JP2008087188A - Method for forming sipe forming blade, sipe forming blade formed using it, tire molding master model using tire molding blade and tire molded using tire molding master model - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sipe forming blade which provides a uniform product and is enhanced in durability. <P>SOLUTION: In the method for forming the sipe forming blade, a plurality of slits 15 opened on one edge sides thereof are formed to a thin-walled metal plate 10' at predetermined places by laser cutting, and the regions separated using the slits 15 as boundaries are alternately inclined in reverse directions by press processing to form alternately reverse inclined parts 12, 13 and 14 to the plate part 11 of the sipe forming blade 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for forming a sipe forming blade blade for forming a sipe groove in a tire tread portion in order to improve grip performance on a tire tread surface, a sipe forming blade formed using the method, and the tire formation The present invention relates to a tire molding master model using an industrial blade, and a tire molded using the tire molding master model.

  Conventionally, in winter tires such as snow tires and studless tires for running on icy and snowy roads, tire treads defined by tread grooves formed on the tire surface so as to intersect the tire circumferential direction and the tire width direction It is well known that a sipe groove extending in the tire width direction is formed in the portion.

  A plurality of sipe grooves are formed at predetermined or constant intervals along the tire circumferential direction to increase the flexibility of the tire tread portion and increase the actual contact area with respect to the road surface. As a result, the performance on ice and snow such as grip is ensured. Further, the performance on ice and snow improves as the conditions such as the number of sipe grooves formed as described above, that is, the edge density is increased.

  However, if the edge density is excessively increased, the rigidity of the tire tread portion is reduced, and the entire tire tread portion is collapsed and the entire function of the tire tread portion is deteriorated. On the other hand, if the edge density is reduced too much, the edge function of the sipe groove cannot be fully exhibited, and the above-described scratching effect is impaired.

Furthermore, by reducing the depth of the sipe groove, it is conceivable to increase the edge density while suppressing a decrease in rigidity of the tire tread portion. However, in this case, the sipe groove is worn out at an early stage, so that the edge function of the sipe groove cannot be maintained for a long period of time, and an early tire replacement is forced.
Thus, the performance on ice and snow greatly depends on conditions such as the number and depth of the sipe grooves.

  Therefore, as a sipe groove that maintains such high performance on ice and snow, a straight or wavy slit shape is formed on the tire surface, and a substantially Y-shaped (that is, reverse) cross section in the depth direction of the tire tread portion. Various types of sipe grooves having shapes have been proposed (see, for example, Patent Documents 1 to 3).

FIG. 5 is a cross-sectional view of a main part showing an example of such a sipe groove.
As shown in FIG. 5, the plurality of sipe grooves 2 formed in the tire tread portion 1 of a tire (entire drawing is omitted) has a depth direction on the paper surface as a tire width direction, extends in the tire width direction, and extends in the tire circumferential direction. Are formed adjacent to each other. Each sipe groove 2 is formed in a substantially Y shape downward in the drawing, that is, in the depth direction of the tire tread portion 1.

  By the way, in the sipe groove 2 formed so as to exhibit a substantially Y-shaped cross section on the same plane, if the distance W1 between adjacent lower ends (depths) is narrow, the gap between the adjacent sipe grooves 2 The part located in the region is easily excised (dropped). Therefore, the interval W2 between the sipe grooves 2 located on the tire surface, that is, the interval directly related to the edge density is widened, and it is practically difficult to ensure the edge density.

Therefore, as shown in FIG. 6B, the interval W3 between the adjacent sipe grooves 2 is narrowed by dividing the Y-shaped branching portion and forming the sipe grooves 2 so as to be alternately separated from each other. (For example, refer to Patent Document 4).
Further, such a sipe groove 2 can be easily formed by matching a sipe forming blade provided in the tire forming mold with the shape of the sipe groove 2.

  Therefore, as shown in FIG. 6A, the sipe forming blade 3 includes a plate portion 3a for forming a sipe groove surface portion made of a pressed product of a thin metal plate and opened to the tire surface of the sipe groove 2. The plate portion 3a is integrally provided with inclined portions 3b and 3c which are alternately inclined in opposite directions.

JP 2001-145921 A Japanese Patent No. 3145139 USP 5316063 Japanese Patent No. 3359000

By the way, in the sipe forming blade 3 configured as described above, the inclined portions 3b and 3c adjacent to each other are cut and raised on a single thin metal (for example, stainless steel) plate and simultaneously separated from each other. It can be formed by alternately bending in the direction.
However, when the sipe forming blade 3 is formed by a cutting and raising press (benting machine or the like), it extends to a broken portion (fracture surface) by the cooperation of an upper die and a lower die of a press die (not shown). Or return.

  Since the amount of such extension or return (see the edge-shaped portion surrounded by a circle in FIG. 7) slightly changes depending on the inclined portions 3b and 3c, the amount of spring back when the inclined portions 3b and 3c are bent. It also has a big impact. Therefore, even if the completed sipe forming blade 3 is a single sipe forming blade 3, the inclination angles of the inclined portions 3b and 3c are slightly different, and it is difficult to provide a uniform product. There was a problem.

  In addition, since the sipe forming blade 3 alternately forms three (6 in total) inclined portions 3b and 3c, the strength of the inclined portions 3b and 3c is low, and the tire forming mold is formed. When the tires are molded by mounting, there is a problem that the die durability is low with respect to the number of tires formed.

  In order to solve the above-mentioned problems, the present invention is capable of providing a uniform product, and is equipped with a sipe forming blade molding method, a sipe forming blade and a sipe forming blade capable of improving durability. The purpose is to provide a master model.

In order to achieve the object, the method for forming a sipe forming blade according to claim 1 is the method of forming a plurality of slits opened to one edge at a predetermined portion of a thin metal plate by laser cutting, and then forming the boundary between the slits. The parts separated as described above are alternately inclined in the opposite direction by press working.
The method for forming a sipe forming blade according to claim 2, wherein a plurality of slits that are open to one edge at a predetermined portion of a thin metal plate are formed by laser cutting, and the slits are equally divided. 4. The method of forming a sipe forming blade according to claim 3, wherein the portions equally divided with respect to the boundary are alternately inclined in the opposite direction by press working. Two slits to be opened are formed by laser cutting, and the portion near the one edge is divided into three equal parts, and then the parts divided into three equal parts with the slit as a boundary are alternately inclined in the reverse direction by pressing. And
The method for forming a sipe forming blade according to claim 4 includes a cutting step of laser cutting a plurality of slits opened to one edge on a thin metal plate that is rectangular in advance with a predetermined size, and this laser cutting An inclined machining step for setting the subsequent thin metal plate on a press die having a press working surface in which irregularities are alternately different between the upper die and the lower die, and alternately inclining the portions separated by the radar cutting in the opposite direction; It is characterized by having.
According to a fifth aspect of the present invention, there is provided a method of forming a sipe forming blade, wherein a plurality of slits that are open to one edge are formed by laser cutting at a predetermined portion of a thin metal plate, and the slits are equally divided. After the part equally divided as the boundary is alternately inclined in the reverse direction by pressing, at least a part located on the opposite side to the one edge of the thin metal plate so as to have a ridge line on the extension line of the slit It is characterized in that it is bent into a mountain shape in the end face direction.
A sipe forming blade according to claim 6 is formed by the sipe forming blade forming method according to any one of claims 1 to 5.
A tire molding master model according to a seventh aspect is characterized in that the sipe forming blade according to the sixth aspect is erected.
A tire according to an eighth aspect is characterized in that a sipe groove is formed in a tire tread portion using the tire molding master model according to the seventh aspect.

  According to the method for forming a sipe forming blade of the present invention, it is possible to provide a uniform product by alternately performing inclined press processing on a thin metal plate after laser cutting to form inclined portions in opposite directions, Moreover, durability can be improved.

Next, the sipe forming blade of the present invention will be described with reference to the drawings.
In FIG. 1A, reference numeral 10 denotes a sipe forming blade. The sipe forming blade 10 is integrally provided with a plate portion 11 positioned on the tire surface side and three inclined portions 12, 13, and 14 that are alternately inclined in the opposite direction from the plate portion 11.
The inclined portions 12, 13, and 14 are formed into tongue pieces that are divided into three equal parts, and the inclined angle from the plate portion 11 is bent uniformly or at a predetermined angle.

  The height of the plate portion 11 (in the depth direction of the sipe groove) and the height of the inclined portions 12, 13, and 14 are set according to the tire molded product. Further, the inclination angles of the inclined portions 12, 13, and 14 are also set according to the tire molded product.

  On the other hand, as shown in FIG. 1 (B), the inclined portions 12, 13, and 14 have slits 15 that are opened toward one edge in the unfolded thin metal plate 10 ′ at two equal position points. After the formation, as shown in FIG. The slit 15 is formed by a laser (including a jet water stream). Therefore, the cut surface is cut very sharply, and the slit 15 can be formed with no elongation or return at the cut portion.

The press die 20 includes uneven processing surfaces 23 and 24 that are alternately different from each other on both the upper die 21 and the lower die 22. When the thin metal plate 10 ′ after forming the slit 15 is set between the molds 21 and 22 in a positioned state, the processed surfaces 23 and 24 are directed from one edge side to the back side of the thin metal plate 10 ′. It is inclined to approach each other.
In such a press die 20, a plurality of slits 15 opened to one edge are laser-cut (jet-jet) at predetermined locations (preferably two locations, particularly preferably two equal locations) of the thin metal plate 10 ′ in advance. Including water flow cutting).

Next, a portion separated (preferably divided into three, particularly preferably divided into three equal parts) with the slit 15 as a boundary is set in the press die 20, and the inclined portions 12, 13, 14 is formed.
Here, the inclined portions 12, 13, and 14 are divided into three equal parts, considering the formation width (for example, 20 cm to 50 cm) of the tire tread portion 1 in the tire width direction, the edge function is fully exhibited. This is due to consideration of durability against abrasion and the like. Further, the inclination angles of the inclined portions 12, 13, and 14 (with respect to the plate portion 11) are determined in consideration of spring back when the press mold 20 is bent.

By the way, in the above-described embodiment, the sipe groove is described as being linear along the tire width direction. However, even when the sipe groove has a mountain shape extending in the tire width direction on the tire surface, the inclined portion is It is preferable to set it as a trisection point. At this time, it is preferable that the chevron-shaped ridge lines are three ridge lines positioned on the extension line of the slit 15 from the viewpoint of dimensional accuracy and strength at the time of press working, but it is not necessary to be particularly limited, and processing is possible. .
Further, a plurality of such sipe forming blades 10 are provided in a tire molding master model (not shown), and of course, a tire having a sipe groove is molded.

The sipe formation blade of this invention is shown, (A) is a perspective view of the sipe formation blade, (B) is a perspective view of the thin metal plate after slit formation. The press metal mold | die for bending the sipe formation blade of this invention is shown, (A) is a front view of the press metal mold | die before press work, (B) is a front view of the press metal mold after press work. is there. It is a side view of the press die before the press processing, showing the press die for bending the sipe forming blade of the present invention. The press metal mold | die for bending the sipe formation blade of this invention is shown, and is the press metal mold | die before press work. It is sectional drawing of the tire principal part which shows the relationship between a tire tread part and a sipe groove | channel. A conventional sipe forming blade is shown, (A) is a perspective view of the sipe forming blade, and (B) is an explanatory view showing a relationship between a tire tread portion and a sipe forming blade. It is explanatory drawing of the principal part of the blade for sipe formation.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Blade for sipe formation, 11 ... Plate part, 12 ... Inclined part, 13 ... Inclined part, 14 ... Inclined part, 15 ... Slit, 10 '... Thin metal Plate, 20 ... press mold.

Claims (8)

  A plurality of slits that are open to one edge at a predetermined portion of a thin metal plate are formed by laser cutting, and then the portions separated with the slit as a boundary are alternately inclined in the reverse direction by pressing. A method for forming a sipe forming blade.   A plurality of slits that are open to one edge at a predetermined location on a thin metal plate are formed by laser cutting, and the portions near the one edge are equally divided, and then the equally divided portions with the slit as a boundary are alternately reversed by pressing. A method for forming a sipe forming blade, wherein the blade is inclined in a direction.   Two slits that open to one edge of a thin metal plate at one edge are formed by laser cutting, and the part near the one edge is divided into three equal parts. A method for forming a sipe forming blade, wherein the blade is inclined in the opposite direction.   A cutting step for laser cutting a plurality of slits that are opened to one edge on a thin metal plate that is rectangular in advance with a predetermined size, and the upper and lower molds are uneven on the thin metal plate after laser cutting. Forming a sipe forming blade, characterized in that it comprises an inclined machining step for alternately inclining a portion separated by radar cutting in a press die having alternating press working surfaces. Method.   A plurality of slits that are open to one edge at a predetermined location of a thin metal plate are formed by laser cutting, and the portions near the one edge are equally divided, and the divided portions with this slit as a boundary are alternately reversed by pressing. And forming a sipe formed by bending at least a portion of the thin metal plate on the side opposite to the one edge so as to have a ridge line on the extended line of the slit. Blade forming method.   A sipe forming blade formed by the method for forming a sipe forming blade according to any one of claims 1 to 5.   A tire molding master model, wherein a plurality of sipe forming blades according to claim 6 are erected.   A tire comprising a plurality of sipe grooves formed in a tire tread portion using the tire molding master model according to claim 7.

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