JPH10142131A - Method for testing hole-spreading property of hole-hole spreading metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the occurrence of an enlargement hole-opening part crack in a hole enlargement process by pushing a punch into a metal plate hole-opening part while the punch is in contact with the metal plate hole-opening part and picking up the image of the hole enlargement process of the hole-opening part with a television camera. SOLUTION: A hole 2 is punched in a flat metal plate 1 to create a test piece, and then a punch 3 is brought into contact with the part of the hole 2 of the flat metal plate 1 and then is pushed in. The part of the hole 2 is gradually enlarged and at the same time the image of the enlargement process of the part of the hole 2 is picked up by a television camera 4, and the image is introduced to a data-processing device 5. In the data-processing device 5, image is processed so that an outer-periphery part 7 and an inner-periphery part 8 of a plate thickness section 6 of the flat metal plate 1 of the part of the hole 2 of the flat metal plate 1 become dark and the plate thickness section 6 of the flat metal plate 1 and the surface of the metal plate other than the punch 3 located at the part of the hole 2-and the part of the hole 2 become bright. When a crack is generated in the axial direction of the plate thickness section 6 of the part of the hole 2 of the flat metal plate 1, the occurrence of crack is judged by operation and is displayed by the data-processing device 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for testing hole expandability of a hole-hole expandable metal plate.

[0002]

2. Description of the Related Art A hole-expanding test method of a hole-expanding metal plate is performed by contacting a punch with an opening of a metal plate, gradually pushing the punch into the hole, and expanding the hole. The diameter of the hole to be expanded when a crack occurs in the hole is measured, and the quality of the hole-hole expanded metal plate is controlled by checking the quality of the hole expansion ratio. The detection of the occurrence of such a crack in the hole opening / opening portion is visually determined. Further, the actual situation is that the diameter of the hole-expanding hole portion is manually measured using a caliper or the like.

[0003]

As described above, the judgment of cracks in the hole expanding and opening portions by visual inspection has individual differences, and the judgment at the time of the occurrence of the exact cracks varies, so that the accurate metal sheet hole expanding ratio cannot be accurately determined. I can't confirm. Further, the measurement of the diameter of the hole expanding and opening portion has a problem that it is not preferable in terms of labor saving because it is manually performed. The method of the present invention has been made to advantageously solve such a problem, and an image of a hole enlarging process of an opening portion is taken by a television camera, and the hole enlarging process is subjected to data processing, and the opening portion of the hole enlarging process is processed. It is an object of the present invention to provide a hole-expandability test method for a hole-hole expansion metal plate that detects the occurrence of cracks.

[0004]

The feature of the method of the present invention is that a punch abuts and pushes into a metal plate opening,
A hole-expandability test method for a hole-hole-expansion metal plate, wherein a television camera captures an image of a hole-expansion process in an aperture-opening portion and detects occurrence of an enlarged aperture-hole crack in the hole-expansion process. A punch is brought into contact with the opening of the metal plate and pushed in, and the process of enlarging the hole at the opening is imaged with a television camera, and the occurrence of a crack in the hole enlarging process is detected. A hole-expandability test method for a hole-hole-expansion metal plate, comprising measuring a diameter of an enlarged hole portion from an image of a portion.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS For example, an opening is formed in a metal plate by inward machining, and after a cone-shaped punch of the opening is brought into contact with the opening, the opening is gradually enlarged by pushing the opening. Is captured by a television camera, and the captured image is introduced into a data processing device to process the television camera image to darken the inner peripheral edge and the outer peripheral edge of the plate thickness cross section of the metal plate opening in the enlarging process (hereinafter referred to as dark). By brightening (hereinafter referred to as "bright") the metal plate other than the opening portion (punch) and the outer peripheral edge of the plate thickness section of the opening portion, the inner peripheral edge and the outer peripheral edge of the plate thickness section of the metal plate opening portion are sharpened. .

[0008] Cracks in the thickness section of the metal plate opening are divided into axial cracks in the thickness section, oblique cracks in the thickness section, and partial cracks in the thickness section. Such crack detection methods include, for example, calculating the inner and outer radii along the thickness cross section of the hole in the process of expanding the hole in the metal plate, and tracking the trajectory of the crack from the clockwise and counterclockwise directions. As a result, it is possible to reliably detect a crack that occurs at an undefined position from the inner and outer surfaces of the plate thickness section.

In this way, after detecting a crack in a thick section of a metal plate opening portion in the process of expanding a hole, the diameter of the enlarged hole at the time of the crack is measured.
As described above, the diameter of the dark portion at the inner peripheral edge at the plate thickness cross section of the metal plate enlarged opening is measured. In other words, the illuminance at the inner peripheral edge of the plate thickness section of the metal plate opening is defined as peak coordinates, a plurality of coordinates are obtained as symmetric coordinates in order to remove noise from the peak coordinates, and the distance between the respective peak coordinates is measured to accurately determine the time of cracking. The diameter of the enlarged hole is measured.

As described above, by detecting cracks in the process of enlarging a hole in a metal plate and measuring the diameter of the enlarged hole at the time of occurrence of a crack, a hole-hole expansion ratio test of a metal plate can be quickly and accurately performed. And quality control of the hole-to-hole expanding metal plate can be reliably performed. Thus, the crack detection as described above and the measurement of the inner enlarged hole diameter of the enlarged hole diameter measurement can be accurately performed even by manual measurement using a caliper or the like. Therefore, if the labor saving is neglected, the crack detection can be performed by the crack detection method of the present invention, and the hole-hole spreadability of the metal plate can be accurately grasped by measuring the enlarged hole diameter manually.

[0009]

Next, examples of the method of the present invention will be described. As shown in FIG. 1, a test piece is formed by opening a hole 2 in a flat metal plate 1 (steel plate), and then a punch 3 is pressed into contact with the opening 2 of the flat metal plate 1 as shown in FIG. At the same time as the hole 2 is gradually enlarged, the enlarging process of the hole 2 is imaged by the television camera 4 (CCD camera) as shown in FIG. In this data processor 5, as shown in FIG. 4A, the outer peripheral end 7 and the inner peripheral end 8 of the metal plate 1 thick section 6 of the metal plate 1 opening 2 are dark, and the metal plate 1 thick section 6 and the opening Image processing is performed so that the punch 3 located at the second part and the metal plate surface outside the two holes are bright. Then, FIG.
As shown in (b), the coordinates are incorporated into the coordinates by a binarization process.

However, as shown in FIG. 5, when the punch 3 is pushed in, the metal plate 1 opening 2 part gradually expands in the axial direction (cross-sectional direction) of the metal plate 1 opening 2 part thickness section 6 in the expanding process. ) Is detected. As such a crack detection logic, the data processing device 5 shown in FIG. In the process of enlarging the hole, the inner and outer radii are calculated along the thickness section of the opening, and the trajectory of the crack is tracked and detected from the clockwise and counterclockwise directions to detect the inner and outer radii. Detect cracks that occur at undefined positions. Therefore, as shown in FIG.
When a crack 9 occurs in the direction (cross-sectional direction), it is determined by calculation that the crack 9 has occurred, and is displayed on the data processing device 5. Also, as shown in FIG.
Is generated, r is increased and it is determined that the oblique crack 9 (crack). Further, in a state where no crack 9 has occurred up to the outer peripheral end 7 of the two-part plate thickness section 6 as shown in C, the darkness of the sheet thickness section 6 is not continuous and it is determined that no crack has occurred. The crack 9 advances to the outer end 7 of the cross section 6 and is tracked and detected as described above until it is determined that the crack 9 has occurred.

As described above, after detecting the occurrence of a crack in the enlarged opening 2 portion, the punch 3 is lowered and removed from the enlarged opening 2 as shown in FIG. 6, and the data shown in FIG. In the processing device 5, image processing is performed so that the initiality of the inner peripheral edge 8 of the plate thickness section 6 of the enlarged opening 2 becomes the peak A shown in FIG. Are plotted and used as the inner diameter coordinates of the two enlarged apertures. Thus, from the coordinates shown in FIG. 8, Y diameter = Y2-Y1,
X-diameter = X2-X1, and the quality of the hole-hole-expanding metal plate is controlled by measuring the diameter of the two enlarged holes to test the hole-expandability (rate) of the metal plate.

[0012]

According to the method of the present invention, it is possible to accurately detect cracks in the enlarged opening of the hole-to-hole expanding metal plate, so that strict quality control can be performed. In addition, the diameter of the enlarged opening can be accurately and quickly measured. In addition, it is possible to automatically detect cracks in the enlarged hole and measure the diameter of the enlarged hole, thereby achieving excellent effects such as labor saving.

[Brief description of the drawings]

FIG. 1 is a plan view of a hole-hole enlarging metal plate.

FIG. 2 is a perspective view showing an enlarged state of an opening of a hole-hole expanding metal plate.

FIG. 3 is a side view showing an example of detection of a crack in a hole-hole expansion hole portion of a metal plate.

FIG. 4 is a schematic view of an opening portion subjected to image processing.

FIG. 5 is a flowchart showing an example of detecting a crack in an enlarged hole.

FIG. 6 is a side view showing an example of diameter measurement of a hole-hole expanding metal plate enlarged opening portion.

FIG. 7 is a schematic view of a cross section of a plate thickness of an enlarged opening portion due to illuminance.

FIG. 8 is a plan view showing an example of measuring the diameter of the enlarged opening.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hisao Senokuchi 5-3 Tokai-cho, Tokai City, Aichi Prefecture Inside Nippon Steel Corporation Nagoya Works (72) Inventor Ichiro Arai 5-3 Tokai-cho, Tokai City, Aichi Prefecture Nippon Steel Corporation Nagoya Works

Claims (2)

[Claims] The present invention is characterized in that a punch is brought into contact with an opening of a metal plate and pushed in, and a process of enlarging the hole in the opening is imaged by a television camera to detect the occurrence of a crack in the enlarging opening in the enlarging process. Hole-hole expansion test method of hole expansion metal plate. 2. A punch is brought into contact with a metal plate opening portion and pushed in, and the process of enlarging the hole in the opening portion is imaged by a television camera to detect the occurrence of a crack in the hole enlarging process. And measuring the diameter of the enlarged hole portion from the image of the enlarged hole portion.