JP6950267B2 - Polishing device for the inner surface of the tread - Google Patents

Description

The present invention relates to a device for buffing the inner surface of a tread of a pneumatic tire.
Regarding.

Patent Document 1 below proposes a pneumatic tire in which a sponge material for absorbing the cavity resonance sound generated in the tire cavity is adhered to the inner surface of the tread. Further, a pneumatic tire (sealant tire) in which a sealing agent for sealing a nail hole is previously applied to the inner surface of the tread is proposed in Patent Document 2 below.

Generally, a mold release agent such as silicone oil remains on the inner surface of the tread in order to improve the mold release property from the bladder for vulcanization molding. The release agent interferes with the adhesion of the sponge material and the sealing agent described above. In order to remove the release agent from the inner surface of the tread, in Patent Document 1 below, the inner surface of the tread is polished by rotating a disk-shaped buff that descends between the pair of bead portions.

However, when such polishing is performed, since the bead portion is not held, the bead portion may meander and come into contact with the buff during polishing, and the bead portion may be damaged. Therefore, conventionally, damage is prevented by using a buff whose width is sufficiently narrower than the distance between the bead portions. As a result, there arises a problem that the inner surface of the tread cannot be polished to a required width.

JP-A-2007-152789 Japanese Unexamined Patent Publication No. 2016-78818

The present invention has been devised in view of the above circumstances, and can buff the inner surface of the tire while expanding the space between the bead portions, and can polish the inner surface of the tread while preventing damage to the bead portions and expanding the polishing width. The challenge is to provide the equipment.

The present invention is a device for buffing the inner surface of a tread of a pneumatic tire held in an upright position.
Provided with a polishing unit capable of descending between the pair of beads of the held pneumatic tire.
The polishing unit includes a support shaft that can be raised and lowered, a polishing tool that is supported by the support shaft and whose outer peripheral portion is in contact with the inner surface of the tread to perform buffing, and a shaft that is supported by the support shaft and is supported by the polishing tool. With conical bead expansion rings arranged on both sides in the direction of the center,
In the bead expansion ring, the outer surface in the axial direction forms a conical surface, so that the conical surface expands the bead portions on both sides to the outer side in the axial direction as the descent occurs.

In the polishing device for the inner surface of the tread according to the present invention, the polishing tool is rotatably attached to the support shaft, and the bead expansion ring is rotatably supported independently of the polishing tool. preferable.

In the tread inner surface polishing apparatus according to the present invention, the conical surface of the bead expansion ring preferably has an inclination angle α of 5 to 50 degrees with respect to a plane perpendicular to the axial direction.

In the tread inner surface polishing apparatus according to the present invention, the polishing tool is preferably a brush.

In the present invention, conical bead expansion rings are provided on both sides of the polishing tool in the axial direction. This bead expansion ring has a conical outer surface in the axial direction. Therefore, as the polishing unit is lowered, the bead expansion ring can expand the bead portions on both sides by pushing them outward in the axial direction.

That is, only by lowering the polishing unit, it is possible to accurately buff the center of the inner surface of the tread while centering the bead portions on both sides. Moreover, since the bead portion is positioned, meandering during buffing can be suppressed. Therefore, it is possible to secure a large width of the polishing tool while preventing damage to the bead portion, and it is possible to expand the polishing width.

Further, since the polishing unit uses a conical bead expansion ring, the bead portion can be expanded without causing malfunction due to buff powder or the like, as compared with the case where the bead portion is expanded by using a cylinder or the like. Can be performed stably and reliably.

Further, since the polishing unit itself has a diameter-expanding function, it is possible to easily carry in and out the pneumatic tire into and out of the tire holding device.

It is a side view which shows one Embodiment of the polishing apparatus of the inner surface of a tread of this invention. It is sectional drawing which shows the polishing unit. It is sectional drawing which shows the action effect by a polishing unit.

Hereinafter, embodiments of the present invention will be described in detail.
As shown in FIG. 1, the tread inner surface polishing device (hereinafter, simply referred to as “polishing device”) 1 of the present embodiment is a device for buffing the tread inner surface TS of the pneumatic tire T held in the standing posture Y. Is.

The pneumatic tire T is held in the standing posture Y by a tire holding device (not shown). Various tire holding devices can be used. In this example, a case where a pair of rotatable holding rollers 3 is provided is shown. The holding rollers 3 are horizontal and parallel to each other, and the pneumatic tire T is straddled and held between the holding rollers 3 and 3. One of the holding rollers 3 is driven by a motor, and the pneumatic tire T held by the motor can rotate around the tire axis.

The polishing device 1 includes a polishing unit 5, a vertical moving means 6 for moving the polishing unit 5 up and down, and a horizontal moving means 7 for moving the polishing unit 5 in the tire axial direction.

The vertical moving means 6 includes, for example, a vertical moving table 13 that is supported so as to be vertically movable via a guide 12 on a support column 11 that rises from the base plate 10. Further, the horizontal moving means 7 includes a horizontal moving table 15 that is supported by the vertical moving table 13 so as to be movable in the tire axial direction via a guide 14. The vertical moving table 13 and the horizontal moving table 15 are driven by an appropriate linear driving means (not shown) having, for example, a ball screw mechanism.

A driving motor 17 for rotationally driving the polishing unit 5 is attached to the horizontal moving table 15.

The polishing unit 5 includes a support shaft 20, a polishing tool 21, and a pair of conical bead expansion rings 22.

The support shaft 20 can be raised and lowered, and is rotationally driven by the motor 17. In this example, the case where the support shaft 20 is linearly connected to the motor shaft 17A of the motor 17 is shown. However, the present invention is not limited to this. It can also be connected via a chain / sprocket mechanism or the like.

As shown in FIG. 2, the polishing tool 21 and the bead expansion ring 22 can be lowered through between the bead portions Tb and Tb by lowering the support shaft 20. Then, the outer peripheral portion 21S of the polishing tool 21 rotates while being in contact with the tread inner surface TS to buff the tread inner surface TS. In this example, the case where the polishing tool 21 is a brush is shown.

Specifically, the polishing tool 21 is formed of a cylindrical core material portion 21A rotatably attached to the support shaft 20 and a large number of brush bristles 21B planted on the outer peripheral surface of the core material portion 21A. Will be done. In this example, recesses 23 concentric with the core material portion 21A are formed on both side surfaces of the core material portion 21A. A ring-shaped first bearing member 24 is arranged on the inner wall of the recess 23.

The bead expansion rings 22 are arranged on both sides of the polishing tool 21 in the axial direction. In this example, the inner side surface 25i of the bead expansion ring 22 in the axial direction is a plane perpendicular to the axial direction, and is in close proximity to or in contact with the outer surface of the polishing tool 21. On the other hand, the outer surface 25o of the bead expansion ring 22 in the axial direction forms a conical surface. Specifically, the outer surface 25o is inclined inward in the radial direction toward the outside in the axial direction.

The bead expansion ring 22 is rotatably pivotally supported independently of the polishing tool 21. In this example, the inner surface 25i is provided with an annular rib 26 that is interpolated and supported in the inner hole of the first bearing member 24. The outer portion of the bead expansion ring 22 in the central hole 22H in the axial direction is supported by the support shaft 20 via the second bearing member 27.

With this configuration, as shown in FIG. 3, the bead expansion ring 22 can expand the bead portions Tb on both sides by pushing them outward in the axial direction as the polishing unit 5 descends.

As a result, the bead portions Tb on both sides can be centered, and buffing can be performed accurately at the center of the tread inner surface TS. Further, since the bead portion Tb is positioned by the expansion, meandering during buffing can be suppressed. Moreover, since the bead expansion ring 22 is interposed between the bead portion Tb and the polishing tool 21, damage to the bead portion Tb can be reliably prevented.

As shown in FIG. 2, the width W21 of the polishing tool 21 can be expanded to a value substantially equal to the interval WT between the bead portions Tb and Tb before expansion, and a large polishing width can be secured.

Further, the bead expansion ring 22 can rotate independently of the polishing tool 21. Therefore, while the polishing tool 21 is rotationally driven by the support shaft 20 for polishing, the bead expansion ring 22 can rotate following the bead portion Tb and reduce the contact resistance with the bead portion Tb. Can be done.

The inclination angle α of the outer surface 25o (conical surface) of the bead expansion ring with respect to the plane perpendicular to the axial direction is preferably 5 to 50 degrees. If the inclination angle α is less than 5 degrees, the expansion effect of the bead portion Tb cannot be sufficiently exerted, and it becomes difficult to perform centering on a flat tire having a tire cross-sectional height of 90 mm or less, for example. On the contrary, if the inclination angle α exceeds 50 degrees, the bead portion Tb is pressed inward in the radial direction of the tire when descending, and the bead expansion and centering cannot be performed. From such a viewpoint, the lower limit of the inclination angle α is preferably 10 degrees or more, more preferably 15 degrees or more, and the upper limit is preferably 45 degrees or less, more preferably 40 degrees or less.

The diameter D2 of the bead expansion ring 22 is smaller than the diameter D1 of the polishing tool 21, and the difference (D1-D2) is preferably in the range of 10 to 40 mm.

In this example, the polishing tool 21 and the bead expansion ring 22 are removable from the support shaft 20. Therefore, it can be appropriately replaced with a polishing tool 21 and a bead expansion ring 22 having a size corresponding to the bead width of the tire T and the cross-sectional height of the tire.

Although the particularly preferable embodiments of the present invention have been described in detail above, the present invention is not limited to the illustrated embodiments and can be modified into various embodiments.

Using the polishing device having the structure shown in FIGS. 1 and 2, the following three tires A, B, and C having different tire sizes were buffed on the inner surface of the tread. A polishing tool a is used for the tire A, a polishing tool b is used for the tire B, and a polishing tool c is used for the tire C. The rotation speed of the polishing tools a to c is 1700 rpm. The same bead expansion ring is used.
Tire A --- 215 / 60R16
Tire B --- 225 / 60R17
Tire C --- 215 / 45R17
Polishing tool a (brush)
・ Diameter D1--350mm
・ Width W21 --- 100 mm
Polishing tool b (brush)
・ Diameter D1--350mm
・ Width W21 --- 120 mm
Polishing tool c (brush)
・ Diameter D1--350mm
・ Width W21 --- 100 mm
Bead expansion ring (common)
・ Diameter D2-260mm
・ Inclination angle α --- 18 °

It was confirmed that for each of the tires A, B, and C, the bead portion could be centered with high accuracy, meandering during buffing could be suppressed, and buffing could be performed with high accuracy. It was also confirmed that it was possible to prevent the bead portion from being scratched due to the polishing tool coming into contact with the bead portion. It was also confirmed that since the contact area between the bead expansion ring and the bead portion is large during expansion, the occurrence of scratches and deformation on the bead portion is suppressed.

1 Tread inner surface polishing device 5 Polishing unit 20 Support shaft 21 Polishing tool 21S Outer circumference 22 Bead expansion ring 25o Outer side surface T Pneumatic tire Tb Bead part TS Tread inner surface Y Standing posture

Claims (4)

A device for buffing the inner surface of a pneumatic tire tread that is held in an upright position.
Provided with a polishing unit capable of descending between the pair of beads of the held pneumatic tire.
The polishing unit is supported by a support shaft that can be raised and lowered, a polishing tool that is integrally rotatably supported by the support shaft and whose outer peripheral portion is in contact with the inner surface of the tread for buffing due to the lowering, and is supported by the support shaft. With conical bead expansion rings arranged on both sides of the polishing tool in the axial direction,
The bead expansion ring is a tread inner surface polishing device in which the outer surface in the axial direction forms a conical surface, and the conical surface expands the bead portions on both sides outward in the axial direction as the conical surface forms a conical surface.
Before SL bead expansion ring, said polishing tool independently rotatably polishing apparatus of the tread inner surface of the pivoted by claim 1, wherein the.
A device for buffing the inner surface of a pneumatic tire tread that is held in an upright position.
Provided with a polishing unit capable of descending between the pair of beads of the held pneumatic tire.
The polishing unit includes a support shaft that can be raised and lowered, a polishing tool that is supported by the support shaft and whose outer peripheral portion is in contact with the inner surface of the tread to perform buffing, and a shaft that is supported by the support shaft and is supported by the polishing tool. With conical bead expansion rings arranged on both sides in the direction of the center,
In the bead expansion ring, the outer surface in the axial direction forms a conical surface, so that the conical surface expands the bead portions on both sides to the outer side in the axial direction as the descent occurs.
Wherein the conical surface of the bead expansion ring, the inclination angle α is 5 to 50 degrees der belt Red inner surface of a polishing apparatus for axially perpendicular plane. The polishing device for the inner surface of a tread according to any one of claims 1 to 3, wherein the polishing tool is a brush.

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