JPH07113625A - Device for inspecting inside peripheral face of cylindrical body - Google Patents

Abstract

PURPOSE:To provide a device capable of inspecting the inside peripheral face of a slender hollow part in a short time, and capable of suitably corresponding even when the diameters of the hollow parts are different. CONSTITUTION:In a tube 27 for imaging, the upper tube 41, the lower tube 43 and a light emission ring 44 are connected, and in the lower tube 43, a slide part 45 up and down slidable is inserted. In the slide part 45, a CCD camera 7a is installed, in an end side of the camera 7a a wide-angle fisheye lens is installed as an objective, and in the other end side, a camera cable 46 is installed. To the lower tube 43, second slit guide parts 51 for guiding the slide part 45 are provided axially facing in two rows. On the outsides of both tubes 41, 43, first concave guide parts 49 by which bundles of optical fibers 47 are guided from a light source to the light emission ring 44 are provided axially in four rows.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for continuously inspecting the inner peripheral surface of an elongated hollow portion of a tubular metal formed body such as a cast or forged tube.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
For example, an inspection device as shown in FIG. 5 has been used to inspect the inner peripheral surface of an elongated hollow portion such as a cast or forged tube. In this inspection apparatus, a conical reflection plate P1 and a conical mirror (cone mirror) P2 are provided on the tip side of the camera, and light is emitted from a ring-shaped light guide P3 arranged around the camera to an inspection target surface of a work P4. It is irradiated and the reflected light is photographed by a camera (see Japanese Patent Application Laid-Open No. 2-95205).

However, the above-mentioned apparatus has a problem that the field of view at the same time is narrow, and it takes a long time to continuously inspect the slender inner peripheral surface. Further, if the diameter of the inner peripheral surface changes significantly, the cone mirror P2 having a large diameter must be replaced accordingly, which causes a problem in that the operation takes time.

Therefore, the present invention has been made in order to solve the above-mentioned problems, and a cylindrical body capable of inspecting the inner peripheral surface of an elongated hollow portion in a short time and suitably responding even when the diameter of the hollow portion is different. An object is to provide an inner peripheral surface inspection device.

[0005]

In order to achieve the above object, the invention according to claim 1 is an image pickup camera having an objective lens of a wide-angle lens, which is located substantially coaxially with the axis of the hollow portion of the tubular body. One end side is connected to a light source, the other end side is arranged around the imaging camera in a branched manner, and an optical fiber arranged around the objective lens of the imaging camera, and the other ends on the branched side of the optical fiber are respectively arranged. A gist of the present invention is an inner peripheral surface inspection device for a cylindrical body, which is provided with a light emitting ring embedded so as to reach a lower surface.

According to a second aspect of the invention, the inner circumference of the cylindrical body according to the first aspect is characterized in that the image pickup camera can advance and retreat with respect to the light emitting ring in a hollow portion of the cylindrical body. The main point is the surface inspection device.

According to a third aspect of the present invention, the hollow portion of the cylindrical body has a non-circular cross section, and the projection ring has a shape substantially similar to that of the first or second aspect. The gist of the described inner peripheral surface inspection device for a cylindrical body is to be summarized.

According to a fourth aspect of the present invention, the inner circumference of the cylindrical body according to any one of the first to third aspects is characterized in that ultraviolet rays are supplied from the light source and flaw detection is performed by irradiation of the ultraviolet rays. The main point is the surface inspection device.

Here, examples of the cylindrical body include a cast or forged tube. Further, as the cross-sectional shape of the hollow portion of the tubular body, for example, a circular shape may be considered in the case of a cylinder, but other than that, a polygonal shape such as a substantially square shape or a rectangular shape may be considered depending on the shape of the cylinder.

As a method of inspecting the inner peripheral surface of the cylindrical body,
Examples include fluorescent magnetic particle flaw detection and fluorescence penetration flaw detection. The light supplied from the light source may be, for example, visible light, but it is preferable to use ultraviolet light having a wavelength generally used for flaw detection.

[0011]

In the inner peripheral surface inspection apparatus of the present invention, the optical fiber for guiding the light from the light source branches to the periphery of the image pickup camera and reaches the lower surface of the light emitting ring arranged around the objective lens. The light emitted from the lower surface of the light emitting ring can efficiently and brightly illuminate the inner peripheral surface of the hollow portion. Further, since the imaging camera is arranged substantially coaxially with the axis of the hollow portion of the cylindrical body and a wide-angle lens is used as the objective lens thereof, the hollow portion of the hollow portion is irradiated with light from the light emitting ring. It is possible to take clear pictures of a wide area on the inner surface.

Further, when the image pickup camera is capable of advancing and retracting with respect to the light emitting ring in the hollow portion of the cylindrical body, as will be described later in detail with reference to FIG. 4, irradiation determined by the inner diameter of the hollow portion to be inspected. It is possible to arrange the imaging camera at a suitable position according to the surface. Further, when the hollow portion of the tubular body has a non-circular cross section, the light emitting ring has a shape similar to that of the hollow portion, so that the inner peripheral surface of the hollow portion is irradiated with light almost uniformly. Clear shooting is possible.

In addition, when the ultraviolet light is supplied from the light source, it is possible to perform fluorescent magnetic powder flaw detection, fluorescent permeation flaw detection and the like by irradiating the inner peripheral surface of the hollow portion with ultraviolet light.

[0014]

Next, preferred examples will be described in order to further clarify the present invention. FIG. 1 shows an inner peripheral surface inspection device for a cylindrical body of the present embodiment (hereinafter simply referred to as an inner peripheral surface inspection device),
FIG. 1A is a plan view thereof, and FIG. 1B is a front view thereof.

As shown in FIG. 1, the inner peripheral surface inspection apparatus of this embodiment is used, for example, for fluorescent magnetic particle flaw detection, in which a turntable 3 is provided on a base 1, and the turntable 3 is provided. A cast tube 5 to be inspected is placed on the top. Further, in order to movably hold the three imaging cameras 7a to 7c (collectively referred to as 7), the base 1 is provided with a first unit perpendicular to the base 1.
A pillar 9 and a second pillar 11 are provided.

The rotary table 3 is driven by the first motor 13, and on the surface thereof, three pieces are raised toward the outside on the stairs in order to stably mount the casting tube 5. The support portion 15 of is attached. A moving rod 21 (threaded) is provided on the first supporting column 9 in parallel with the first supporting column 9.
1, an imaging unit 19 for inspecting the inner peripheral surface of the casting tube 5 is attached so as to be vertically movable. That is, the moving rod 21 is gripped by one end of the horizontally extending arm 23 of the imaging unit 19, and the arm 23 (locks to the one end of the arm 23 and the first support column 9) by the second motor 25. That is, the entire imaging unit 19) is movable in the vertical direction.

The light source 17 is attached to the center of the arm 23 of the image pickup section 19. This light source 17
This is for irradiating near-ultraviolet light having a wavelength of 330 to 390 nm in order to cause the defect indicating pattern to emit light and identify it in the fluorescent magnetic particle flaw detection. An imaging tube 27 (described later) equipped with an imaging camera 7a inserted into the hollow portion 5a of the casting tube 5 is attached to the other end of the arm 23. The arm 23 (hence the imaging unit 19)
As shown in FIG. 1A, the whole) is rotatable around the moving rod 21.

Supporting members 29, 3 are attached to the second support column 11.
Two imaging cameras 7b and 7c are mounted in parallel vertically so as to photograph and inspect the outer surface of the casting tube 5 via 1. Both imaging cameras 7b and 7c are
The third and fourth motors 33 and 35 can move vertically, and the motor (not shown) can move horizontally (closer to each other). The third and fourth motors 33 and 35 may be omitted, and the motors may be manually moved up and down.

Next, regarding the imaging tube 27,
The details will be described with reference to FIG. As shown in FIG. 2, the imaging tube 27 includes an upper tube 41 and a lower tube 4.
3 and the light emitting ring 44 are connected to each other, and the lower tube 43 is fitted with a sliding portion 45 capable of sliding up and down. An imaging camera 7a, which is a CCD camera, is attached to the sliding portion 45, a wide-angle fisheye lens (not shown) is attached as an objective lens to the front end side of the imaging camera 7a, and a camera cable is attached to the rear end side. 46 is attached.

Further, the lower tube 43 has a structure shown in FIG.
As shown in (a) and (c), slit-shaped second guide portions 51 for guiding the sliding portion 45 are provided so as to face each other in two rows in the axial direction. Further, as shown in FIGS. 2B and 2C, on the outer surfaces of the tubes 41 and 43, a concave first guide for guiding a bundle of optical fibers 47 (which guides ultraviolet rays) from the light source 17 to the light emitting ring 44. The 1 guide part 49 is provided in four rows in the axial direction.

That is, as shown in FIG. 3A, the optical fiber 47 is led out from the light source 17 in a bundle, but is guided to the first guide portion 49 (see FIG. 2C) on the way. It is branched into four bundles, and is guided as it is to the upper end of the projection ring 44 made of quartz. Then, as shown in FIG. 3B, each of the optical fibers 47 is branched into one optical fiber 47 inside, and the lower end of the optical fiber 47 is arranged in a ring shape (see FIG. 2D). To be done. Therefore, from the lower surface of the light emitting ring 44, ultraviolet rays are emitted in a ring shape so as to surround the imaging camera.

Next, the operation of the inner peripheral surface inspection apparatus of this embodiment having the above-mentioned structure will be described with reference to FIGS. 1 and 4. First, as shown in FIG. 1, when inspecting the inner peripheral surface of the casting tube 5, a magnetic powder (for example, fluorescent magnetic powder) that emits fluorescence when exposed to ultraviolet rays is applied to the inner peripheral surface of the casting tube 5 in advance. I'll do it. Then, the casting tube 5 is placed on the support portion 15 of the turntable 3, and the arrow A in FIG.
The entire imaging unit 19 is rotated in the direction, and the imaging camera 7a is set at the position of the axial center of the casting tube 5. Next, in this state, the second motor 25 is driven to move the entire imaging unit 19 downward, and the tip portion of the imaging tube 27 is inserted into the hollow portion 5a of the casting tube 5. Then, when the predetermined inspection start position is reached, the light source 17 is turned on to irradiate the inner peripheral surface of the hollow portion 5a with ultraviolet rays, and an image of fluorescence generated thereby is taken by the imaging camera 7a,
This image is displayed on a monitor (not shown) for inspection.

When carrying out this inspection, the hollow portion 5a is previously prepared.
The vertical position of the imaging camera 7a (maximum outer diameter 23 mm, camera viewing angle θ = 100 degrees) with respect to the light emitting ring 44 (inner diameter 23.5 mm × outer diameter 38 mm × length 50 mm) according to the inner diameter of Set like.

As shown in FIG. 4 (a), the irradiation angle of ultraviolet rays spreads outward from the axial direction by β (= 9.5 degrees) by α (= 11.5 degrees). It is a thing. That is, the irradiation angle of ultraviolet rays is α, and the irradiation surface (the flaw detection surface) is determined corresponding to this irradiation angle α. Therefore, for example, when the inner diameter is small, such as about 50 mm, in order to enter the field of view of the imaging camera 7a from the upper end of the flaw detection surface, taking the viewing angle θ into consideration, the tip of the imaging camera 7a is the tip of the projection ring 44. It is arranged at a substantially coincident position (accurately, the tip of the imaging camera 7a is projected by about 3 mm). And in this state,
By lowering the entire imaging unit 19 by the second motor 25, it is possible to continuously and efficiently inspect the inner peripheral surface of the hollow portion 5a.

As shown in FIG. 4B, for example, the inner diameter is 6
In the case of about 5 mm, even if the irradiation angle α of ultraviolet rays is the same, a flaw detection surface having a wider width in the vertical direction than in the above case is determined. Therefore, in order to enter the field of view of the image pickup camera 7a from the upper end of the flaw detection surface, the tip of the image pickup camera 7a should be attached to the projection ring 4.
It is arranged so as to project to a certain extent from the tip of No. 4 (accurately, the tip of the imaging camera 7 is projected by about 16 mm). Then, in this state, by lowering the imaging unit 19, the inner peripheral surface of the hollow portion 5a having a large inner diameter can be continuously inspected.

As shown in FIG. 4C, for example, the inner diameter is 9
When it is as large as about 5 mm, a flaw detection surface having a wider width in the vertical direction than that in the above case is determined. Therefore, in order to enter the field of view of the imaging camera 7a from the upper end of the flaw detection surface, the imaging camera 7a
Is arranged so as to project larger than the tip of the light emitting ring 44 (more precisely, the tip of the image pickup camera 7 projects by about 43 mm). Then, in this state, by lowering the imaging unit 19, the inner peripheral surface of the hollow portion 5a having a large inner diameter can be continuously inspected.

As described above, in the inner peripheral surface inspection apparatus of this embodiment, in order to irradiate the object to be inspected with the ultraviolet rays guided from the light source 17 by the optical fiber 47, the annular projection ring 44 is used.
Is provided, and an image pickup camera 7a capable of moving up and down is provided on the center side of the light emitting ring 44, and a fisheye lens is attached to the image pickup camera 7a as an objective lens. Therefore, for example, when inspecting the inner peripheral surface of the casting tube 5, since the field of view that can be simultaneously captured is wide, the slender inner peripheral surface can be continuously and quickly inspected simply by moving the imaging unit 9 in the vertical direction. It has a remarkable effect of being able to.

Further, in this embodiment, since the fish-eye lens is used, even if the inner diameter of the hollow portion 5a changes, the imaging state does not change so much, but especially when the inner diameter changes greatly. Has an effect that it is possible to cope with the change of the inner diameter very easily only by changing the position of the imaging camera 7a with respect to the light emitting ring 44 according to the change of the inner diameter.

Further, in the case of the present embodiment, the irradiation ring 44 corresponds to the sectional shape of the hollow portion 5a of the casting tube 5.
Since the ring-shaped ultraviolet rays are radiated from the lower surface of the above, there is an advantage that the flaw detection surface can be uniformly radiated and an appropriate image can be picked up. Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to these embodiments and can be implemented in various modes without departing from the scope of the invention.

[0030]

In the inner peripheral surface inspection apparatus of the present invention, the optical fiber branches from the light source to the periphery of the image pickup camera and reaches the lower surface of the projection ring arranged around the objective lens. The inner surface can be illuminated efficiently and brightly. In addition, since the imaging camera is arranged almost coaxially with the axis of the hollow part of the cylindrical body and a wide-angle lens is used as the objective lens of the hollow part, clear imaging of a wide range of the inner peripheral surface of the hollow part can be continuously performed. It can be performed quickly and objectively.

Further, in the case where the image pickup camera is capable of advancing and retracting with respect to the light emitting ring in the hollow portion of the cylindrical body, there is an advantage that suitable image pickup can be performed even if the inner diameter of the hollow portion changes greatly. Further, when the hollow portion of the tubular body has a non-circular cross section, the light emitting ring has a shape similar to that of the hollow portion, so that the inner peripheral surface of the hollow portion is irradiated with light almost uniformly. Clear shooting is possible.

In addition, there is an advantage that flaw detection by fluorescent magnetic powder flaw detection or fluorescence permeation flaw detection can be easily performed by supplying ultraviolet rays from a light source and irradiating the inner peripheral surface of the hollow portion with ultraviolet rays.

[Brief description of drawings]

FIG. 1 shows an inner peripheral surface inspection apparatus according to an embodiment, (a) is a plan view thereof, and (b) is a front view thereof.

FIG. 2 shows an imaging tube, (a) is a sectional view thereof,
(B) is the AA sectional view, (c) is the BB sectional view, (d) is the CC sectional view.

3A and 3B are diagrams showing an ultraviolet ray path, FIG. 3A is an explanatory view showing an optical fiber, and FIG. 3B is an explanatory view showing the inside of a light emitting ring.

FIG. 4 is an explanatory diagram showing an operation of the inner peripheral surface inspection device for different inner diameters.

FIG. 5 is an explanatory diagram showing a conventional technique.

[Explanation of symbols]

7, 7a, 7b, 7c ... Imaging camera 17 ... Light source 19 ... Imaging unit 27 ... Imaging tube 43 ... Lower tube 44 ... Emissive ring 47 ... Optical fiber

Claims (4)

[Claims] 1. An imaging camera having a wide-angle objective lens, which is located substantially coaxially with an axis of a hollow portion of a tubular body, one end of which is connected to a light source, and the other end of which is branched around the imaging camera. An optical fiber arranged around the objective lens of the imaging camera, and a projection ring embedded so that each of the other ends of the branching side of the optical fiber reaches the lower surface. Inspection device for inner surface of tubular body. 2. The apparatus for inspecting an inner peripheral surface of a tubular body according to claim 1, wherein the imaging camera is capable of advancing and retracting with respect to the light emitting ring in a hollow portion of the tubular body. 3. The tubular body according to claim 1 or 2, wherein the hollow portion of the tubular body has a non-circular cross section, and the projection ring has a shape substantially similar thereto. Inner surface inspection device. 4. The apparatus for inspecting the inner peripheral surface of a cylindrical body according to claim 1, wherein ultraviolet rays are supplied from the light source and flaw detection is performed by irradiation of the ultraviolet rays.