WO2019083010A1

WO2019083010A1 - Inspection system and inspection method

Info

Publication number: WO2019083010A1
Application number: PCT/JP2018/039846
Authority: WO
Inventors: 信悟佐藤; 大知長谷川; 遠藤　正浩; 孝山浦; 研弥山浦
Original assignee: 長野オートメーション株式会社
Priority date: 2017-10-26
Filing date: 2018-10-26
Publication date: 2019-05-02

Abstract

A system 100 has: a movement table (40) which includes a clamp (41) for holding the outer-peripheral sides of a workpiece (2) which includes a through-hole (3); an inspection head (10) which inserts into and withdraws from the through-hole an inspection probe (12) for scanning the inner-circumferential surface of the through-hole by outputting an inspection light from the tip thereof through a first opening (3a) on one side of the through-hole (3) in the workpiece at a first position (P1) to which the workpiece is transported by the movement table; a preliminary test unit (5) for inserting a dummy probe (51) into the interior of the through-hole and withdrawing the same therefrom through a second opening (3b) on the other side of the through-hole in the workpiece at the first position; and a unit (47) for verifying whether there is contact between the workpiece and the dummy probe.

Description

Inspection system and inspection method

The present invention relates to an inspection system and method for inspecting a surface by irradiating a laser beam for inspection from an inspection head to an object to be inspected.

In Japanese Patent Application Laid-Open No. 2007-315821, an axial inspection head provided with a mirror at its tip is moved along an axis while being rotated around the axis by a drive mechanism, and the axis is inserted into the inspection head. The light path of the inspection light incident along is changed by a mirror, and the inspection light whose light path is changed is irradiated to the inspection object, and the inspection object is reflected by the inspection object and the light quantity of the inspection light reentered into the inspection head In a surface inspection apparatus for detecting the surface condition of an inspection object, the inspection head includes a head main body attached to a drive mechanism, and a holding unit detachably provided to the head main body and holding a mirror. Have been described.

In recent years, inspection of the surface of a microfabricated article is required, for example, inspection of the surface of an inspection object (inspection object) provided with a small-diameter (ultra-fine) hole having a diameter of about several mm It is requested.

One aspect of the present invention is a moving table including a clamp for holding an outer peripheral side of a work including a through hole, and an inspection head including an inspection probe for outputting an inspection light from a tip to scan an inner peripheral surface of the through hole. System (inspection system). The inspection head takes the inspection probe into and out of the through hole from the first opening on one side of the through hole of the work at a first position where the work is transported by the moving table. The system further includes, in the first position, a preliminary test unit for bringing the dummy probe into and out of the through hole from the second opening on the other side of the through hole of the work, and the presence or absence of contact between the dummy probe and the work And a unit for confirming.

In this system, the dummy probe is inserted from the second opening opposite to the through hole at the first position where the inside of the through hole is inspected by the inspection probe before the inside of the through hole is inspected using the inspection probe. Includes test unit (pre-test unit). By checking the contact between the dummy probe and the work by the unit for checking the presence or absence of the contact, it can be determined whether or not the through hole of the work is accurately set to the inspection probe. Therefore, it is possible to prevent in advance that the expensive and easily damaged inspection probe, particularly the very thin and easily damaged inspection probe, contacts the inner surface of the through hole of the workpiece and the like. Therefore, it is possible to provide a system for safely inspecting the state of the surface inside the through hole at low cost.

The checking unit may comprise a unit, eg a sensor, for checking the damage of the dummy probe. One method of confirming the presence or absence of contact between the dummy probe and the work may be to confirm damage to the dummy probe with a sensor.

The diameter of the dummy probe may be larger than the diameter of the inspection probe. It may be checked in advance, including whether or not the minimum clearance is secured between the inspection probe and the through hole. The diameter Dd of the dummy probe and the diameter Dn of the inspection probe may satisfy the following condition (1). It can be pre-tested by the preliminary test unit, including the presence or absence of clearance.
1 <Dd / Dn <2 (1)

The diameter Dn of the inspection probe may satisfy the following condition (2).
0.5 mm ≦ Dn ≦ 1.5 mm (2)

This system (inspection system) further has a camera unit that confirms the position of the first opening or second opening of the work held by the clamp of the moving table at the second position where the work is transported by the moving table. You may have. The position of the first opening of the work relative to the moving table can be confirmed by image processing or the like. Therefore, the moving table can be moved so that the through hole of the workpiece is set to the first position more accurately.

The system may further include a moving unit that moves the moving table from a third position for loading the work, through the second position to the first position. The workpiece can be loaded at the third position, the position of the workpiece relative to the moving unit can be confirmed at the second position, and the inner surface inspection of the through hole of the workpiece can be performed at the first position.

The system further supplies a laser beam for inspection along the central axis through the inside of the inspection head, which is hollow extending in a rod shape along the central axis and rotated around the central axis, along the central axis. You may have an optical system which receives the reflected light from the surface of the to-be-inspected object returned. The inspection head is a very thin, hollow, needle-like inspection probe mounted along a central axis on a rotating portion that is rotationally driven, a cylindrical holder portion mounted on the rotating portion and having a front wall, and the front wall And may be included. The inspection probe is an optical element disposed at the tip, and emits an inspection laser beam (inspection light) toward the object to be inspected and guides the reflected light in the central axis direction with respect to the central axis. May be included.

In order to inspect the inner surface of a small diameter (very thin) hole of a few mm in diameter, for example, a very thin head with a diameter of around 1 mm, for example, is inserted into the hole to be inspected. It is desirable to stably rotate a very thin head to avoid the interference of In this system, the tip of the inspection head is made into a very thin hollow needle-like shape, which is supported by the thick holder and rotated, so that the very thin inspection probe can be stably rotated even in the small diameter hole. Can inspect the inner surface of the hole.

In addition to the following condition (2), the diameter Dn of the ultrafine inspection probe may satisfy the following condition (3) in relation to the diameter Dh of the front wall of the holder portion or in the vicinity thereof.
5 ≦ Dh / Dn ≦ 40 (3)

The diameter Dn of the inspection probe and the thickness L of the front wall of the holder may satisfy the following condition (4).
5 ≦ L / Dn ≦ 30 (4)

The optical system is an optical fiber bundle inserted into the inspection probe, which includes a non-rotational optical fiber bundle, and the inspection probe is a light control lens disposed between the tip of the optical fiber bundle and the optical element, It may include a light control lens that rotates with the probe.

The system may have a rotation unit that rotates the inspection head about a central axis. The system may further include a moving unit that moves the inspection object (workpiece, workpiece) including the hollow portion into which the inspection probe is inserted and the inspection head relative to the central axis. The inner diameter Di of the hollow portion (through hole) to be inspected may satisfy the following condition (5).
(Dn + 0.5 mm) ≦ Di ≦ (Dn + 3.0 mm) (5)
However, the unit of the diameter Dn and the inner diameter Di is mm.

One of the other aspects of this invention is the method of test | inspecting the internal peripheral surface of the through-hole of the workpiece | work containing a through-hole by an inspection system. The inspection system is inserted from the first opening on one side of the through hole of the workpiece at the first position where the workpiece is conveyed by the movable table and the movable table including the clamp that holds the outer peripheral side of the workpiece, An inspection probe that outputs inspection light from the inside to scan the inner circumferential surface of the through hole, a dummy probe inserted from the second opening on the other side of the through hole of the workpiece at the first position, and a dummy probe And a sensor unit for confirming the presence or absence of contact with the work. The method comprises the following steps.
1. The movement table is set to the first position.
2. The dummy probe is taken in and out of the through hole from the second opening.
3. Check the presence or absence of contact between the inserted dummy probe and the workpiece using the sensor unit.
4. If the contact between the dummy probe and the workpiece is not confirmed, the inspection probe is inserted into and removed from the through hole and inspection is performed.

The inspection system further includes a camera unit disposed at a second position at which the movable table transports the workpiece, and the method further comprises moving the workpiece to the first position at the movable table to the second position. It may include conveying and confirming the position of the first opening or the second opening of the work held by the clamp of the moving table by the camera unit.

The block diagram which shows the outline | summary of a test | inspection system. The surface inspection unit is extracted, The perspective view which shows the outline. Sectional drawing which shows schematic structure of a surface inspection unit. The perspective view which shows the outline | summary of a test | inspection head. Sectional drawing which shows schematic structure of a test | inspection head. Sectional drawing which expands and shows the structure of the front-end | tip of a test | inspection head. Sectional drawing which expands and shows the structure of the probe of a test | inspection head. The flowchart which shows the outline | summary of the process in a test | inspection system. The figure which shows a mode that a workpiece | work is set to a movement table and it test | inspects with a camera unit. The figure which shows a mode that the state of the inner surface of a through-hole is test | inspected by an inspection probe, after testing the position of a workpiece | work beforehand with a dummy probe.

Embodiment of the Invention

An overview of the inspection system 100 is shown in FIG. The inspection system 100 includes a movable table 40 including a clamp 41 for holding an outer peripheral side 2 a of a workpiece (inspection object, workpiece) 2 including a through hole 3, and a first movable workpiece 40 transported by the movable table 40. From the surface inspection unit 1 which inspects the inner peripheral surface 4 of the through hole 3 at the position P1, and from the second opening 3b opposite to the first opening 3a of the through hole 3 of the work 2 at the first position P1. And a control unit 70 for controlling these systems, and a preliminary test unit 50 for taking the dummy probe 51 into and out of the through hole 3. The surface inspection unit (surface inspection apparatus, surface inspection system) 1 outputs an inspection light to scan the inner peripheral surface 4 of the through hole 3, and the first of one side of the through hole 3 of the workpiece 2 The inspection head 10 for moving the inspection probe 12 into and out of the through hole 3 from the opening 3a, and the moving unit 25 for moving the inspection head 10 up and down. The movement table 40 includes a sensor 46 for position confirmation of the workpiece 2 and a sensor (sensor unit) 47 for confirming presence or absence of contact between the dummy probe 51 and the workpiece 2.

The inspection system 100 further moves the camera unit 80 for photographing the side of the first opening 3a of the work 2 and the movement table 40 further at the second position P2 at which the work 2 is transported by the movement table 40, At a third position P3 at which the work 2 is loaded and unloaded, a work transfer robot 90 for loading and unloading the work 2 on the moving table 40 is included. The moving table 40 may include a moving unit 44 self-propelled along a rail or other guide 45 connecting these positions P1, P2 and P3, and the function of moving the moving table 40 by the guide 45 The mobile unit may be included.

The control unit 70 controls the transfer position (move position) of the move table 40, the load / unload control unit 72 controls the transfer robot 90, and the work 2 for the move table 40 by the camera unit 80. An image processing unit 73 for confirming the position of the through hole 3 and a preliminary test control unit 74 for confirming the position of the through hole 3 by the dummy probe 51 before the inner surface 4 of the through hole 3 is inspected by the inspection probe 12; And an inspection control unit 75 that inspects the inner surface 4 of the through hole 3 by the inspection probe 12.

The surface inspection unit 1 including the inspection probe 12 and the preliminary test unit 50 including the dummy probe 51 are fixed to the common frame 101, and the inspection probe 12 and the dummy probe 51 are common at the first position P1. (Coaxially) along the axis 11 of the, to face with high precision, and to move up and down. The preliminary test unit 50 includes a moving unit 52 that moves the dummy probe 51 up and down along the axis 11. The moving unit 52 includes, for example, a ball screw 53 and a motor 54 that drives the ball screw 53.

The surface inspection unit 1 and the preliminary test unit 50 may be disposed upside down, and may be disposed to face each other horizontally or horizontally. The arrangement of the upper and lower sides is suitable in order to avoid the influence of deflection due to gravity or the like when the inspection probe 12 and the dummy probe 51 are very thin with a diameter of several mm or less. Further, in consideration of the operation such as maintenance or replacement of the inspection probe 12, it is preferable to dispose the surface inspection unit 1 on the upper side.

FIG. 2 shows the appearance of the surface inspection unit (surface inspection system, inspection apparatus, inspection unit) 1, and FIG. 3 shows a schematic configuration of the inspection apparatus 1 using a cross section (cross section III-III in FIG. 2) It shows. The inspection unit 1 is suitable for inspecting the shape or state of the inner surface 4 of a hollow portion (through hole) 3 such as a hole or a recess provided in a workpiece 2 to be inspected. An example of the hollow portion 3 is a through hole having a diameter of several mm.

The inspection unit 1 extends along the central axis 11 through a hollow inspection head 10 extending in a rod shape along the central axis 11, a rotation unit 20 that rotates the inspection head 10 around the central axis 11, and the inspection head 10. An optical system 30 for supplying laser light for inspection and receiving reflected light from the surface 4 of the inspection object 2 returned along the central axis 11, and a central axis of the inspection head 10 and the inspection object 2 11 includes a moving unit 25 relatively moving along 11, and a housing 5 incorporating the rotating unit 20, the optical system 30 and the moving unit 25.

The moving unit 25 may move the inspection head 10 relative to the workpiece 2 to be inspected, and in the present embodiment, the inspection head 10 housed in the housing 5 as the moving unit 25 may be a housing 5 Is a unit that moves relative to the The moving unit 25 includes a carriage 28 mounted with the inspection head 10, the rotating unit 20 and the optical system 30, and a combination of a ball screw 26 and a motor 27 for moving the carriage 28 back and forth (left and right in FIG. 3). The inspection head 10 includes a fixing portion 19 serving as a base end and a rotating portion 18 mounted so as to rotate with respect to the fixing portion 19, and the fixing portion 19 is mounted on the carriage 28 via the mounting unit 29. There is. Inspection head (head for inner surface inspection s) 10 has a very thin needle portion (inspection probe, probe) projecting forward (in this system, lower side) 16 along central axis (rotational axis, axial center) 11 at the tip. Including 12. The inspection probe 12 is fixed to the front wall 14 a of the thick cylindrical holder portion 14 with respect to the inspection probe 12 so as to protrude along the central axis 11, and is fixed to the rotating portion 18 via the holder portion 14 It rotates around the central axis 11 together with the rotating portion 18.

The configuration of the moving unit 25 is an example, and may be a slider, a moving table, or the like. The moving unit 25 moves the inspection head 10 to a position P 1 projecting forward from the housing 5 and a position P 2 at which the inspection head 10 retracts into the housing 5. Instead of moving the inspection head 10 back and forth, or while moving the inspection head 10 back and forth, the inspection object 2 may be moved using a robot or the like.

The configuration of the moving unit 25 is an example, and may be a slider, a moving table, or the like. The moving unit 25 moves the inspection head 10 to an inspection position 10 a projecting forward from the housing 5 and a position 10 b where the inspection head 10 retracts into the housing 5.

The optical system 30 includes a semiconductor laser (laser diode, LD) 31 that generates a laser beam for inspection, a light receiving element (for example, a photodiode, CCD, CMOS, etc.) 32 that receives reflected light, and a drive of the semiconductor laser 31. And a control unit 33 including a circuit, a circuit for processing a signal received by the light receiving element 32, and the like. A signal received by the optical system 30 is sent to a computer (personal computer) (not shown) via the control unit 33, and is further data processed and used for analysis of the surface 4 of the inspection object 2. The optical system 30 further includes an optical fiber 35 inserted into the inside of the inspection probe 12 through the inspection head 10.

An example of the rotation unit 20 is a motor 21 mounted on a carriage 28. The pulley 22 driven by the motor 21 is connected to the rotating portion 18 of the inspection head 10 by the drive belt 23, and the motor 21 rotates the rotating portion 18 of the inspection head 10 around the central axis 11 via the drive belt 23. It rotates at high speed (about the central axis 11).

The inspection head 10 is extracted and shown in FIG. FIG. 5 shows a schematic configuration of the inspection head 10 using a cross section (cross section VV in FIG. 4). Further, FIG. 6 shows the tip portion (front portion) of the inspection head 10 using an enlarged cross section, and FIG. 7 shows the configuration of the inspection probe 12 at the tip of the inspection head 10 using an enlarged cross section .

The inspection head 10 is a hollow cylindrical body generally extending along the rotation axis 11 and coaxially mounted so as to rotate via the bearing 17 with respect to the fixed portion 19 at the proximal end and the fixed portion 19. , A rotating portion 18 extending towards the tip 16. The rotating portion 18 is rotationally driven, and a relatively thick drive portion 15 to which rotational force is transmitted via the drive belt 23, a holder portion 14 attached to the front 16 of the drive portion 15, and a front wall 14a of the holder portion 14 And a needle-like inspection probe (insertion portion) 12 extending from the center of the head to a thin tip (forward). A radially directed opening (notch) 13 is provided at the tip 12 a of the inspection probe 12, and a laser beam for inspection (probe light, inspection light) 61 is an inspection object through the opening 13. The reflected light 62 from the surface 4 of the through hole 3 of the inspection object 2 is emitted from the inspection probe 12 back to the inspection head 10 so as to be emitted toward the hollow portion of the workpiece 2, in this example, the surface 4 of the through hole 3 It has become.

An optical fiber bundle 35 for guiding the probe light 61 and the reflected light 62 along the central axis 11 is inserted into the inspection head 10. The optical fiber bundle 35 constituting the optical system 30 is a bundle of a plurality of fibers, and a light emitting optical fiber 35a for guiding the probe light 61 emitted from the LD 31 toward the inspection object 2 and a reflected light 62 from the inspection object 2 And a light receiving fiber 35 b leading to the light receiving element 32. Furthermore, the optical system 30 includes, inside the inspection head 10, a holding cylinder 34 that holds the optical fibers 35 in a bundled state.

The inspection probe 12 extends forward from the front wall 14a of the holder portion 14 along the central axis 11 and has an optical element 39 attached to the tip (near the tip) 12a for controlling the emission direction of the probe light 61. One example of the optical element 39 is a plane mirror, and may be an optical element having a reflection surface such as a prism that can control the emission direction and the incident direction of other light. In the inspection apparatus 1 of this example, the angle of the mirror surface (reflection surface) 38 of the optical element 39 is set to 45 degrees, and the probe light 61 emitted from the optical fiber 35 with the central axis 11 as the optical axis is the central axis The light is emitted in the direction orthogonal to the axis 11). Further, light (reflected light) 62 reflected from the inner surface 4 of the inspection object is reflected in the direction of the optical fiber 35 of the central axis 11 by the reflection surface 38 of the optical element 39. Inside the inspection probe 12, the optical fiber 35 supported by the holding cylinder 34 is inserted to a position retracted from the tip 12a, and the light control lens 36 is approximately in the middle between the tip 35c of the optical fiber 35 and the optical element 39. It is attached to be supported by the inspection probe 12.

The light adjustment lens 36 is an objective lens having a focal length suitable for condensing the probe light 61 output from the tip 35 c of the optical fiber 35 on the inspection target surface 4 via the reflection surface 38. The light adjustment lens 36 also includes a function of condensing the reflected light 62 introduced to the inspection head 10 via the reflection surface 38 on the tip 35 c of the optical fiber 35. The optical system 30 for supplying the probe light 61 along the central axis 11 of the inspection head 10 and detecting the reflected light 62 is not limited to the one using the optical fiber 35, but as an optical pickup etc. provided with a dichroic prism etc. It may be another known optical system. In order to input and output the probe light 61 and the reflected light 62 inside the very thin inspection probe 12, an optical system 30 using an optical fiber 35 is preferable.

In recent years, the precision of microfabrication has been improved, and in various applications, for example, a nozzle or path through which a fluid such as liquid passes, an optical device, a machine, a product or a machine in which an extremely thin through hole or bottomed hole is processed Parts are manufactured. One example of the extremely thin holes 3 has a diameter Di of several mm or less, for example, 5 mm or less, or 3 mm or less, or 2 mm or less. The diameter Dn of the inspection probe 12 for irradiating the probe light 61 to the inner surface 4 of the hole (through hole, hollow portion) 3 of such dimensions and collecting the reflected light 62 takes into account the clearance with the inner surface 4 As shown in the condition (2), it is required to be 1.5 mm or less. In particular, when the diameter Di of the hole 3 to be inspected is about 3 mm or less, the upper limit of the condition (2) indicating the diameter (outer diameter) Dn of the inspection probe 12 is 1.2 mm or less, for example It is desirable that it is 0 mm. At present, the diameter (inner diameter) Di of the hole 3 which can be inspected in the inspection apparatus 1 of this type is about 1.0 mm or more, and the range shown in the equation (5) is preferable, including the clearance.

An example of the inspection probe 12 is a stainless steel needle-like cylinder having an outer diameter Dn of 1.0 mm and an inner diameter of 0.8 mm. The inspection unit 1 provided with the inspection probe 12 can inspect the condition of the inner surface 4 of the hole 3 for the hole 3 having a diameter Di of 3 mm or less. Inside the inspection probe 12, an optical fiber 35 supported by a non-rotational holding cylinder 34 having a diameter (outside diameter) of about 0.6 mm is inserted. The holding cylinder 34 extends from the inspection probe 12 to the inside 14 b of the holder portion 14 and is fixed to a forwardly extending portion 19 a of the fixing portion 19. On the other hand, the inspection probe 12 is connected to the rotating unit 18 via the holder unit 14, and rotates around the central axis (rotational axis) 11 by the rotating unit 20. The optical element 39 attached (disposed) to the tip 12 a rotates with the inspection probe 12. Therefore, the probe light 61 reflected by the optical element 39 is emitted radially through the opening 13 and scans the inner surface 4 of the hole 3 in the circumferential direction. The reflected light 62 from the inner surface 4 is returned to the inside of the inspection probe 12 through the opening 13 and the optical element 39, reflected along the central axis 11, and input to the optical fiber 35.

A light control lens 36 is fixed to the inspection probe 12, and the light control lens 36 rotates around the central axis 11 together with the inspection probe 12, that is, with the optical element 39. Therefore, the probe light 61 and the reflected light 62 are input to and output from the inner surface 4 through the light adjustment lens 36 and the optical element 39 which rotate together (in synchronization with each other). For this reason, the dependence of the rotation angle of the optical path constituted by the light adjustment lens 36 and the optical element 39 is small, and the inspection apparatus 1 makes the probe light 61 and the reflected light 62 Input and output, and can collect stable signals. It is difficult to fix the lens 36 in a state in which the dependence of the rotation angle is small on the inside of the very thin inspection probe 12 in which the diameter Di is about 1 mm and the inner diameter may be less than 1 mm. In the inspection apparatus 1 of this example, by attaching and rotating the lens 36 to the inspection probe 12, the probe light 61 and the reflected light 62 can be input / output under the same condition with respect to the rotation angle.

In order to inspect the state of the inner surface 4 of the hole 3 with an inner diameter Di of several millimeters or less with high accuracy, the inspection probe 12 with a diameter Dn of 1.5 mm or less is accurately off-centered around the central axis 11 or It is desirable to rotate without differential movement. For this reason, in the inspection apparatus 1, as shown in an enlarged manner in FIG. 6, the holder portion 14 is supplied with the front wall 14 a of a sufficient size and with a sufficient thickness, and the inspection probe along the central axis 11 thereof. An attachment hole 14c having a length L and an inner diameter approximately equal to 1 mm and having an inner diameter substantially equal to the outer diameter Dn of 12 is provided. By supporting the inspection probe 12 along the central axis 11 with the attachment hole 14c of sufficient length L with respect to the diameter Dn of the inspection probe 12, it is possible to stably rotate the very thin inspection probe 12. The inspection probe 12 is assembled and shipped to the holder unit 14 by a dedicated jig.

The diameter (outer diameter) Dh of the holder portion 14 is a size easy to handle on site, and preferably satisfies the following condition (6).
5 mm ≦ Dh ≦ 30 mm (6)
The lower limit of the condition (6) is preferably 10 mm, while the upper limit is more preferably 20 mm in consideration of weight and cost. Therefore, it is preferable that the outer diameter Dh of the holder portion 14 with respect to the diameter Dn of the probe 12 satisfy the condition (3) described above. Further, the lower limit of the condition (3) is preferably 10, the upper limit is preferably 30, and the more preferably 25.

In addition, the length L of the mounting hole 14c (the wall thickness of the front wall 14a) is the above-mentioned condition (4) with respect to the outer diameter Dn of the probe 12 in order to stably hold the extra thin probe 12. It is preferable to satisfy Furthermore, the lower limit of the condition (4) is preferably 10, and the upper limit is preferably 20 in consideration of weight and cost. Specifically, it is preferable that the length (thickness of the front wall 14a) L of the mounting hole 14c satisfy the following condition (7).
5 mm ≦ L ≦ 30 mm (7)
The lower limit of the condition (7) is preferably 10 mm, and the upper limit is preferably 20 mm.

As described above, the inspection unit 1 mounts the very thin inspection probe 12 with a diameter of about 1 mm at the tip of the inspection head 10 and inspects the inner surface 4 of the hollow portion 3 with a diameter of about several mm, for example 3 mm or less And is suitable for evaluating the condition of its inner surface (surface).

On the other hand, the probe 12 having a diameter Dn of about 1 mm and containing the above-mentioned structure is expensive. Moreover, in order to insert the probe 12 with a diameter of about 1 mm into the through hole 3 with a diameter Di of about 2 to 3 mm and rotate it at high speed, it is necessary to align the workpiece 2 with the probe 12 with high accuracy. If the value of x is low, the probe 12 interferes with the workpiece 2 and is damaged or destroyed. Therefore, in the inspection system 100, by inserting the dummy probe 51 first, the accuracy of alignment of the inspection probe 12 with the workpiece 2, specifically, the through hole 3 to be inspected, is verified in advance.

FIG. 8 shows a process of inspecting the inner surface 4 of the through hole 3 of the work 2 in the inspection system 100 by a flowchart. Further, FIG. 9 shows a state in which the movable table 40 has been moved to the third position P3 and the second position P2, and in FIG. 10, the movable table 40 is moved to the first position P1 and the dummy probe 51 is used. The state of inspection by the inspection probe 12 after verifying the position is shown.

First, at step 111, the table control unit 71 of the control unit 70 moves the moving table 40 to the third position P3. The load / unload control unit 72 controls the transfer robot 90 to set the new work 2 on the clamp 41 of the moving table 40, and the clamp 41 holds the outer peripheral surface 2 a of the work 2. The moving table 40 incorporates a sensor 46 for detecting the presence and the position of the workpiece 2 and confirms that the workpiece 2 is clamped at a predetermined position.

In step 112, the table control unit 71 moves the moving table 40 on which the work 2 is set to the second position P 2 below the camera unit 80 along the guide 45 by the moving unit 44. In step 113, the image processing unit 73 acquires an image of the workpiece 2 gripped by the moving table 40, in particular, an image including the first opening 3 a on the upper side of the through hole 3 of the workpiece 2. Analyze and confirm the position of the opening 3a. By confirming the position of the first opening 3a with respect to the moving table 40, the first opening 3a can be accurately set to the first position P1 where the inspection probe 12 is inserted. For example, the moving table 40 or the clamp 41 may be provided in advance with a plurality of markers from which an image is to be acquired along with the first opening 3a. Detailed stop position when the movable table 40 is moved to the first position P1 based on the relative position of the marker of the movable table 40 and the first opening 3a in the image acquired by the camera unit 80 Control of the

Thereafter, in step 114, the table control unit 71 moves the moving table 40 on which the work 2 is set to the first position P1 along the guide 45 by the moving unit 44. At this time, the table control unit 71 causes the central axis of the through hole 3 of the workpiece 2 to coincide with the central axis 11 of the inspection probe 12 at the first position P1, based on the data obtained in step 113. , Control the position of the moving table 40.

In step 115, as shown in FIG. 10A, the preliminary test control unit 74 uses the preliminary test unit 50 to open the dummy probe 51 on the opposite side (other side) of the through hole 3 of the work 2 2. Insert from the opening 2) 3b, and verify whether or not the position of the through hole 3 coincides with the first position P1, that is, the axis 11. The dummy probe 51 is set such that the diameter Dd satisfies the condition (1). In this example, the diameter Di of the through hole 3 to be inspected is 2 mm, the diameter Dn of the inspection probe 12 is 1 mm, and the diameter Dd of the dummy probe 51 is 1.5 mm.

The dummy probe 51 moves up and down along the axis 11 at the first position P1 by the moving unit 52, and is inserted into the through hole 3 of the work 2 from the lower opening 3b. Since the diameter Dd of the dummy probe 51 is larger than the diameter Dn of the inspection probe 12, if the dummy probe 51 is inserted into the through hole 3 without contact with the through hole 3, the axis 11 coaxial with the dummy probe 51 is inserted. The inspection probe 12 which is set to move up and down is inserted into the through hole 3 while maintaining a predetermined clearance, for example, a clearance of 0.25 mm or more.

In step 116, as shown in FIG. 10 (b), the preliminary test control unit 74 pulls the dummy probe 51 out of the through hole 3 and uses the sensor (for example, camera unit) 47 mounted on the moving table 40. Check for 51 damage. For example, when the dummy probe 51 is bent or a scratch is observed on the surface, it is determined that there is interference with the work 2 when the dummy probe 51 is inserted into the through hole 3. If the dummy probe 51 is damaged, an error is displayed in step 119 and the inspection system 100 is stopped.

On the other hand, when the dummy probe 51 is not damaged, the inspection control unit 75 operates the surface inspection unit 1 in step 117 as shown in FIG. 10C to set the inspection probe 12 to the first position P1. The head is moved downward (forward) 16 along the central axis 11 of the head and inserted into the through hole 3 of the work 2 from the upper opening 3a. As described above, the inspection unit 1 rotates the inspection probe 12 around the central axis 11 and uses the inspection light (probe light) 61 emitted from the tip 12 a of the inspection probe 12 to form the through hole 3 of the workpiece 2. Inspect the condition of the inner surface 4 of. When the inspection is completed, the inspection probe 12 is pulled out to the upper side of the through hole 3 to retract the inspection probe 12 from the moving table 40.

When the inspection is completed, in step 118, the table control unit 71 moves the moving table 40 to the third position P3, and the load / unload control unit 72 is clamped on the moving table 40 using the transfer robot 90. Replace 2 By repeating these steps, the inspection system 100 inspects the state of the inner surface 4 of the through hole 3 provided in the plurality of workpieces 2 automatically and without damaging the inspection probe 12. The four states can be evaluated.

In the inspection system 100, the presence or absence of contact between the dummy probe 51 and the work 2 is determined based on whether or not the dummy probe 51 is damaged after the dummy probe 51 is pulled out. A contact sensor may be provided at 51 to determine whether or not the workpiece 2 is in contact with the workpiece 2 when inserted into the workpiece 2. It may be determined whether a current flows between the dummy probe 51 and the workpiece 2 or The presence or absence of contact between the dummy probe 51 and the workpiece 2 may be determined by a method of detecting the state of the electric field around the dummy probe 51 or the like. The method for determining the presence or absence of damage to the dummy probe 51 can determine the presence or absence of contact with the work 2 without affecting the state of the inner surface 4 of the work 2 due to current or electric field, in a favorable case. . In this example, the sensor 47 for determining the presence or absence of contact between the dummy probe 51 and the work 2 is built in the moving table 40 in order to detect at a position close to the work 2, but the position of the sensor 47 is limited to this Alternatively, it may be incorporated in the head moving with the dummy probe 51 or may be provided in the preliminary test unit 50.

Further, this inspection system 100 is an example of a system specialized for inspecting the state of the inner surface 4 of the through hole 3 of the work 2, and this inspection system 100 can be used as an assembly line of products using the work 2 or It is also possible to incorporate it into part of the production line of the workpiece 2. A product can be manufactured using the work (part) 2 in which the state of the inner surface 4 is confirmed. Further, immediately after processing the through hole 3 in the work 2, the state of the inner surface 4 of the through hole 3 can be confirmed.

Further, in this inspection system 100, the inspection probe 12 and the dummy probe 51 are vertically arranged at the first position P1 along the axis 11, but may be arranged in the opposite direction. May be In addition, each dimension described above is an example, and the inspection system 100 is suitable for protecting the ultrafine inspection probe (inspection needle) 12, but the diameter is not limited to the diameter of the inspection probe 12. Verifying the position of 2 is useful to avoid damage to the probe 12.

The surface inspection unit (surface inspection system) disclosed above is a hollow inspection head extending in a rod shape along a central axis, the inspection head being rotated around the central axis, and the inspection head passing through the inspection head And an optical system for supplying a laser beam for inspection along the central axis and receiving reflected light from the surface of the inspection object returned along the central axis. The inspection head includes a rotary unit driven to rotate, a cylindrical holder mounted on the rotary unit, and a holder unit having a front wall, and a very thin hollow needle mounted on the front wall along the central axis. A portion (inspection probe), the needle portion being an optical element disposed at the tip, and emitting the laser beam for inspection toward the object to be inspected with respect to the central axis It includes an optical element that guides reflected light in the central axis direction. The diameter Dn of the needle portion and the diameter Dh of the front wall of the holder portion or in the vicinity thereof may satisfy the conditions (2) and (3). The diameter Dn of the needle portion and the thickness L of the front wall of the holder portion may satisfy the condition (4).

Further, the optical system is an optical fiber bundle inserted into the needle portion, and the optical system includes a non-rotational optical fiber bundle, and the needle portion is a light control disposed between the tip of the optical fiber bundle and the optical element. The lens may include a light control lens that rotates with the needle unit. Furthermore, the surface inspection unit may comprise a rotation unit that rotates the inspection head around the central axis. The object to be inspected includes a hollow portion into which the needle portion is inserted, and the surface inspection unit further includes a moving unit for relatively moving the inspection head and the object to be inspected along the central axis. May be Further, the inner diameter Di of the hollow portion may satisfy the condition (5).

Claims

A moving table including a clamp for holding an outer peripheral side of the workpiece including the through hole;
An inspection head including an inspection probe that outputs inspection light from a tip to scan an inner circumferential surface of the through hole, wherein the through hole of the work is at a first position where the work is transported by the moving table An inspection head for moving the inspection probe into and out of the through hole from a first opening on one side of the
A preliminary test unit for taking a dummy probe into and out of the through hole from the second opening on the other side of the through hole of the work at the first position;
A system comprising: a unit for confirming presence or absence of contact between the dummy probe and the work.
In claim 1,
The system, wherein the unit to confirm includes a unit to confirm damage to the dummy probe.
In claim 1 or 2,
The system wherein the diameter of the dummy probe is larger than the diameter of the inspection probe.
In any one of claims 1 to 3,
A system in which the diameter Dd of the dummy probe and the diameter Dn of the inspection probe satisfy the following conditions.
1 <Dd / Dn <2
In claim 4,
The system in which the diameter Dn of the inspection probe satisfies the following condition.
0.5 mm ≦ Dn ≦ 1.5 mm
In any one of claims 1 to 5,
The camera further includes a camera unit that confirms the position of the first opening or the second opening of the workpiece held by the clamp of the movable table at a second position where the workpiece is conveyed by the movable table. ,system.
In claim 6,
The system further comprising: a moving unit that moves the moving table from a third position to load the workpiece, through the second position to the first position.
In any one of claims 1 to 7, further,
A hollow rod extending along a central axis and supplying a laser beam for inspection along the central axis through the inside of the inspection head rotated about the central axis and returning along the central axis Have an optical system that receives light reflected from the surface of the inspected object,
The inspection head is a rotary unit driven to rotate.
A holder portion having a cylindrical front wall mounted on the rotating portion, the ultra-fine hollow inspection probe including the holder portion mounted on the front wall along the central axis;
The inspection probe is an optical element disposed at the tip, and emits the laser light as the inspection light toward the inspection object with respect to the central axis and the reflected light in the central axis direction A system that includes an optical element leading to the
In claim 8,
A system in which the diameter Dn of the inspection probe and the diameter Dh of the front wall of the holder portion or in the vicinity thereof satisfy the following conditions.
0.5 mm ≦ Dn ≦ 1.5 mm
5 ≦ Dh / Dn ≦ 40
In claim 8 or 9,
The system in which the diameter Dn of the inspection probe and the thickness L of the front wall of the holder unit satisfy the following conditions.
5 ≦ L / Dn ≦ 30
In any one of claims 8 to 10,
The optical system is an optical fiber bundle inserted into the inspection probe, and includes a non-rotational optical fiber bundle.
The test probe is a light control lens disposed between the tip of the fiber optic bundle and the optical element, the light control lens including a light control lens that rotates with the test probe.
In any of claims 8 to 11, further,
A rotating unit that rotates the inspection head around the central axis;
A moving unit for moving the inspection head along the central axis.
In claim 12,
A system in which the diameter Dn of the inspection probe and the inner diameter Di of the through hole satisfy the following conditions.
(Dn + 0.5 mm) ≦ Di ≦ (Dn + 3.0 mm)
However, the unit of the diameter Dn and the inner diameter Di is mm.
A method of inspecting an inner circumferential surface of the through hole of a work including the through hole by an inspection system,
The inspection system
A moving table including a clamp for holding an outer peripheral side of the work;
At the first position where the work is transported by the moving table, the work is inserted from the first opening on one side of the through hole, the inspection light is output from the tip, and the inner circumferential surface of the through hole An inspection probe to scan the
A dummy probe inserted from a second opening on the other side of the through hole of the work at the first position;
A sensor unit for confirming presence or absence of contact between the dummy probe and the workpiece;
The method is
Setting the moving table to the first position;
Bringing the dummy probe into and out of the through hole from the second opening;
Confirming with the sensor unit whether or not the dummy probe brought in and out comes into contact with the work;
And, if the contact between the dummy probe and the workpiece is not confirmed, the inspection probe is inserted into and removed from the through hole to perform an inspection.
In claim 14,
The inspection system further includes a camera unit disposed at a second position at which the movable table transports the workpiece;
The method further comprises
Conveying the workpiece to the second position before conveying the workpiece to the first position with the movement table;
Checking the position of the first opening or the second opening of the work held by the clamp of the moving table by the camera unit.