JPS62179643A - Appearance inspector - Google Patents

Abstract

PURPOSE:To enable highly reliable inspection of appearance state automatically and in non-contact manner, by causing an object to be inspected to spin and irradiating its appearance surface to receive a reflected light. CONSTITUTION:A rotor 4 on a table 1 to be rotated in the direction of the arrow (alpha) driven by a motor 2 receives the supply of work at a point (A), is spun with a motor 5 at a point (C) and reflects light from a light source 7 to be incident into a light receiver 8. A signal S1 from a detection of the circumferential surface of the work on the rotor 4 is corrected to a data corrector section 9 to be judged with a decision circuit 13. When the results of inspection are accepted, an eject controller 14 ejects the work when the rotor 4 reaches the point (E). If judgement is disabled, the work is exhausted at the point (F) and if it is defective, it is done at the point (G) - all by operating an air jet 6 separately. Thus, the appearance of the object being inspected can be inspected and sorted automatically and in a non-contact manner with a high reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an appearance inspection device suitable for inspecting the condition of a wrapping portion formed on the surface of a circular-shaped object to be inspected, such as a piston ring.

[Technical background of the invention and its problems] In an internal combustion engine, a pressure ring is installed on the outer circumferential surface of a piston that reciprocates within a cylinder to prevent gas leakage, or a hydraulic ring is used to remove lubricant oil that adheres to the inner wall of the cylinder. A piston ring such as Killing is fitted. The outer circumferential surface of the piston ring is lapped, but if there is variation in the wrapping due to scratches or unevenness, it will adversely affect the reciprocating motion of the piston. For this reason, the surface of the piston ring was required to have high precision.

However, in the past, there was no means for automatically and non-contactly inspecting the surface condition of piston rings, and inspection was performed solely by visual inspection by an inspector. For this reason, the test results are not only inconsistent, but also there is a risk that scratches or unevenness may be overlooked, resulting in unreliable results. Also, self-help,
This was also a problem from the perspective of labor saving, and a solution was desired.

[Purpose of the invention]

The present invention was made based on these circumstances,
The purpose is to be able to automatically and non-contactly inspect the external appearance of the object to be inspected with high reliability.
The object of the present invention is to provide an appearance inspection device that can automate the inspection process and save labor.

[Summary of the invention]

In order to achieve the above object, the present invention holds a circular inspection object in a perfect circle state by a holding means, optically measures the external surface of the inspection object held by the holding means, Based on the measurement results, the quality of the external surface condition is determined, and the objects to be inspected are sorted according to the determination results.

[Embodiments of the invention]

FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of the present invention. In the same figure, reference numeral 1 denotes a rotary table, which is rotated by an arrow α around a rotation shaft 3 by the drive of a drive motor 2.
It rotates in the direction. This rotary table 1
A plurality of (eight in this case) rotors 4 are provided for holding and fixing an annular object to be inspected (hereinafter referred to as a workpiece), and these rotors 4 move as the table 1 rotates. The rotor 4 receives a workpiece by a supply mechanism (not shown) at a point A in the figure, and rotates at a point C in the figure by driving the rotation motor 5. At this time, the external appearance is inspected by an optical system to be described later. was carried out, and based on the test results E and F in the figure
, G to the air jets 6a, 6b, 6
The work is discharged by the action of c.

Reference numeral 7 denotes a light source that irradiates light onto the surface to be inspected of a rotating workpiece at point C in the figure, and the light reflected from the workpiece is detected by a light receiver 8. The light receiver 8 converts the incident light into an analog electrical signal S1, and this electrical signal S1 is supplied to a data collecting section 9, which collects measurement data of the surface to be inspected. Reference numeral 10 denotes a determination section, which includes a preprocessing circuit 11 that performs preprocessing such as filtering on the analog signal S2 corresponding to the survey data collected by the data collection section 9, and a preprocessing circuit 11 that performs preprocessing such as filtering processing. A binarization circuit 12 that binarizes the preprocessed analog signal S3, and a determination circuit 13 that decides the state of the surface to be inspected based on the 2I signal S4 output from the binarization circuit 12. It is composed of. The above judgment circuit 1
3 is a good command if there are no scratches or unevenness on the surface to be inspected and the quality is above the desired quality standard, a bad command if there are scratches or unevenness and the quality is below the desired quality standard, and if neither can be determined, it cannot be determined. Air jet controller 1
4. If a good command is given, the air jet controller 14 starts the air jet 6a when the rotor 4 holding the workpiece to be measured reaches point C, and if an undetermined command is given, the air jet controller 14 starts the air jet 6a when the rotor 4 holding the workpiece to be measured reaches the point C. The air jet 6b is started when the rotor 4 holding the workpiece reaches point F, and if a defect command is given, the air jet 6c is started when the rotor 4 holding the workpiece to be measured reaches point C. As a result, the workpieces are sorted based on the pass/fail judgment results.

Reference numeral 15 in the figure indicates the drive motor 2. The drive controller 15 is a drive controller that controls the startup timing and drive time of the rotation motor 5 and the light source 7, and in other words, the drive controller 15 controls the drive motor 2 when the rotor 4 reaches point C due to drive of the drive motor 2. The rotation motor 5 is stopped and the rotation motor 5 is started. At this time, the light source 7 is started to measure the surface to be inspected of the workpiece held by the rotor 4. When this measurement is completed, the rotation motor 5 and the light source are started. 7, restart the drive motor 2, and rotate the rotary table 1.
is rotated, and the drive motor 2 is stopped when the next rotor 4 is located at point C.

2 and 3 are diagrams showing the detailed structure of the rotor 4, with FIG. 2 being a side sectional view and FIG. 3 being a top sectional view. Note that the 1 side in Figure 2 shows the state when it is located at point C in Figure 1, and the ■ side in Figure 2 shows the state from E-G in Figure 1.
It shows the state when located at the point. In FIG. 2, a shaft 21 is slidably supported by the rotary table 1 via a bearing 22, and a support base 24 having an inclined surface 23 is integrally fixed to the top of the shaft 21. Three arms 25 are provided on the inclined surface 23 of the support stand 24.
a to 25G (25c is not shown) are supported via rollers 26a to 26G at approximately equal intervals, and claw portions 27a to 27a are provided at the tips of these arms 25a to 25c, respectively.
7C is fixed. Further, as shown in FIG. 3, springs 28a to 280 for self-alignment are interposed between each of the arms 25a to 25G.
The workpiece 30 placed on the workpiece 9 is held in a perfect circle by the claws 27a to 27G. The support plate 29 is supported and fixed to the rotary table 1 by support means (not shown), and the claw portions 2 are provided on the table surface.
Holes 31a to 31C are formed through which holes 7a to 27c can pass, respectively. Note that the support plate 29 and the claw portions 27a to 27C are made of a material with low reflectance.

On the other hand, a pulley 32 is fitted onto the shaft 21. At point C in FIG. 1, there is a rotation mechanism, that is, a rotation motor 5, and a Leherto wheel 33 that transmits the driving force of this motor 5. Belt 34. A belt wheel 35 is installed, and a pulley 32
When the shaft 21 is fitted with the belt pulley 35, the shaft 21 rotates due to the rotation 61ei, and the workpiece 30 also rotates accordingly. Further, the shaft 21 is slid on a cam plate 37 by a roller 36, and the entire shaft 21 moves up and down according to the cam plate 37, and the arms 25a to 25G and claw portions 27a to 27G have a radius of It also opens and closes in both directions.

Next, the operation of this embodiment will be explained. In this embodiment, the cam plate 37 is set so that points B and C are the highest so that the claws 27a to 27G protrude from the support plate 29 and are in the open state.

Points D and H are set at intermediate levels so that the claws 27a to 27G protrude from the support plate 29 and are in a closed state, and points E-C are set to the lowest level so that the claws 27a to 27C do not protrude.

Now, the support plate 2 of the rotor 4 located at point A in FIG.
Assume that the workpiece 30 is placed on the workpiece 9.

The rotor 4 is rotated by a drive controller 15 so that it rotates by a certain angle (the angle at which the rotor 4 sequentially moves to the C point) every certain period of time (the measurement time of the surface of the workpiece 30 at the C point). As the table 1 moves, it moves in the α direction in FIG. First, when moving to point B, the shaft 21. The support stand 24 rises, and the arms 25a to 25C and claw parts 27a to 27C
After the upper surface of each arm 25a to 25G contacts the lower surface of the support plate 29, the rollers 26a to 26G move to the inclined surface 23.
It opens by going down. Then, the workpiece 30 is aligned by the springs 28a to 28G, and the workpiece 30 becomes a perfect circle.

After that, when moving to point C, the pulley 32 moves to the belt wheel 3.
5, and the entire rotor 4 starts to rotate by starting the rotation motor 5. At this time, the workpiece 30 is emitted from the light source 7.
Light is irradiated onto the surface to be measured, for example, the outer circumferential surface, and the reflected light from this outer circumferential surface is detected at any time by the light receiver 8, and the electric signal S
1 and collected by the data collection unit 9. and,
The measurement data on the outer peripheral surface of the workpiece 30 collected by the data collecting section is provided to the determining section 10, and the determining section 10 determines whether there are scratches or unevenness on the outer peripheral surface.

FIG. 4 is a flowchart showing the operation of the determination function in the determination unit 10. When the analog signal S2 corresponding to the collected data is given from the data collecting section 9 (step (hereinafter abbreviated as ST) 1), the preprocessing circuit 11 first performs preprocessing such as filtering processing, and the claws 27a to Noise caused by reflected light from 27C or the support plate 29 is removed (Sr2). Next, the preprocessed analog signal @S
3 is binarized by a binarization circuit 12 using a predetermined threshold,
It is converted into a binary signal S4 (Sr3). Next, this 2
The value signal S4 is given to the judgment circuit 13 (Sr1), and it is determined whether the outer peripheral surface is scratched or Gl! It is determined whether there is unevenness, etc. (
Sr5).

In other words, if the measurement surface is flat without scratches or unevenness, the amount of reflected light will be approximately constant, so the analog signal S3
becomes a smooth signal having a level higher than a predetermined threshold value SHL, as shown in FIG. 5(a). In contrast,
If there are scratches or unevenness on the measurement surface, the amount of reflected light from this area will decrease, so the analog signal S2 will be as shown in Figure 5 (
As shown in b), only this region meets the predetermined threshold 1ii.
The level is lower than sHL. Therefore, it is possible to judge the quality of the surface to be inspected based on the 2Wi signal S4. In addition, when the level of the analog signal S3 is generally low and difficult to distinguish using the predetermined threshold 1asHL, or when it is difficult to distinguish whether the level is low due to scratches, unevenness, etc. or the level is decreased due to noise. is judged as undeterminable.

In this manner, the determination result obtained by the determination circuit 13 is provided to the air jet controller 14, and any one of the air jets 6a to 6C is activated at a predetermined timing. That is, if the outer peripheral surface is determined to be good, the air jet 6a is started when the workpiece 30 is measured at point C or when the workpiece 30 moves to point E, and if it is determined that the outer peripheral surface is not good, the workpiece 30 is measured. The air jet 6b is started when the workpiece 30 moves to point F, and if the workpiece 30 is determined to be defective, the air jet 6C is started when the workpiece 30 moves to point C.

On the other hand, when the rotor 4 moves to point E or C, the shaft 21 and the support base 24 descend according to the cam plate 37, and each arm 25a to 25C
After the claws 27a to 27C also close, the holes 318 to 3
1c, the workpiece 30 becomes free. Therefore, a workpiece with a good outer circumferential surface is blown off by the air jet 6a at point E, a workpiece that cannot be determined is blown off by the air jet 6b at point F, and a defective workpiece is blown off at point C by the air jet 6C. As a result, the workpieces 30 are classified into three levels: good, defective, and undeterminable.

After that, the rotor 4 moves again to point A, and the workpiece 3
0 is supplied and the above-described operation is repeated.

Thus, according to this embodiment, the workpiece 30 having an annular shape
The outer peripheral surface of the product can be automatically inspected without contact, and the product can be sorted according to the evaluation. Therefore, there is no need to perform a visual inspection as in the past, so there is no variation in inspection results and inspection can be performed with high precision. In addition, it is possible to reduce the labor of the operator, and it is possible to automate the inspection process and save labor. Furthermore, the claw portions 27a to 27c of the rotor 4
Since it is supported in the circumferential direction by the springs 28a to 28G for interest, it is easy to respond to changes in the size of the workpiece, and workpieces of various sizes can be inspected.

Note that the present invention is not limited to the above embodiments.

For example, in the embodiment described above, the claws 27a to 27c and the support plate 29 are made of a material with low reflectance to suppress reflection from these materials, but as shown in FIG. By tilting the light receiver 8 with respect to the surface to be measured, the amount of light reflected from the claws 27a to 27c is
Since the reflected light from the workpiece 30 is detected by the light receiver 8, the amount of light reflected from the workpiece 30 is stabilized, and inspection with higher precision becomes possible. In addition, manufacturing variations in each rotor 4 or light source 7
Since there is a possibility that accuracy may be lowered due to variations in the amount of light emitted, a means for correcting these may be provided. Furthermore, in the embodiment, the support plate 29 has a claw portion 27a.
-27c Although holes 31a to 31c for insertion and removal are provided, grooves may be used, and the shape thereof is not limited. Further, although the above embodiment shows the case where the outer circumferential surface of the workpiece 30 is measured, it goes without saying that by changing the shape of the claws 27a to 27c, the entire external surface such as the inner surface, upper surface, lower surface, etc. can be inspected.

Further, although the embodiment described above shows a case in which the rotary table 1 is used as the workpiece conveyance mechanism, the same effect can be achieved even if a conveyor is used. Further, in the above embodiment, the cam plate 3
7 is used to move the rotor 4 up and down, but another bridge may be used to move the rotor 4 up and down. It goes without saying that various other modifications can be made without departing from the spirit of the invention.

〔Effect of the invention〕

As detailed above, according to the present invention, a circular-shaped object to be inspected is held in a perfect circle state by a holding means, and the external surface of the object to be inspected held by this holding means is optically measured,
Based on this measurement result, the quality of the external surface condition is judged, and the object to be inspected is sorted according to the judgment result, so the external condition of the object to be inspected can be checked automatically and without contact. Tests can be performed with high reliability and the testing process can be automated.

It is possible to provide an appearance inspection device that can save labor.

[Brief explanation of drawings]

1 to 5(a) and 5(b) are diagrams showing one embodiment of the present invention, in which FIG. 1 is a schematic diagram showing a schematic configuration, and FIG.
3 and 3 are a side sectional view and a top sectional view showing the detailed configuration of the rotor, FIG. 4 is a flowchart showing the determination operation in the determination section, and FIGS. 5(a) and 5(b) are diagrams for explaining the determination criteria. , FIG. 6 is a schematic diagram showing a modification of the present invention. 1... Rotary table, 2... Drive motor, 4...
Rotor, 5... Rotation motor, 6a-6C... Air jet, 7... Light source, 8... Light receiver, 9... Data collection unit, 10... Judgment unit, 14... Air jet controller, 15... Drive controller, 21.
...Axis, 24...Support stand, 25 a to 25 c-.
・Arm, 27a to 27c ---Claw part, 28a
~28G...Self-aligning spring, 29...Support plate, 30...Work, 31a-31G...Hole, 32...Pulley, 36...Roller, 37...Cam plate . Applicant's representative Patent attorney Takehiko Suzue Figure 1 1. 1 Figure 2 Figure 3 (a) < b > Figure 5

Claims (2)

[Claims] (1) A holding means for holding a circular inspected object in a perfect circle state, a measuring means for optically measuring the external appearance of the inspected object held by this holding means, and a measuring means for optically measuring the external appearance of the inspected object held by this holding means. Appearance inspection apparatus characterized by comprising: a determination means for determining the quality of the external surface condition based on the measurement results obtained by the determination means; and a sorting means for sorting the objects to be inspected according to the determination results obtained by the determination means. . (2) The measuring means measures the condition of the external surface by rotating the object to be inspected, irradiating the external surface with light, and receiving reflected light. The appearance inspection device described in (1).