JP2021084329A - Tire vulcanization mold, method for manufacturing tire vulcanization mold, and method for manufacturing tire - Google Patents

Abstract

To provide a tire vulcanization mold capable of ensuring discriminability of a sign on a tire after vulcanization molding, and suppressing poor appearance.SOLUTION: A tire vulcanization mold has: a tire molding surface; a mounting groove provided on the tire molding surface; and an unevenness formation portion for forming unevenness on a tire outer surface. The tire vulcanization mold comprises: a stencil plate mounted on the mounting groove; a screw for fixing the stencil plate on the mounting groove; and a bottom-up portion positioned between a bottom surface of the mounting groove and a region excluding the unevenness formation portion of the stencil plate. The bottom-up portion includes a first region positioned at a place that surrounds the screw.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to a tire vulcanization die, a method for manufacturing a tire vulcanization die, and a method for manufacturing a tire.

Conventionally, a tire is vulcanized using a tire vulcanization mold in which a stencil plate (also referred to as a "cerial plate") is fixed in a mounting groove on the tire molding surface, and an uneven sign is formed on the outer surface of the tire. There are known ways to do this. Here, as a method of fixing the stencil plate to the mounting groove, a method of using a screw is known (see Patent Document 1).

When fixing the stencil plate to the mounting groove using screws, if the tightening force of the screw is too large, the stencil plate will be pulled into the tightened screw and the stencil plate will be in a bent or tilted state. There was something. If the tire is vulcanized in such a state, rubber flows from the gap between the stencil plate and the mounting groove, which is enlarged due to inclination or bending, and a pinch or burr is formed on the tire after vulcanization. The burr is an excess film formed on the tire surface, which causes a decrease in the distinctiveness of the sign. A pinch is an unintended step that occurs on the surface of a tire and causes a poor appearance of the tire.

Japanese Unexamined Patent Publication No. 2014-172360

An object of the present disclosure is to provide a tire vulcanization die, a method for manufacturing a tire vulcanization die, and a method for manufacturing a tire, which can secure the distinctiveness of a label on a tire after vulcanization molding and suppress an appearance defect. is there.

The tire vulcanization die of the present disclosure includes a tire molding surface and
The mounting groove provided on the tire molding surface and
A stencil plate having a concavo-convex forming portion that forms concavities and convexities on the outer surface of the tire and mounted in the mounting groove,
With screws for fixing the stencil plate to the mounting groove,
A bottom raising portion located between the bottom surface of the mounting groove and the region of the stencil plate excluding the uneven forming portion is provided.
The bottom raising portion includes a first region located at a location surrounding the screw.

In the method for manufacturing a tire vulcanization die of the present disclosure, a stencil plate for forming irregularities on the outer surface of a tire is fixed to a mounting groove provided on a tire molding surface by using a screw. In the mold manufacturing method
Before or when mounting the stencil plate in the mounting groove, a bottom raising portion is formed in the mounting groove.
The bottom raising portion includes a first region located at a location surrounding the screw.

The tire manufacturing method of the present disclosure uses the tire vulcanization mold described above or the tire vulcanization mold manufactured by the tire vulcanization mold manufacturing method described above to vulcanize the tire. Includes molding process.

With the above configuration, it is possible to provide a tire vulcanization die, a method for manufacturing a tire vulcanization die, and a method for manufacturing a tire, which can enhance the distinctiveness of a label on a tire after vulcanization molding and suppress an appearance defect.

Cross-sectional view of the tire vulcanization die along the tire meridian cross section Top view of X arrow in FIG. Sectional view on line C1 in FIG. A cross-sectional view schematically showing a state before the stencil plate of FIG. 2 is mounted in the mounting groove. Top view showing an example of the bottom raising part Enlarged view of part E in FIG. Enlarged view of part F in FIG. The figure explaining the 2nd Embodiment of the bottom raising part The figure explaining the modification of the 2nd Embodiment of the bottom raising part The figure explaining the 3rd Embodiment of the bottom raising part The figure explaining the modification of the 3rd Embodiment of the bottom raising part. The figure which shows the example of the method of fixing a spacer in a mounting groove. The figure which shows the example of the method of fixing a spacer in a mounting groove. The figure which shows the method of fixing a stencil plate with a spacer in a mounting groove. The figure which shows the bottom raising part integrated with a mold

Hereinafter, embodiments will be described with reference to the drawings. In each drawing, the dimensional ratio of the drawings and the actual dimensional ratio do not always match, and the dimensional ratios between the drawings do not necessarily match.

<First Embodiment>

A tire vulcanization die used for vulcanization molding of a tire will be described with reference to FIG. FIG. 1 shows a cross section of a tire vulcanization die 10 (hereinafter referred to as a die 10) along a cross section of the tire meridian. The mold 10 is in the mold closed state. The tire T is set with the tire width direction facing up and down. In FIG. 1, the left direction is the outside in the tire radial direction, and the right direction is the inside in the tire radial direction.

In the mold 10, a tread mold portion 11 for molding the tread portion of the tire T, a pair of side mold portions (12, 13) for molding the sidewall portion of the tire T, and a bead portion of the tire T are fitted. It includes a pair of bead rings (14, 15). The mold 10 includes a tire molding surface 1 in contact with the outer surface of the tire T set in the cavity 16. The tire molding surface 1 includes an inner surface of the tread mold portion 11, an inner surface of the side mold portions (12, 13), and an inner surface of the bead ring (14, 15). Although not shown, the inner surface of the tread mold portion 11 is provided with an uneven portion for forming a tread pattern on the tread surface of the tire T.

An aluminum material is exemplified as the material of the inner surface of the tread mold portion 11. This aluminum material is a concept that includes not only pure aluminum-based materials but also aluminum alloys. For example, Al-Cu-based, Al-Mg-based, Al-Mg-Si-based, Al-Zn-Mg-based, and Al-Mn-based. , Al-Si system can be mentioned. Examples of the material of the inner surface of the side mold portion (12, 13) and the inner surface of the bead ring (14, 15) include a steel material such as a rolled steel material for general structure (for example, SS400).

The mold 10 has a tire molding surface 1 in contact with the outer surface of the tire T set in the cavity 16, a mounting groove 2 provided on the tire molding surface 1, and a concave-convex forming portion forming irregularities on the outer surface of the tire T. It is provided with a stencil plate 3 to be mounted in the mounting groove 2. The mounting groove 2 is provided by locally recessing a part of the tire molding surface 1. In the present embodiment, the mounting groove 2 is provided on the inner surface of the side mold portion 12 which is the tire molding surface 1.

FIG. 2 is a plan view taken along the line X of FIG. 1, showing a stencil plate 3 fitted in a mounting groove 2 on the inner surface of a side mold portion 12 located on the lower side of FIG. In FIG. 2, the left-right direction corresponds to the tire circumferential direction, the upward direction is the outside in the tire radial direction, and the downward direction is the inside in the tire radial direction.

The stencil plate 3 has an unevenness forming portion 5 which is a region capable of forming unevenness on the outer surface of the tire. The unevenness formed on the outer surface of the tire indicates, for example, a sign consisting of characters or symbols indicating the tire size, road index, manufacturer name, year and week of manufacture, or a pattern or design. The unvulcanized tire is pressed against the stencil plate 3 mounted in the mounting groove 2 of the tire molding surface 1 of the mold 10, and the unevenness of the unevenness forming portion 5 is transferred to the tire surface after vulcanization molding. FIG. 2 shows an example in which a sign consisting of the character string “TT” is formed in the recess 34. Details of the recess 34 will be described later.

The stencil plate 3 is detachably mounted in the mounting groove 2 via a screw 4. When the stencil plate 3 is a sign indicating the year and week of manufacture, the stencil plate 3 is replaced regularly.

In the present disclosure, the screw 4 refers to all fastening elements having a rod provided with a spiral groove and a head provided at one end of the rod, and includes bolts and screws. In the present embodiment, the top surface of the screw 4 has a cross-shaped recess for inserting the tip of a Phillips screwdriver, but the screw 4 is not limited to this. For example, the top surface of the screw 4 may have a ground-shaped recess for inserting the tip of a flat-blade screwdriver or a hexagonal recess for inserting the tip of a hexagon wrench. Further, it does not have to have such a recess. For example, the screw head when viewed from the screw head side may be formed in a hexagonal shape, and the hexagonal screw head may be turned.

The mounting groove 2 and the stencil plate 3 may have a horizontally long shape in which the length in the tire circumferential direction is larger than the width in the tire radial direction. In the present embodiment, the longitudinal LD of the mounting groove 2 and the stencil plate 3 is in the direction along the tire circumferential direction, and the width direction WD is in the direction along the tire radial direction. In the present embodiment, the mounting groove 2 and the stencil plate 3 have a shape curved in an arc shape along the tire circumferential direction, but the shape is not limited to this, and the longitudinal LD may be linearly extended.

The length L3 of the longitudinal LD of the stencil plate 3 is slightly smaller than the length L2 of the longitudinal LD of the mounting groove 2. The width W3 of the width direction WD of the stencil plate 3 is slightly smaller than the width W2 of the width direction WD of the mounting groove 2. Therefore, it is difficult for rubber to enter through the gap between the mounting groove 2 and the stencil plate 3. The width W5 of the WD in the width direction of the unevenness forming portion 5 represents the width at which the unevenness can be formed on the stencil plate 3.

The stencil plate 3 mounted in the mounting groove 2 will be described with reference to FIGS. 3 and 4. FIG. 3 shows a cross-sectional view taken along the line C1 in FIG. FIG. 4 shows a cross section of the line C1 in FIG. 2 before mounting the stencil plate 3 in the mounting groove 2. The line C1 is a line passing through the center of the mounting groove 2 or the stencil plate 3 in the width direction WD. In FIGS. 3 and 4, the left-right direction corresponds to the longitudinal LD of the mounting groove 2 and the stencil plate 3.

The stencil plate 3 has through holes 39 for attaching the screws 4 at both ends of the longitudinal LD. The screw 4 is screwed into the female screw of the hole 24 on the bottom surface 21 of the mounting groove 2 through the through hole 39. Looking at FIG. 3, the top surface of the screw 4 is arranged substantially flush with the tire molding surface 1, but the present invention is not limited to this, and for example, the top surface of the screw 4 may be brought close to the bottom surface 21 of the mounting groove 2. The groove depth D2 of the mounting groove 2 is set to, for example, 1.2 mm.

In the present embodiment, a counterbore 25 is provided around the hole 24 on the bottom surface 21 of the mounting groove 2. By providing the counterbore 25, when the screw 4 is tightened, the screw 4 can be stably supported and the screw tightening work is facilitated. The peripheral region 38 of the through hole 39 in the stencil plate 3 is formed by being tapered in a tapered shape, and the bottom surface 41 of the head of the screw 4 is formed in a tapered shape so as to correspond to the counterbore 25.

The stencil plate 3 has a front surface 31 facing the cavity 16 and a back surface 32 facing the bottom surface 21 of the mounting groove 2. At the time of vulcanization molding, the outer surface of the tire T is pressed against the front surface 31 of the stencil plate 3, and a label is formed on the outer surface of the tire T by transfer. The front surface 31 is preferably arranged flush with the tire molding surface 1. The front surface 31 may have a step between the front surface 31 and the tire molding surface 1 as long as the pinch of the transferred tire T is not a concern.

In the present embodiment, the front surface 31 is provided with a recess 34 for forming a convex sign on the outer surface of the tire. The recess 34 is formed by being depressed by, for example, embossing (embossing method) from the front 31 side. The back surface 32 has a convex portion 36 corresponding to the concave portion 34. The convex portion 36 is formed as a result of the concave portion 34 being depressed and formed. Therefore, the convex portion 36 is a view of the concave portion 34 from the back surface 32 side of the stencil plate 3. When the stencil plate 3 is mounted in the mounting groove 2, the convex portion 36 of the stencil plate 3 may be configured to be in contact with the bottom surface 21 of the mounting groove 2.

The stencil plate 3 in the present embodiment is for forming a convex sign on the outer surface of the tire, but is not limited to this, and is a stencil plate for forming a concave sign or pattern on the outer surface of the tire. But it doesn't matter.

The stencil plate 3 may be formed of a metal plate material such as stainless steel or aluminum. The thickness T3 (see FIG. 4) of the stencil plate 3 is preferably 0.6 mm or less from the viewpoint of ease of processing and the like. The thickness T3 is preferably 0.3 mm or more from the viewpoint of imparting appropriate strength to the stencil plate 3.

The bottom raising portion 6 is located between the bottom surface 21 of the mounting groove 2 and the region of the stencil plate 3 excluding the unevenness forming portion 5 (details of the unevenness forming portion 5 will be described later). The bottom raising portion 6 is used to partially raise the bottom surface 21 on which the stencil plate 3 is placed (that is, to position the bottom surface 21 inside in the tire width direction (cavity 16 side)). The thickness T6 of the bottom raising portion 6 is smaller than the groove depth D2 of the mounting groove 2. The thickness T6 is, for example, preferably 0.6 mm or more, and preferably 0.9 mm or less.

In the present embodiment, the bottom raising portion 6 is configured as a spacer 6a separate from the mounting groove 2 and the stencil plate 3. The method of attaching the spacer 6a to the mounting groove 2 to form the bottom raising portion 6 has an advantage that the bottom raising portion 6 can be formed even with an existing mold. The spacer 6a is not particularly limited as long as it is a material capable of raising a part of the bottom surface 21 of the mounting groove 2, but it is preferably made of a metal such as stainless steel. Although the details will be described later, the spacer 6a is arranged at a place where it does not interfere with the unevenness forming portion 5. The length L5 shown in FIG. 3 represents the length between both end edges of the unevenness forming portion 5 in the longitudinal direction LD.

FIG. 5 shows the spacer 6a shown in FIG. 4 in a plan view. The spacer 6a has a frame shape having a through hole in the center. In the present embodiment, the length L6 of the longitudinal LD of the spacer 6a is formed to be smaller than the length L2 of the longitudinal LD of the mounting groove 2, and the length W6 of the width direction WD of the spacer 6a is the width direction of the mounting groove 2. It is formed smaller than the width W2 of the WD. In this embodiment, the spacer 6a includes a first region (S1, S3) located at a location surrounding the screw 4 (not shown in FIG. 5).

The first region S1 of the spacer 6a will be described. The first region S1 is located at a location surrounding the head of the screw 4 and the outside of the peripheral region 38 (see FIG. 4) of the stencil plate 3. If the tightening force of the screw 4 is too large when fixing the stencil plate 3 to the mounting groove 2, the portion of the stencil plate 3 surrounding the screw 4 may be pulled in and the stencil plate 3 may bend or tilt. In particular, in the stencil plate 3 that forms a convex sign on the outer surface of the tire, the ratio of the area of the convex portion 36 in contact with the bottom surface 21 to the area of the uneven forming portion 5 is small, so that the stencil plate 3 is the whole. It tends to float without being supported by the bottom surface 21, which tends to cause bending and inclination. However, since the first region S1 of the bottom raising portion 6 composed of the spacer 6a supports the stencil plate 3 located at a position surrounding the screw 4, even if the tightening force of the screw 4 is too large, the stencil plate 3 The bending and tilting of the stencil plate 3 can be suppressed without being drawn into the screw 4.

The shape of the first region S1 of the spacer 6a will be described with reference to FIG. FIG. 6 is an enlarged view of part E in FIG. The first region S1 is a region sandwiched between an outer peripheral 61 close to the inner wall of the end portion of the mounting groove 2 and an inner peripheral 62 located inside the outer peripheral 61 and close to the screw 4 (not shown in FIG. 6). It has a C-shape. This shape was obtained as a result of the following diligent research by the present inventor.

The bottom raising portion 6 formed of the spacer 6a fixed to the mounting groove 2 needs to avoid the uneven forming portion 5 so as not to come into contact with the convex portion 36 of the stencil plate 3. When the area of the bottom raising portion 6 is expanded, the range in which the bottom raising portion 6 supports the stencil plate 3 is expanded, and the effect of suppressing the pulling in of the stencil plate 3 is increased. However, in that case, the region of the unevenness forming portion 5 must be reduced in order to prevent the unevenness forming portion 5 from interfering with the bottom raising portion 6. On the other hand, the larger the region of the unevenness forming portion 5, the larger the sign or the like can be formed.

The present inventor has adopted a C-shaped first region in order to solve two contradictory problems of expanding the region of the bottom raising portion 6 and securing the region of the unevenness forming portion 5. In the present specification, the C-shape represents a shape in which one direction of the ring is missing and is open, and the opening angle α is larger than 0 degrees and smaller than 180 degrees. The opening angle α means an angle formed between a straight line from the point O at the center of the open ring to one end of the ring and a straight line from the point O to the other end of the ring. In the present embodiment, the C-shaped bottom raising portion 6 is formed along the inner wall of the end portion of the mounting groove 2, and the C-shaped open portion is located on the unevenness forming portion 5 side.

Since the C-shaped bottom raising portion 6 surrounds the screw 4 in a wide range, the effect of suppressing the pulling of the stencil plate 3 due to the excessive tightening force of the screw 4 is large. Further, since the C-shaped open portion is located on the unevenness forming portion 5, the uneven forming portion 5 is raised to a position close to the head of the screw 4 and the peripheral region 38 (see FIG. 4) of the stencil plate 3. This makes it possible to increase the length L5 (see FIG. 3) of the LD in the longitudinal direction of the unevenness forming portion 5 without interfering with the portion 6. Therefore, the unevenness forming portion 5 can be widely secured while enhancing the pull-in suppressing effect of the stencil plate 3. The opening angle α is preferably 30 degrees or more, and more preferably 45 degrees or more. The opening angle α is preferably 80 degrees or less, and more preferably 65 degrees or less.

The shape of the outer circumference 61 may be similar to the shape of the inner wall at the end of the mounting groove 2. The inner circumference 62 has an arc shape centered on the point O in FIG. 6, but the shape of the inner circumference 62 is not particularly limited. The inner circumference 62 may have an inner diameter larger than that of the screw 4 so as not to come into contact with the screw 4.

As seen in FIG. 6, the first region S1 may have protrusions (P1, P2) protruding inward from the outside of the widthwise WD of the bottom raising portion 6. The protrusions (P1, P2) are formed between the inner circumference 62 and the connecting line 66 connected to the inner edge 65 of the second region S2, which will be described later. By providing the protrusions (P1, P2), the range surrounding the screw 4 is expanded, and the pull-in suppressing effect of the stencil plate 3 is increased. Since the protrusions (P1, P2) are located at positions where the unevenness forming portion 5 does not interfere with each other, even if the protrusions (P1, P2) are provided, the unevenness forming portion 5 is not reduced.

FIG. 7 is an enlarged view of the F portion in FIG. In the present embodiment, as shown in FIG. 7, the tip 67 of the protrusion P1 has a rounded chamfered shape. The chamfered shape, for example, has a radius of 0.1 mm or more, and preferably 0.5 mm or less. With respect to the tip angle β between the inner circumference 62 and the connecting line 66, the unevenness forming portion 5 can be enlarged as the tip angle β is reduced, and the rigidity of the protrusion P1 is increased as the tip angle β is increased to raise the bottom. The part 6 can be hard to be damaged. In the tip 67 having a chamfered shape, the angle between the straight line B1 extending the inner circumference 62 toward the tip 67 and the straight line B2 extending the connecting line 66 toward the tip 67 is defined as the tip angle β. The tip angle β is, for example, 15 degrees or more, preferably 30 degrees or more. The tip angle β is, for example, 65 degrees or less, preferably 50 degrees or less. The connecting line 66 should be smoothly connected without forming a corner with the inner edge 65. For example, an arc having a radius of 0.5 mm may be formed from the central portion of the connecting line 66 to the end portion 66e on the inner edge 65 side, and the inner edge 65 may be located on an extension line of the arc. By connecting smoothly, it is possible to prevent local stress concentration in the bottom raising portion 6 and suppress deformation of the bottom raising portion 6 itself when the stencil plate 3 is fixed with the screw 4.

Although the first region S1 shown on the left side has been described above in FIG. 5, the first region S3 shown on the right side may have the same shape as the first region S1 on the left side.

The spacer 6a may have a second region S2 along the inner wall extending in the longitudinal direction LD of the mounting groove 2 between the two first regions (S1, S3). The second region S2 has an outer edge 64 close to the inner wall extending in the longitudinal direction LD of the mounting groove 2 and an inner edge 65 located inside the outer edge 64. The second region S2 may be formed so as to be arranged in two in the width direction WD of the mounting groove. When the stencil plate 3 is fitted into the mounting groove 2, the second region S2 of the spacer 6a supports the stencil plate 3 and limits the stencil plate 3 from tilting in the width direction WD. Therefore, when the stencil plate 3 fitted in the mounting groove 2 is fixed with the screw 4, the stencil plate 3 can be held in an appropriate posture.

Further, if the spacer 6a has two first regions (S1, S3) respectively but does not have the second region S2, the two first regions (S1, S3) are separated, so that the spacer 6a is separated twice. It is necessary to carry out the work of mounting the above in the mounting groove 2. However, when the spacer 6a has a second region S2 in addition to each of the two first regions (S1, S3), the second region S2 connects the two first regions (S1, S3). A spacer 6a having a shaped shape is formed. Therefore, only one mounting operation is required to arrange the spacer 6a in the mounting groove 2.

<Second embodiment>
A second embodiment of the bottom raising portion will be described with reference to FIG. 8A. Matters other than those described below can be implemented in the same manner as in the first embodiment. The same applies to the third and subsequent embodiments.

The bottom raising portion 6 has a first region S1 located at a location surrounding the screw 4 (not shown in FIG. 8A). The first region S1 exhibits a ring that surrounds the screw 4 without fail. Specifically, the ring is sandwiched between an outer circumference 61 near the inner wall of the end of the mounting groove 2 and an inner circumference 62 located inside the outer circumference 61 and close to the screw 4 (not shown in FIG. 8A). Area. The outer peripheral 61 has a first edge 61a along the inner wall of the mounting groove 2 and a second edge 61b connecting the inner walls facing each other in the width direction. Further, as shown in FIG. 8A, it may have a rounded connecting edge 61c connecting between the first edge 61a and the second edge 61b. The inner circumference 62 has an annular shape. The outer circumference 61 may have an annular shape similar to that of the inner circumference 62. Since the first region S1 surrounds the screw 4 without fail, the pull-in suppressing effect of the stencil plate 3 in the present embodiment is larger than the pull-in suppressing effect of the first embodiment. Further, the first region S3 (not shown in FIG. 8A) surrounding the other screw 4 may also be provided with a ring that surrounds the screw 4 without fail.

In the present embodiment, since the bottom raising portion is composed of only the first region (S1, S3), the width W5 in the width direction WD of the unevenness forming portion 5 is larger than the width W5 of the unevenness forming portion 5 in the first embodiment. Can be expanded.

FIG. 8B shows a modified example of the second embodiment. The bottom raising portion 6 of the present embodiment has a first region S1 that exhibits a ring that surrounds the screw 4 (not shown in FIG. 8B) without fail, and a second region S2 described above. Since it has the second region S2, the second region S2 can support the stencil plate 3 and limit the stencil plate 3 from tilting in the width direction WD.

<Third Embodiment>
A third embodiment of the bottom raising portion will be described with reference to FIG. 9A. The bottom raising portion 6 has a first region S1 having a shape that makes a half circumference at a place surrounding the screw 4. Since there is no first region S1 on the unevenness forming portion 5 side from the point O at the center of the ring, the length L5 of the longitudinal LD of the unevenness forming portion 5 in the present embodiment is the unevenness forming portion 5 of the first embodiment. It can be expanded beyond the length L5. Further, the bottom raising portion 6 may have a first region S1 having a shape less than half a circumference (for example, 1/3 circumference) at a place surrounding the screw 4.

FIG. 9B shows a modified example of the third embodiment. The bottom raising portion 6 has a first region S1 having a half-circular shape and a second region S2 described above at a location surrounding the screw 4.

<Fourth Embodiment>
A method of fixing the spacer 6a to the mounting groove 2 will be described. When the spacer 6a is fixed to the bottom surface 21 of the mounting groove 2, the spacer 6a does not come off from the mounting groove 2 together with the stencil plate 3 when the stencil plate 3 is replaced. For fixing the spacer 6a to the bottom surface 21 of the mounting groove 2, for example, an adhesive, an adhesive tape, or welding may be used. Further, the spacer 6a may be attracted by a magnetic force by forming the bottom surface 21 of the mounting groove 2 with a magnetic material.

Another method of fixing the spacer 6a to the mounting groove 2 will be described with reference to FIGS. 10A and 10B. FIG. 10A is a cross-sectional view of the mounting groove 2 to which the spacer 6a is fixed in the width direction WD. Protrusions 27 are formed on the opposing inner walls of the mounting grooves 2. The side surface of the spacer 6a is pushed and deformed so that the width of the spacer 6a becomes smaller, and the protrusion 27 is overcome and arranged in the mounting groove 2. As a result, the spacer 6a is fixed to the mounting groove 2.

FIG. 10B is a cross-sectional view in the width direction WD before inserting the spacer 6a into the mounting groove 2. In this method, the width W6 in the width direction WD of the spacer 6a before being inserted into the mounting groove 2 is set to be larger than the width W2 in the width direction WD of the mounting groove 2. The side surface of the spacer 6a is pushed to deform the spacer 6a so that the width W6 becomes smaller, and the spacer 6a is arranged in the mounting groove 2. The spacer 6a arranged in the mounting groove 2 generates a force for pushing the inner wall of the mounting groove 2 due to elastic deformation, and this pushing force generates a frictional force, and the spacer 6a is fixed to the mounting groove 2.

FIG. 11A is a cross-sectional view in the width direction WD before the spacer 6a is inserted into the mounting groove 2. A spacer 6a is attached to the back surface of the stencil plate 3, and the stencil plate 3 with the spacer 6a is fixed to the mounting groove 2. As a modification, the spacer 6a may be integrated with the stencil plate 3. That is, the stencil plate 3 to which the spacer 6a is attached may be manufactured in advance. As a result, the process of inserting the spacer 6a alone into the mounting groove 2 can be reduced.

Further, the spacer 6a does not have to be fixed to the mounting groove 2 by the spacer 6a alone. The stencil plates 3 may be laminated and the stencil plates 3 may be fixed with the screws 4 without fixing the spacer 6a. The spacer 6a is sandwiched between the stencil plate 3 and the bottom surface 21 of the mounting groove 2 and is in a fixed state.

<Fifth Embodiment>
FIG. 11B shows a bottom raising portion 6 integrated with the mold 10. That is, when the mold is manufactured, the bottom raising portion 6 is formed on the bottom surface 21 of the mounting groove 2. As a result, the steps of creating the spacer 6a and inserting the spacer 6a can be reduced.

As described above, the molds 10 of the first to fifth embodiments are
Tire molding surface 1 and
The mounting groove 2 provided on the tire molding surface 1 and
A stencil plate 3 having a concave-convex forming portion 5 for forming irregularities on the outer surface of the tire T and being mounted in the mounting groove 2.
A screw 4 for fixing the stencil plate 3 to the mounting groove 2 and
A bottom raising portion 6 located between the bottom surface 21 of the mounting groove 2 and the region of the stencil plate 3 excluding the unevenness forming portion 5 is provided.
The bottom raising portion 6 includes a first region S1 located at a position surrounding the screw.

Even when the screw 4 is tightened with a force larger than the specified force, the stencil plate 3 is pulled in by the tightened screw 4 because the bottom raising portion 6 is provided between the bottom surface 21 of the mounting groove 2 and the stencil plate 3. It becomes difficult. Then, it is possible to prevent the stencil plate 3 from being bent or tilted. As a result, the expansion of the gap between the stencil plate 3 and the mounting groove 2 is prevented, and the inflow of rubber into the gap is suppressed. In this way, burrs and pinches can be reduced, the distinctiveness of the label on the tire after vulcanization molding is ensured, and poor appearance is suppressed.

The shape of the first region S1 may be a C shape formed along the inner wall of the end portion of the mounting groove 2.

As a result, since the bottom raising portion 6 surrounds the screw 4 in a wide range, the tightened screw 4 makes the stencil plate 3 more difficult to be pulled in, and suppresses bending and inclination of the stencil plate 3. Further, the unevenness forming portion 5 can be expanded to be close to the screw 4.

The first region S1 may have protrusions (P1, P2) protruding inward in the width direction of the mounting groove 2.

By having the protrusions (P1, P2), the range surrounding the screw 4 is expanded by the bottom raising portion 6, and the stencil plate 3 is more difficult to be pulled in by the tightened screw 4. Further, since the protrusions (P1, P2) are located at positions that do not interfere with the unevenness forming portion 5, the area of the unevenness forming portion 5 is unlikely to be affected. Therefore, it is possible to make the stencil plate 3 difficult to be pulled in, and to achieve both the effect of suppressing the bending and inclination of the stencil plate 3 and the effect of securing the area of the unevenness forming portion 5.

The bottom raising portion 6 may include a second region S2 along an inner wall extending in the longitudinal direction LD of the mounting groove 2.

When the stencil plate 3 is inserted into the mounting groove 2, the second region S2 of the bottom raising portion 6 supports the stencil plate 3 and limits the inclination of the WD in the width direction of the stencil plate 3. Therefore, when fixing the stencil plate 3 with the screw 4, the stencil plate 3 can be held in an appropriate posture and the inclination and bending of the stencil plate 3 can be suppressed.

The bottom raising portion 6 may be configured as a spacer 6a, which is separate from the mounting groove 2 and the stencil plate 3.

As a result, the bottom raising portion 6 having a desired shape can be easily manufactured.

Although the embodiments of the present disclosure have been described above with reference to the drawings, it should be considered that the specific configuration is not limited to these embodiments. The scope of the present disclosure is shown not only by the description of the embodiment described above but also by the scope of claims, and further includes all modifications within the meaning and scope equivalent to the scope of claims.

It is possible to adopt the structure adopted in each of the above-described embodiments in any other embodiment. The specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present disclosure.

The tire vulcanization die is not limited to the configuration of the above-described embodiment, and is not limited to the above-mentioned action and effect. In addition, it goes without saying that the tire vulcanization die can be modified in various ways without departing from the gist of the present invention. For example, each configuration or each method of the plurality of embodiments or modifications described above may be arbitrarily adopted and combined (each configuration or each method according to one embodiment may be combined with another configuration or the like according to another embodiment. It may be applied to a method or the like), and further, one or a plurality of configurations and methods according to further modification examples shown below may be arbitrarily selected and adopted for the configurations and methods according to the above-described embodiment. Of course it is good.

In the bottom raising portion 6 according to the above-described embodiment, the first region S1 and the first region S3 have the same shape. However, the bottom raising portion 6 is not limited to such a configuration, and the first region S1 and the first region S3 may have different shapes. For example, when the bottom raising portion 6 is a spacer 6a separate from the mold 10 and the stencil plate 3, the inner circumference of the first region S3 is centered in order to improve the detachability of the spacer 6a into the mounting groove 2. It may be slightly longer (for example, about 2 mm) than the inner circumference of the first region S1 which is a simple circle, such as by making a figure circumscribing two circles that are offset from each other. Further, when the spacer 6a has a distinction between the front and the back, the spacer 6a may be provided with a mark such as a notch so that the spacer 6a can be inserted into the mounting groove 2 without making a mistake.

1: Tire molding surface 2: Mounting groove 3: Stencil plate 4: Screw 5: Concavo-convex forming part, 6: Bottom raising part, 6a: Spacer, 10: Mold, 11: Tread mold part, 12, 13: Side molds, 14, 15: bead ring, 16: cavity, 21: bottom surface (of mounting groove), 24: hole (of mounting groove), 25: counterbore, 27: protrusion, 31: front surface (of stencil plate) , 32: Back surface (of stencil plate), 34: Concave (of stencil plate), 36: Convex (of stencil plate), 38: Peripheral area (of through hole of stencil plate), 39: Through hole, 41: ( Bottom surface (of screw), 61: Outer circumference (in the first area of the bottom raising part), 62: (In the first area of the bottom raising part): Inner circumference, 64: Outer edge (in the second area of the bottom raising part), 65: (Bottom raising part) Inner edge (of the second region of the part), 66: connecting line, 67: tip, LD: longitudinal direction, P1, P2: protrusion, S1, S3: first region (of the bottom raising part), S2: (of the bottom raising part) Second area, T: Tire

Claims (7)

Tire molding surface and
The mounting groove provided on the tire molding surface and
A stencil plate having a concavo-convex forming portion that forms concavities and convexities on the outer surface of the tire and mounted in the mounting groove,
With screws for fixing the stencil plate to the mounting groove,
A bottom raising portion located between the bottom surface of the mounting groove and the region of the stencil plate excluding the uneven forming portion is provided.
The bottom raising portion is a tire vulcanization die including a first region located at a place surrounding the screw. The tire vulcanization die according to claim 1, wherein the shape of the first region is a C shape formed along the inner wall of the end portion of the mounting groove. The tire vulcanization die according to claim 1 or 2, wherein the first region has a protrusion protruding inward in the width direction of the mounting groove. The tire vulcanization die according to any one of claims 1 to 3, wherein the bottom raising portion includes a second region along an inner wall extending in the longitudinal direction of the mounting groove. The tire vulcanization die according to any one of claims 1 to 4, wherein the bottom raising portion is configured as a spacer separate from the mounting groove and the stencil plate. In a method for manufacturing a tire vulcanization die, in which a stencil plate for forming irregularities on the outer surface of a tire is fixed to a mounting groove provided on a tire molding surface using screws.
Before or when mounting the stencil plate in the mounting groove, a bottom raising portion is formed in the mounting groove.
A method for manufacturing a tire vulcanization die, wherein the bottom raising portion includes a first region located at a position surrounding the screw. A tire is formed by using the tire vulcanization mold according to any one of claims 1 to 5 or the tire vulcanization mold manufactured by the method for manufacturing a tire vulcanization mold according to claim 6. A method for manufacturing a tire, which includes a step of vulcanization and molding.

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