JP5265290B2 - Surface inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface inspection apparatus, which returns the reflected light to a determining processing apparatus concurrently with irradiating laser beam to the inner surface in an aperture, so as to implement high-speed inspection of the inner surface in a small aperture by reducing the diameter of the rotating drum used to be durable to high-speed rotation. <P>SOLUTION: While a rotating drum 10 is rotatably connected to a body section 7 equipped with a laser beam oscillator 11 for transmitting a laser beam from the laser beam oscillator 11 through a hollow laser guidance space 17 of the rotating drum 10 to the inner surface in the small aperture, the reflected light from the inner surface is retrieved through an optical fiber 15 arranged in a circular form and along a longitudinal direction, to form an optical path for irradiating and reflected light on the inner surface of the single rotating drum 10. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a surface inspection apparatus, and more particularly to a surface inspection apparatus suitable for inspecting internal wall surfaces such as screw holes formed for assembly and connection in metal bodies such as housings of mechanical devices.

  Conventionally, as a technique for inspecting scratches and cracks on the inner wall surface of a hole drilled in a metal body, the presence or absence of deposits, etc., light is projected onto the inner wall surface of the hole, and the light reflected from this is reflected from the optical signal. A technique for determining whether or not the inner peripheral wall surface of a hole is in a normal state by converting it into an electrical signal and analyzing the signal and inspecting the finished state and the like is widely known and put into practical use.

  This light inspection has different methods and apparatuses depending on the object to be inspected, but in principle, the light from the light source is projected onto the inner peripheral wall surface of the hole to be inspected and reflected from this. The reflected light is taken out of the hole, the reflected light thus taken is passed through a photoelectric converter or the like to be converted into an electrical signal, and this signal is analyzed to be normal or abnormal with scratches or the like. It is determined whether or not hole processing or screw formation is normally performed.

  In this case, the analysis of the electrical signal and the determination based on the result of the analysis vary depending on the purpose of the inspection, etc., but the light is projected on the inner wall surface of the hole and reflected from the surface. The technique for discriminating normality / abnormality of the inner wall surface of the hole by capturing the light and analyzing the change is basically common.

  However, in this inspection method using light, if the diameter of the hole to be inspected becomes extremely small, such as a screw hole for assembling an automobile engine room, for example, several millimeters, many more When screw holes are inspected continuously and in a short time, it is not always easy, and it is technically difficult to inspect stably with high accuracy.

Conventionally, for example, methods and apparatuses described in Patent Documents 1 to 3 are known as surface inspection apparatuses that inspect the inner peripheral wall surface of a hole using this type of light.
JP 51-106488 A Japanese Patent No. 3887482 JP 2002-340809 A

  The apparatus described in Patent Document 1 is a head that includes a converging lens 23 and a refraction mirror 26 at the tip of a hollow cylinder 9 rotated by a motor 14 for inspecting the inner wall surface of a subject 31. 16, and on the other hand, a light pipe 17 having an optical fiber 18 is inserted on the outer peripheral surface along the axis of the cylinder 9 to form a double-structured cylinder. The head 16 provided at the support end 9 is inserted into the object 31 to be inspected, and the light (A) from the light source 1 provided outside through the hollow portion formed in the axial center portion of the pipe from the base end side of the light pipe 17. The light is passed through a light collecting lens 23 provided in the head 16, refracted at right angles through a mirror 26, and then this convergent light (b) is projected onto the inner wall surface of the subject 31. Fiber 18 It was taken out to the outside so as to wrap the inner cylinder 9, and converted into an electric signal through photoelectric conversion sensor 39, which is intended to image representations in CRT 37.

  The apparatus of Patent Document 1 moves along the inner circumference of the subject 31 by rotating the converged light (b) refracted at right angles by the mirror 26 by the rotation of the cylinder 9 by the motor 14, and this movement. In addition, the reflected light (c) from the inner wall surface can be collected outside through the optical fiber 18 attached along the outer peripheral surface of the light pipe 17 and the state of the inner wall surface of the subject 31 can be inspected continuously. It has become.

One feature of the apparatus of Patent Document 1 is that when the light (a) from the light source 1 is irradiated to the surface of the subject 31 as convergent light (b) through the converging lens 23, the light (a) is irradiated to the light pipe. The reflected light (c) from the subject 31 is collected through the optical fiber 18 provided on the outer peripheral surface of the light pipe 17 while being guided to the converging lens 23 through the hollow portion 17.
That is, here, the light collected as reflected light (c) is collected through the optical fiber 18 attached to the outer peripheral surface of the light pipe 17 serving as the inner cylinder inserted inside the cylinder 9 serving as the outer cylinder. The light and reflected light are reciprocated by using a light pipe 17 for inserting the light into the inside of the cylinder 9.

  However, the device comprising the inner and outer double cylinders (cylinder 9 and light pipe 17) has a predetermined interval between the two when inserting the light pipe 17 into the inside of the cylinder 9 in addition to assembling the cylinder into the inner and outer double. There is a problem that the entire outer diameter of the cylindrical body becomes large because it is necessary to secure a gap, and furthermore, a space is required for light (b) to pass through the axial center portion of the light pipe 17 serving as the inner cylinder. As a result, when the hole diameter to be examined becomes small, for example, when it becomes a small hole with a diameter of several millimeters like a screw hole for receiving a fastening screw, it is sufficient between the cylinder and the inner wall surface of the screw hole. There is a problem that a sufficient gap cannot be secured, and the cylindrical body cannot be inserted and further cannot be rotated in the inserted state.

  On the other hand, the surface inspection apparatus described in Patent Document 2 applies the light from the light source 2 to the reflecting mirror 7 through the projecting optical fiber 3 disposed in the center of the fiber holding cylinder 5, although the subject of the invention is different. The 90 ° direction is changed and projected onto the inner wall surface of the inspected object 1, the reflected light is again received by the reflecting mirror 7, and this is applied to the receiving optical fibers 4 a and 4 b attached along the inner wall surface of the fiber holding cylinder 5. It has a basic structure in which it is received and taken out to the outside, and is in line with the device of Patent Document 1. Here, the fiber holding cylinder 5 is fixed, the armature shaft 9a fitted on the outer periphery thereof is rotated by a motor, and the rotating cylinder 8 at the tip of the armature shaft 9a is rotated to provide reflection inside. The mirror 7 is rotated so that the inner wall surface of the inspection object 1 can be scanned along the circumferential direction.

  However, the apparatus of Patent Document 2 is also the same as the apparatus of Patent Document 1 in that a double structure is formed by covering an armature shaft 9a that is rotated by a motor on the outside of a fiber holding cylinder 5 that is fixedly provided. The tube has a disadvantage that the substantial outer diameter is large, in other words, a structure that cannot be reduced.

  On the other hand, the surface inspection apparatus described in Patent Document 3 eliminates the double structure of the cylindrical body by using the hollow inspection optical support member 3 serving as an outer cylinder as a single unit in each of the apparatuses. A light source 13 is provided inside the support member 3, and the light from the light source 13 is applied to the half mirror 12 also provided inside the support member 3 to irradiate the inner peripheral surface 1 a of the cylindrical inspection object 1 and its reflected light. Is received by the CCD camera 4 provided inside the base of the inspection optical support member 3.

As a result, the apparatus in Patent Document 3 automatically abolishes the double structure by disposing the inspection optical support member 3 corresponding to the cylindrical body as a single unit. However, the double structure is abolished. As a result, it becomes impossible to irradiate light from the outside, and the light source 13 is directly provided inside the support member 3 here.
However, in this case, since the light source 13 is directly installed inside the cylinder as described above, a space for accommodating the light source 13 is required inside the cylinder, and as a result, the cylinder, that is, The outer diameter of the inspection optical support member 3 cannot be reduced, and the inspection object to be inspected is automatically limited to inspection of a large-diameter hole.

The present invention has been developed in view of such circumstances, and particularly intends to provide a surface inspection apparatus suitable for inspecting the state of the inner surface of a small diameter unit of several millimeters such as a screw hole. It is.
As described above, when optically inspecting the inner surface of a hole, it is necessary to bring light into the hole and irradiate the inner peripheral wall surface, and at the same time, it is necessary to extract reflected light of the irradiated light to the outside. is there.

  At this time, in the devices of Patent Documents 1 and 2, a light pipe 17 (fiber holding cylinder 5) is fitted inside the cylinder 9 (armature shaft 9a) as a means for extracting reflected light to the outside, and a double cylinder. In this structure, the optical pipe 18 (fiber holding cylinder 5) is provided with an optical fiber 18 (receiving optical fibers 4a and 4b) to extract reflected light to the outside. As described above, the cylindrical body has a double structure. This is unsuitable as an inspection apparatus for small-diameter holes because the outer diameter of the cylinder is increased.

  Therefore, in the present invention, the double structure of the cylindrical body is abolished to form a single cylindrical body, and the optical path for extracting the irradiation light and the reflected light, that is, the optical fiber can be arranged inside the cylindrical body. The arrangement of the inner cylinder to support the cylinder, that is, the optical fiber, is omitted, and accordingly, the substantial outer diameter of the cylinder is reduced, and the necessary cylinder thickness is secured accordingly. Therefore, it is an object of the present invention to provide a surface inspection apparatus that can achieve the strength that can cope with high-speed rotation.

The primary mission of surface inspection equipment is accurate inspection. And, in the mass production of products, the inspection time is shortened. For that purpose, it is a big problem that the inner peripheral wall surface of the hole can be inspected quickly through high-speed rotation.
In this case, it is necessary to prevent the thickness of the cylinder from decreasing as the diameter of the cylinder is reduced, and to secure the necessary thickness to obtain the required strength.

  The present invention is improved so that optical surface inspection can be performed at high speed and stably with respect to a small diameter hole which has not been solved in the past. In particular, the present invention is applied to a small diameter hole such as a screw hole. While it is a rotating cylinder with a small mirror that can be easily inserted, even when high-speed rotation is applied, it allows stable insertion into the inspected object and continuous and rapid inspection while suppressing shake during rotation. The object is to provide a surface inspection apparatus.

  In order to achieve the above object, the present invention inserts into a small-diameter hole serving as an object to be inspected, irradiates light from the light source onto the inner peripheral wall surface of the hole, and extracts the reflected light of the irradiated light to the outside. The optical fiber that guides the reflected light is arranged in a cylindrical shape on the inner peripheral surface thereof, and a light guiding space that becomes the irradiation light is formed in a hollow portion surrounded by the optical fiber to form an interior of the cylindrical body. Is that two guiding paths for irradiation light and reflected light are formed.

  In the present invention, the cylindrical body is supported in a freely rotating manner, and the light irradiated through the guide space in the central portion is rotated through the mirror provided at the supporting end of the cylindrical body, and the inside of the hole is rotated. The peripheral wall surface is continuously irradiated, and the reflected light is again taken out by the optical fiber attached to the inner peripheral surface of the cylindrical body through the mirror.

  On the other hand, in the present invention, a main body provided with a light source that emits light to the light guide space of the cylindrical body and a light receiving means that receives the reflected light is opposed to the cylindrical body, and the cylindrical body is supported to rotate freely. The light from the light source is sent to the guide space of the cylindrical body, the reflected light from the optical fiber is received, and connected to a determination processing device that analyzes the state of the inner peripheral wall surface of the hole by analyzing the optical signal.

  The present invention will be described in further detail. The feature of the present invention is that a laser oscillator and a main body having an optical path space for guiding laser light from the laser oscillator toward the front end, and the optical path space at the front end of the main body. A rotating cylinder that is mounted so as to freely rotate along the extension line, and a plurality of the rotating cylinders are provided along a concentric circle over the entire circumference of the inner peripheral surface and over substantially the entire length. A laser beam guiding space communicating with the optical path space is simultaneously formed at the center of the optical fiber, and a laser beam sent through the laser beam guiding space is inspected at the tip of the rotating cylinder. Equipped with a mirror that irradiates the body surface and sends reflected laser light to the light receiving part at the tip of the optical fiber, and on the inner wall surface of the optical path space of the main body part, a number of light receiving optical fibers are arranged in a concentric circle along a concentric circle And its tip Near the proximal end of the optical fiber on the rotating cylinder side, and the reflected laser light from the optical fiber on the rotating cylinder side is received by the optical fiber for receiving light to the determination processing device equipped on the main body side. The surface inspection apparatus is configured to transmit.

  According to the present invention, the laser light from the laser oscillator that irradiates the inner wall surface of the hole to be inspected and the reflected light that is reflected off the inner wall surface of the hole and extracted, and the optical fiber Since the structure is arranged and processed inside the rotating cylinder, the rotating cylinder has a space for arranging the optical fiber and a space surrounded by the optical fiber, that is, a guiding space through which the laser beam can pass. As long as there is enough space, the rotating cylinder can be the smallest diameter cylinder that can contain them, so that it can be inserted into a small-diameter hole and the inner wall surface can be inspected. It can be a device.

  Further, as described above, a rotating cylinder is provided as a single unit, and is provided with an optical path for guiding reflected light, that is, an arrangement of an optical fiber and a guide space for laser light serving as irradiation light through a space surrounded by the optical fiber. Since it becomes possible to make the cylindrical body the cylindrical body of the smallest diameter, the thickness of the rotating cylindrical body itself can be increased by utilizing this possible range, and based on this, the strength is increased and the high speed is increased. It is possible to prevent shakes that occur during rotation.

  According to the present invention, in the above invention, a cylindrical fixing member is closely attached to a plurality of optical fibers attached in a cylindrical shape along the inner peripheral surface of the rotating cylinder, and the optical fiber is attached to the rotating cylinder. An object of the present invention is to provide a surface inspection apparatus that is fixed in a state of being sandwiched between an inner peripheral surface of a body.

  According to the present invention, the optical fiber can be easily and stably disposed on the inner peripheral surface of the rotating cylinder, and a circular laser beam path space can be formed by the fixing member at the center of the optical fiber.

  According to the present invention, in the above invention, an adhesive is interposed between the cylindrical fixing member and the optical fiber so that the optical fiber is stably placed between the outer peripheral surface of the cylindrical fixing member and the inner peripheral surface of the rotating cylindrical body. An object of the present invention is to provide a surface inspection apparatus characterized by being fixed.

  According to this invention, since the optical fibers arranged along the inner peripheral surface of the rotating cylinder and the optical fiber and the rotating cylinder are integrally bonded and fixed, the optical fiber does not move when the rotating cylinder rotates, High-speed rotation of the rotating cylinder itself is stably performed.

  Further, according to the present invention, in any one of the above-mentioned inventions, a connecting means is provided at the tip of the main body, and the rotating cylinder is connected and supported through the connecting means so as to freely rotate, and the optical path space and the laser light guiding space. Another object of the present invention is to provide a surface inspection apparatus in which each of a base end portion of an optical fiber and a tip end portion of a light receiving optical fiber is arranged on a straight line.

  According to the present invention, the main body and the rotating cylinder are connected in a predetermined positional relationship via the connecting means from the main body, and the rotating cylinder is rotatably supported with respect to the main body. Thus, the reflected light returned through the optical fiber of the rotating cylinder can be correctly received by the optical fiber for receiving light.

  The present invention also provides a surface inspection apparatus according to the above invention, characterized in that a rotary drive device is mounted on the outer peripheral surface portion of the rotary cylinder, and the rotary drive device is supported by a main body portion via a connecting means. There is.

  According to the present invention, since the rotary drive device that rotationally drives the rotary cylinder directly on the outer peripheral surface portion of the rotary cylinder is incorporated via the connecting means, a stable rotational force is applied to the rotary cylinder. In addition, since the rotating cylinder rotates integrally with the rotation driving device, it can be rotated at high speed without giving unnecessary vibration.

  Further, according to the present invention, in any one of the above-described inventions, a plurality of light receiving optical fibers can be formed by arranging a plurality of light receiving optical fibers along a concentric circle drawn in multiple layers on the inner wall surface of the optical path space of the main body. An object of the present invention is to provide a surface inspection apparatus characterized by being formed.

  According to the present invention, the optical fiber for receiving light attached to the inner wall surface of the optical path space of the main body portion becomes a plurality of layers, and the light receiving area of the distal end portion is widened. As a result, from the proximal end portion of the optical fiber of the rotating rotating cylinder A large amount of reflected light can be received as much as possible. Accordingly, it is possible to effectively avoid a reduction in the amount of reflected light received on the fixed main body side, and an accurate optical signal can be analyzed.

  Still further, in another aspect of the present invention, in any one of the above-described inventions, the rotating cylindrical body cuts the inner wall surface portion of the tip portion to form a mirror storage space that substantially increases the inner diameter, and the mirror is stored in the storage space. Another object of the present invention is to provide a surface inspection apparatus characterized by facing a front-end light receiving portion of an optical fiber provided along the inner peripheral surface of a rotating cylinder.

  According to the present invention, the inner wall surface of the tip of the rotating cylinder is cut to enlarge the inner diameter, and this enlarged space is used as a mirror storage chamber, so that the laser beam sent through the laser beam guiding space is covered. This makes it possible to provide a large mirror that can be reflected at the tip light receiving portion of the optical fiber without leaving the reflected light that is reflected and taken in by the inspection object, and the reflected light can be received efficiently.

  As is apparent from the above description, the present invention has a structure in which a rotating cylinder is formed as a single unit, a plurality of optical fibers are incorporated therein, and a space for guiding laser light is formed by the space between the optical fibers. For example, the irradiation light and the reflection light are sent through one rotating cylinder, and the rotation cylinder is rotated to enable the irradiation of the laser beam and the reception of the reflection light. It is possible to eliminate the disturbance of light and the trouble of rotation caused by the contact with the other cylindrical body when the rotating cylindrical body is generated in the case of the double cylindrical structure, thereby enabling high-speed rotation.

Further, according to the present invention, since the rotating cylinder is a single body, it is possible to minimize the substantial outer diameter of the entire cylinder, and it is possible to cope with a hole that is a small-diameter inspection object. At the same time, since the substantial outer diameter can be reduced, the substantial thickness of the cylinder can be increased within the range in which the outer diameter can be increased. It can be set as a corresponding surface inspection apparatus.
Next, the present invention will be further described based on embodiments, and the features thereof will be clarified.

  FIG. 1 of the accompanying drawings is an overall schematic explanatory view showing an example of a surface inspection apparatus according to the present invention. Reference numeral 1 in the drawing is a main body of the surface inspection apparatus, 2 is a base serving as a base of the apparatus, and 3 is a base. 2 is a lifting device that slides up and down along the column 3, 5 is an arm that extends horizontally from the lifting device 5, and 6 is the above-described arm at the tip of the arm 5. It is an attachment member for fixing the main body 1 of the surface inspection apparatus of the present invention.

  As shown in FIG. 2 in an enlarged manner, the main body 1 of the surface inspection apparatus includes a rotating cylinder 10 that inserts a tip portion into a hole 9 (hole 9 in this embodiment) formed in the main body 7 and the inspection object 8. The oscillator 11 that emits laser light is attached to the rear end portion of the main body portion 7 that is formed in a large-diameter rod shape, and the center portion of the main body portion has a circular shape that passes the laser light penetrating toward the front end portion. An optical path space 12 is formed.

A lens 13 for condensing laser light is attached to the rear end portion of the optical path space 12 of the main body 7, and the light receiving light is drawn into the optical path space 12 along the inner wall surface. An optical fiber 14 is provided.
The light receiving optical fiber 14 receives reflected light transmitted through the rotating cylinder 10 to be described later, and sends out an optical signal to the determination processing device. A plurality of optical fibers 14 drawn from the outside through the main body 7 are provided. Arranged concentrically along the inner wall surface of the optical path space 12 and arranged in a cylindrical shape as a whole and solidified with an adhesive, and the light receiving part 14a is formed by aligning the respective distal ends in an annular shape at the distal end opening of the optical path space 12. To do.

  The plurality of light receiving optical fibers 14 are arranged in a cylindrical shape along the inner wall surface of the optical path space 12, thereby forming a hollow space in the central portion between the optical fibers to form a substantially circular optical path space 12. Will be formed. In this case, the auxiliary pipe P is disposed along the inner periphery so that the light receiving optical fiber 14 is stably disposed on the inner wall surface of the optical path space 12, and a substantial optical path space 12 is formed inside the pipe. I have to do it.

  In this embodiment, the light receiving optical fibers 14 are arranged in multiple layers along a plurality of concentric circles, and are hardened with an adhesive to increase the thickness of the entire optical fiber so as to be stabilized, and to receive light in an annular shape. The area of the end face of the portion 14a is enlarged so that the light receiving capacity is increased. The enlargement of the light receiving capacity will be described in detail in relation to the optical fiber of the rotating cylinder 10 described later.

On the other hand, the rotating cylinder 10 serves as a laser light guiding means for sending laser light emitted from the laser light oscillator 11 in the main body 7 to the hole 9 of the inspection object 8 and recovering the reflected light from the hole 9. Thus, a metal pipe material having a required length is formed as a material.
For this rotating cylinder 10, a pipe material having an outer diameter smaller than the diameter of the hole 9 is selected because of being inserted into the hole 9, but an optical fiber through which the reflected light of the laser beam passes on the inner peripheral surface of the cylinder 15 and a mirror 16 at the tip, and a laser light guide space 17 through which the laser light from the oscillator 11 passes is formed at the center of the shaft.

  The plurality of optical fibers 15 are densely arranged on the inner peripheral surface of the rotating cylinder 10 along a concentric circle in the circumferential direction, and are arranged over substantially the entire length to form a cylindrical shape as a whole ( 4B), the rear end 15a of each optical fiber 15 is arranged in a ring shape at the rear end opening of the rotating cylinder 10 so as to face the light receiving portion 14a of the light receiving optical fiber 14. As shown in FIG.

  On the other hand, each tip portion 15b of the optical fiber 15 is also arranged in a ring-like manner in a mirror housing space 18 formed by cutting and expanding the inner peripheral surface of the tip portion of the rotating cylinder 10.

  In the figure, reference numeral 19 denotes a cylindrical fixing member for stably fixing the optical fiber 15 in a state of sticking to the inner peripheral surface of the rotating cylinder 10. This fixing member 19 is the same kind of pipe as the auxiliary pipe P, and is also used as an introduction member when the optical fiber 15 is attached to the inner peripheral surface of the rotary cylinder 10. When arranged in a cylindrical shape along the inner peripheral surface of the body 10, the inner periphery of the optical fiber 15 is pressed to be integrated with the rotating cylindrical body 10 to stabilize the optical fiber 15. At the same time, a circular space is secured inside these optical fibers 15, and a laser light guide space 17 that forms a linear shape over the entire length along the axial center portion of the rotating cylinder 10 is formed.

  The mirror housing space 18 expands the inner diameter of the rotating cylinder 10 that becomes the laser light guiding space 17 at the tip, and can accommodate a large mirror 16 that can face the tip 15b of the optical fiber 15. To do.

  In this mirror housing space 18, a window 20 through which laser light passes is opened on the inner peripheral surface where the mirror surface of the mirror 16 faces, and the light transmitted through the laser light guiding space 17 is reflected by the mirror 16 and refracted at a right angle. The inner wall surface of the hole 9 is irradiated through the window 20, and the reflected light can be received and returned to the light receiving portion of the distal end portion 15b of the optical fiber 15.

In the figure, reference numeral 21 denotes a hollow motor as a rotational drive device mounted via bearing portions 22 and 22 arranged on the outer peripheral surface of the base end portion (rear end portion) of the rotary cylinder 10 at an interval in the front-rear direction. This is a connecting arm that is a connecting means for connecting the rotary cylinder 10 to the main body 7 via the hollow motor 21.
The hollow motor 21 is mounted so as to cover the base end portion of the rotary cylinder 10, and the connecting arm 23 extending from a hook-shaped attachment portion 24 provided on the outer peripheral surface of the distal end portion of the main body portion 7 is connected to the hollow motor 21. The rotating cylinder 10 is rotated by using the bearings 22 and 22 as support means during rotational driving.

  The main body 7 and the rotating cylinder 10 are connected by the connecting arm 23 so that the central axes thereof coincide with each other, and at the same time, the tip of the optical path space 12 of the main body and the laser light of the rotating cylinder 10 are connected. It connects so that it may face in the close state of the range which does not contact the rear-end part of the guidance space 17 directly.

  FIG. 3 is an enlarged view showing a state in which the main body portion 7 and the rotating cylinder body 10 are opposed to each other. By this orientation, the optical path space 12 and the laser light guiding space 17 are aligned with each other at the same time, and at the same time, the light receiving portion 14a of the light receiving optical fiber 14 and the rear end portion 15a of the optical fiber 15 disposed in each of the spaces 12 and 17 respectively. They will face each other in close proximity.

  The end portions 14a and 15b of the optical fibers 14 and 15 face each other in an annular manner. As described above, the light receiving optical fiber 14 is arranged in multiple layers. The area of the light receiving end 14a is larger than that of the rear end 15a on the optical fiber 15 side. Therefore, the reflected laser beam sent from the rear end 15a and passing through the narrow gap 25 between the two is efficiently It is received by the light receiving optical fiber 14 and sent to the determination processing device 26.

  The determination processing device 26 is a photoelectric converter 27 that converts the reflected laser light that is irradiated onto the inner wall surface of the hole 9 of the object 8 to be inspected and reflected therefrom into an electric signal, and the electric power sent from the photoelectric converter 27. The processing unit 28 that analyzes the signal and determines the state of the surface of the hole 9, the display unit 29 that displays the determination result as an image, and the lifting device 4 toward the other hole 9 for the next determination upon completion of the determination. The control unit 30 is configured to control and operate the hollow motor 21.

The apparatus of the present invention is configured as described above, and will be further described in accordance with an operation procedure.
When the hole 9 is inspected, the hollow motor 21 is driven to hold the rotary cylinder 10 in a high-speed rotation state. In this state, the rotating cylinder 10 is set in a vertical posture directly above the hole 9 of the inspection object 8 placed on the pedestal 2, and then the lifting device 4 is operated according to an instruction from the control device 30 to rotate the rotating cylinder. The tip of 10 is lowered into the hole 9.

During this descent operation, laser light is emitted from the laser light oscillator 11 toward the optical path space 12.
The laser light emitted toward the optical path space 12 enters the laser light guiding space 17 of the rotary cylinder 10 having a common axis, reaches the mirror 16 disposed at the tip, is reflected, and is reflected by the window 20. The inner peripheral wall surface 9a of the hole 9 is irradiated through the through hole. Then, the reflected laser light reflected from the inner peripheral wall surface 9a of the hole 9 is reflected again by the mirror 16 and refracted at a right angle, and then received by the tip light receiving portion 15b of the optical fiber 15 facing the mirror housing space 18, and the optical fiber. 15, after passing through the rotary cylinder 10, it is received from the rear end portion 15 a to the light receiving portion 14 a of the light receiving optical fiber 14 facing it through the gap 25, and to the determination processing device 26 connected to this through the light receiving optical fiber 14. And sent in the state of an optical signal.

  While the laser beam is emitted and the reflected laser beam is received by the determination processing device 26, the hollow motor 21 continues to rotate at a high speed to rotate the rotating cylinder 10 that enters the hole 9. Therefore, the light passing through the laser light guiding space 17 rotates and moves in the circumferential direction of the hole 9 through the same rotating window 20 according to the mirror 16 rotating together with the rotating cylinder 15, and at the same time, ascends and descends. When the rotary cylinder 10 is moved up and down by the operation of the apparatus 4, the laser beam can be continuously irradiated over the entire inner wall surface of the hole 9. Therefore, the reflected laser light can be continuously received by the determination processing device 26.

  At this time, the optical fiber 15 for returning the reflected laser light rotates at a high speed along with the rotation of the rotating cylinder 10 together with the mirror 16, but a plurality of rings are continuously formed in an annular shape along the inner peripheral surface of the rotating cylinder 10. The light receiving optical fiber 14 disposed in the cylindrical shape and disposed on the inner peripheral surface of the optical path space 12 of the main body 7 is also configured in a cylindrical shape, and the light receiving end 14a and the rear of the optical fiber 15 are also formed. Since the end portion 15a is placed in a close-to-face relationship, the reflected laser beam sent from the rotating optical fiber 15 to the non-rotating light receiving optical fiber 14 has a sufficient amount of light smoothly and stably. Will be delivered.

  At this time, as described above, if the light-receiving optical fiber 14 on the light-receiving side is formed in a multilayer shape and the area of the light-receiving end portion 14a is expanded, the amount of light received by the reflected laser light can be amplified. It is possible to stably transmit the reflected laser light which is not inferior to the case where the optical fibers 14 and 15 are directly connected to each other, that is, not insufficient as a determination material.

  The surface inspection apparatus of the present invention can continuously inspect the entire inner wall surface of the hole 9 from the above-described configuration, and the optical fiber 15 that passes the reflected light through the inside of the rotating cylinder 10 inserted into the hole 9 as a single unit. Are formed as a single unit, and at the same time, a hollow portion of the axial center surrounded by the optical fiber 15 is used as the laser light guide space 17, so that both the irradiation light and the reflected light can be separated and accurately guided thereby. Since it is structured so as to be housed in one rotating cylinder 10 in all, it is possible to make the substantial outer diameter the minimum diameter.

  In particular, as in the case of Patent Documents 1 and 2 described above, since the irradiation light and the reflected light are guided separately, the inner tube is inserted when the tube is divided into an inner and outer double tube and the optical path is distributed. For this reason, the outer cylinder has been enlarged, and it has been difficult to substantially reduce the outer diameter. By securing the laser beam guiding space 17 in the center and the space for placing the optical fiber 15, it is not necessary to secure the space for inserting the inner cylinder and the space between the inner and outer cylinders, so that the minimum outer diameter shape is obtained. It becomes possible to form the rotating cylinder 10 with the pipe material.

  Then, along with the fact that the diameter of the rotating cylinder 10 can be reduced, the outer diameter of the rotating cylinder 10 is increased due to the relationship with the object to be inspected. As a result, the thickness of the rotating cylinder 10 is reduced. It becomes possible to expand, and the strength of the rotating cylinder can be increased after the diameter is reduced.

  The reduction of the substantial outer diameter and the enhancement of the strength of the rotating cylinder 10 are one of the most required elements when, for example, inspecting a small-diameter screw hole used in the assembly of members as a surface inspection device. In addition, a rotating cylinder having a small diameter can be easily inserted into the hole and at the same time can be quickly moved in and out, and the strengthening of the strength is particularly effective in stopping the deflection of the tip during high-speed rotation. become.

  When inspecting a large number of screw holes according to the flow of the line as in the surface inspection of the assembly assembly screw holes that are continuously flowed in the production line of the product to be inspected 4 such as an automobile engine In addition to having a small diameter suitable for the hole 9, the rotating cylinder 10 must be able to withstand high-speed rotation. However, the rotating cylinder 10 of the device of the present invention can withstand this and is accurate. In addition, it enables quick inspection.

  By the way, in this embodiment, an automobile engine that is an object to be inspected 8 is formed with a hole 9 having a diameter of 8 mm as a screw hole for assembly. Was formed with a steel pipe material having a length of 6 mm, a thickness of 2 mm, and a length of 100 mm, a surface inspection device capable of withstanding 12,000 revolutions per minute could be obtained.

  A rotating cylinder having a double cylinder structure in which a rotating outer cylinder having a mirror at the tip is covered on a fixed inner cylinder in which an optical fiber that guides reflected laser light is disposed on an object to be inspected under the same conditions. As implemented in the used surface inspection apparatus, the rotation of the rotating outer cylinder is limited to 7,000 rotations per minute, and if the rotation exceeds this, the rotating cylinder is shaken and can be used for surface inspection. The reflected light from the inspected object could not be obtained.

  As described above, according to the surface inspection apparatus of the present invention, it is possible to provide an inspection apparatus corresponding to the inspection of an inner surface such as a small-diameter hole such as a screw hole, and at the same time, Because it can handle high-speed rotation, it can be a high-speed surface inspection device that can inspect quickly and accurately. For example, when inspecting the inside of many small-diameter holes in a production line, the line is delayed. There is an advantage that an accurate inspection can be performed without any problems.

It is the schematic explaining the actual use of the surface inspection apparatus which concerns on this invention. It is an enlarged longitudinal cross-sectional view in which a part of the main part is omitted. FIG. 3 is an enlarged view of a portion in FIG. 2. 3A is an end view taken along line AA in FIG. 3, and FIG. 4B is an end view taken along line BB in FIG. It is an expanded vertical sectional view explaining the state which inserted the front-end | tip part of the rotating cylinder into the hole of a to-be-inspected object.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body of surface inspection apparatus which concerns on this invention 7 Main body part 8 Inspected object 9 Hole formed in to-be-inspected object 10 Rotating cylinder 11 Laser light oscillator 12 Optical path space 14 Optical fiber for light reception 14a Light receiving part of optical fiber for light reception 15 Optical fiber 15a Optical fiber rear end portion 15b Optical fiber tip light receiving portion 16 Mirror 17 Laser light guide space 18 Mirror storage space 19 Optical fiber fixing member 20 Window 21 Rotating drive hollow motor 23 Connecting arm 26 Connecting means 26 Judgment processing device

Claims (6)

A main body having a laser oscillator and an optical path space for guiding laser light from the laser oscillator toward the tip, and a rotating cylinder that is rotatably attached to the tip of the main body along an extension of the optical path space; The rotating cylindrical body has a concentric circle extending along the entire circumference of the inner peripheral surface, and a plurality of optical fibers are attached in a cylindrical shape over substantially the entire length of the rotating cylindrical body . Sowase in close contact with the fixed member, as well as the shape formed the laser beam guiding space that communicates with the optical path space, the inner peripheral surface of the outer peripheral surface and the rotary cylinder of the plurality of optical fibers to the cylindrical fixing member The laser beam sent to the tip of the rotating cylinder through the laser beam guiding space is irradiated on the surface of the object to be inspected, and the reflected laser beam is applied to the light receiving unit at the tip of the optical fiber. Equipped with a mirror to send, the other body A plurality of optical fibers for receiving light are arranged in a cylindrical shape along a concentric circle on the inner wall surface of the optical path space, and the leading end thereof is brought close to the base end portion of the optical fiber on the rotating cylinder side, and the rotating cylinder A surface inspection apparatus configured to receive reflected laser light from a body-side optical fiber by a light-receiving optical fiber and transmit the light to a determination processing apparatus provided on the main body side. Claim optical fibers between the outer peripheral surface and the inner peripheral surface of the rotating cylinder of interposed adhesive cylindrical fixing member is characterized by stably fixed between the cylindrical fixing member and the optical fiber 1 The surface inspection apparatus described in 1. The front end of the main body is equipped with a connecting means, and the rotating cylinder is connected to and freely supported through the connecting means, and the optical path space, the laser light guiding space, the base end of the optical fiber, and the tip of the optical fiber for receiving light Each of a part is arrange | positioned on a straight line, The surface inspection apparatus of Claim 1 or 2 characterized by the above-mentioned. The surface inspection apparatus according to any one of claims 1 to 3 , wherein a rotation driving device is mounted on an outer peripheral surface portion of the rotating cylinder, and the rotation driving device is supported on the main body portion via a connecting means. On the inner wall surface of the optical path space of the main body, a plurality of light receiving optical fibers are respectively arranged along a plurality of concentric circles drawn in multiple layers to form a plurality of light receiving optical fiber groups , and for receiving the plurality of layers of light receiving light. surface inspection apparatus according to any one of claims 1 to characterized in that the area at the receiving end of the optical fiber group that expanded from the base end portion of the optical fiber of the rotary cylinder side 4. The rotating cylinder forms a mirror storage space in which the inner wall surface portion of the tip portion is cut off to substantially increase the inner diameter, and the tip of the optical fiber is provided along the inner peripheral surface of the rotating cylinder by storing the mirror in the storage space. claims 1 to, characterized in that to face the part surface inspection apparatus according to any one of 5.