side surface of the component is imaged by a camera provided above a pallet. 2. The pallet according to claim 1, wherein the plurality of through holes or slots provided in the pallet are capable of receiving the rivet-shaped parts in an aligned state at equal intervals. Inspection method for the side of the head of rivet-shaped parts. 3. The image processing apparatus according to claim 1, wherein the image captured by the camera is further processed by an image processing device.
A method for inspecting a side surface of a head of a rivet-shaped component as described. 4. A semi-transparent pallet having at least one through hole or slot for accommodating a rivet-like component, illuminating means for applying light from below the pallet, and a camera provided above the pallet. A head side inspection device for rivet-shaped parts. 5. The pallet according to claim 4, wherein the plurality of through holes or slots provided in the pallet can accommodate the rivet-shaped parts in an aligned state at equal intervals. Head side inspection device for rivet-shaped parts. 6. The distance between the through holes or the slots is a distance that does not affect each other by the reflected light from the side face of the head of each rivet-shaped part housed in the holes. 5. A head side inspection device for a rivet-shaped part according to 5. 7. The apparatus for inspecting a head side surface of a rivet-shaped component according to claim 4, further comprising an image processing device for performing image processing of an image captured by the camera.