JPH0578765B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating condition monitoring method and apparatus suitable for monitoring the presence or absence of paint omission on a coated surface of a suitable material coated with a transparent coating.

[Prior art]

Conventionally, the presence or absence of paint loss on the painted surface has been strictly investigated, for example in joined cans where cylindrical members that have been subjected to drawing or ironing processes are joined together to form one can. There is a pre-applied primer.

In other words, as shown in Figure 7, for example, such a bonded can is a body BDY that is formed by punching, drawing, ironing, etc. from a material such as aluminum, and then slightly squeezing the periphery of the material inward using a mouth drawing machine. Then, the dome DOM, which is also made of aluminum or other material and shaped into the desired cylindrical shape using a drawing machine, is fitted so that its edges overlap, and the fitted part is further bonded and fixed with an appropriate adhesive. It is formed into one CAN by
Usually, before such bonding, a transparent paint made of thermosetting vinyl or the like is applied as a primer to a thickness of about 1 μm to 5 μm on the mating portion, and this coats the bonded can when bonded. We are trying to improve the airtightness of CAN. The structure of such a joint will be described in further detail with reference to FIG.

In other words, Fig. 8 shows the joint can shown in Fig. 7.
This corresponds to an enlarged cross-sectional view of the circle A section of CAN. The paint applied to materials MT1 and MT2, PRT the printing film attached to the surface of the above body BDY, VNH further the finishing varnish applied over this printing film PRT, and
PM is a paint that is applied in advance as the primer before joining, and BND is also applied as a film on this primer PM before joining, and is heated when joining the body BDY and dome DOM. The same joint is melted
The adhesives (for example, modified polyester adhesives) used to bond and fix UCN are shown, and the adhesion of these joints is maintained by applying the above primer coating as a base for this adhesive BND. ing. Incidentally, if such a primer is simply adhered without applying a primer coating, the adhesion will be impaired, and reliability in terms of airtightness will be significantly impaired.

In this way, paint loss from the primer applied to the joints of jointed cans directly leads to the occurrence of defective cans (leaking cans), and even if it is a minute part, such paint loss can be overlooked. It is necessary to strictly check that there is no such thing.

However, conventionally, no method or device has been proposed that can effectively monitor the presence or absence of paint loss from the primer. This situation is also common in other cases where the presence or absence of paint loss on painted surfaces is strictly questioned, such as those coated with waterproof paint and whose waterproofness or water resistance is guaranteed.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a coating condition monitoring method and apparatus that can accurately monitor and determine the presence or absence of paint loss on the above-mentioned painted surface.

[Structure of the invention]

The coating condition monitoring method of the present invention uses a metal cylindrical body as a base having a large number of linear microgrooves on the circumferential surface that are generated due to machining, and has a transparent metal cylinder on the circumferential surface in a continuous manner in the circumferential direction of the circumferential surface. Applied to cans coated with paint, the process includes rotating the can around its axis, irradiating the painted surface of the can with light having high straightness, and the painted surface based on the irradiated light. The present invention is characterized in that it includes a step of detecting whether or not the reflection mode of the reflected light is in a predetermined reflection mode, and determining whether or not paint is missing based on the detection result.

Further, the coating condition monitoring device of the present invention includes a can rotation means for rotating the can around its axis, a light irradiation means for irradiating the painted surface of the can with light having high straightness, and the irradiation light. a light receiving means for receiving reflected light from the painted surface based on the above, and whether or not the reflection mode of the reflected light from the painted surface based on the irradiated light shows a predetermined reflection mode based on the output of the light receiving means. The present invention is characterized by comprising a paint omission determination means for detecting paint omission.

〔Effect of the invention〕

As described above, the present invention uses a metal cylindrical body as a base body having a large number of linear microgrooves on the circumferential surface that are generated as a result of machining, and provides a transparent metal cylinder on the circumferential surface in a manner continuous in the circumferential direction of the circumferential surface. This applies to cans coated with paint.

In the present invention, the above-mentioned can exhibits a unique light reflection mode in the non-painted part and the painted part, and the above-mentioned can is coated in a continuous manner in the circumferential direction of the can. Focusing on this, we detected the reflection mode of the reflected light from the painted surface while rotating the can around its axis.
It is also possible to accurately determine the presence or absence of paint loss, which cannot be confirmed visually.

〔Example〕

First, the principle of this invention will be explained with reference to FIGS. 1 to 4.

Here, as an example, a case will be described in which a plurality of light receiving elements are used to monitor the presence or absence of paint removal from the primer applied in advance to the joint portion of the above-mentioned joint can.

Now, as shown in Figure 1 or Figure 2, the can
Primer is applied to the edge of CAN (body BDY section in a joint can - see Figure 7) while rotating it in the direction of arrow F with its central axis as the rotation axis.
Light at the PM site (laser light is assumed here)
While continuously irradiating the LB, this reflected light is sent to three fixed light receiving elements 11 and 1 shown in the figure.
2 and 13, the shape of the reflected light differs as shown in Figures 1 and 2 depending on whether there is any paint loss in the primer PM or not. These light receiving elements 11,1
The light receiving modes of 2 and 13 are also different as shown in FIGS. 3 and 4.

That is, first of all, regarding the optical shape of the reflected light, if there is no paint loss in the primer PM as shown in Figure 1, the primer PM will absorb the irradiated light LB due to its own diffraction phenomenon and will be diffused due to diffuse reflection. As shown in the figure, the reflected light LB' has a substantially conical light shape that is uniformly diffused over a relatively wide area with the irradiation point (reflection point) as the apex. Furthermore, on the circumferential surface of the metal cylindrical body that is the base of the above-mentioned can CAN, there are many linear microgrooves that are generated in the height direction due to processing (drawing and ironing), as shown in Fig. 2. In this case, paint loss TO occurs in the primer PM, and the paint loss TO occurs.
When the light LB is irradiated to the exposed part of the can CAN, the light LB is reflected along the micro grooves, so the reflected light LB'' is
As shown in FIG. 2, the light has a substantially triangular shape that is diffused in a plane with the irradiation point (reflection point) as the apex.
Therefore, the light receiving mode by the light receiving elements 11, 12, 13 corresponds to the shape of the reflected light, and the primer without paint omission shown in FIG.
As for PM, as shown in Figure 3 a, b, and c, when the light LB is irradiated onto the can CAN (more precisely, the primer PM part), its received light output (actually, it is amplified appropriately). waveform shaped)
Both become approximately equal intermediate values M, and this value will be maintained during the monitoring after that, and for the primer PM with paint loss TO shown in Figure 2, the values shown in Figure 4 a, b, and c. CAN CAN as shown
At the point when the light LB is irradiated on the CAN (at this point, it is assumed that the light LB is irradiated on the actual painted part of the primer PM), the received light outputs both show approximately the same intermediate value M as above, but the same can CAN When the irradiation position of the light LB reaches this paint removal TO portion as the light LB rotates in the direction of the arrow F, for example, only the light receiving element 12 in the center intensively receives the reflected light LB'', and the maximum The light receiving output corresponds to the value H, and the other light receiving elements 11 and 13 temporarily stop receiving light, and the light receiving output corresponds to the minimum value L.

Since it is like this, these light receiving elements 11, 1
As long as the changes in the light reception outputs of the lenses 2 and 13 are monitored, the presence or absence of the above-mentioned paint loss can be accurately determined. By providing a plurality of light-receiving elements in this manner, it is possible to perform general monitoring even if the direction of reflection of the light LB is shifted due to deformation of the can CAN, for example.

FIGS. 5 and 6 show an embodiment of a coating condition monitoring device according to the present invention constructed based on this principle.

First, an overview of this embodiment of the monitor device will be explained with reference to FIG.

In FIG. 5, 1 is a conveyor, 2a and 2b
is a guide roller which is attached to the conveyor 1 as shown in the figure and grips the joined can CAN (more precisely, this body BDY part - see FIG. 7) so that it can freely rotate around its central axis as the rotation axis. Then apply the required primer as described above using a primer coater.
The above can CAN with PM coating is indicated by the arrow in the figure.
It is assumed that the materials are transferred to the device from directions F1 and F2, and are sequentially loaded onto guide rollers 2a and 2b as shown in the figure as the conveyor 1 rotates in the direction of arrow F3 in the figure.

Further, in the same figure, 3a and 3b indicate that the target can CAN is actually transferred to the above-mentioned conveyor 1 (more precisely, these guide rollers 2a and 2b) when carrying out the coating condition monitoring of the present invention, which will be explained below. Sensors 4a and 4b (consisting of limit switches, optical sensors, etc.) for detecting whether or not the device is loaded rotate in conjunction with each other in the direction of arrow F4 in the figure. Can CAN whose existence was confirmed by 3b
arrow F5 in the figure with each center axis as the rotation axis.
Rotating rollers 5a and 5 rotate as shown in FIG.
b is applied to the primer PM portion of the can CAN (see FIG. 8), which is given the above rotation by these rotating rollers 4a and 4b, in the manner shown in FIG. 1 or 2 based on the above-mentioned principle. A primer that irradiates the irradiated light, receives the reflected light of this irradiated light with multiple light receiving elements, and converts it into photoelectricity.
The optical sensor 6 for detecting paint loss of PM receives the photoelectric conversion output from the light receiving elements of these optical sensors 5a and 5b, and detects paint loss of the primer PM applied to the can CAN based on the change in this output. Based on the determination by the determination circuit 6, the determination circuit 7a and 7b determines the presence or absence of the
If the can CAN is a good can with no paint loss, it will be located at the position shown by the solid line in the figure, and the arrow F indicates the transport path for transferring to the next process.
Eject the can CAN in the direction of 6a and F6b,
In addition, if the above can CAN is a defective can with paint loss, the can will be placed in the position shown by the broken line in the figure.
CAN from the above conveyance path with arrows F7a and F7b
It is a rejector that eliminates

The device shown in FIG. 5 is assumed to be a 12-pocket double index (150° stop) type, and the paint loss detection operation based on the above-mentioned principle of the optical sensors 5a and 5b and the rejector It is assumed that the above-described discrimination operations and the like by 7a and 7a are appropriately controlled based on this machine timing.

Next, the optical sensor 5 which forms the main part of this invention
a or 5b (hereinafter collectively referred to as optical sensor 5)
The determination circuit 6 will be described in detail with reference to FIG.

In FIG. 6, 50 is a laser projector for irradiating the above-mentioned light (laser light) LB to the primer PM section of the can CAN to be monitored, and 51, 52, 53 are the light receiving elements 11, 12, 1.
3 (see FIGS. 1 and 2), and are each fixedly supported by appropriate supports (not shown). By irradiating the laser beam LB and receiving the reflected light LB' or LB'' by the light-receiving elements 51, 52, and 53, paint loss is detected based on the principle described above.However, this detection Processing of the signal and determination based on the detection result are carried out in the subsequent discrimination circuit 6. In other words, in FIG. A CPU (Central Processing Unit) that comprehensively manages the control of the redirectors 7a and 7b based on the discrimination, also 6
1a-61b, 62a-62b, 63a-63b
64 is the carrier machine shown in FIG. The sensor 65 detects machine timing such as
A redirect solenoid 66 controls the drive of the redirectors 7a and 7b (see FIG. 5), respectively, based on instructions from the CPU 60.
The above machine timing and rejectors 7a and 7
The CPU 60, which is the central part of the judgment circuit 6, is a display device that visually displays the drive mode of the drive mode b, as well as the monitor contents related to the presence or absence of the paint in question.
Signals amplified and waveform-shaped by the light receiving elements 51, 52, 53 (Fig. 3 a, b, c or 4
(corresponding to the signals shown in Figures a, b, and c) and A/D converts them appropriately, and the logic configured in a predetermined manner corresponding to the level content of these signals satisfies the required conditions. In other words, in the example shown in the previous principle, only the signal corresponding to one light-receiving element (for example, light-receiving element 52) has a level corresponding to the maximum value H, and the signals corresponding to other light-receiving elements have a level corresponding to the minimum value. When the level corresponding to L or intermediate value M is reached, the primer PM of the monitor can
When it is determined that paint is missing in the can and the can is discharged from the conveyor 1 (see FIG. 5), the corresponding one of the rejectors 7a and 7b is driven through the solenoid 65. It operates to remove the poorly painted cans from the conveyance path (arrows F6a, F6b - see FIG. 5). Further, this fact is displayed on the display 66.

In this way, according to this embodiment monitor device,
It is possible to monitor the quality of the coating state and to discriminate between good and defective products based on the monitoring results, all automatically.

In addition, in this embodiment, the structure of the conveyor 1 shown in FIG. 5, the method of carrying out the can CAN, the method of discharging, etc. are arbitrary, and an appropriate structure and method can be freely selected according to the actual situation. .

Furthermore, in this embodiment, the device (particularly the optical sensor) is configured to directly reflect the principles shown in FIGS. 1 to 4, but the principles themselves are not fundamentally limited to these aspects. Various other detection modes can be used depending on the material and surface finish of the material to be coated, as well as the shape and arrangement of the light-receiving element.

In other words, in the example described above, a can that has been drawn and ironed and has many linear microgrooves formed on its surface was selected as the material to be coated, so the coating method was applied according to the principles shown in Figures 1 to 4. However, when the material to be coated is other than the above-mentioned material, in general, it is a material (regardless of shape) that has a surface close to a mirror surface without grooves, etc. as described above. Even if the paint is coated on it, as mentioned above, the paint itself acts as a collection element or a diffuse reflection element for light. Even if the size of the diffusion area of the reflected light is discriminated, or even if a single light-receiving element with a relatively large light-receiving area is prepared and the quantity of the same reflected light is discriminated, the above-mentioned implementation will not work. The presence or absence of paint omission can be detected satisfactorily in a manner similar to the discrimination mode in the example. At least, using a plurality of light-receiving elements or increasing the light-receiving area even with a single light-receiving element is effective in absorbing blurring of the material coated with the paint to be monitored. Of course, the same material may be fixed and the optical sensor side may be displaced as required. Furthermore, in order to widen the area to be monitored, that is, the detection area of the painted surface, it is optional to increase the spot diameter of the light irradiated thereon, or to convert the same spot light into a linear form and irradiate it. Furthermore, if it is desired to recognize the shape of reflected light with particularly high resolution, an integrated optical sensor consisting of several tens to several hundreds of the above-mentioned light receiving elements may be used. In any case, the point is that highly straight light is irradiated onto the painted surface to be monitored, and the presence or absence of paint loss on the irradiated surface is detected based on the reflection mode such as the amount or shape of the reflected light. That's fine.

[Brief explanation of the drawing]

1 and 2 are perspective views showing an example of the monitoring principle of the present invention, and FIGS. 3 and 4 are examples of monitor signals obtained corresponding to the states shown in FIGS. 1 and 2. FIG. 5 is a schematic diagram showing an overview of an embodiment of the coating condition monitoring device according to the present invention, FIG. 6 is a block diagram showing the main structure of the device of the embodiment, and FIG. 7 is a diagram showing the connection FIG. 8 is a front view showing an example of a can, and FIG. 8 is a partially enlarged cross-sectional view showing the joining structure of the joining can shown in FIG. 1... Conveyor, 2a, 2b... Guide rollers,
3a, 3b...Transportation can detection sensor, 4a, 4b
...Rotating roller, 5... Optical sensor for detecting paint omission, 50... Laser projector, 51-53, 11-
13... Light receiving element, 6... Discrimination circuit, 60...
CPU, 64...sensor for machine timing detection,
65...Redirect solenoid, 66...Display device.

Claims (1)

[Scope of Claims] 1. A metal cylindrical body having a large number of linear microgrooves on its circumferential surface formed during processing is used as a base, and a transparent paint is applied to the circumferential surface in a continuous manner in the circumferential direction of the circumferential surface. Applied to painted cans, the method includes a step of rotating the can around its axis, a step of irradiating the painted surface of the can with light having high straightness, and a step of irradiating light from the painted surface based on the irradiated light. A coating condition monitoring method comprising the steps of detecting whether or not the reflection mode of reflected light is in a predetermined reflection mode, and determining the presence or absence of paint omission based on the detection result. 2. The coating state monitoring method according to claim 1, wherein the comparison standard for the reflection mode is the amount of the reflected light. 3. The coating state monitoring method according to claim 1, wherein the comparison standard for the reflection mode is the shape of the reflected light. 4. The coating condition monitoring method according to claim 1, wherein the comparison standard for the reflection mode is a diffusion area of the reflected light. 5. A can made of a metal cylindrical body having a large number of linear microgrooves on the circumferential surface that are generated due to processing, and a transparent paint coated on the circumferential surface in a continuous manner in the circumferential direction of the circumferential surface. a can rotation means for rotating the can around its axis; a light irradiation means for irradiating the painted surface of the can with light having high straightness; and reflection from the painted surface based on the irradiated light. a light receiving means for receiving light; and a paint omission determination means for detecting, based on the output of the light receiving means, whether or not a reflection state of light reflected from the painted surface based on the irradiated light shows a predetermined reflection state. A paint condition monitoring device comprising: 6. The coating condition monitoring device according to claim 5, wherein the light receiving means comprises a plurality of light receiving elements arranged along a plane perpendicular to the optical axis of the reflected light. 7. Claim 6, wherein the determining means is configured to determine whether or not the paint is missing based on whether the relationship between the logical levels of the outputs of the respective light receiving elements satisfies a predetermined condition. Paint condition monitoring device described.