JP2021070175A - Tire vulcanization mold - Google Patents

Abstract

To provide a tire vulcanization mold that does not easily cause a problem even if a stencil plate is repeatedly replaced.SOLUTION: The tire vulcanization mold in which a stencil plate 30 is arranged in a mounting recess part 20 is characterized in that a tire molding surface 14a for molding a tire, the mounting recess part 20 formed concave with respect to the tire molding surface 14a, the stencil plate 30 with a label forming part 31 formed on a front side, a spacer 40 arranged between a bottom surface 21 of the mounting recess part 20 and the stencil plate 30, a first connecting member 50 for connecting at least the stencil plate 30 and the spacer 40, and a second connecting member 51 for connecting the spacer 40 and the mounting recess part 20 are provided.SELECTED DRAWING: Figure 3

Description

The present invention relates to a tire vulcanization die.

Signs indicating the manufacturer name, manufacturing factory, size, manufacturing week, manufacturing year, etc. are formed on the side portion of the pneumatic tire. The sign is formed as a concave or convex on the surface of the side portion of the pneumatic tire.

In order to form such a label, an uneven stencil plate for forming the label is provided on the tire vulcanization die. Specifically, a recess is formed on the tire molding surface of the side plate or the like constituting the tire vulcanization mold, and the stencil plate is arranged in the recess. As described in Patent Document 1 and Patent Document 2, the stencil plate is fixed in the recess with screws.

Japanese Unexamined Patent Publication No. 2014-172660 Japanese Unexamined Patent Publication No. 2014-133402

By the way, the stencil plate is frequently replaced because the markings on the side of the pneumatic tire are changed frequently. As the stencil plate is repeatedly replaced, the screw holes in the recesses such as the side plate may be deformed. If the screw holes are deformed, the side plates and the like must be replaced.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a tire vulcanization die that does not easily cause a problem even if the stencil plate is repeatedly replaced.

In one aspect of the present invention, a tire molding surface for molding a tire, a mounting recess formed in a concave shape with respect to the tire molding surface, and a stencil plate having a label forming portion formed on the front side are provided, and the mounting is performed. In a tire vulcanization mold in which the stencil plate is arranged in the recess, a spacer arranged between the bottom surface of the mounting recess and the stencil plate, and at least a first connecting member for connecting the stencil plate and the spacer. A second connecting member for connecting the spacer and the mounting recess is provided.

According to the above-mentioned tire vulcanization die, even if the stencil plate is repeatedly replaced, problems such as the need to replace the side plate are unlikely to occur.

Sectional drawing of the tire vulcanization die of embodiment. The figure which looked at the side plate of an embodiment from the inside of a mold. Sectional drawing of mounting recess, spacer and stencil plate of embodiment. FIG. 2 is a cross-sectional view taken along the line XX of FIG. In this figure, the number and shape of the marker forming recesses are simplified with respect to FIG. FIG. 3 is an exploded view showing the mounting recess, spacer, and stencil plate of FIG. Partial side view of a pneumatic tire molded by the tire vulcanization die of the embodiment. Cross-sectional view of the mounting recess, spacer and stencil plate of the modified example. FIG. 2 is a cross-sectional view at a position corresponding to XX in FIG. FIG. 6 is a disassembled view of the mounting recess, spacer and stencil plate of FIG.

FIG. 1 shows the tire vulcanization die 10 of the present embodiment. The tire vulcanization die 10 includes a plurality of sectors 12 arranged in a circumferential shape, a pair of side plates 14 provided on both sides of the circumference formed by the plurality of sectors 12 in the axial direction, and a pair of bead rings. It has 16. The side plate 14 and the bead ring 16 are circular when viewed from the axial direction.

The sector 12, the side plate 14, and the bead ring 16 are molding members having molding surfaces 12a, 14a, 16a for molding a pneumatic tire (hereinafter referred to as "tire"). The molded surface 12a of the plurality of sectors 12 mainly serves as the tread portion of the tire, the molded surface 14a of the pair of side plates 14 mainly serves as the side portion of the tire, and the molded surface 16a of the pair of bead rings 16 mainly serves as the bead of the tire. Mold each part.

The material of the sector 12 is not limited, but is, for example, aluminum or an aluminum alloy (for example, an Al-Cu-based, Al-Mg-based, Al-Mn-based, or Al-Si-based alloy). The material of the side plate 14 and the bead ring 16 is not limited, but is, for example, a steel material such as a rolled steel material for general structure (for example, SS400). At the time of vulcanization molding, the sector 12, the side plate 14, and the bead ring 16 are heated to a vulcanization temperature (for example, 130 to 200 ° C.) by an electric heater (not shown) or high-temperature steam.

As shown in FIGS. 1 to 4, a stencil plate 30 is provided on the side plate 14. As a structure for mounting the stencil plate 30, the side plate 14 is formed with a concave mounting recess 20 (see FIG. 4) with respect to the molding surface 14a. A stencil plate 30 and a spacer 40 are provided in the mounting recess 20. The spacer 40 is provided between the bottom surface 21 of the mounting recess 20 and the stencil plate 30.

The stencil plate 30 is a plate-shaped member having a front surface 33 for molding the front surface of the tire and a back surface 34 (see FIG. 4) thereof. The material of the stencil plate 30 is not limited, but is, for example, aluminum or an aluminum alloy. The thickness t1 of the stencil plate 30 (see FIG. 4) is, for example, 0.4 to 0.6 mm. As shown in FIG. 2, the stencil plate 30 has an elongated shape that is extended so as to be curved along the circumferential direction of the side plate 14 when viewed from the surface 33 side.

On the surface 33 near the center of the stencil plate 30 in the extension direction, a plurality of recesses (hereinafter referred to as “label forming recesses 31”) as label forming portions are formed side by side. As shown in FIG. 5, these sign forming recesses 31 are recesses for forming the label M on the side portion of the tire T. The sign M is formed by arranging letters, symbols, figures, and the like, and represents a part or all of the manufacturer name, manufacturing factory, size, manufacturing week, manufacturing year, and the like as a whole. When the stencil plate 30 is viewed from the surface 33 side (that is, when FIG. 2 is viewed), the plurality of label forming recesses 31 have a shape in which the label M is inverted as a whole.

The sign forming recess 31 is formed by pressing to sink a part of a flat plate-shaped member. Therefore, on the back surface 34 side of the stencil plate 30, a bulging portion 32 corresponding to the sign forming recess 31 appears. The depth t2 (see FIG. 4) of the sign forming recess 31 is, for example, 0.2 to 0.8 mm, and the height of the bulge of the bulging portion 32 is equivalent to the depth of the marking forming recess 31.

Screw holes 35 penetrating the stencil plate 30 are formed on both sides of the stencil plate 30 in the extension direction. The screw hole 35 is a circular hole whose diameter gradually decreases toward the spacer 40 side, and has a shape in which the head of a countersunk screw fits.

The spacer 40 is a plate-shaped member having the same shape as the stencil plate 30 when viewed from the stencil plate 30 side. The material of the spacer 40 is not limited, but is stainless steel such as SUS631. At room temperature, that is, at 5 to 35 ° C., the area of the spacer 40 (the area of the surface parallel to the molding surface 14a) may be the same as the area of the stencil plate 30, but may be smaller than the area of the stencil plate 30. Note that FIG. 3 shows an example in which the area of the spacer 40 is smaller than the area of the stencil plate 30.

Convex portions 42 that are convex toward the stencil plate 30 are formed on both sides of the spacer 40 in the extension direction. The surface of the convex portion 42 on the stencil plate 30 side is in contact with the back surface 34 of the stencil plate 30 as shown in FIG. Further, a concave portion 41 that is concave with respect to the convex portion 42 is formed between the two convex portions 42. Further, the back surface of the spacer 40 (the surface of the mounting recess 20 on the bottom surface 21 side) 44 has one flat surface as a whole, and is in contact with the bottom surface 21 of the mounting recess 20 as shown in FIG. The thickness t3 of the spacer 40 at the convex portion 42 (see FIG. 4) is, for example, 1.1 to 1.3 mm, and the thickness t4 of the spacer 40 at the concave portion 41 (see FIG. 4) is, for example, 0.5 to 0.7 mm. Is.

The location of the recess 41 is a location on the back side of the marker forming recess 31 of the stencil plate 30, that is, a location facing the bulging portion 32 of the stencil plate 30. Further, the depth of the recess 41 is equal to or greater than the bulging height of the bulging portion 32 of the stencil plate 30. Therefore, in a state where the back surface 34 of the stencil plate 30 and the convex portion 42 of the spacer 40 are in contact with each other, the bulging portion 32 of the stencil plate 30 is contained in the concave portion 41 of the spacer 40. The bulging portion 32 and the recess 41 may or may not be in contact with each other.

First screw holes 45 penetrating the spacer 40 are formed on both sides of the spacer 40 in the extension direction. The first screw hole 45 is formed in the convex portion 42 of the spacer 40. Further, the first screw hole 45 is formed at a position corresponding to the screw hole 35 of the stencil plate 30 in the vertical direction (direction perpendicular to the surface 33 of the stencil plate 30). Further, a second screw hole 46 different from the first screw hole 45 described above is also provided at two positions of the recess 41 of the spacer 40. The second screw hole 46 also penetrates the spacer 40.

The spacer 40 preferably has a higher hardness than the stencil plate 30. Further, the spacer 40 preferably has a smaller coefficient of thermal expansion than the stencil plate 30. If the spacer 40 is made of stainless steel and the stencil plate 30 is made of aluminum as illustrated above, the spacer 40 has a higher hardness and a lower coefficient of thermal expansion than the stencil plate 30.

As shown in FIG. 3, the stencil plate 30 and the spacer 40 are housed in the mounting recess 20 of the side plate 14. The surface 33 of the stencil plate 30 and the molding surface 14a of the side plate 14 are flush with each other. The depth t5 (see FIG. 4) of the mounting recess 20 is, for example, 1.5 to 1.9 mm.

The mounting recess 20 has the same shape as the stencil plate 30 when viewed from a direction perpendicular to the bottom surface 21. The area of the mounting recess 20 at the open end 20a (that is, the position where the stencil plate 30 fits, in other words, the position where it contacts the edge of the stencil plate 30) is not limited, but is larger than the area of the spacer 40 at room temperature, for example. It is smaller than the area of the plate 30.

According to the area relationship of this example, when the operator mounts the stencil plate 30 in the mounting recess 20 at room temperature, the stencil plate 30 having a larger area than the mounting recess 20 is pushed into the mounting recess 20 with force. become. The pushed stencil plate 30 is plastically deformed and enters the mounting recess 20, so that no gap is formed between the stencil plate 30 and the open end 20a of the mounting recess 20.

The area of the mounting recess 20 at the open end 20a may be larger than the area of the stencil plate 30 at room temperature. In that case, at room temperature, a slight gap is formed between the open end 20a of the mounting recess 20 and the stencil plate 30. However, at the vulcanization temperature, the stencil plate 30 expands, and the area of the mounting recess 20 at the open end 20a becomes the same as the area of the stencil plate 30. As a result, the gap between the stencil plate 30 and the open end 20a of the mounting recess 20 that occurs at room temperature is closed at the vulcanization temperature.

As shown in FIG. 4, first pilot holes 25 are formed on the bottom surfaces 21 on both sides of the mounting recess 20 in the extension direction. The first pilot hole 25 is formed at a position that coincides with the screw hole 35 of the stencil plate 30 and the first screw hole 45 of the spacer 40 in the vertical direction.

Further, on the bottom surface 21 of the mounting recess 20, two second pilot holes 26 different from the first pilot hole 25 are formed at a location between the two first pilot holes 25. The second pilot hole 26 is formed at a position corresponding to the second screw hole 46 of the spacer 40.

One first screw 50 as a first connecting member is passed through the screw hole 35 of the stencil plate 30, the first screw hole 45 of the spacer 40, and the first pilot hole 25 of the mounting recess 20. As a result, the stencil plate 30 is connected to the spacer 40, and is further connected to the mounting recess 20.

The first screw 50 is a countersunk screw, the head 52 thereof fits into the screw hole 35 of the stencil plate 30, and the surface 52a of the head 52 and the surface 33 of the stencil plate 30 are flush with each other. Further, the threaded portion 53 of the first screw 50 is screwed into the first screw hole 45 of the spacer 40 and the first pilot hole 25 of the mounting recess 20.

Further, one second screw 51 as a second connecting member is passed through the second screw hole 46 of the spacer 40 and the second pilot hole 26 of the mounting recess 20. As a result, the spacer 40 is connected to the mounting recess 20.

When the pneumatic tire is vulcanized and molded by the tire vulcanizing die 10 having the above structure, an unvulcanized tire (not shown) is set inside the tire vulcanizing die 10 as shown in FIG. .. Then, the bladder (not shown) arranged inside the set unvulcanized tire expands, and the surface of the unvulcanized tire is pressed against the inner surface of the mold (molding surface of the molding member). In this state, the side plate 14 and the like of the tire vulcanization die 10 are held at the above vulcanization molding temperature, and the unvulcanized tire is vulcanized.

As shown in FIG. 5, a label M is formed on the tire T after vulcanization molding by the stencil plate 30. Since the label forming recess 31 of the stencil plate 30 is a recess as described above, the label is formed as a convex portion on the tire T after vulcanization molding.

Then, when changing the tire sign, the operator pulls out the first screw 50 from the screw hole 35 of the stencil plate 30, the first screw hole 45 of the spacer 40, and the first pilot hole 25 of the mounting recess 20, and the stencil. Remove only the plate 30. Then, the operator places the new stencil plate 30 on the spacer 40 in the mounting recess 20, passes the first screw 50 through the stencil plate 30, the spacer 40 and the mounting recess 20, and mounts the new stencil plate 30.

At this time, the operator does not need to remove the second screw 51 and the spacer 40 in order to replace the stencil plate 30. However, if the spacer 40 is deformed while the stencil plate 30 is repeatedly replaced, the operator pulls out the second screw 51 to remove the spacer 40 and replaces it with a new spacer 40.

According to the above embodiment, since the spacer 40 is sandwiched between the bottom surface 21 of the mounting recess 20 and the stencil plate 30, the operator strongly tightens the first screw 50 when mounting the stencil plate 30. However, the force is dispersed throughout the spacer 40. Therefore, it is difficult for a large force to act between the first screw 50 and the first pilot hole 25 of the mounting recess 20, and the first pilot hole 25 is less likely to be deformed.

Further, even if the first pilot hole 25 is deformed, if the first screw hole 45 of the spacer 40 is not deformed, the operator can fix the stencil plate 30 to the spacer 40, whereby the stencil plate 30 can be fixed. Can be attached to the side plate 14.

Further, according to the present embodiment, it is not necessary to remove the spacer 40 when replacing the stencil plate 30, and it is not necessary to remove the second screw 51 connecting the spacer 40 to the mounting recess 20, so that the mounting recess 20 does not need to be removed. The second pilot hole 26 is not easily deformed.

For these reasons, even if the stencil plate 30 is repeatedly replaced, problems such as the need to replace the side plate 14 are unlikely to occur.

Further, since the sign forming recess 31 of the stencil plate 30 is a recess and the sign is formed as a convex portion on the tire, the visibility of the sign is good. In addition, there is a recent demand that the sign should be formed as a convex portion, and the demand can be met.

Further, the spacer 40 is formed with a convex portion 42 toward the stencil plate 30 side and a concave portion 41 with respect to the convex portion 42, and the convex portion 42 is formed at a connecting portion with the stencil plate 30 by the first screw 50, and the concave portion 41 is formed. Is formed at a location on the back side of the marker forming recess 31 of the stencil plate 30. Due to this configuration, the bulging portion 32 of the stencil plate 30 fits inside the recess 41 of the spacer 40. Therefore, it is possible to prevent the bulging portion 32 of the stencil plate 30 from being pushed by the spacer 40 and the stencil plate 30 from floating.

Further, since the area of the spacer 40 is smaller than the area of the stencil plate 30, it is easy to put the spacer 40 in and out of the mounting recess 20, and there is a gap between the stencil plate 30 and the opening end 20a of the mounting recess 20. Is unlikely to occur.

Further, since the hardness of the spacer 40 is higher than the hardness of the stencil plate 30, the spacer 40 is not easily deformed and can withstand long-term use, and the stencil plate 30 can be easily attached to and detached from the attachment recess 20.

Further, since the coefficient of thermal expansion of the spacer 40 is smaller than the coefficient of thermal expansion of the stencil plate 30, the stencil plate 30 expands during vulcanization molding so that the stencil plate 30 can be brought into close contact with the opening end 20a of the mounting recess 20. It is possible to prevent the spacer 40 from thermally expanding and hitting the inner wall of the mounting recess 20 to damage the mounting recess 20.

The above embodiments are examples, and the scope of the invention is not limited to the above embodiments. Various changes can be made to the above embodiments without departing from the spirit of the invention. Although a plurality of modification examples will be described below, any one of the plurality of modification examples may be applied to the above embodiment, or any two or more of the plurality of modification examples may be combined. May be applied.

(Change example 1)
In the modified examples shown in FIGS. 6 and 7, the same stencil plate 30 as that of the above embodiment is used, but the spacer and the mounting recess are different from those of the above embodiment.

In the spacer 140 of this modified example, instead of the first screw hole 45 of the spacer 40 in the above embodiment, as shown in FIG. 7, a screw hole 145 that does not penetrate the spacer 40 and is terminated in the middle is formed. .. Further, the mounting recess 120 of this modified example does not have a hole corresponding to the first pilot hole 25 of the mounting recess 20 of the above embodiment.

The spacer 140 is connected to the mounting recess 120 by the second screw 51, which is the same as that of the above embodiment. However, in the present embodiment, the first screw 150 as the first connecting member connects only the stencil plate 30 and the spacer 140. It is connected.

In this modification, since the first screw 150 has not reached the side plate 14, even if the stencil plate 30 is frequently replaced, it does not affect the side plate 14 and the side plate 14 is damaged. Hateful.

(Change example 2)
The molding member on which the stencil plate 30 is provided is not limited to the side plate 14. For example, the bead ring 16 may be provided with a mounting recess 20, a spacer 40, and a stencil plate 30 in the same manner as in the above embodiment.

(Change example 3)
The sign forming portion of the stencil plate may be formed as a convex portion contrary to the above embodiment. When the marking forming portion of the stencil plate is a convex portion, the marking on the side portion of the tire is formed as a concave portion.

(Change example 4)
The mold is not limited to the one provided with the sector 12, the side plate 14, and the bead ring 16 as in the above embodiment. For example, there is known a mold composed of an upper mold and a lower mold, and the entire outer surface of the tire including a tread portion is molded by two molds, an upper mold and a lower mold. In such a mold, a stencil plate may be provided with the same configuration as that of the above embodiment.

(Change example 5)
At least the first connecting member that connects the stencil plate 30 and the spacer 40 may be any one that can connect them, and is not limited to the screw as in the above embodiment. Further, the second connecting member that connects the spacer 40 and the mounting recess 20 is not limited to the screw as in the above embodiment.

T ... Tire, M ... Mark, 10 ... Tire sulfide mold, 12 ... Sector, 12a ... Molded surface, 14 ... Side plate, 14a ... Molded surface, 16 ... Bead ring, 16a ... Molded surface, 20 ... Mounting recess, 20a ... Open end, 21 ... Bottom surface, 25 ... First pilot hole, 26 ... Second pilot hole, 30 ... Stencil plate, 31 ... Mark forming recess, 32 ... Swelling part, 33 ... Front surface, 34 ... Back surface, 35 ... Screw holes, 40 ... spacers, 41 ... concaves, 42 ... convex parts, 44 ... backsides, 45 ... first screw holes, 46 ... second screw holes, 50 ... first screws, 51 ... second screws, 52 ... heads , 53 ... Threaded part, 120 ... Mounting recess, 140 ... Spacer, 145 ... Screw hole, 150 ... First screw

Claims (6)

A tire molding surface for molding a tire, a mounting recess formed concavely with respect to the tire molding surface, and a stencil plate having a sign forming portion formed on the front side are provided, and the stencil plate is arranged in the mounting recess. In the tire vulcanization mold
A spacer arranged between the bottom surface of the mounting recess and the stencil plate, at least a first connecting member that connects the stencil plate and the spacer, and a second connecting member that connects the spacer and the mounting recess. A tire vulcanization die characterized by being provided with. The spacer is formed with a convex portion toward the stencil plate side and a concave portion with respect to the convex portion.
The convex portion is formed at the connecting portion with the stencil plate by the first connecting member.
The recess was formed at a location on the back side of the sign forming portion.
The tire vulcanization die according to claim 1. The tire vulcanization die according to claim 1 or 2, wherein the first connecting member connects only the stencil plate and the spacer. The tire vulcanization die according to any one of claims 1 to 3, wherein the spacer has a smaller area than the stencil plate. The tire vulcanization die according to any one of claims 1 to 4, wherein the spacer has a hardness higher than that of the stencil plate. The tire vulcanization die according to any one of claims 1 to 5, wherein the spacer has a smaller coefficient of thermal expansion than the stencil plate.

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