JP6512583B2 - Pipe material inner surface automatic inspection device - Google Patents

Description

  The present invention relates to an automatic inspection apparatus used for inspecting the inner surface of a pipe material.

  A wide variety of tubing is used for a variety of applications, but visual inspection is still being conducted, particularly for tubing where internal flaws significantly affect the reliability of the tubing. However, with the progress of globalization, there is an urgent need to improve productivity, and the need for automation of this visual inspection is extremely large in a variety of various pipe materials.

  The inventors of the present invention have disclosed in Patent Documents 1 to 3 an automatic pipe inner surface inspection device that meets the above-mentioned needs.

  FIG. 3: is the figure which showed the structure of the pipe material internal-surface automatic inspection apparatus disclosed to patent documents 1-3. FIG. The camera and the movable focus zoom lens 108 are attached to one of the tubes 112, and the diffused light source 109 is installed on the opposite side. Then, the inner surface image of the pipe material is zoomed from the front of the pipe material 112, and a plurality of images are captured while changing the focus to obtain an image. Further, an integrated image in which those images are integrated is created, and image analysis is performed to judge its quality. From the end of the long pipe to the center of the pipe, the image inspection is repeated twice sequentially from both ends of the pipe.

  That is, the inspection method in the tube inner surface automatic inspection device disclosed in Patent Documents 1 to 3 combines the inner surface observation images of a plurality of tubes obtained by continuously changing the focal point into one integrated image, and then, The integrated image is subjected to image analysis by the flaw detection and analysis means to perform a pass / fail judgment inspection.

JP, 2011-69616, A JP, 2016-090293, A Japanese Patent Application No. 2016-186098

  However, in the automatic inspection device for the inner surface of the tubular material disclosed in Patent Documents 1 to 3, it is necessary to keep the distance between the zoom lens 108 and the end of the tube constant when acquiring an image. Therefore, as shown in FIG. 3, before setting the tube 112 on the stage to be inspected, the tube end of the tube 113 such as the stopper 113 is mechanically pressed to make the distance between the zoom lens 108 and the tube end constant. A mechanism 106 is provided. Therefore, there has been a problem that the occupied area of the automatic inspection apparatus is increased.

  Moreover, for image processing, in order to cut out a focused range from the acquired image in a ring shape, it is essential to measure the center coordinates of the pipe material 112, but in the automatic inspection apparatus up to this point, the center coordinates are measured. At times, it is difficult to obtain a clear tube end image due to the influence of ambient light, and it is necessary to provide a light blocking mechanism 107 for blocking the ambient light of the tube material. Therefore, there is a problem that the configuration of the automatic inspection apparatus becomes complicated and expensive.

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

  The tube inner surface automatic inspection apparatus according to the present invention comprises: a light source unit disposed on one open end side of the tube; and a camera / lens unit having a movable focusing zoom lens disposed on the other open end side of the tube. A camera / lens is obtained so as to obtain a diameter value (pixel unit) on an image of a tube under test having a constant diameter by imaging and processing a tube end image of the tube material. A mechanism is provided to move the unit back and forth to make the distance between the camera / lens unit and the end of the tube to be inspected constant.

  Another tube inner surface automatic inspection apparatus according to the present invention is a camera having a light source unit disposed on one open end side of the tube, and a movable focus zoom lens disposed on the other open end side of the tube. A lens unit is provided, and an image processing mechanism is provided to obtain center coordinates of the tube to be inspected by imaging the tube end image of the tube and performing image processing, and an image processing mechanism for excluding an out-of-focus image area is provided. 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 image-processing the tube end image and measuring the diameter of the tube. Can be omitted. As a result, the occupied area of the automatic inspection apparatus for the inner surface of the pipe can be reduced, and the installation and movement of the apparatus can be facilitated.

  In addition, the introduction of the ring illumination makes it possible to easily obtain a clear tube end image, so that the measurement accuracy of the center coordinates of the tube material is increased, the extraction accuracy of the image in focus is improved, and the inspection accuracy is improved. In addition, the light shielding mechanism is not required, and the occupied area and simplification of the automatic inspection apparatus for the inner surface of the pipe can be realized. Therefore, installation and movement of the device are facilitated, and cost reduction is also possible.

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

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The present invention is not limited to the following embodiments. Moreover, changes can be made as appropriate without departing from the scope in which the effects of the present invention are exhibited.

  FIG.1 and FIG.2 is the figure which showed typically the structure of the pipe material internal-surface automatic inspection apparatus in one Embodiment of this invention.

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

  First, the tube end image is image-processed to measure the diameter value of the tube 20 to be inspected. The smaller the distance A between the camera / lens unit 16 and the end of the tube 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 end of the tube 20 to be inspected so that the diameter value becomes constant. Do. As a result, it is possible to omit the stage of the tube alignment mechanism such as a stopper for making the distance A constant, which has been required conventionally.

  Also, the central coordinates of the tube 20 can be easily measured by image analysis of the tube end image, and the image processing mechanism that leaves the image region in focus from the central coordinates and excludes the region outside that region is therefore conventionally used. The need for the light shielding mechanism that was necessary for As a result, the area occupied by the device can be reduced, and installation and movement of the device can be facilitated.

  Hereinafter, the configuration of the pipe 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 inner surface automatic inspection device in the present embodiment includes a pipe insertion unit 11 on which an uninspected pipe 20 is placed, an inspection unit 12 for fixing a pipe at an inspection position for acquiring an inner surface image of the pipe 20, and a pipe A camera for photographing the inner surface of the 20, a camera lens unit 16 comprising lenses, a light source unit 17 for irradiating the inner surface of the pipe, a pipe stocker unit 13 for collecting the inspected pipe 20, a control board 18 for controlling them and a computer (Image Processing & Control Device) 19 Further, in the present embodiment, the LED ring illumination 23 is attached to the end of the camera / lens unit 16 so that the tube end of the inspection tube 20 can be irradiated to obtain a clear tube end image. The support 24 supporting the camera and lens unit 16 shown in FIG. 1 is provided with X, Y, Z, and angle optical axis adjustment means, and is configured to move vertically and horizontally, and back and forth electrically. .

  In the present embodiment, the internal surface flaws of the tube 20 are automatically inspected by an inspection stage A for imaging from one end (A end) of the tube to the central portion, and from the other end (B end) to the central portion The structural example divided into two and performed the test stage A to image is shown.

  In the automatic inspection apparatus for the inner surface of a pipe according to the present embodiment, first, the type name (diameter) and the lot number of the pipe 20 to be inspected are input. Next, when the tube 20 to be inspected is inserted and the tube is arranged in the inspection unit, first, a tube 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 slightly moved back and forth so that the diameter value becomes a specified value previously set for each tube material type. Adjustment is performed so that the distance A between the lens unit 16 and the end of the tube 20 to be inspected 20 becomes a specified value.

  Next, the tube end image is image-analyzed, and the central coordinates of the tube 20 are measured. In the automatic inspection apparatus, an image range in which a plurality of necessary tube material inner surface image acquisition positions are in focus is set for each type of the tube material 20 to be inspected. Therefore, a focused range of the acquired image of the tube material to be inspected is automatically cut out based on the input product name (diameter), and image processing is performed to determine pass / fail.

  An example of automatically inspecting an inner surface flaw of a clean steel pipe will be described using the pipe inner surface automatic inspection apparatus in the present embodiment. In addition to the inspected tube 20 and the steel pipe targeted by the tube inner surface automatic inspection apparatus of the present invention, any of cylindrical, polyvinyl chloride, plastic, resin, rubber, etc. is possible.

  The pipe material 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 thickness of 1.00 mm to 1.24 mm. The material is stainless steel, and the special processing of the inner surface is electropolishing Mirror finish (EP grade) or surface finish (BA grade) by bright annealing. With regard to the outer diameter, thickness, and length, if an optical system (diffuse light source, camera, lens, etc.) and automatic inspection device are prepared according to the tube material to be inspected, the outer diameter is 5.00 to 450.0 mm, thickness It can correspond to 1.00 to 12.7 mm and length 3.5 to 4.5 m.

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

  The zoom lens 22 has, for example, a focal length of 8-136 mm, a maximum aperture ratio of 1: 1.6, a zoom ratio of 17 times, an inclusive angle of 43.6 ° × 33.4 ° to 2.7 ° × 2.2 ° The aperture stop F1.6 to Close can be used. Further, as the close-up ring, for example, one 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. Further, as the diffusion light source 26, for example, a white LED surface light source can be used. The condensing unit 25 can use, for example, a Fresnel lens having a focal length of 35 mm, a diameter of 175 mm, and a pitch of 0.25 mm. The distance between the diffused light source 206 (white LED surface light source) and the focusing means 205 (Fresnel lens) can be set to, for example, 35 mm of the focal length.

  The inspection unit 12 includes, for example, a first inspection unit which inspects from one pipe end (A end), and a second inspection unit which inspects from the other pipe end (B end). The first inspection unit has a camera / lens unit 16 at the A end, a white LED and a Fresnel lens as the light source unit 17 at the B end, and the steel pipe 20, the camera / lens unit 16, and the light source unit 17 are parallel. To install.

  The second inspection unit is arranged reverse to the first inspection unit. The automatic inspection apparatus performs control by means of pneumatic pressure in cooperation with a computer to carry out the transport operation. In conjunction with this, the camera, the zoom lens, and the diffused light source are simultaneously controlled from the computer.

  When the start button of the automatic inspection apparatus is pressed, the steel pipe is conveyed from the pipe material feeding unit 11 to the first inspection unit so as to be horizontal to the camera. After transportation, take a tube end image at A end and adjust the tube end installation position. After the position adjustment is completed, the automatic inspection apparatus transmits a command to start A-end inspection to the computer for inspection. When the inspection on the A end side is completed, the command is transmitted to the automatic inspection device.

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

  When the inspection of both ends is completed, the computer transmits an instruction to end the inspection to the automatic inspection device, and the automatic inspection device converts the steel pipe of the pipe material feeding unit 11 to the first inspection unit and the steel pipe of the first inspection unit the second inspection unit If both inspection units are non-defective products from the second inspection unit, they are simultaneously transported in parallel to the non-defective product stocker 14, and otherwise to the non-defective product stocker 15.

11 Pipe feeding unit
12 inspection unit
13 Pipe stocker unit
14 good stocker
15 Defective stocker
16 Camera and 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 Focusing means (Fresnel lens)
26 Diffuse light source

Claims (2)

A light source unit disposed on one open end side of the tube;
A camera / lens unit having a movable focusing zoom lens disposed on the other open end side of the tube ;
A tube inner surface automatic inspection apparatus comprising: a mechanism for installing a ring illumination on the camera and lens unit; irradiating a tube end of the tube; and capturing a tube end image ;
A diameter value (pixel unit) on an image of a tube under test whose diameter is a constant value is determined by capturing an image of a tube end of the tube and performing image processing, and the camera can be made to have a constant diameter. A tube inner surface automatic inspection apparatus comprising: a mechanism for controlling the movement of a lens unit back and forth to make the distance between the camera / lens unit and the tube end of the tube to be inspected constant. By performing imaging by image processing the pipe end image before Symbol tubing obtains central coordinates of the test tube material, characterized in that a exclude image processing mechanism an image area that is not focused, claim The pipe inner surface automatic inspection device according to 1.