JP2003121373A - Method and apparatus for inspecting smoothed surface of article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inspection method and an inspection apparatus of the smoothed surface of an article that remove the restrictions of an inspection range in a non-contact system, can accurately inspect the smoothed surface even if an object to be inspected varies, and can inspect entire expansion and recesses as well as thin recesses and projections on the surface to be inspected. SOLUTION: A first reference point (CP1) and a second reference point (CP2) are set to an object to be inspected in a direction (b) for crossing a traveling direction (a) of a traveling article (B) to be inspected, at the same time a plurality of measurement points (Pn) are set onto a line for connecting the first and second reference points to a surface (F) to be inspected, an amount of displacement (Dnm) in a height direction of a surface to be inspected in the measurement point when the article to be inspected travels (Tm) is detected as a distance difference to a virtual reference straight line (CL) for connecting the first and second reference points, and the distance difference is compared with a preset setting value for judging whether the smoothness in the surface to be inspected is conforming or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for inspecting a smooth surface of an article.

[0002]

2. Description of the Related Art For example, in a packaging bottle or a plastic container such as PET, after molding, a straight body portion is often provided with a display portion such as a label or a print.
In such a case, if there is unevenness or the like on the straight body portion, there is a possibility that appearance defects such as wrinkles on the label may occur. In addition, this type of container is generally molded by blow molding, but if the air holes formed in the mold are clogged during this blow molding, uniform heat transfer to the mold is achieved. Is impaired and the cooling is partially inadequate, resulting in abnormalities that create uneven defects in the body of the molded product. In order to deal with such a problem, conventionally, the following body smoothness inspection means has been proposed.

For example, in the inspection device disclosed in Japanese Patent Laid-Open No. 8-114441, a bottle is rotated (rotated) and the surface displacement of the body is measured by a contact type sensor, and the ellipticity (maximum-minimum difference) of the body is measured. Is calculated and the quality is judged.
However, in this means, since the inspection is performed only on the circumferential position where the contact type sensor is arranged, for example, it is not possible to cover the entire body in the height (vertical) direction of the bottle to which the label is attached. Also, because the mechanical displacement sensor is in contact with the bottle body for measurement, the sensor may jump at a slight protrusion or step formed at the seam of the mold when the bottle rotates, especially Accurate measurement cannot be performed by high-speed inspection. Further, in this conventional technique, since the determination is made based on the ellipticity, it is possible to detect only a large dent or bulge of the body, and it is not possible to inspect fine unevenness or the entire bulge or dent, and the like. Had a point.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, the present invention is a non-contact type, removes the restriction of the inspection range, and makes an accurate inspection even when the object to be inspected is moved. The present invention also provides a method and apparatus for inspecting a smooth surface of an article, which is capable of detecting even fine undulations on the surface to be inspected and bulges and depressions as a whole.

[0005]

That is, the invention according to claim 1 relates to a method for inspecting a smooth surface of an article, in a direction (b) intersecting a moving direction (a) of a moving inspected article (B), A first reference point (CP1) and a second reference point (CP2) are set for the object to be inspected, and on the line connecting the first reference point and the second reference point to the surface to be inspected (F). When a plurality of measurement points (Pn) are set and the article to be inspected is moved (T
The displacement amount (Dnm) in the height direction of the surface to be inspected at the measurement point of m) is detected as a distance difference from a virtual reference line (CL) connecting the first reference point and the second reference point, and It is characterized in that the quality of the smoothness of the surface to be inspected is judged by comparing with a predetermined set value.

According to a second aspect of the present invention, in the first aspect, whether the smoothness is good or bad is determined by the difference (Svn) in the displacement amount between adjacent measurement points in the intersecting direction (b).
m) and the difference (Scnm) in the amount of displacement between adjacent measurement points before and after the movement in the movement direction (a) are detected, and these are compared with a predetermined set value to perform a smooth surface of the article. Pertaining to the inspection method of.

A third aspect of the present invention relates to an apparatus for inspecting a smooth surface of an article, comprising moving means for moving the inspected article (B) for inspecting the inspected surface (F), and moving the inspected article. A first reference point (CP1) and a second reference point (CP2) are set for the object to be inspected in a direction (b) intersecting the movement direction (a), and to the surface to be inspected (F). And a plurality of measurement points (Pn) are set on a line connecting the first reference point and the second reference point, and when the object to be inspected moves (T
Displacement amount detection for detecting a displacement amount (Dnm) in the height direction of the surface to be inspected at the measurement point of m) as a distance difference from a virtual reference straight line (CL) connecting the first reference point and the second reference point. And a determination unit that determines whether the smoothness of the surface to be inspected is good or bad based on the displacement amount detected by the displacement amount detection unit.

According to a fourth aspect of the present invention, in the third aspect, the displacement amount detecting means includes a camera for taking an image of the article to be inspected, and a smooth surface of the article including an image processing means for an image taken by the camera. Related to inspection equipment.

The invention of claim 5 is the invention according to claim 4, wherein the moving means comprises a rotating device for rotating the article to be inspected at a predetermined position, and the camera is a peripheral edge of an inspected surface of the article to be inspected. The present invention relates to an apparatus for inspecting a smooth surface of an article, which is an image of a part.

Further, the invention of claim 6 relates to the inspection device of the smooth surface of an article according to claim 3, wherein the displacement amount detecting means includes a plurality of surface displacement sensors arranged with respect to the article to be inspected. .

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the accompanying drawings. 1 is a front view conceptually showing a first reference point, a second reference point and a plurality of measurement points when inspecting a smooth surface of a round bottle according to the present invention, and FIG.
3 is a side view conceptually showing the amount of displacement in the height direction of the surface to be inspected at each measurement point, FIG. 3 is a first reference point, a second reference point and a plurality of measurements when inspecting a smooth surface of a square bottle. 4 is a front view conceptually showing points, FIG. 4 is a side view conceptually showing the amount of displacement in the height direction of the surface to be inspected at each measurement point in FIG. 3, and FIG. 5 is an example of the inspection apparatus of the present invention. 6 is a schematic plan view showing the same, FIG. 6 is a schematic side view thereof, and FIG. 7 is a schematic plan view showing another example of the inspection apparatus of the present invention.

In the following examples, the following two inspected articles B (B1, B2) are illustrated. One of them is a so-called round bottle B1 as shown on the upper side of FIG. 1, and the surface F to be inspected is a continuous circumferential surface F1 of the body. The round bottle B1 is rotated (rotated) in the circumferential direction during inspection. Therefore, the moving direction a1 of the round bottle B1 is the rotating direction. The others are so-called square bottles B2 shown on the upper side of FIG. This square bottle B2 is moved in parallel with the surface direction at the time of inspection. Therefore, the moving direction a2 of the square bottle B2 is a linear direction.

First, a method for inspecting a smooth surface of an article according to the first aspect of the invention will be described. In the present invention, as shown in FIG. 1 and FIG.
The first reference point CP1 and the second reference point CP2 for the inspection object B are set in the direction b intersecting the moving direction a (a1, a2) of (1, B2). Then, the inspection object B
Of the first reference point CP with respect to the inspection surface F (F1, F2) of
A plurality of measurement points P on the line connecting the first and second reference points CP2
1, P2, P3 and Pn are set. In the embodiment, in both the round bottle B1 and the square bottle B2, the direction b intersecting the moving direction a (a1, a2) is the vertical direction (vertical direction) in the drawing.

The first reference point CP1 and the second reference point CP2 are
It is provided at any position other than the inspected surface F of the inspected object B,
Both reference points CP1 and CP2 are provided at contact points, which are positions at which the so-called bottles in the upper and lower portions of the bottle body are in contact with each other, which are the maximum projecting portions. The measurement points P1, P2, P3 and Pn are the first reference points CP1.
And a plurality of second reference points CP2. The intervals between the respective measurement points P1, P2, P3, Pn are appropriately determined according to the need for measurement accuracy and the like. For example, in the embodiment, they are provided at intervals of 10 mm in the vertical direction of the surface F to be inspected.

Then, in this inspection method, as shown in FIGS.
As shown in FIG. 3, the displacement amounts D1, D2, D3, Dn (in the height direction of the surface F to be inspected at the measurement points P1, P2, P3 and Pn at the time of movement T (m) of the object B to be inspected. m)
Is detected. Particularly, in the present invention, the displacement amount Dn
(M) is the first reference point CP1 and the second reference point CP2
A virtual reference straight line CL connecting the points and the measurement points P1, P2, P
3, detected as a distance difference from Pn. The detection of such a distance difference can be performed by image processing of a camera image, a surface displacement sensor, or the like, as described in an apparatus invention described later.

In the present invention, the displacement amount Dnm in the height direction of the surface F to be inspected at the measurement points P1, P2, P3 and Pn at the time Tm when the object B to be inspected is moved is the first reference point CP.
By detecting as a distance difference between the virtual reference straight line CL connecting the first and second reference points CP2 and the measurement points P1, P2, P3, Pn, it is possible to cope with fluctuations and positional deviations of the article B to be inspected during movement. It is possible to perform accurate measurement of the inspection surface.

The distance difference between the virtual reference line CL connecting the first reference point CP1 and the second reference point CP2, which is the displacement amount Dnm in the height direction of the surface F to be inspected, and the measurement points P1, P2, P3, Pn. Is calculated as follows. That is, the coordinates (x, y) of the first reference point CP1, the second reference point CP2, and the measurement point Pn are obtained, and CP1 (xa, ya), respectively.
Let CP2 (xb, yb) and Pn (xn, yn). A virtual reference straight line CL connecting the first reference point CP1 and the second reference point CP2 is expressed by the following equation.

[0018]

[Equation 1]

Using the virtual reference straight line CL as a reference, y = yn is substituted in the equation, x is obtained by the following equation, and the distance Dn (that is, xn-x) is obtained by the following equation.

[0020]

[Equation 2]

In this way, the measurement points P1, P2, P
Table 1 shows displacement amounts Dnm at 3 and Pn sequentially detected in the moving direction. Here, in Table 1, T
1, T2 and Tm can be set to appropriate travel times (distances). In the embodiment, the displacement amount is detected every 0.25 seconds in the moving direction a of the moving bottle B, and the surface F to be inspected of the article B is inspected at intervals of about 10 mm.

[0022]

[Table 1]

Displacement amount Dnm detected in Table 1 above
Is judged to be “good” if it is within an allowable range (for example, ± 0.2 mm) and “not possible” if it is outside the allowable range by comparing with a preset value by the judging means. Whether the smoothness of F is good or bad is determined. For example, Lmin
If <Dnm <Lmax (Lmin is the minimum value and Lmax is the maximum value), it is “good”, and if it is out of this range, it is “impossible”. As a result, the unevenness at each measurement point on the surface F to be inspected can be inspected, and thus the quality of the smoothness can be inspected.

[0024] Next, the invention of claim 2 is the same as in claim 1, wherein the pass / fail judgment of the smoothness is further made by the cross direction b.
At the measurement points (eg, P1 and P2, P2 and P3) adjacent to each other in Svnm,
In, the difference Scnm of the displacement amount at each measurement point before and after the adjacent movement (for example, the positions T1 and T2, T2 and T3 which are adjacent to each other in the movement direction of Pn) is detected, and these are compared with a predetermined set value. It is something to do.

That is, as shown in Table 2 below,
From the displacement amount Dnm shown in Fig. 2, the difference Svnm (that is, | D
nm-D (n + 1) m |) is calculated.

[0026]

[Table 2]

Similarly, as shown in Table 3 below, from the displacement amount Dnm shown in Table 1 above, a displacement amount difference Scnm (that is, | Dnm-Dn ( m + 1) |) is required.

[0028]

[Table 3]

The difference S between the displacements obtained in Tables 2 and 3 above
vnm and Scnm are compared with a preset value by the determination means, and are within an allowable range (for example, 0.2 mm).
If it is within the range, it is judged as “good”, and if it is out of the allowable range, it is judged as “impossible” and the quality of the smoothness of the surface F to be inspected is judged. For example, Svnm <Lv (Lv is the maximum value), Scnm <Lc
If (Lc is the maximum value), it is "good", and if it is more than this, "not good". Accordingly, it is possible to inspect the unevenness in the adjacent portion in the intersecting direction and the moving direction of each measurement point on the surface F to be inspected, and thereby to inspect the fineness of the smoothness.

Next, the device invention will be described with reference to FIGS. According to the invention of claim 3, a moving means 10 for moving the inspected article B in order to inspect the inspected surface F,
A first reference point CP1 and a second reference point C with respect to the object to be inspected in a direction b intersecting the moving direction a of the moving object to be inspected.
P2 is set, and a plurality of measurement points Pn are set on the line connecting the first reference point and the second reference point with respect to the surface (F) to be inspected.
A displacement amount detecting means 2 for detecting a displacement amount Dnm in the height direction of the surface to be inspected at the measurement point of m as a distance difference from a virtual reference straight line CL connecting the first reference point and the second reference point.
0, and a judging means 30 for judging whether the smoothness of the surface to be inspected is good or bad on the basis of the displacement amount detected by the displacement amount detecting means.

First, the examples of FIGS. 5 and 6 are suitable examples for the inspection of the round bottle B1, and as defined in the invention of claim 4, the displacement amount detecting means 20 images the inspected article. The camera 21 and the image processing means 22 for the image captured by the camera 21 are included. Further, in this example, further, as defined as the invention of claim 5, the moving means 10 comprises a rotating device 11 for rotating the inspected article B1 at a predetermined inspection position 55, and the camera 2
1 relates to the one for imaging the peripheral portion of the inspected surface of the inspected article B1 as in the plan view of FIG.

In FIGS. 5 and 6, reference numeral 50 designates a conveyor device for loading and unloading the round bottle B1 as the article to be inspected.
Reference numeral 51 is an index wheel (star wheel) that rotates intermittently to take the round bottle B1 into the inspection position 55, 54 is an illumination (light source) for inspection, and 56 and 57 are outer peripheral guide members of the round bottle B1. The rotating device 11 is a rotating roller that rotates in contact with the body of the round bottle B1 at the inspection position 55, and its drive mechanism (not shown) is known. The camera 21 for picking up an image of the article B1 to be inspected is, for example, a known CCD.
In the camera, the image processing means 22 and the determination means 30 are arithmetically controlled by a known computer device. Reference numeral 58
Is a reject device that eliminates defective articles by a signal from the determination means 30.

The example of FIG. 7 is a suitable example for the inspection of the square bottle B2 as shown in the figure, and as defined as the invention of claim 6, the displacement amount detecting means 20 applies to the article to be inspected. Surface displacement sensors 25 (25
a, 25b, 25n. Note that the present invention relates to an apparatus including (see FIG. 4). Surface displacement sensor 25 (25a, 25b, 25n)
The laser beam method and the like are widely marketed. Reference numeral 26 is a surface displacement sensor 25 (25a, 25b, 25
It is a computer that calculates and processes the signal from n).

In FIG. 7, the square bottle B2 of the article to be inspected is sequentially sent to the inspection position 65 by the conveyor device 12 which is the moving means 10. Reference numeral 61 is a position regulation roller for regulating the inspection attitude of the square bottle B2, 62 is a position regulation guide for accurately holding the position of the square bottle B2 at the inspection position 65, 63 is an inspection timing sensor, and 64 is a determination means. A rejecting device 66 for rejecting defective articles in response to a signal from 30 is a discharging portion thereof.

[0035]

As shown and described above, according to the present invention, since it is a non-contact type with respect to the article to be inspected, there is no restriction on the inspection range, and it is possible to inspect any part of the surface to be inspected. became. In addition, it is possible to reliably perform the inspection at a high speed without causing a drop in the accuracy of the inspection due to a slight protrusion or step when the object is rotated as in the conventional case.

Particularly, in the present invention, the first reference point and the second reference point are set for the article to be inspected, and
A plurality of measurement points are set with respect to the surface to be inspected on the extension line of the reference point, and the displacement amount in the height direction of the surface to be inspected at the measurement point when the object to be inspected is moved is the first reference point. And the distance from the virtual reference straight line connecting the second reference points, and the quality of the smoothness of the surface to be inspected is determined by this, so that the fluctuation or displacement of the article to be inspected during movement is detected. Accurate measurement is possible even if.

Further, the displacement amount in the height direction of the surface to be inspected is compared with each adjacent measuring point in the moving direction and the direction orthogonal thereto, and the difference in the displacement amount is obtained. The effect of the present invention is enormous, for example, it becomes possible to inspect the entire bulge and dent.

[Brief description of drawings]

FIG. 1 is a front view conceptually showing a first reference point, a second reference point and a plurality of measurement points when inspecting a smooth surface of a round bottle according to the present invention.

FIG. 2 is a side view conceptually showing the amount of displacement in the height direction of the surface to be inspected at each measurement point in FIG.

FIG. 3 is a front view conceptually showing a first reference point, a second reference point, and a plurality of measurement points when inspecting a smooth surface of a square bottle.

FIG. 4 is a side view conceptually showing the amount of displacement in the height direction of the surface to be inspected at each measurement point in FIG.

FIG. 5 is a schematic plan view showing an example of the inspection apparatus of the present invention.

FIG. 6 is a schematic side view thereof.

FIG. 7 is a schematic plan view showing another example of the inspection apparatus of the present invention.

[Explanation of symbols]

10 means of transportation 20 Displacement amount detecting means 30 Judgment means B (B1, B2) Inspected article F (F1, F2) Inspection surface CP1 first reference point CP2 Second reference point P measurement point

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2F065 AA49 FF04 JJ19 JJ26 MM04                       PP11 SS04 TT03                 2F069 AA60 BB40 GG04 GG07 GG58                       HH09 HH30 JJ17 PP06                 2G051 AA14 AB07 CA03 CA07 CB02                       DA01 DA08 EA11 EA12 EB01

Claims (6)

[Claims] 1. A first reference point (CP1) and a second reference point (CP2) with respect to the inspection object in a direction (b) intersecting a moving direction (a) of a moving inspection object (B). And a plurality of measurement points (Pn) are set on a line connecting the first reference point and the second reference point with respect to the surface (F) to be inspected, and when the article to be inspected is moved (Tm). A virtual reference straight line (CL) connecting the displacement amount (Dnm) in the height direction of the surface to be inspected at the measurement point, connecting the first reference point and the second reference point.
Is detected as a difference in distance between the surface of the article and the predetermined value, and the quality of the smoothness of the surface to be inspected is determined by comparing these values with a preset value. 2. The smoothness determination according to claim 1, further comprising determining whether the difference in displacement amount (Svnm) between adjacent measurement points in the intersecting direction (b) is the same as the difference in displacement direction (a). A method for inspecting a smooth surface of an article, which is performed by detecting a difference (Scnm) in displacement amount at each measurement point before and after the movement and comparing these with a predetermined set value. 3. A moving means for moving the inspected article (B) for inspecting the inspected surface (F), and the object to be inspected in a direction (b) intersecting the moving direction (a) of the inspected object. A first reference point (CP1) and a second reference point (CP2) are set for the inspection object, and on the line connecting the first reference point and the second reference point to the surface to be inspected (F). Multiple measurement points (Pn) are set,
A displacement amount (Dnm) in the height direction of the surface to be inspected at the measurement point when the object to be inspected is moved (Tm) is defined as a virtual reference straight line (CL) connecting the first reference point and the second reference point. Displacement amount detecting means for detecting as a distance difference, the smooth surface of the article characterized by including a determining means for determining the quality of the smoothness of the surface to be inspected based on the displacement amount detected by the displacement amount detecting means Inspection device. 4. The inspection device for the smooth surface of an article according to claim 3, wherein the displacement amount detecting means includes a camera for capturing an image of the inspected article and an image processing means for an image captured by the camera. 5. The moving device according to claim 4, wherein the moving means comprises a rotating device for rotating the inspected article at a predetermined position, and the camera captures an image of a peripheral portion of an inspected surface of the inspected article. Inspection device for smooth surface of articles. 6. The apparatus for inspecting a smooth surface of an article according to claim 3, wherein the displacement amount detecting means includes a plurality of surface displacement sensors arranged with respect to the article to be inspected.