JP2020203474A - Method for cleaning tire and method for manufacturing tire - Google Patents

Abstract

To provide a cleaning method capable of satisfactorily removing unnecessary adhesive matters without damaging a rubber on a tire surface using a plasma treatment, and a method for manufacturing tire cleaned by the cleaning method.SOLUTION: A method for cleaning a tire grasps in advance an irradiation condition of a plasma P in which a rubber on a tire surface in a predetermined area 11A is not damaged by the irradiated plasma P, and irradiates the plasma P from an irradiation head 3 onto the predetermined area 11A in an inner surface 11 of the tire 10 under the atmospheric pressure in the irradiation condition grasped in advance while controlling movement of at least one of the irradiation head 3 held in an arm 5 and a tire 10 held by a rotation mechanism 7 by a controller 6, and continuously or intermittently moving, to remove unnecessary adhesive matters such as a mold release agent adhering in the predetermined area 11A.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for cleaning a tire and a method for manufacturing a tire, and more specifically, cleaning a tire capable of reliably removing unnecessary deposits on the tire surface without damaging the rubber on the tire surface by using plasma treatment. It relates to a method and a method of manufacturing a tire to which this cleaning method is applied.

The mold release agent used in the manufacturing process adheres to the tire surface. Since it is difficult to attach a sound absorbing material or the like to the tire surface with such a mold release agent attached, a method of removing the mold release agent from the tire surface has been proposed (see Patent Document 1). In the method proposed in Patent Document 1, the mold release agent is removed by irradiating the tire surface with a laser beam.

However, since the laser beam has a high output energy, the rubber on the tire surface to which the release agent has adhered is also removed together with the release agent (see paragraph 0006, etc.). That is, there is a problem that sound rubber that does not need to be removed is removed and the tire surface is damaged. Since unnecessary deposits other than the mold release agent are attached to the tire surface, there is room for improvement in surely removing these deposits without damaging the rubber on the tire surface.

Japanese Unexamined Patent Publication No. 2015-21405

An object of the present invention is a method for cleaning a tire that can reliably remove unnecessary deposits on the tire surface without damaging the rubber on the tire surface by using plasma treatment, and a method for manufacturing a tire to which this cleaning method is applied. Is to provide.

In order to achieve the above object, the tire cleaning method of the present invention is a tire cleaning method for removing unnecessary deposits adhering to the predetermined range by irradiating a predetermined range of the tire surface with plasma from an irradiation head. Therefore, the irradiation conditions of the plasma in which the rubber on the tire surface in the predetermined range is not damaged by the irradiated plasma are grasped in advance, and under the irradiation conditions grasped in advance, the plasma from the irradiation head in the predetermined range. Is irradiated to remove the deposits.

The tire manufacturing method of the present invention is characterized in that a predetermined attachment is joined to the predetermined range cleaned by the above tire cleaning method via an adhesive.

According to the tire cleaning method of the present invention, plasma having a lower output intensity (output energy) than laser light and extremely high safety is used. Moreover, the plasma is irradiated from the irradiation head to the predetermined range under the irradiation conditions that are known in advance so that the rubber on the tire surface is not damaged by the plasma irradiation. This makes it possible to reliably remove unnecessary deposits such as a mold release agent adhering to the tire surface without damaging the rubber on the tire surface.

According to the tire manufacturing method of the present invention, a predetermined attachment is bonded to the predetermined range to which unnecessary deposits have been removed by cleaning by the above-mentioned tire cleaning method via an adhesive. Therefore, it is advantageous to firmly fix the joined deposits within the predetermined range for a long period of time. Along with this, it is possible to prevent a problem that the fixed attachment is separated from the tire surface.

It is explanatory drawing which illustrates the tire in which the attachment is joined to the inner surface of the tire in the cross-sectional view. It is explanatory drawing which illustrates the inner surface of the tire of FIG. 1 in a plan view. It is explanatory drawing which illustrates the tire cleaning system used in this invention. It is explanatory drawing which illustrates the cleaning process of the inner surface of a tire in the cross-sectional view of the tire. It is explanatory drawing which illustrates the cleaning process of FIG. 4 from the top view. It is explanatory drawing which illustrates the movement of the irradiation head in the plan view of the inner surface of a tire. It is explanatory drawing which illustrates the modification of the cleaning process of the inner surface of a tire in the cross-sectional view of the tire. It is explanatory drawing which illustrates the process of joining an attachment to the inner surface of a washed tire in the cross-sectional view of the tire.

The tire cleaning method and the tire manufacturing method of the present invention will be described based on the embodiments shown in the drawings.

In the tire manufacturing method of the present invention, the tire 10 illustrated in FIGS. 1 and 2 is manufactured. A predetermined attachment 12 is joined to a predetermined range 11A of the inner surface 11 of the tire 10 via an adhesive 13. In this embodiment, a pressure sensor for detecting the tire internal pressure is joined as the attachment 12. Examples of the attachment 12 include sensors such as a temperature sensor and a sound absorbing material such as a sponge. The adhesive surface of the attachment 12 with the predetermined range 11A is formed of a resin or the like which is a different material from the rubber of the predetermined range 11A. In the drawings, unnecessary deposits X remaining on the inner surface 11 and adhering to the inner surface 11 are schematically shown by diagonal lines.
Further, as the attachment 12, a sealing material arranged inside the tire 10 in order to prevent air leakage from the tire 10 when the tire 10 steps on a nail can be exemplified. Some of such puncture-preventing sealants have adhesiveness (adhesiveness) by themselves.

In the tire cleaning method of the present invention, unnecessary deposits X adhering to the predetermined range 11A are removed in order to join such an attachment 12 to the predetermined range 11A or to join them more firmly. To do. Examples of the deposit X include a mold release agent used in the manufacturing process of the tire 10 and an oil that inhibits the joining of the attachment 12.

In order to remove such deposits X, the tire cleaning system 1 illustrated in FIGS. 3 to 6 is used. The cleaning system 1 includes a plasma source supply device 2, an irradiation head 3 that irradiates the plasma P, an arm 5 that holds the irradiation head 3, and a control device 6 that controls the movement of the arm 5. In this embodiment, a rotation mechanism 7 for rotating and moving the tire 10, a camera 8, and a temperature sensor 9 are further provided.

The predetermined range 11A to be cleaned is a desired range on the inner surface 11 and the outer surface of the tire 10. In this embodiment, the case where the predetermined range 11A exists on the inner surface 11 will be described as an example, but for example, the predetermined range 11A may exist on the outer surface (tire side portion or the like) of the tire 10. Alternatively, a wide range such as the entire inner surface 11 of the tire 10 and the inner surface 11 corresponding to the tread portion (a range continuous with the entire circumference in the circumferential direction) may be the predetermined range 11A.

The irradiation head 3 includes an induction coil to which high-frequency power is supplied, and irradiates the plasma P with a set output intensity. This plasma P is generated by applying electromagnetic energy (high frequency power) to a known reaction gas supplied from the plasma source supply device 2. By adjusting the magnitude of the applied electromagnetic energy (frequency of high-frequency power), the output intensity of the plasma P can be set to a desired magnitude.

The plasma P is irradiated to a predetermined range 11A under atmospheric pressure from the irradiation port 3a at the tip of the irradiation head 3. Since the irradiation port 3a has a small diameter, in order to clean the predetermined range 11A, it is necessary to move the irradiation port 3a above the predetermined range 11A and arrange it. That is, it is necessary to move the irradiation head 3 and the tire 10 relative to each other.

Therefore, in this embodiment, the irradiation head 3 is held by an arm 5 that moves freely. The arm 5 is rotatably attached to the arm base 4, and is configured by rotatably connecting a plurality of arm portions 5a, 5b, and 5c. The irradiation head 3 is detachably attached to the tip of the arm 5. Therefore, by controlling the movement of the arm 5 by the control device 6, the irradiation head 3 can be freely moved in three dimensions, and the irradiation direction of the plasma P can be set to an arbitrary direction.

In this embodiment, the tire 10 is rotatably held around the tire shaft by the rotation mechanism 7. The movement of the rotation mechanism 7 is controlled by the control device 6, and the tire 10 can be moved in an arbitrary rotation direction at an arbitrary rotation speed by an arbitrary rotation angle. It suffices if the irradiation head 3 and the tire 10 can be relatively moved so that the irradiation port 3a can be moved above the irradiation port 3a so as to cover the predetermined range 11A. Therefore, if at least one of the arm 5 and the rotation mechanism 7 is provided. Good.

A digital video camera or the like is used for the camera 8 that acquires the image data of the inner surface 11 of the tire 10. By attaching the camera 8 to the tip of the irradiation head 3 or the arm 5, the image data of the predetermined range 11A irradiated with the plasma P can be sequentially acquired. The acquired image data is input to and stored in the control device 6.

The temperature sensor 9 sequentially detects the temperature in the predetermined range 11A where the plasma P is irradiated. A non-contact type such as thermography is used for the temperature sensor 9. In this embodiment, the temperature sensor 9 is attached to the irradiation head 3, but can also be attached to the tip of the arm 5. The temperature data detected by the temperature sensor 9 is input to and stored in the control device 6. The camera 8 and the temperature sensor 9 can be optionally provided.

Next, a procedure for cleaning the inner surface 11 of the tire 10 using the cleaning system 1 will be described.

First, the irradiation conditions of plasma P are set in advance. Therefore, using a tire having the same specifications as the tire 10 to be cleaned or a rubber sample similar thereto, the rubber surface is irradiated with plasma P from the irradiation head 3 under atmospheric pressure so that the rubber on the rubber surface is not damaged. Understand the conditions in advance.

Specifically, since there is an output strength of plasma P required to remove unnecessary deposits X, the output strength of plasma P is set to a predetermined value within the range of the required output strength. Then, the output intensity of the plasma P is set to this predetermined value, the distance d between the irradiation port 3a and the rubber surface of the predetermined range 11A and the irradiation time t of the plasma P are made different, and the irradiation head 3 and the tire 10 are made relative to each other. Plasma P is pinpointed to a predetermined range 11A without moving. After that, the predetermined range 11A irradiated with the plasma P is observed, and the degree of removal of the deposit X adhering to the predetermined range 11A and the damaged state of the rubber on the rubber surface of the predetermined range 11A are observed.

The degree of removal of the deposit X is determined, for example, by measuring the water contact angle of the rubber surface. When a mold release agent or the like is attached to the rubber surface, the water contact angle is about 110 ° to 130 °, but when such deposit X is removed, the water contact angle becomes smaller. Therefore, for example, when the water contact angle is 80 ° or less, more preferably 75 ° or less, it is determined that the deposit X is completely removed.

The damaged state of the rubber is observed with a microscope or the like to confirm whether or not the shape of the rubber surface is different from the shape of the rubber surface in the peripheral portion not irradiated with plasma P. If the difference between the two cannot be confirmed, it is judged that the rubber has not been damaged.

In this way, the irradiation conditions of the plasma P (predetermined value of output intensity, separation interval d, and irradiation time t, each of the allowable ranges) that can remove the deposit X without damaging the rubber on the rubber surface are grasped in advance. .. The predetermined value of this output strength is, for example, about 200 kHz to 500 kHz in terms of the frequency of the high frequency power to be supplied. The separation distance d is, for example, about 10 mm to 30 mm, and the irradiation time t is, for example, about 5 to 60 seconds.

Data necessary for operating the cleaning system 1 is input to the control device 6 within the permissible range of the grasped irradiation conditions. Within the permissible range of the irradiation conditions, it is preferable to set the irradiation head 3 and the tire 10 to move relative to each other so that the entire cleaning of the predetermined range 11A can be completed in a shorter time.

Next, in the cleaning system 1, at least one of the tire 10 to be cleaned and the irradiation head 3 is continuously or intermittently moved to a predetermined range 11A under atmospheric pressure under the above-mentioned irradiation conditions grasped in advance. Plasma P is irradiated from the irradiation head 3. In this embodiment, as illustrated in FIGS. 4 and 5, the movement of the arm 5 is controlled and the irradiation head 3 is mounted on the inner surface without rotating the tire 10 while maintaining it in a predetermined position in a horizontal position. Move along 11. By using the arm 5 that can be freely moved in three dimensions, the irradiation head 3 can be accurately moved along the curved surface shape of the inner surface 11 of the tire 10. The tire 10 may be placed vertically.

While moving the irradiation head 3 intermittently or continuously as illustrated in FIG. 6, plasma P is irradiated from the irradiation head 3 to a predetermined range 11A. The deposit X adhering to the predetermined range 11A is decomposed and vaporized by the irradiated plasma P, and is removed from the predetermined range 11A. As a result, the predetermined range 11A is in a washed state to which no deposit X is attached.

Here, in order to suppress the irradiation unevenness of the plasma P, the moving direction of the irradiation head 3 and the irradiation direction of the plasma P are controlled so as to keep the distance d between the irradiation port 3a and the tire surface of the irradiation range 11A constant. It is good to do. When the irradiation head 3 is moved intermittently or continuously, it is preferable to keep the moving speed as constant as possible and move the irradiation head 3 so as to cover a predetermined range 11A.

In this embodiment, the image data of the predetermined range 11A irradiated with the plasma P is sequentially acquired, and the removal state of the deposit X can be grasped by the control device 6 based on the acquired image data. The location where the deposit X is attached has a slight difference in the surface color of the predetermined range 11A as compared with the location where the deposit X is not attached. Therefore, for example, the difference in the threads on this surface can be seen in the image data. The removal state of the deposit X can be determined by distinguishing by the color (shade) of. Even if the deposit X is a transparent color, by irradiating the predetermined range 11A with light, it becomes easy to clarify the difference in the surface color of the predetermined range 11A.

Therefore, the permissible range in the image data of the surface color (shade) of the predetermined range 11A to which the deposit X is not adhered is set in advance. Then, if the surface color (shade) of the predetermined range 11A in the acquired image data is within this allowable range, it is determined that the deposit X has been removed, and if it is out of the allowable range, the deposit X is removed. Is not removed.

The relative movement of the irradiation head 3 and the tire 10 is controlled based on the removal state of the deposit X grasped in this way. In this embodiment, the coordinate data of the portion where it is determined that the deposit X has not been removed is stored in the control device 6. Then, the irradiation head 3 is moved again to the portion to irradiate the plasma P.

Further, in this embodiment, the surface temperature of the predetermined range 11A irradiated with the plasma P can be sequentially detected by the temperature sensor 9. The permissible temperature is input to the control device 6 in advance. This permissible temperature is set to a predetermined temperature (for example, 70 ° C. or lower) at which the rubber on the rubber surface in the predetermined range 11A is not immediately deformed or deteriorated.

When the surface temperature of the predetermined range 11A detected by the temperature sensor 9 exceeds a preset allowable temperature, the irradiation of plasma P is interrupted. For example, even if an unintended deposit X is attached and the plasma P reacts violently when irradiated to a temperature higher than expected, according to this configuration, the plasma P to be irradiated has a predetermined range. 11A will not be overheated. That is, it is possible to prevent a problem that the rubber surface in the predetermined range 11A is damaged by the plasma P.

As illustrated in FIG. 7, the rotation mechanism 7 can be used to irradiate the predetermined range 11A with the plasma P while rotating the tire 10 at a predetermined position. That is, the irradiation head 3 can be fixed without being moved, and the tire 10 can be continuously or intermittently rotated by the rotation mechanism 7 to change the relative positions of the two. Alternatively, the relative positions of the two can be changed continuously or intermittently by moving the irradiation head 3 and rotating the tire 10.

In the tire cleaning method described above, plasma P, which has lower output energy than laser light and is remarkably safer, is used. Therefore, large-scale equipment for preventing danger becomes unnecessary. Moreover, the irradiation conditions in which the rubber in the predetermined range 11A is not damaged by the plasma irradiation P are grasped in advance, and under these irradiation conditions, at least one of the tire 10 and the irradiation head 3 is continuously or intermittently moved while being large. Plasma P is irradiated to a predetermined range 11A under atmospheric pressure.

Therefore, unnecessary deposits X such as a mold release agent adhering to the tire surface in the predetermined range 11A can be reliably removed without damaging the rubber on the tire surface. That is, by substantially removing only the deposit X, the rubber on the sound tire surface can be maintained in the initial state without causing deformation, deterioration or the like. When the plasma P is irradiated to remove the deposit X, no smoke or offensive odor is generated. Therefore, from this viewpoint as well, the equipment can be significantly simplified as compared with the case of using the laser beam.

After cleaning the predetermined range 11A in this way, as illustrated in FIG. 8, the predetermined attachment 12 is joined to the predetermined range 11A via the adhesive 13. In the predetermined range 11A, unnecessary deposits X are removed and the water contact angle is reduced. That is, since the predetermined range 11A is adhesively activated, the joined attachment 12 can be firmly fixed to the predetermined range 11A for a long period of time. Along with this, it is advantageous to prevent a problem that the fixed attachment 12 is separated from the predetermined range 11A during use of the tire 10.

Further, even immediately after cleaning with the deposit X removed, the adhesive 13 can be applied to the predetermined range 11A to join the attachment 12 to the predetermined range 11A. Therefore, the tire 10 in which the attachment 12 is joined to the predetermined range 11A can be manufactured with high productivity. In order to avoid adhesion of dust and the like floating in the air to the predetermined range 11A from which the deposit X has been removed, the attachment 12 may be joined immediately after cleaning the predetermined range 11A. When the attachment 12 is a sealing material or the like having adhesiveness (adhesiveness) by itself, the attachment 12 is directly joined to the cleaned predetermined range 11A without using the adhesive 13.

If the rubber surface on the inner surface of a general passenger car tire is treated with PFW10 manufactured by Plazma Treat as a plasma irradiation device and the plasma irradiation time is different in 7 ways as shown in Table 1 under the following irradiation conditions. The experiment was carried out (test samples 1 to 7). A mold release agent was attached to the inner surface of the tire irradiated with plasma. The plasma output intensity (frequency of high-frequency power) was set to 230 kHz, and the distance between the irradiation port of the irradiation head for irradiating the plasma and the rubber surface was maintained at about 20 mm, and the plasma was continuously irradiated to a predetermined position.

The water contact angle of the rubber surface before plasma irradiation (test sample 1) and after irradiation was compared to confirm the state of removal of deposits after plasma irradiation. In addition, the rubber surface before plasma irradiation (test sample 1) and after irradiation was observed with a microscope to confirm the degree of rubber damage on the rubber surface after plasma irradiation. These results are shown in Table 1.

The smaller the value of the water contact angle, the more cleanly the deposits are removed, and if it is 80 ° or less, it can be judged that the cleaning is practically good. If there is no difference in the degree of damage to the rubber on the rubber surface from that before irradiation, it can be determined that the rubber is not damaged.

From the results in Table 1, it can be seen that by appropriately setting the irradiation time of plasma irradiation, unnecessary deposits on the rubber surface can be reliably removed without damaging the rubber on the tire surface.

1 Cleaning system 2 Plasma source supply machine 3 Irradiation head 3a Irradiation port 4 Arm base 5 Arm 5a, 5b, 5c Arm part 6 Control device 7 Rotation mechanism 8 Camera 9 Temperature sensor 10 Tire 11 Inner surface 11A Predetermined range 12 Attachment 13 Adhesive P Plasma X deposits

Claims (6)

A method for cleaning a tire, which removes unnecessary deposits adhering to the predetermined range by irradiating a predetermined range of the tire surface with plasma from an irradiation head.
The irradiation conditions of the plasma in which the rubber on the tire surface in the predetermined range is not damaged by the irradiated plasma are grasped in advance, and the plasma is irradiated to the predetermined range from the irradiation head under the irradiation conditions grasped in advance. A method for cleaning a tire, which comprises removing the deposits. The method for cleaning a tire according to claim 1, wherein the predetermined range is the inner surface of the tire. The tire cleaning method according to claim 1 or 2, wherein the relative movement of the irradiation head and the tire is controlled so as to maintain a constant separation interval between the irradiation port of the irradiation head and the tire surface in the irradiation range. Image data in the predetermined range that is irradiated with plasma is sequentially acquired, the state of removal of the deposits is grasped based on the acquired image data, and the irradiation head and the tire are based on the grasped result. The method for cleaning a tire according to any one of claims 1 to 3 for controlling relative movement. A method for manufacturing a tire, which comprises joining a predetermined attachment to the predetermined range cleaned by the tire cleaning method according to any one of claims 1 to 4 via an adhesive. A method for manufacturing a tire, which comprises directly joining a predetermined attachment having adhesiveness to the predetermined range cleaned by the tire cleaning method according to any one of claims 1 to 4.

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