JP2010089468A - Spew trimming method and apparatus for tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire spew trimming method and an apparatus which enable an excellent tire appearance to be provided by making the cutting remnant length of a spew shorter, and also, suppressing the unevenness in the length. <P>SOLUTION: The spew 2 is cut by bringing a cutting blade 3 into contact with the vicinity of the root of the spew 2 while rotating the tire after vulcanization on the surface of which a plurality of spews 2 have been formed in the spew trimming of the tire. In the spew trimming, on a moving path of the spew 2, an external force imparting means 4 which makes the spew 2 incline to the cutting blade 3 side is installed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tire spew trimming method and apparatus, and more particularly, to reduce the length of the spew remaining on the spew on the tire surface after vulcanization, and to obtain an excellent appearance by suppressing variation in length. The present invention relates to a tire spew trimming method and apparatus.

  Generally, a tire vulcanization mold is provided with a number of vent holes for releasing gas between a green tire and a mold in order to prevent a vulcanization failure. In this vent hole, after the green tire is pressed against the inner surface of the mold and the gas is discharged, unvulcanized rubber flows into it, and it is formed as hook-like protrusions called spews on the tire surface after vulcanization. The The tire after vulcanization is made into a product tire by removing such spew by trimming.

  As a conventional trimming method for removing the spew, as shown in FIG. 6A, the cutting blade 3 is generally brought into contact with the spew 2 protruding on the surface and cut while rotating the tire 1. . However, since the spew 2 is flexible and does not have rigidity, when it hits the cutting blade 3, it bends to escape from the cutting blade 3 (see FIG. 6B). Therefore, the cut end was cut in a slanting state (see FIG. 6C). Therefore, as shown in FIG. 6 (d), the spew 2a on the base side after cutting has an obliquely tapered shape, and the uncut length L becomes longer, and the uncut length for each spew. Variation in L occurred, which caused the tire appearance to deteriorate.

As a countermeasure for this problem, Patent Document 1 discloses that a vent hole provided in a tire vulcanization mold is inclined with respect to the mold surface so that spews formed after the tire is formed are inclined with respect to the tire surface. Propose to do. Since the spew is standing upright in this way, the above-mentioned problem is solved by making it difficult to escape from the cutting blade by applying the cutting blade to the inclined side of the spew. However, in this method, since the vent hole is formed obliquely, when the tire is released from the mold after vulcanization, there is a problem that spew is broken and remains in the vent hole. There was a problem that the cleaning work was costly.
JP 2002-301777 A

  The object of the present invention is to solve the above-mentioned problems, while keeping the spew from remaining in the vent hole, shortening the uncut length of the spew of the pneumatic tire after vulcanization, and variation in length. It is an object of the present invention to provide a spew trimming method and apparatus for a tire that suppresses the above and enables an excellent tire appearance.

  In order to achieve the above object, a method of spew trimming a tire according to the present invention comprises rotating a vulcanized tire having a plurality of spews formed on a surface thereof, contacting a cutting blade near the root of the spew, and In the spew trimming method for a tire to be cut, the spew is cut while applying an external force that causes the spew to be inclined toward the cutting blade.

  In the configuration described above, it is preferable to configure as described in (1) to (3) below.

(1) The external force is applied to the tip of the spew by bringing a drum or belt into contact with the tip of the spew at a speed faster than the speed of movement of the spew in the same direction as the rotational direction of the tire.
(2) The external force is applied to the spew by injecting a fluid at a speed higher than the movement speed of the spew in the same direction as the rotation direction of the tire.
(3) When the cutting blade is brought into contact with the spew, the inclination angle of the spew with respect to the normal of the tire surface is set to 15 ° to 60 °.

  In addition, the spew trimming device for a tire according to the present invention is a tire spew that rotates a vulcanized tire having a plurality of spews formed on a surface thereof and contacts a cutting blade near the root of the spew to cut the spew. In the trimming apparatus, an external force applying means for inclining the spew toward the cutting blade is provided in the movement path of the spew, and is preferably configured as described in (4) and (5) below.

(4) The external force applying means is a drum or a belt that contacts the tip of the spew at a speed higher than the moving speed of the spew in the same direction as the rotation direction of the tire.
(5) The external force applying means is a fluid ejecting nozzle that ejects fluid to the spew at a speed higher than the moving speed of the spew in the same direction as the rotation direction of the tire.

  According to the spew trimming method and apparatus for a tire of the present invention, a tire that cuts a spew by rotating a vulcanized tire having a plurality of spews formed on the surface thereof and contacting a cutting blade near the root of the spew. In spew trimming, the spew is inclined to the cutting blade side by the external force imparting means, so that the flexible spew can be cut so as not to escape from the cutting blade, and the uncut length of the spew is shortened. , Variation in length between spews can be suppressed. Therefore, trimming of an excellent tire appearance can be performed.

  FIG. 1 is an explanatory view showing a spew trimming method for a tire according to an embodiment of the present invention in the order of steps.

  In FIG. 1A, reference numeral 1 denotes a tire that rotates in the direction of arrow a, and a spew 2 is formed on the outer peripheral surface of the tire 1 so as to protrude in the normal direction of the surface of the tire 1. A cutting blade 3 is provided in the vicinity of the outer peripheral surface of the tire 1. The cutting blade 3 is installed along the surface of the tire 1 so as to be in contact with the vicinity of the root of the spew 2. Further, an external force applying means 4 for applying an external force to the tip of the spew 2 by moving in the direction of the arrow f so as to temporarily overlap the moving path of the spew 2 at a position away from the outer peripheral surface of the tire 1. Is provided.

  The external force applying means 4 moves in the same direction of the arrow f as the tire rotation direction a at a speed faster than the moving speed of the spew 2, and applies an external force in the direction of the arrow f to the spew 2 by contacting the tip of the spew 2. To be inclined to the cutting blade 3 side. Then, the spew 2 is inclined and brought into contact with the cutting blade 3 (see FIG. 1B).

  And the spew 2 is cut | disconnected by the cutting blade 3 in the state inclined to the cutting blade 3 side in this way (refer FIG.1 (c)). Therefore, when the spew 2 comes into contact with the cutting blade 3, the spew 2 does not bend so as to escape backward, and the root side of the spew 2a after cutting has a cross section on the surface of the tire 1 as shown in FIG. On the other hand, since it is substantially parallel to each other, the uncut length L is short, and variations in the length L for each spew are suppressed, it is possible to obtain an excellent tire appearance.

  In the present invention, an apparatus embodying the principle shown in FIG. 1 is not particularly limited, but the embodiments of FIGS. 2 to 4 can be exemplified.

  The embodiment of FIG. 2 is an example in which a rotating drum 4 a is provided as the external force applying means 4. The rotating drum 4 a is installed at a position in contact with the tip of the spew 2 so as to be close to the moving path of the spew 2, and its surface speed is rotated in the direction of the arrow fa in the same direction as the tire 1 with respect to the surface of the tire 1. In addition, it is installed so as to rotate at a speed faster than the movement speed of the spew on the tire surface. In this way, the rotating drum 4a applies an external force to the spew 2 toward the front side in the traveling direction and inclines toward the cutting blade 3 side. The surface of the rotating drum 4a may be rotated in the same direction as the surface of the tire 1 so that the spew 2 is inclined toward the cutting blade 3, and the diameter of the rotating drum 4a may be any size. Good. Further, the shape, material, and the like of the surface of the rotating drum 4a are not particularly limited as long as an external force can be transmitted to the spew 2 by friction.

  The embodiment of FIG. 3 is an example in which a belt 4 b is provided as the external force applying means 4. In this apparatus, as in the case of the drum 4a described above, the surface of the belt 4b is installed at a position in contact with the tip of the spew 2, and the spew 2 on the tire surface is aligned in the direction of the arrow fb in the same direction as the surface of the tire 1. It rotates at a speed faster than the moving speed. By doing so, the surface of the belt 4b is inclined to the cutting blade 3 side by applying an external force so that the spew 2 is tilted forward in the traveling direction. As with the drum 4a, the belt 4b only needs to rotate in the same direction as the surface of the tire 1 so that the spew 2 is inclined toward the cutting blade 3, and the shape, material, and the like of the belt 4b are particularly limited. It is not a thing.

  The embodiment of FIG. 4 is an example in which a fluid ejection nozzle 4 c that ejects fluid to the spew 2 is provided. As the fluid to be sprayed, a gas such as air or a liquid such as water can be used. In FIG. 4, the fluid ejection nozzle 4 c is provided on the rear side in the movement direction of the spew 2, and sprays the fluid in the direction of the arrow fc, that is, in the same direction as the movement direction of the spew 2 at a speed higher than the movement speed of the spew 2. . By doing so, the spew 2 can be inclined toward the cutting blade 3 side. The amount of fluid ejection is not particularly limited as long as the spew 2 can be inclined toward the cutting blade. Further, the shape and installation position of the fluid ejection nozzle 4c are not particularly limited as long as the spew 2 can be inclined at an appropriate inclination angle.

  The external force applying means 4 is not limited to the implementation method shown in FIGS. 2 to 4, as long as the external force for inclining the spew 2 in the same direction as the movement direction of the spew 2, that is, the cutting blade 3 side can be applied. Any means may be used.

  In the present invention, when the spew 2 is cut by the cutting blade 3, the inclination angle at which the spew 2 is inclined by the external force applying means 4 is an inclination angle A with respect to the normal line of the tread of the spew 2 (see FIG. 1B). It may be 15 ° to 60 °, preferably 40 ° to 55 °. If the inclination angle is smaller than 15 °, the cut end becomes a tapered shape in which the front side in the traveling direction of the spew 2 is slanted as in the conventional trimming method, and there is a possibility that the uncut length becomes long ( (See FIG. 5 (a)). On the contrary, if the inclination is larger than 60 °, the spew 2 is excessively inclined at the time of cutting, so that the cut end becomes a tapered shape in which the rear side in the advancing direction of the spew 2 is inclined, and there is a possibility that the uncut length is increased. Yes (see FIG. 5C). When the inclination angle is 15 ° to 60 °, as shown in FIG. 5B, it becomes easy to make the cut end of the spew 2 substantially parallel to the tire surface and shorten the length.

  Examples of vulcanized tires having a large number of spews with a diameter of 1.3 mm, a conventional example in which no external force applying means is provided, and a rotating drum as an external force applying means and Examples 1 to 1 having different inclination angles A at the time of cutting Sputum trimming was performed by the four types of methods. In the first to third embodiments, the rotation speed of the rotating drum when the spew is cut with the cutting blade is varied, and the inclination angle A of the spew is 45 ° in the first embodiment, 30 ° in the second embodiment, and the third embodiment. Was 60 °.

  The uncut length and length variation after spew trimming by the above four methods were compared. The uncut length was measured by measuring the length of the spew after trimming and comparing the average values. Variations in length were compared by calculating the difference between the maximum and minimum uncut length. The smaller the value of the uncut length and the variation in the length, the better.

It is explanatory drawing which showed the spew trimming method of the tire by embodiment of this invention in order of the process. It is a schematic diagram which shows embodiment of this invention. It is a schematic diagram which shows other embodiment of this invention. It is a schematic diagram which shows other embodiment of this invention. It is a side view which shows the spew after the spew trimming by the former and embodiment of this invention. It is explanatory drawing which showed the spew trimming method of the conventional tire in order of the process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tire 2 Spew 3 Cutting blade 4 External force provision means

Claims (7)

In the spew trimming method for a tire, in which a cutting blade is brought into contact with the vicinity of the root of the spew and the spew is cut while rotating a vulcanized tire having a plurality of spews formed on the surface,
A method for trimming a spew of a tire, wherein the spew is cut while applying an external force for inclining the spew toward the cutting blade.   2. The tire spew trimming method according to claim 1, wherein the external force is applied to a tip of the spew by bringing a drum or a belt into contact with the tip of the spew at a speed higher than a moving speed of the spew in the same direction as the rotation direction of the tire.   The tire spew trimming method according to claim 1, wherein the external force is applied by injecting fluid to the spew in a direction faster than a moving speed of the spew in the same direction as the rotation direction of the tire.   4. The tire spew trimming method according to claim 1, wherein an inclination angle of the spew with respect to a normal line of the tire surface when the cutting blade is brought into contact with the spew is set to 15 ° to 60 °. In a spew trimming apparatus for a tire that cuts the spew by contacting a cutting blade near the root of the spew while rotating a vulcanized tire having a plurality of spews formed on the surface,
A spew trimming apparatus for tires, wherein an external force applying means for inclining the spew toward the cutting blade is provided on the spew moving path.   The tire spew trimming device according to claim 5, wherein the external force applying means is a drum or a belt that contacts the tip of the spew at a speed faster than a moving speed of the spew in the same direction as the rotation direction of the tire.   6. The tire spew trimming device according to claim 5, wherein the external force applying means is a fluid ejection nozzle that ejects fluid to the spew at a speed higher than a moving speed of the spew in the same direction as the rotation direction of the tire.

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