JP2023083914A - Device and method for inspecting rubber-coated cord member - Google Patents

Abstract

To provide a device for inspecting a rubber-coated cord member, capable of enhancing detection accuracy of exposure of a cord.SOLUTION: An inspection device 2 for inspecting a rubber-coated cord member inspects a rubber-coated cord member G having: a rubber topping sheet T; and a number of cords K coated with the topping sheet T and having a charging property charged positively more easily than the topping sheet T. The inspection device 2 includes: a pair of charge bodies 11 having a charging property charged negatively more easily than the cord K and in contact with surfaces of the rubber-coated cord member G; a pair of charging device 12 that irradiates and causes the pair of charge bodies 11 to be charged negatively, respectively; and a pair of potential sensors 13 that detect surface potential of the pair of charged bodies 11, respectively.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an inspection apparatus and inspection method for a rubberized cord member.

In manufacturing a tire, a rubberized cord member is produced by sandwiching a large number of parallel cords between two sheets of unvulcanized rubber (hereinafter also referred to as a topping sheet). A carcass or belt component is prepared from this rubberized cord member. In addition, the inspection is performed so that the rubberized cord member whose cord is exposed due to peeling of the topping sheet or the like is not included. This inspection has hitherto been carried out visually by the operator, but in order to reduce the burden on the operator, an apparatus for inspecting the rubberized cord member is being developed.

For example, Patent Literature 1 discloses a technique of irradiating the surface of a rubberized cord member with light, photographing the surface with a camera, and analyzing the photographed image to detect the exposure of the cord.

Japanese Patent Application Laid-Open No. 2021-3308

As in Patent Document 1, the method of analyzing an image captured by a camera is greatly affected by the resolution of the camera and the analysis software, and it is difficult to detect the exposure of a small code.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inspection apparatus and inspection method for a rubberized cord member that can improve the detection accuracy of cord exposure.

An inspection device for a rubberized cord member according to one aspect of the present invention comprises:
1. An apparatus for inspecting a rubberized cord member having a rubber topping sheet and a number of cords covered with the topping sheet and having charging properties that are more likely to be positively charged than the topping sheet, the apparatus comprising:
a charged body having a charging property that is more likely to be negatively charged than the cord and being in contact with the surface of the rubberized cord member;
a charging device that negatively charges the charged body;
a potential sensor that detects the surface potential of the charged body.

According to this configuration, when the negatively charged charged body is brought into contact with the surface of the rubberized cord member and the charged body contacts the exposed cord due to peeling of the topping sheet or the like, the negative charge of the charged body is discharged to the cord. and the surface potential of the charged body partially changes. The exposure of the cord of the rubberized cord member can be detected by detecting this potential change with the potential sensor.

Preferably, the charged body comprises a first charged body contacting a first surface on one side of the rubberized cord member and a second charged body contacting a second surface opposite to the first surface. include.
According to this configuration, it is possible to simultaneously detect the exposure of the cords on both the first surface and the second surface of the rubberized cord member.

Preferably, the charged body is a material having the same charging properties as the topping sheet or a charging property that is more easily negatively charged than the topping sheet.
With this configuration, it becomes difficult for the charged body to discharge to the topping sheet, and the discharge to the exposed cord can be promoted.

Preferably, the charged body has a cylindrical shape and is provided so as to be able to roll on the surface of the rubberized cord member.
According to this configuration, it is possible to reduce resistance when a charged body is brought into contact with the surface of the topping sheet.

Preferably, a plurality of protrusions are provided on the contact surface of the charged body that contacts the surface of the rubberized cord member.
According to this configuration, even when the cord exposure is small, the tip of the protrusion can be brought into contact with the cord, and the detection accuracy of the cord exposure can be improved.

Preferably, the protrusion is elastically deformable.
According to this configuration, the protrusions are elastically deformed by contact with the surface of the topping sheet, and the protrusions are elastically restored at the part where the topping sheet is peeled off, so that the tips of the protrusions can be easily brought into contact with the cord.

Preferably, the rubberized cord member is strip-shaped, and the charged body has a length that spans the entire width of the rubberized cord member.
According to this configuration, exposure of the cord can be detected over the entire width of the rubberized cord member.

Preferably, a plurality of the potential sensors are arranged side by side along the longitudinal direction of the charged body.
According to this configuration, it is possible to specify the portion of the charged body where the potential has changed, based on the difference in the detection value of each potential sensor.

Preferably, the charging device negatively charges the entire length of the charging body.
According to this configuration, it is possible to uniformly negatively charge the entire length of the charged body, and to accurately detect a change in potential at the portion of the charged body that contacts the cord.

A method for inspecting a rubberized cord member according to one aspect of the present invention comprises:
1. A method for inspecting a rubberized cord member having a rubber topping sheet and a number of cords covered with the topping sheet and having charging properties that tend to be more positively charged than the topping sheet, the method comprising:
a step of negatively charging a charged body having a charging property that is more easily negatively charged than the code;
contacting the charged body with the surface of the rubberized cord member and detecting the surface potential of the charged body.

According to this configuration, when the negatively charged charged body is brought into contact with the surface of the rubberized cord member and the charged body contacts the exposed cord due to peeling of the topping sheet or the like, the negative charge of the charged body is discharged to the cord. and the surface potential of the charged body partially changes. The exposure of the cord of the rubberized cord member can be detected by detecting this potential change with the potential sensor.

INDUSTRIAL APPLICABILITY The inspection device and inspection method of the present invention can improve the detection accuracy of cord exposure in a rubberized cord member.

FIG. 1 is a schematic diagram showing an example of a rubberized cord member inspection apparatus according to an embodiment of the present invention. FIG. 2 is a plan view showing an example of the surface condition of the rubberized cord member. FIG. 3A is a cross-sectional view showing a state where the charged body is not in contact with the portion of the rubberized cord member where the topping sheet has come off. FIG. 3B is a cross-sectional view showing a state in which a charged body is in contact with a portion of the rubberized cord member where the topping sheet has come off. FIG. 4 is an electrification series table showing the electrification properties of various substances. FIG. 5 is a table showing the results of tests using the detection device.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

FIG. 1 is a schematic diagram showing an example of a rubberized cord member inspection apparatus according to an embodiment of the present invention. The inspection apparatus 2 for the rubberized cord member G is an apparatus for inspecting whether or not the rubberized cord member G has defects, specifically, whether or not the cord is exposed.

FIG. 2 is a plan view showing an example of the surface condition of the rubberized cord member. FIG. 3A is a cross-sectional view showing a state where the charged body is not in contact with the portion of the rubberized cord member where the topping sheet has come off. As shown in FIGS. 2 and 3A, the rubberized cord member G is composed of a large number of parallel cords K and a topping sheet T covering these cords K. As shown in FIGS. The cord K of this embodiment is made of metal such as iron or steel, and a steel cord is used, for example. The cord K may consist of organic fibres. Examples of organic fibers include nylon fibers and rayon fibers.

The topping sheet T is an unvulcanized rubber composition (hereinafter also referred to as unvulcanized rubber). The unvulcanized rubber is obtained by mixing the base rubber and chemicals using a kneader such as a Banbury mixer. The base rubber includes natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR), isoprene rubber (IR), ethylene-propylene rubber (EPDM), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR). ) and butyl rubber (IIR). Chemicals include reinforcing agents such as carbon black and silica, plasticizers such as aromatic oils, fillers such as zinc oxide, lubricants such as stearic acid, anti-aging agents, processing aids, sulfur and Vulcanization accelerators are exemplified. The selection of the base rubber and chemicals, the content of the selected chemicals, etc. are appropriately determined according to the specifications of the components to which the rubber is applied.

The rubberized cord member G is formed by sandwiching a cord array body composed of a large number of cords K arranged side by side between two sheets of the topping sheet T. As shown in FIG. This rubberized cord member G is used for belts, bands, carcasses, etc., which are components of tires, for example. The rubberized cord member G is formed in a long belt shape.

As shown in FIG. 1, the inspection device 2 has a transport device 3 . For example, the conveying device 3 horizontally supports the rubberized cord member G with one surface (first surface) G1 facing upward and the other surface (second surface) G2 facing downward. The cord member G is conveyed in the band longitudinal direction (direction of arrow A). The conveying device 3 can be configured by a roller conveyor, a belt conveyor, or the like.

The inspection device 2 has a charged body 11 . The charged body 11 is composed of an elongated cylindrical rod. The charged body 11 has a length greater than the width of the rubberized cord member G. The charged body 11 is arranged perpendicular to the longitudinal direction of the rubberized cord member G. As shown in FIG.

The charged body 11 includes a first charged body 11A contacting the upper surface G1 of the rubberized cord member G and a second charged body 11B contacting the lower surface G2. The charged body 11 is rotatably supported around an axis C of a cylindrical shape. Therefore, when the rubberized cord member G is conveyed in the band longitudinal direction A, the charged body 11 rotates around the axis C. As shown in FIG.

As shown in FIG. 3A, at least the surface (contact surface) of the charged body 11 is made of rubber. For example, the charged body 11 is made of the same material as the topping sheet T. As shown in FIG. Therefore, the surface of the charged body 11 has substantially the same charging property as the topping sheet T. As shown in FIG. A plurality of projections 11a are formed on the surface of the charged body 11 of this embodiment. This protrusion 11a is formed in a conical or columnar shape. The tip diameter of the protrusion 11a is, for example, 0.5 mm to 1.5 mm, preferably 1.0 mm. The projection 11a is elastically deformable. As shown in FIG. 3A, the protrusion 11a is elastically deformed by contacting the topping sheet T. As shown in FIG. Further, as shown in FIG. 3B, the protrusion 11a is elastically restored at the peeled portion T1 of the topping sheet T, and the tip contacts the cord K. As shown in FIG.

Pyramid-shaped or prism-shaped projections 11 a may be formed on the surface of the charged body 11 . The surface of the charged body 11 may not have the projections 11a formed thereon, and may be formed on a simple cylindrical surface.

FIG. 4 is an electrification series table showing the electrification properties of various substances. Comparing the electrical resistance properties of the rubber topping sheet T and the charged body 11 with the steel code K, the topping sheet T and the charged body 11 tend to be negatively charged, and the code K is the same as the topping sheet T. And, it has a property of being easily positively charged relative to the charged body 11 . The inspection device 2 of this embodiment detects the exposure of the cord K of the rubberized cord member G by utilizing these charging properties.

The inspection device 2 has a charging device 12 that negatively charges a charged body 11 . The charging device 12 of the present embodiment is an ion irradiation device 12 that negatively charges the charged body 11 by irradiating the charged body 11 with ions (electrically charged particles). The ion irradiation device 12 irradiates the entire length of the charged body 11 with ions. The ion irradiation device 12 is configured, for example, by arranging a plurality of devices that irradiate ions in a range smaller than the length of the charged body 11 along the longitudinal direction of the charged body 11 . However, the ion irradiation device 12 may be one that can irradiate the entire length of the charged body 11 with ions.

The inspection device 2 has a potential sensor 13 . The potential sensor 13 detects the potential of the surface of the charged body 11 . The potential sensor 13 measures the surface potential of the charged body 11 within the width of the rubberized cord member G. FIG. The potential sensor 13 is configured by arranging a plurality of sensors that measure the potential in a range smaller than the length of the charged body 11 along the longitudinal direction of the charged body 11 .

The inspection device 2 has a control device 10 . The control device 10 is composed of, for example, a microcomputer having an arithmetic unit such as a CPU and a storage unit including a RAM and a ROM. The control device 10 controls operations of the transport device 3 and the ion irradiation device 12 . Specifically, when inspecting the rubberized cord member G, the control device 10 drives the conveying device 3 to convey the rubberized cord member G, and drives the ion irradiation device 12 to cause the charged body 11 to move. irradiate with ions.

Control device 10 receives detection data of potential sensor 13 . The control device 10 compares the detection data of the multiple potential sensors 13 and obtains the difference. Then, the control device 10 identifies a portion of the charged body 11 where a higher potential is measured (portion with less negative charge).

As described above, the charging body 11 and the topping sheet T are both made of rubber and have substantially the same charging property, whereas the cord K is made of steel and has the charging body 11 and the topping sheet T. have charging properties different from those of As shown in FIG. 4, the charged body 11 and the topping sheet T have the property of being easily charged negatively, whereas the code K (iron or steel) is opposite to the charged body 11 and the topping sheet T. It has the property of being easily charged positively.

As shown in FIG. 3A, when the charged body 11 negatively charged by the ion irradiation device 12 comes into contact with the topping sheet T, the two have substantially the same charging properties. is difficult to occur. On the other hand, as shown in FIG. 3B, when the charged body 11 and the code K come into contact with each other, the negative charges charged by the charged body 11 are easily released (discharged) to the code K because the two have different charging properties. This discharge reduces the negative charge of the charged body 11, partially increases the potential of the charged body 11, and generates a potential difference between the charged body 11 and other portions. The control device 10 can detect exposure of the code K by identifying the portion where this potential difference is generated.

In addition, since the charged body 11 includes a first charged body 11A that contacts the surface G1 on one side of the rubberized cord member G and a second charged body 11B that contacts the surface G2 on the other side, The exposure of the code K can be detected simultaneously on both the surface G1 on one side of the code member G and the surface G2 on the other side.

The charged body 11 is formed in a cylindrical shape and rolls on the surfaces G1 and G2 of the rubberized cord member G. As shown in FIG. Therefore, the charged body 11 is unlikely to become a resistance to the transportation of the rubberized cord member G, and wear can be suppressed. In addition, the entire outer peripheral surface of the charged body 11 can be used for detection of code K exposure.

In the charging member 11, the outer peripheral surface (contact surface) that contacts the surfaces G1 and G2 of the rubberized cord member G is provided with a plurality of projections 11a, so that the peeled portion of the topping sheet T is small, and the code K can be obtained. Even if the exposure is slight, the tip of the protrusion 11a can be brought into contact with the exposed cord K. Therefore, it is possible to improve the detection accuracy of the exposure of the code K.

Also, the projection 11a of the charged body 11 is elastically deformable. Therefore, by contacting the surface of the topping sheet T, the projection 11a is elastically deformed, and the projection 11a is elastically restored at the part where the topping sheet T is peeled off. can.

The rubberized cord member G is strip-shaped, and the charged body 11 is arranged over the entire width of the rubberized cord member G. As shown in FIG. Therefore, the exposure of the cord K can be detected over the entire width of the rubberized cord member G.

The ion irradiation device 12 has the entire length of the charged body 11 as an ion irradiation range. Also, the potential sensor 13 detects the potential of the charged body 11 over the entire length of the charged body 11 . Therefore, the entire length of the charged body 11 can be uniformly negatively charged, and the potential difference generated in the charged body 11 at the portion in contact with the code K can be accurately detected.

A plurality of potential sensors 13 are arranged side by side along the longitudinal direction of the charged body 11 . Therefore, it is possible to specify the portion of the charged body 11 where the potential has changed, by the difference in the detected value of each potential sensor 13 .

[Example]
The inventors of the present application conducted a test to detect the peeled portion of the topping sheet (the exposed portion of the cord) in the rubberized cord member using the inspection device in the above embodiment. FIG. 5 is a table showing the test results.
For this test, a rubberized cord member was used, in which a steel cord having an outer diameter of 1.03 mm was covered with a topping sheet having a width of 1120 mm and a length of 2.0 m. A total of 9 peeling portions with diameters of about 20 mm, 10 mm and 5 mm were formed in the center, right and left of the topping sheet. A charged body having a length of 1200 mm was used. Protrusions with a tip diameter of 1.0 mm were formed on the surface of the charged body. An ion irradiation apparatus having an irradiation effective width of 1200 mm was used, and the charged body was irradiated with ions of 5 to 10 kV. Six potential sensors 13 having a maximum effective measurement range of 200 mm were arranged and used.

Under the above conditions, the inspection was performed 5 times using the inspection device, and the detection rate of the peeled portions (exposed portions of the cords) at 9 locations on the topping sheet was determined.

As shown in FIG. 5, the inspection apparatus of the present embodiment can detect a peeled portion with a diameter of 20 mm with a detection rate of 100%, and can detect a peeled portion with a diameter of 10 mm with a detection rate close to 100%. rice field. Although the detection rate partially decreased to 60% for the peeled portion of 5 mm, it was possible to obtain sufficiently practical results.
When a similar rubber-coated cord member is detected by a conventional camera-type inspection device, the detection rate for peeled portions with a diameter of 10 mm or less is 20% or less, and the superiority of the inspection device of this embodiment has been clarified. .

The embodiments disclosed this time are illustrative in all respects and are not restrictive. The technical scope of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope of equivalents to the configuration described in the claims.

2: inspection device 11: charged body 11A: first charged body 11B: second charged body 11a: protrusion 12: ion irradiation device 13: potential sensor G: rubberized cord member G1: upper surface (first surface)
G2: lower surface (second surface)
K: Code T: Topping sheet

JP 2021-67513 A

Claims (10)

1. An apparatus for inspecting a rubberized cord member having a rubber topping sheet and a number of cords covered with the topping sheet and having charging properties that are more likely to be positively charged than the topping sheet, the apparatus comprising:
a charged body having a charging property that is more likely to be negatively charged than the cord and being in contact with the surface of the rubberized cord member;
a charging device that negatively charges the charged body;
and a potential sensor for detecting the surface potential of the charged body. wherein said charged element comprises a first charged element contacting a first surface on one side of said rubberized cord member and a second charged element contacting a second surface opposite said first surface. Item 2. An inspection device for a rubberized cord member according to item 1. 3. The apparatus for inspecting a rubberized cord member according to claim 1 or 2, wherein said charged body is made of a material having the same electrification property as said topping sheet or having an electrification property more likely to be negatively electrified than said topping sheet. The rubberized cord member inspection device according to any one of claims 1 to 3, wherein the charged body has a cylindrical shape and is provided to be rotatable on the surface of the rubberized cord member. The rubberized cord member inspection device according to any one of claims 1 to 4, wherein a plurality of projections are provided on the contact surface of the charged body that contacts the surface of the rubberized cord member. 6. The apparatus for inspecting a rubberized cord member according to claim 5, wherein said projection is elastically deformable. The rubberized cord member according to any one of claims 1 to 6, wherein the rubberized cord member is strip-shaped, and the charged body has a length that spans the entire width of the rubberized cord member. inspection equipment. 8. The apparatus for inspecting a rubberized cord member according to claim 7, wherein a plurality of said potential sensors are arranged along the longitudinal direction of said charged body. 9. The apparatus for inspecting a rubberized cord member according to claim 7 or 8, wherein the charging device negatively charges the entire length of the charging body. 1. A method for inspecting a rubberized cord member having a rubber topping sheet and a number of cords covered with the topping sheet and having charging properties that tend to be more positively charged than the topping sheet, the method comprising:
a step of negatively charging a charged body having a charging property that is more easily negatively charged than the code;
A method of inspecting a rubberized cord member, comprising: bringing the charged body into contact with the surface of the rubberized cord member, and detecting the surface potential of the charged body.

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