JP2018205098A - Device for automatically inspecting inner surface of pipe material - Google Patents

Abstract

The present invention aims to simplify the configuration of a pipe inner surface automatic inspection apparatus and reduce the occupied area, and to automate the adjustment at the time of switching the type of pipe material to be inspected for general use. A tube inner surface automatic inspection apparatus includes a light source unit 17 disposed on one opening end side of a tube member 20 and a movable focus type zoom lens disposed on the other opening end side of the tube member. 16, by obtaining a tube end image of the tube material and performing image processing, a diameter value (in pixels) on the image of the tube material to be inspected having a constant diameter is obtained, and the diameter value is made constant. A mechanism is provided for controlling the movement of the camera / lens unit back and forth so that the distance between the camera / lens unit and the tube end of the tube to be inspected is constant. [Selection] Figure 2

Description

  The present invention relates to an automatic inspection apparatus used for inner surface inspection of pipe materials.

  Various pipe materials are used for various applications, but visual inspection is still performed especially for pipe materials whose inner surface flaws greatly affect the reliability of the pipe material. However, with the progress of globalization, there is an urgent need to improve productivity, and there is a great need for automation of this visual inspection in various diverse pipe materials.

  The inventors of the present application disclose pipe material inner surface automatic inspection devices corresponding to the above needs in Patent Documents 1 to 3.

  FIG. 3 is a diagram showing a configuration of the pipe material inner surface automatic inspection apparatus disclosed in Patent Documents 1 to 3. A camera and a movable focus type zoom lens 108 are attached to one of the tube materials 112, and a diffusion light source 109 is installed on the opposite side. Then, the tube inner surface image is zoomed from the front surface of the tube material 112, and a plurality of images are captured while changing the focus to acquire an image. Further, an integrated image obtained by integrating these images is created, and image quality analysis is performed to determine whether the image is acceptable. From the end of the long tubular material to the center of the tubular material, the image is inspected twice in order from both ends of the tubular material.

  That is, the inspection method in the tubular material inner surface automatic inspection apparatus disclosed in Patent Documents 1 to 3 combines the inner surface observation images of a plurality of tube materials obtained by continuously changing the focus into one integrated image, and then The integrated image is subjected to pass / fail determination inspection by image analysis by a flaw detection analysis means.

JP 2011-69616 A JP 2006-090293 A Japanese Patent Application No. 2006-186098

  However, in the automatic inspection device for the inner surface of the pipe material disclosed in Patent Documents 1 to 3, it is necessary to keep the distance between the zoom lens 108 and the pipe end constant at the time of image acquisition. Therefore, as shown in FIG. 3, before setting the tube material 112 to the stage to be inspected, the tube material is mechanically pushed to align the tube material such as the stopper 113 so that the distance between the zoom lens 108 and the tube end is constant. A mechanism 106 is provided. For this reason, there is a problem that the area occupied by the automatic inspection apparatus increases.

  In addition, for image processing, it is essential to measure the center coordinates of the tube material 112 in order to cut out a focused range from the acquired image in a ring shape. Sometimes, it is difficult to acquire a clear tube end image due to the influence of ambient light, and it is necessary to provide a light shielding mechanism 107 for shielding ambient light from the tube material. For this reason, there is a problem that the configuration of the automatic inspection apparatus is complicated and expensive.

  The present invention has been made in view of such problems, and its main purpose is to simplify the configuration of the pipe inner surface automatic inspection apparatus and reduce the occupied area, and to automate the adjustment at the time of switching the pipe material type to be inspected. The purpose is to generalize.

  The tube inner surface automatic inspection apparatus according to the present invention includes a light source unit disposed on one opening end side of a tube member, and a camera / lens unit having a movable focus type zoom lens disposed on the other opening end side of the tube member. By taking a tube end image of the tube material and performing image processing, the diameter value (pixel unit) on the image of the tube material to be inspected having a constant diameter is obtained, and the camera lens so that the diameter value is constant It is characterized in that a mechanism for moving the unit back and forth to make the distance between the camera / lens unit and the tube end of the tube to be inspected constant is provided.

  In addition, another tube inner surface automatic inspection apparatus according to the present invention includes a light source unit disposed on one opening end side of the tube material and a movable focus type zoom lens disposed on the other opening end side of the tube material. A lens unit, and an image processing mechanism is provided that obtains the center coordinates of the tube material to be inspected by taking a tube end image of the tube material and performing image processing, and excludes an unfocused image region. To do.

  According to the present invention, a tube alignment mechanism such as a stopper for making the distance between the camera / lens unit and the tube end of the tube to be inspected constant by performing image processing on the tube end image and measuring the diameter of the tube. Can be omitted. As a result, it is possible to reduce the area occupied by the pipe inner surface automatic inspection apparatus, and the apparatus can be easily installed and moved.

  In addition, by introducing ring illumination, it is possible to easily acquire a clear tube end image, so that the measurement accuracy of the center coordinates of the tube material is improved, the accuracy of cutting out a focused image is improved, and the inspection accuracy is improved. In addition, a light shielding mechanism is not required, and a small occupied area and simplification of the pipe inner surface automatic inspection apparatus can be achieved. For this reason, the apparatus can be easily installed and moved, and the cost can be reduced.

It is the figure which showed typically the structure of the pipe material inner surface automatic inspection apparatus in one Embodiment of this invention. It is the figure which showed typically the structure of the pipe material inner surface automatic inspection apparatus in one Embodiment of this invention. It is the figure which showed the structure of the conventional pipe material inner surface automatic inspection apparatus.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment. Moreover, it can change suitably in the range which does not deviate from the range which has the effect of this invention.

  1 and 2 are diagrams schematically showing a configuration of a pipe material inner surface automatic inspection apparatus according to an embodiment of the present invention.

  In the present invention, in order to obtain a clear tube end image, as shown in FIG. 1, a ring illumination 23 is installed on the camera / lens unit 16 side including the camera 21 and the zoom lens 22, and the tube end of the tube 20 is irradiated. Then, the above-mentioned problems are solved by acquiring the tube end image, image-processing the tube end image, and controlling the automatic inspection apparatus as described below.

  First, image processing is performed on the tube end image, and the diameter value of the tube 20 to be inspected is measured. The smaller the distance A between the camera / lens unit 16 and the tube end of the tube material 20 to be inspected, the larger the measured diameter value. Therefore, the camera / zoom lens installation support 24 (manipulator) is slightly moved back and forth to adjust the distance A between the camera / lens unit 16 and the tube end of the tube material 20 to be inspected so that the diameter value is constant. To do. As a result, it is possible to omit the stage of the tube alignment mechanism such as a stopper for keeping the distance A constant, which has been conventionally required.

  In addition, the center coordinates of the tube material 20 can be easily measured by image analysis of the tube end image, and an image processing mechanism that leaves an in-focus image area from the center coordinates and excludes the outside area has been conventionally achieved. This eliminates the need for a light-blocking mechanism that was necessary for As a result, the area occupied by the device can be reduced, and the installation and movement of the device can be facilitated.

  Hereinafter, the configuration of the pipe material inner surface automatic inspection apparatus according to the present embodiment will be described in detail with reference to FIG.

  As shown in FIG. 2, the pipe material inner surface automatic inspection apparatus according to the present embodiment includes a pipe material feeding unit 11 for placing an untested pipe material 20, an inspection unit 12 for fixing the pipe material at an inspection position for acquiring an inner surface image of the pipe material 20, and a pipe material. A camera / lens unit 16 including a camera and a lens for photographing the inner surface of the lens 20, a light source unit 17 for irradiating the inner surface of the tube, a tube stocker unit 13 for collecting the inspected tubes 20, a control panel 18 for controlling them, and a computer (Image processing & control device) 19. In this embodiment, the LED ring illumination 23 is attached to the end of the camera / lens unit 16 so that a clear tube end image can be acquired by irradiating the tube end of the tube 20 to be inspected. The support base 24 that supports the camera / lens unit 16 shown in FIG. 1 includes optical axis adjusting means for X, Y, Z, and angles, and is configured to move electrically up and down, left and right, and back and forth. .

  In the present embodiment, the inner surface flaw automatic inspection of the tube material 20 is performed from the inspection stage A for imaging from one end (A end) to the center portion of the tube material and from the other end (B end) to the center portion. A configuration example will be shown in which the inspection stage A to be imaged is divided into two steps.

  In the pipe material inner surface automatic inspection device according to the present embodiment, first, the type name (caliber) and lot number of the pipe material 20 to be inspected are input. Next, when the pipe material 20 to be inspected is loaded and the pipe material is placed in the inspection unit, first, a pipe end image is acquired. Next, the diameter value of the tube material to be inspected is measured from the tube end image, and the camera / lens unit 16 is moved slightly back and forth so that the diameter value becomes a predetermined value set in advance for each tube type. Adjust so that the distance A between the lens unit 16 and the tube end of the tube material 20 to be inspected becomes a specified value.

  Next, image analysis is performed on the tube end image, and the central coordinates of the tube material 20 are measured. In the automatic inspection apparatus, an image range in which a plurality of necessary tube inner surface image acquisition positions are in focus is set in advance for each type of the tube material 20 to be inspected. For this reason, a focused range of the acquired image of the tube material to be inspected is automatically cut out from the input product name (caliber), and image processing is performed to make a pass / fail decision.

  An example of automatically inspecting an inner surface flaw of a clean steel pipe will be described using the pipe material inner surface automatic inspection device in the present embodiment. In addition to the pipe 20 to be inspected and the steel pipe targeted by the pipe inner surface automatic inspection apparatus of the present invention, all are possible as long as they are cylindrical, such as vinyl chloride, plastic, resin, and rubber.

  The tube 20 is a clean steel pipe having a length of 4.0 to 4.1 m, an outer diameter of 6.35 to 12.7 mm, and a wall thickness of 1.00 mm to 1.24 mm. The material is stainless steel, and the special processing of the inner surface is electrolytic polishing. Mirror finish (EP grade) or surface finish (BA grade) by bright annealing. With regard to the outer diameter, thickness, and length, if you prepare an optical system (diffuse light source, camera, lens, etc.) and automatic inspection equipment that matches the tube to be inspected, the outer diameter is 5.00 to 450.0 mm, and the thickness is It can correspond to 1.00-12.7mm and length 3.5-4.5m.

  Moreover, as a stocker for holding a steel pipe, a pipe material feeding unit 11 for an uninspected steel pipe and a pipe material stocker unit 13 for an inspected steel pipe are provided. The pipe stocker unit 13 includes a non-defective stocker 14 for a non-defective steel pipe and a defective stocker 15 for a defective steel pipe, and the non-defective stocker 14 and the defective stocker 15 have different installation heights.

  The zoom lens 22 has a focal length of 8 to 136 mm, a maximum aperture ratio of 1: 1.6, a zoom ratio of 17 times, a comprehensive angle of 43.6 ° × 33.4 ° to 2.7 ° × 2.2 °, for example. , One having an aperture of F1.6 to Close can be used. For example, a close-up ring having a thickness of 1.5 mm can be used. The camera 21 may be, for example, a CMOS camera having a maximum resolution of 648 × 488 to 2592 × 1944. Moreover, the diffused light source 26 can use a white LED surface light source, for example. As the light collecting means 25, for example, a Fresnel lens having a focal length of 35 mm, φ175 mm, and a pitch of 0.25 mm can be used. The distance between the diffused light source 206 (white LED surface light source) and the light collecting means 205 (Fresnel lens) can be set to, for example, a focal length of 35 mm.

  The inspection unit 12 includes, for example, a first inspection unit that inspects from one tube end (A end) and a second inspection unit that inspects from the other tube end (B end). The first inspection unit has a camera / lens unit 16 on the A end side, a light source unit 17 on the B end side, a white LED and a Fresnel lens, and a steel tube 20, the camera / lens unit 16 and the light source unit 17 in parallel. Install as follows.

  The second inspection unit is arranged opposite to the first inspection unit. The automatic inspection device controls the air pressure in cooperation with the computer to perform the conveying operation. In conjunction with this, the camera, zoom lens, and diffused light source are simultaneously controlled from the computer.

  When the start button of the automatic inspection apparatus is pressed, the steel pipe is transported from the pipe material feeding unit 11 to the first inspection unit so as to be horizontal with the camera. After the conveyance, a tube end image at the A end is taken and the tube end installation position is adjusted. After the position adjustment is completed, the automatic inspection apparatus transmits an A-end inspection start command to the computer for inspection. When the inspection at the A end is completed, the command is transmitted to the automatic inspection device.

  Next, the automatic inspection apparatus conveys the steel pipe of the pipe feeding unit 11 to the first inspection unit at the same time as conveying the steel pipe of the first inspection unit to the second inspection unit. After the conveyance, the above operation is repeated.

  When the inspections at both ends are completed, the computer transmits an instruction to end the inspection to the automatic inspection device. The automatic inspection device transfers the steel pipe of the pipe material input unit 11 to the first inspection unit, and the steel pipe of the first inspection unit to the second inspection unit. From the second inspection unit, both inspection units are simultaneously conveyed to the non-defective stocker 14 if they are non-defective, and to the defective stocker 15 otherwise.

11 Tubing input unit
12 Inspection unit
13 Tube stocker unit
14 Good stocker
15 Defective product stocker
16 Camera / Lens Unit
17 Light source unit
18 Control panel
20 Pipe material
21 Camera
22 Zoom lens
23 Ring lighting
24 Camera / zoom lens installation support (manipulator)
25 Condensing means (Fresnel lens)
26 Diffuse light source

Claims (3)

A light source unit arranged on one opening end side of the tube,
In the pipe material inner surface automatic inspection apparatus comprising a camera / lens unit having a movable focus type zoom lens disposed on the other opening end side of the pipe material,
By capturing a tube end image of the tube material and performing image processing, a diameter value (pixel unit) on the image of the tube material to be inspected having a constant diameter is obtained, and the camera An automatic pipe surface inner surface inspection apparatus comprising a mechanism for moving a lens unit back and forth so as to make a distance between the camera / lens unit and a tube end of the tube material to be inspected constant. A light source unit arranged on one opening end side of the tube,
In the automatic inner surface inspection apparatus for a pipe member, comprising a camera / lens unit having a movable focus type zoom lens disposed on the other opening end side of the pipe member,
A tube inner surface automatic, characterized by providing an image processing mechanism for obtaining a center coordinate of a tube to be inspected by taking a tube end image of the tube and performing image processing, and excluding an in-focus image region. Inspection device. In the pipe material inner surface automatic inspection device according to claim 1 or 2,
An apparatus for automatically inspecting a tube inner surface, wherein a ring illumination is installed on the camera / lens unit and a tube end image is captured by irradiating the tube end of the tube material.