JPH10115598A - Detecting method for coating defect - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a detecting method in which a coating defect is detected simply and surely. SOLUTION: An electric resistance across a steel cord part 12 and a rubber part 14 which constitute a coated cord 10 is measured by using a conveyance roller 28 coming into contact with the uncoated steel cord part 12 and by using a rear detecting roller 30A coming into contact with the coated rubber part 14. When the rubber part 14 is coated, the resistance across the steel cord part 12 and the rubber part 14 becomes infinitely great due to the nearly infinitely great resistance value of the rubber part 14 having a prescribed thickness. When a coating defect is caused and the rubber part 14 is not interposed, a resistance value becomes extremely small. On the basis of a large change in the resistance value, the coating defect of the rubber part 14 with reference to the steel cord part 12 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting defective coating, and more particularly to a method for detecting defective coating of a long composite member.

[0002]

2. Description of the Related Art In some cases, a composite member is formed by coating a conductive member with a non-conductive member. Such a composite member includes, for example, fiber-reinforced rubber or the like in which fibers are coated with rubber to have strength. In such a member,
A long conductive member such as a cord wire is coated with a nonconductive material such as rubber at a predetermined thickness. Here, whether or not the wire is uniformly coated with rubber is an important matter that greatly affects the accuracy of the obtained composite member, and therefore, it is necessary to accurately detect a coating defect.

Conventionally, an optical detection method has been used for detecting a coating defect. In the optical detection method, a line or surface is imaged with an image camera by irradiating light after coating, and image processing is performed to detect the amount of reflected light. That is, since the amount of reflected light is different between the covering member and the member to be covered due to the difference in the material, the covering member is exposed and the covering member is covered in the portion where the covering member is not covered due to poor covering. The reflected light amount is different from that of the portion. Therefore, it is possible to detect a coating defect by detecting portions having different amounts of reflected light in the detection area. In this method, image processing requiring a predetermined processing time is performed. However, by providing a plurality of detection devices, a coating defect can be detected even on a high-speed coating line. Also,
Since the imaging region is a detection region, when detecting a coating failure of the double-sided coating composite member in which the coating members are disposed on both surfaces, or when detecting a coating failure of the composite member having a width dimension larger than the imaging region. By providing a plurality of detection devices so that all the detection regions can be imaged, it is possible to reliably detect a desired covering defect in all the regions.

[0004]

However, since the coating defect is detected from the difference in the amount of reflected light, it is difficult to determine that the difference in the amount of reflected light between the coated member and the member to be coated is small, and it is difficult to distinguish the noise from noise. In some cases, and it may not be possible to accurately detect defective coating.

Further, an optical detection device for performing image processing is expensive. Providing a plurality of such expensive devices leads to an increase in manufacturing cost, and an inexpensive composite member free from defective coating cannot be obtained. . The whole area in the width direction of the composite member having a large width can be imaged using one detection device. However, in this case, a high resolution is required in a wide range, so that the device becomes more expensive. In addition, there is a limit in resolution, and it is sometimes impossible to reliably detect a coating defect.

The present invention has been made in view of the above facts, and has as its object to provide a coating defect detection method that can easily and reliably detect a coating defect.

[0007]

According to the first aspect of the present invention,
In the coating defect detection method for detecting a coating defect of a composite member formed by coating a long substrate to be conveyed with a coating member, the substrate is a conductive material made of a conductive material, The coating member is a non-conductive material made of a non-conductive material, and the base material and the composite member before coating are respectively brought into contact with individual conductive contact members, and coated while transporting the composite member. The electric resistance between the base material and the composite member is measured via the contact member, and it is determined whether or not the coating is defective based on the measurement result of the resistance.

According to the present invention, the contact member is individually formed on the cover member and the base member before coating, respectively, of the composite member formed of the conductive base material and the nonconductive cover member. Since the contact member acts as an electrode, the electric resistance between the non-conductive covering member and the conductive base material can be measured. At this time, the electric resistance between the substrate and the covering member changes depending on the presence or absence of the covering member.

That is, when the base member is covered with the coating member, the non-conductive material has an extremely large resistance value, so that the electric resistance between the base member and the composite member before coating is extremely large. , For example, infinite. At this time, the coating failure of the composite member, that is, when the non-conductive material is no longer present, the base material that is a conductive material and the contact member as an electrode are completely in contact with each other,
The resistance during this time is as close to zero as possible. When such poor coating occurs, the electrical resistance between the base material before coating and the composite member also approaches zero as much as possible.

Therefore, the electric resistance between the base material before coating and the composite member is measured, and based on the measurement result, a coating defect in the formed composite member can be detected.
As described above, by measuring the electric resistance, it is possible to easily and reliably detect the defective coating.

As the coating method, as long as the base material and the coating member overlap each other, any of commonly used methods such as coating, dipping, and printing can be adopted. This allows
For example, when a fibrous member is used as a base material, a material obtained by applying a viscous substance to the base material, or a material obtained by immersing the base material in a liquid material, Included in the member.

The coating member may be liquid, semi-solid or solid at the time of coating, as long as it can be coated on the substrate. For example, the coating member may be coated as a liquid paint, or may be coated by applying a viscous semi-solid.

[0013] The contact member with the composite member can be brought into contact with the non-conductive material under a predetermined pressure if it can come into contact with the non-conductive coating member of the base material and the coating member constituting the composite member during measurement. May contact. The same applies to the contact member with the base material before coating.

Further, for example, a transport means for transporting the base material may be used.
In the case of using the transporting means, when transporting the composite member, the composite member comes into contact with the uncoated base material and the composite member, respectively, so that the electrical resistance can be easily measured by transporting the composite member. As a result, without adding new equipment,
Measure the electrical resistance between the substrate and the coated member before coating,
Poor coating can be detected.

According to a third aspect of the present invention, the base member before coating is in the shape of a band, and the contact member is formed in the entire area along the width direction of the composite member formed from the band-shaped base material and the cover member. It is characterized by contacting with.

According to the present invention, while the contact member conveys the composite member formed by the band-shaped substrate and the covering member,
Since the non-conductive material is in contact with the entire region along the width direction, the electrical resistance between the base member and the covering member can be measured over the entire region along the width direction of the composite member. As a result, it is possible to easily detect a poor coverage in the entire area of the composite member along the width direction.

In particular, in the case where the contact member is a conveying means as described in claim 2, when the composite member is conveyed, the conveying means conveys the composite member while contacting the entire area along the width direction of the composite member. In addition, the electric resistance of the entire region along the width direction of the band-shaped and long composite member can be easily measured while transporting the composite member. This makes it possible to easily detect a coating defect in the entire area along the width direction while transporting a belt-shaped member having a predetermined width dimension.

According to a fourth aspect of the present invention, the composite member includes:
A double-sided coated composite member in which both surfaces of a base material that is a conductive material are coated with a coating member that is a non-conductive material, wherein the contact member contacts the non-conductive material on both surfaces of the double-sided coated composite member.
It is characterized in that it is composed of two transport means.

According to the present invention, since the contact member is constituted by the two transfer means which respectively contact the non-conductive material on both surfaces of the double-sided coated composite member, each of the transfer means is a non-conductive material. It can contact the member on each side.
Thereby, even in the case of a double-sided coated composite member having both surfaces coated with a non-conductive covering member, the electric resistance can be similarly measured with a simple and simple device configuration by providing two transport means. It is possible to detect a coating failure of the coating member on each surface based on the change in each resistance.

[0020]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a coating apparatus 20 for producing a coated cord 10 corresponding to the composite member of the present invention.

As shown in FIG. 2, the coated cord 10 includes a steel cord portion 12 and a rubber portion 14. The steel cord portion 12 is formed by twisting a plurality of steel cords having a predetermined diameter. It has a long shape with a predetermined width. The rubber portion 14 is formed of a rubber having a predetermined composition.

The coating device 20 is a calendar 2 comprising an upper roller pair 24 and a lower roller pair 26 for coating the rubber portion 14 on the steel cord portion 12.
2 is provided. One roller of the upper roller pair 24 and one roller of the lower roller pair 26 respectively oppose the steel cord portion 12, and the steel cord portion 12 and the rubber portion 14 in the direction indicated by arrow A in FIG. Is rotating to transport The upper and lower roller pairs 26 are shown in FIG.
As shown in (1), the rollers facing each other constituting each roller pair are slightly separated from each other, and the rubber constituting the rubber portion 14 is guided between them.

A transport roller 28 for transporting the long steel cord portion 12 before being coated with the rubber portion 14 to the calendar 22 is disposed upstream of the calendar 22 in the transport direction indicated by the arrow A. I have.

The transport roller 28 is a conductive member and has a cylindrical shape having a length larger than the width of the steel cord portion 12. The transport roller 28 is arranged so that its longitudinal direction coincides with the direction orthogonal to the transport direction of the steel cord portion 12, and the peripheral surface of the transport roller 28 is in contact with the entire area of the steel cord portion 12 along the width direction.

On the downstream side of the calendar 22 in the transport direction indicated by the arrow A, the steel cord 12
Cord 1 coated with rubber part 14
Detection roller 30 for detecting a coating defect of 0
Is arranged.

The detection roller 30 is a conductive cylindrical member like the transport roller 28, and the peripheral surface of the detection roller 30 is in contact with the entire area of the coated cord 10 in the width direction. The detection roller 30 includes a back surface detection roller 30A that contacts the back surface of the coated cord 10, and a front surface detection roller 30B that contacts the front surface of the coated cord 10. The back surface detection roller 30A and the front surface detection roller 30B are arranged continuously and rotate in different directions from each other (see arrows B and C).

The back detection roller 30A is disposed closer to the calendar 22 than the front detection roller 30B, and the coated cord 10 is wound obliquely around the back detection roller 30A and the front detection roller 30B. The detection roller 30 is completely separated from the surrounding conductive member and is in an electrically independent state.

The coating apparatus 20 is connected to a coating failure detecting apparatus 32. The coating failure detection device 32 is connected to the transport roller 28 and the detection roller 30 via a conductor 34, respectively. The detection roller 30 is connected to the back surface detection roller 30A and the front surface detection roller 30B so as to be connected to the transport roller 28, respectively.

As a result, as shown in FIG. 2, the conveying roller 28 connected to the coating failure detecting device 32 and the back surface detecting roller 30A and the front surface detecting roller 30B are connected to the steel cord portion 12 and the rubber portion 14. Contact each other, the steel cord part 12 and the rubber part 1 on the back and front surfaces
4 is an electrode for measuring resistance.

The coating defect detecting device 32 has a built-in resistance measuring device 38 (see FIG. 3), and is disposed on a circuit between the transport roller 28 and the detecting roller 30. The coating defect detection device 32 includes a defect display lamp 52 that lights up to notify a coating defect.

The coating defect detection device 32 includes a CP
U40, a controller 40 including a RAM 44 and a ROM 46 and connected to an input / output port 50 via a bus 48.
(See FIG. 3). The controller 40 is connected with the resistance measuring device 38 and the fault display lamp 52. Accordingly, the resistance value measured by the resistance measuring device 38 is input to the controller 40.

Next, the operation of this embodiment will be described. First, the operation of the coating device 20 will be described.

When the long steel cord portion 12 is supplied to the coating device 20, the leading end of the steel cord portion 12 in the transport direction is transported while being in contact with the transport roller 28, passes through the transport roller 28, and enters the calendar 22. You will be guided.

In the calendar 22, rubber as a covering member is placed between the rollers of the upper roller pair 24. As the upper roller pair 24 rotates, the rubber moves together with the rollers, and is pushed out to the side where the steel cord portion 12 passes. When the steel cord portion 12 guided to the calendar 22 by the transport roller 28 is transported by the upper roller pair 24 of the calendar 22 and passes through, the surface is coated with rubber that has moved with the rotation of the upper roller pair 24, A rubber part 14 is formed on the surface of the steel cord part 12. At this time, the thickness of the rubber portion 14 is adjusted by adjusting the distance between the rollers of the upper roller pair 24.

On the other hand, in the lower roller pair 26 disposed downstream of the upper roller pair 24 in the transport direction, the upper roller pair 24
Similarly, the lower roller pair 26 rotates with the rubber that is the covering member placed between the rollers. As a result, the back surface of the steel cord portion 12 passing through the lower roller pair 26 is coated with rubber, and the rubber portion 14 is formed on the front surface by the upper roller pair 24.
The rubber part 14 is formed, and the coated cord 10 is completed.

The coated cord 10 passes through the calendar 22 and is guided to a detection roller 30 including a back surface detection roller 30A and a front surface detection roller 30B disposed above the calendar 22.

The coated cord 10 guided by the detection roller 30 is wound around the back surface detection roller 30A arranged on the upstream side in the transport direction while making the back surface contact, and makes a U-turn around the back surface detection roller 30A. To pass through the back surface detection roller 30A.

The coated cord 10 that has passed through the back surface detection roller 30A is wound around the front surface detection roller 30B disposed below the back surface detection roller 30A while making the front surface thereof come into contact with the front surface detection roller 30B. The direction is changed in a right angle direction, and the sheet passes through the surface detection roller 30B.

When passing through the back surface detection roller 30A and the front surface detection roller 30B, the coating defect detection device 32
Thus, the resistance between the steel cord portion 12 and the rubber portion 14 constituting the coated cord 10 is measured at each location, and a coating defect is detected.

Next, the coating defect detection processing will be described with reference to FIGS. In addition, since the coating failure on the front surface and the coating failure on the back surface of the steel cord portion 12 can be detected by substantially the same processing, the coating failure on the back surface will be described as an example.

FIG. 6 shows an example of the coating defect detection processing. When the coating failure detection device 32 is turned on and the measurement preparation is completed, the process starts,
In step 100, it is determined whether or not to start measuring the resistance value for the coating failure detection process. When measurement start is instructed by operating a measurement switch (not shown) of the coating failure detection device 32, the determination is affirmed and the process proceeds to step 102.

In step 102, the resistance value measured by the resistance measuring instrument 38 is fetched. In step 104, it is determined whether or not the fetched resistance value has changed significantly.

The coated cord 10 is usually formed by coating a steel cord portion 12 which is a conductive material with a rubber portion 14 which is a non-conductive material with a predetermined thickness. The back surface detection roller 30A is in contact with the coated cord 10 at the rubber portion 14 on the back surface.

Here, since the conveying roller 28 is in contact with the steel cord portion 12 and the back surface detecting roller 30A is in contact with the rubber portion 14 of the coated cord 10, the coating roller connecting the conveying roller 28 and the back surface detecting roller 30A is connected. In the defect detection device 32, the resistance between the steel cord portion 12 and the rubber portion 14 can be measured (FIG. 5).
(A)).

For this reason, when the coating is performed evenly and the rubber portion 12 is covered with the steel cord portion 12, the steel cord portion 12 and the back surface detecting roller 3
The resistance between 0 A becomes substantially infinite due to the infinite resistance value of the rubber portion 14 on the back surface, the determination is denied, and the process proceeds to step 110.

On the other hand, coating failure occurs (FIG. 4).
(See the portion indicated by arrow B in (A)), the rubber portion 14
Is not interposed between the steel cord portion 12 and the back surface detecting roller 30A, and the steel cord portion 12 and the back surface detecting roller 3
5A, the resistance corresponding to the rubber portion 14 on the circuit is short-circuited, and the resistance between the steel cord portion 12 and the back surface detection roller 30A is reduced, as shown in FIG. 5B. The value suddenly approaches 0, and the judgment is affirmed.

If the determination is affirmative, in step 106, the failure indicator lamp 52 is turned on to notify that a coating failure has occurred.

When the defective display lamp 52 is turned on, the detected position is recorded in step 108. The detection position is
It can be easily confirmed based on the rotation speed of the transport roller 28 and the back surface detection roller 30A by a driving unit (not shown) provided in the coating device 20 and the time from the start of the measurement. In this way, the location of the coating defect is obtained by calculation from the rotation speed and time and recorded, and the process proceeds to step 110.

In step 110, it is determined whether or not the measurement is to be terminated. When the detection of the coating defect is continued, the process proceeds to step 102 and the coating defect detection process is continued.

The defect display lamp 52 that is lit when a coating defect is detected continues to be lit for a certain period of time. If a coating failure is further detected, these locations are recorded together.

On the other hand, when the measurement switch (not shown) of the coating failure detecting device 32 is operated to instruct the end of the measurement, the determination is affirmed and the series of processing is ended.

As a result, coating defects on the back surface of the coated code 10 can be easily detected. In addition, since the back surface detection roller 30A is in contact with the entire area of the width dimension of the coated cord 10 on the peripheral surface, even if a coating defect occurs in any part of the coated cord 10 in the width direction, it is accurately detected. can do.

Further, in the case of coating failure on the surface of the coated cord 10, as shown in FIG.
And the resistance between the surface detection roller 30B and the steel cord portion 12 becomes extremely small,
The coating failure can be detected in the same manner as in the case of the coating failure on the back surface of the coated cord 10.

Therefore, the resistance between the steel cord portion 12 and the rubber portion 14 of the coated cord 10 is reduced by the transport roller 2.
8 and the measurement using the detection roller 30,
Coating defects in the coated cord 10 obtained by coating the conductive steel cord portion 12 with the non-conductive rubber portion 14 can be easily and reliably detected.

In this embodiment, one coating failure detection device 32 is provided for the back surface detection roller 30A and the front surface detection roller 32B, but the present invention is not limited to this. For example, as shown in FIG.
By separately providing the coating failure detection devices 32 corresponding to the 0A and the surface detection roller 32B, the coating failure on the front surface and the back surface of the cored cord 10 can be detected separately and independently.

In the present embodiment, the steel cord 12
Although the coated cord 10 having the rubber portion 14 which is a non-conductive material on both sides of the coated member is described as an example, it is not necessary to have both sides, and even if the rubber portion 14 is provided only on one side, the coating failure is similarly detected. be able to. In this case, the detection can be performed in the same manner as described above by disposing the detection roller 30 only on the side that comes into contact with the rubber portion 14 that is a non-conductive material.

In the embodiment of the present invention, a steel cord which is a conductive material is used for the base material, and a rubber which is a non-conductive material is used for the covering member. However, the present invention is not limited to this.

In the embodiment of the present invention, the conveying means is a conveying means capable of contacting the entire area of the coated cord 10 in the width direction. However, the present invention is not limited to this.
In the case where the defective coating is partially detected in accordance with the characteristics and shape of the base material, the length may correspond to the area where the defective coating needs to be detected.

Further, in the embodiment of the present invention, the contact member is the conveying means, but any member may be used as long as it is in contact with the substrate and relatively moves. For example, a contact member capable of contacting the entire area along the width direction may be used. In addition, although the member that comes into contact with the conductor before coating is used as the transporting unit, the member is not limited to this, and any member that can contact the base material may be used. For example, if it is a planar conductive material, the pressing member can be in contact with the entire region along the width direction of the surface.

[0061]

As described above, according to the present invention, the electric resistance between the base material and the composite member before coating changes depending on the presence or absence of the non-conductive coating member. Based on the above, it is possible to easily and reliably detect defective coating of the composite member.

In the case where the contact member is used as a conveying means, the electric resistance between the base material and the covering member can be easily measured without adding a new device by conveying the composite member. Poor coating can be detected.

Here, assuming that the contact member contacts the non-conductive material of the band-shaped composite member in the entire region along the width direction, the contact member is provided along the width direction of the composite member without providing a plurality of contact members. In this way, it is possible to detect defective coating in the entire area, eliminate the necessity of providing a plurality of devices, and easily and reliably detect defective coating.

Further, in the case where the contact member is constituted by two conveying means which respectively contact the non-conductive material on both surfaces of the composite member, a double-sided composite member having both surfaces coated with a non-conductive covering member is used. Even if there is, a similar resistance value can be measured, and a defective coating on both sides can be easily detected with a simple device configuration.

[Brief description of the drawings]

FIG. 1 is a perspective view of a coating apparatus and a coating failure detection apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of a coating device and a coating defect detection device according to the embodiment of the present invention.

FIG. 3 is a block diagram of a coating defect detection device according to the embodiment of the present invention.

FIG. 4A is a cross-sectional view of a main part of a coated cord wound around a back side detection roller, and FIG. 4B is a cross-sectional view of a main part of a coated cord wound around a front side detection roller.

5A is a circuit diagram when a coating defect has not occurred, FIG. 5B is a circuit diagram when a coating defect has occurred, and FIG. 5C is another circuit when a coating defect has occurred. FIG.

FIG. 6 is a flowchart illustrating an example of a coating failure detection process according to the embodiment of the present invention.

FIG. 7 is a side view of a coating apparatus and a coating defect detection apparatus according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Coated cord (composite member, double-sided covering composite member) 12 Steel cord portion (conductive material) 14 Rubber portion (non-conductive material) 20 Coating device 28 Transport roller 30 Detection roller (contact member, transport means) 30A Back surface detection roller (contact) 30B Surface detection roller (contact member, transport means) 32 Coating failure detection device 38 Resistance detector

Claims (4)

[Claims] 1. A coating defect detection method for detecting a coating defect of a composite member formed by coating a conveyed long base material with a coating member, wherein the base material is made of a conductive material. Wherein the covering member is a non-conductive material made of a non-conductive material, and the base member and the composite member before coating are respectively brought into contact with individual conductive contact members, and the composite member Measuring the electrical resistance between the base material and the composite member before coating through the contact member while conveying, and determining whether or not the coating is defective based on the measurement result of the resistance. Defective coating detection method. 2. The method according to claim 1, wherein the contact member is a transport unit that transports the substrate. 3. The method according to claim 1, wherein the base member before coating is in a belt shape, and the contact member contacts an entire region along a width direction of the composite member formed from the belt-shaped base material and the coating member. The method for detecting a defective coating according to claim 1 or 2, wherein: 4. The composite member is a double-sided coated composite member in which both surfaces of a base material that is a conductive material are coated with a coating member that is a non-conductive material, and the contact member is formed on both surfaces of the double-sided coated composite member. The method according to any one of claims 1 to 3, wherein the method comprises two transporting means each of which is in contact with the non-conductive material.