阅读说明：本技术 轮胎用模板、轮胎硫化模具、以及使用该轮胎硫化模具的轮胎制造方法 (tire mold plate, tire vulcanizing mold, and tire manufacturing method using tire vulcanizing mold ) 是由 小原将明 于 2019-05-09 设计创作，主要内容包括：技术问题：将模板以在进行螺纹紧固时不弯曲的方式安装。解决方案：轮胎硫化模具(10)具备：胎侧成型面(18A)、在胎侧部(T5)的外表面形成凸状的标识(T5)的标识形成用的模板(20)、在胎侧成型面凹陷设置的安装凹部(22)、以及将模板固定于安装凹部的外螺纹件(28)。在安装凹部(22)设置有供外螺纹件(28)螺合的安装孔(34),在安装孔(34)的开口部设置有锥状的锪孔部(36)。在模板(20)设置有鼓出部(38),所述鼓出部(38)呈锥状,其接纳外螺纹件的头部(30)且嵌入锪孔部(36)。在鼓出部(38)设置有相对于该锥状的外周面(38B)向外侧突出而与锪孔部(36)的锪孔面(36A)抵接的突起(42)。(The technical problem is as follows: the form is installed in such a manner that it does not bend when the screw fastening is performed. The solution is as follows: a tire vulcanization mold (10) is provided with: the tire comprises a sidewall molding surface (18A), a template (20) for forming a convex mark (T5) on the outer surface of a sidewall part (T5), an installation concave part (22) concavely arranged on the sidewall molding surface, and a male screw (28) for fixing the template to the installation concave part. A mounting hole (34) into which the male screw (28) is screwed is provided in the mounting recess (22), and a tapered counter-boring section (36) is provided in the opening of the mounting hole (34). The die plate (20) is provided with a bulging portion (38), and the bulging portion (38) is tapered, receives the head portion (30) of the male screw, and is fitted into the counter-boring portion (36). The projection (42) is provided on the projection (38) so as to protrude outward relative to the tapered outer peripheral surface (38B) and come into contact with the counter-boring surface (36A) of the counter-boring section (36).)

1. A mold plate for a tire, which is attached to an attachment recess provided in a recessed manner on a tire side molding surface of a tire vulcanization mold by using a male screw, and which forms a convex mark on an outer surface of a tire side portion of the tire,

The template for a tire is characterized in that,

The tire mold plate includes a tapered bulging portion that receives the head portion of the male screw and is fitted into a tapered counter-boring portion of a mounting hole provided in the mounting recess,

A through hole through which the shaft of the male screw passes is provided at the tip of the bulging portion,

The projection portion is provided with a projection that projects outward with respect to the tapered outer peripheral surface thereof and abuts against the counter-boring surface of the counter-boring portion.

2. The template for a tire according to claim 1,

The projection is provided so that a part of the tapered outer peripheral surface of the projection portion bulges outward.

3. The template for a tire according to claim 1,

The protrusion is provided at the front end of the bulging portion in a curved shape.

4. The template for a tire according to claim 3,

The projection is provided so that the tip of the bulging portion is bent outward so as to expand in a reverse taper shape.

5. The form for a tire according to any one of claims 1 to 4,

The projection is annularly provided over the entire circumference of the bulging portion.

6. The form for a tire according to any one of claims 1 to 4,

The plurality of protrusions are provided along the circumferential direction of the bulging portion.

7. A tire vulcanizing mold is provided with:

A sidewall molding surface for molding an outer surface of a sidewall portion of a tire;

The template of any one of claims 1 to 6;

an installation concave part which is arranged on the side wall molding surface in a concave way and is internally provided with the template;

An external screw member for fixing the formwork to the mounting recess;

a mounting hole for screwing the male screw provided in the mounting recess; and

And a tapered counter bore portion provided at an opening of the mounting hole.

8. A method of manufacturing a tire, comprising:

A step of vulcanizing and molding the green tire by using the tire vulcanizing mold according to claim 7.

Technical Field

Embodiments of the present invention relate to a tire mold plate (hereinafter, simply referred to as a mold plate) for forming a mark on an outer surface of a sidewall portion of a tire, a tire vulcanizing mold for vulcanizing and molding the tire, and a tire manufacturing method using the tire vulcanizing mold.

background

In general, marks such as characters, symbols, and figures are provided on the outer surface of the sidewall portion of a pneumatic tire in order to facilitate recognition of the manufacturer, type, size, year of manufacture, week, and the like of the tire. In order to form such a mark, a technique is known in which a mold plate made of a metal plate such as aluminum or iron is replaceably attached to a sidewall forming surface of a vulcanization mold.

Conventionally, the mark is formed in a concave shape on the outer surface of the sidewall portion. In recent years, it has been desired to form a mark in a convex shape, and techniques for forming a convex mark have been proposed (see patent documents 1 to 3). In these documents, a template having a concave portion for forming a mark is produced by embossing using a thin metal plate. Through holes are provided at both ends of the template, and the template is fixed to the mounting recess of the sidewall molding surface by countersunk screws through the through holes.

Disclosure of Invention

Technical problem to be solved

Fig. 11 is a cross-sectional view showing an example of fixing the die plate 100 to the mounting recess 110 using a countersunk screw 120. The die plate 100 is provided with a tapered bulging portion 101 for receiving a head 121 of the countersunk head screw 120, and a through hole 102 for passing a shaft 122 of the countersunk head screw 120 is provided at a tip of the bulging portion 101. The mounting recess 110 is provided with a mounting hole 111 into which a countersunk screw 120 is screwed, and an opening of the mounting hole 111 is provided with a tapered counter-boring portion 112.

in such a configuration, when the die plate 100 is fitted into the mounting recess 110 and fixed by the countersunk screw 120, the bulging portion 101 may be drawn downward toward the center of the countersink 112 as the countersunk screw 120 is tightened. As a result, as shown by a two-dot chain line 100' in fig. 11, the die plate 100 may be attached in a bent state in which the central portion in the longitudinal direction thereof is raised, and this may cause a molding defect.

An embodiment of the present invention has been made in view of the above points, and an object thereof is to provide a template for a tire, which can be attached so as not to be bent when screwing is performed.

(II) technical scheme

The template for a tire according to the embodiment of the present invention is a template for a tire that is attached to an attachment recess provided in a recessed manner on a side wall molding surface of a tire vulcanization mold using a male screw, and that forms a convex mark on an outer surface of a side wall portion of the tire. The die plate includes a tapered bulging portion that receives the head portion of the male screw and is fitted into a tapered counter-bore portion of a mounting hole provided in the mounting recess. A through hole through which the shaft portion of the male screw passes is provided at the front end of the bulging portion. The projection portion is provided with a projection that projects outward with respect to the tapered outer peripheral surface thereof and abuts against the counter-boring surface of the counter-boring portion.

A tire vulcanization mold according to an embodiment of the present invention includes: a sidewall molding surface for molding an outer surface of a sidewall portion of a tire; the above template; an installation concave part which is arranged on the side wall molding surface in a concave way and is internally provided with the template; an external screw member for fixing the formwork to the mounting recess; a mounting hole for screwing the male screw provided in the mounting recess; and a tapered countersink provided at an opening of the mounting hole.

The tire manufacturing method according to the embodiment of the present invention includes a step of vulcanizing and molding a green tire using the tire vulcanizing mold.

(III) advantageous effects

According to the present embodiment, since the projection projecting outward is provided in the projection portion of the die plate fitted into the spot facing portion of the mounting recess and abuts against the spot facing surface of the spot facing portion, the projection portion can be prevented from being drawn toward the center of the spot facing portion when the die plate is fastened by the male screw. Therefore, the formwork can be attached without bending.

Drawings

Fig. 1 is a half sectional view showing a state at the time of vulcanization of a tire vulcanizing mold according to an embodiment.

Fig. 2 is a front view of the template.

Fig. 3 is a sectional view showing a state of mounting the die plate to the mounting recess along the line III-III in fig. 2.

fig. 4 is a sectional view showing a state in which the die plate is attached to the attachment recess portion along the line IV-IV of fig. 2.

Fig. 5 is an exploded view of fig. 4.

fig. 6 is a side view of the tire.

Fig. 7 is an enlarged cross-sectional view of a sidewall portion formed with a logo.

Fig. 8 is a main portion sectional view of the template of other embodiments.

Fig. 9 is a sectional view showing a mounted state of a template according to another embodiment.

Fig. 10 is a sectional view showing a mounted state of a template according to another embodiment.

Fig. 11 is a sectional view showing a mounted state of a template of a comparative example.

description of the reference numerals

10-tyre vulcanization mould; 18A-sidewall forming surface; 20-template; 22-a mounting recess; 28-external screw thread member; 30-a head; 32-a shaft portion; 34-mounting holes; 36-spot-facing part; 36A-countersink face; 38-a bulge; 38A-front end; 38B-outer peripheral surface; 40-a through hole; 42. 42A, 42B, 42C-protrusions; a T-pneumatic tire; t4-sidewall portion; t5-identification.

Detailed Description

the embodiments are described below with reference to the drawings.

Fig. 1 is a view showing a tire vulcanizing mold (hereinafter, simply referred to as a vulcanizing mold) 10 according to an embodiment for vulcanizing and molding a pneumatic tire T. Here, the pneumatic tire T is configured to include: a tread portion T1 constituting a ground contact surface; a pair of side portions T2, T2 extending from both widthwise ends of the tread portion T1 inward in the tire radial direction; and bead portions T3, T3. The pneumatic tire T may have a general tire structure, other than the marks provided to the sidewall portions T4. Here, the sidewall portion T4 is a concept including a sidewall portion T2 and a bead portion T3.

The vulcanizing mold 10 is a mold for setting an unvulcanized green tire and performing vulcanization molding. The vulcanizing mold 10 includes: a tread mold 12 having a tread molding surface 12A for molding an outer surface of the tread portion T1; a pair of upper and lower sidewall molds 14, 14 having sidewall molding surfaces 14A, 14A for molding an outer surface of the sidewall portion T2; a pair of upper and lower bead molds 16, 16 having bead molding surfaces 16A, 16A for molding an outer surface of a bead portion T3; the vulcanizing mold 10 forms a cavity as a molding space of the tire T.

As shown in fig. 1, the sidewall mold 18 having the sidewall molding surface 18A for molding the sidewall portion T4 includes: a template 20 for forming a mark, and a mounting recess 22 for mounting the template 20. Here, the sidewall mold 18 is a concept including the sidewall mold 14 and the bead mold 16. The sidewall molding surface 18A is a concept including the sidewall molding surface 14A and the bead molding surface 16A.

In this example, the shoe 20 and the attachment concave portion 22 are provided on the side molding surface 14A, but may be provided on the bead molding surface 16A, or may be provided on both the side molding surface 14A and the bead molding surface 16A.

As shown in fig. 1, 6, and 7, the template 20 is a member for forming a convex logo T5 on the outer surface T41 of the sidewall T4. As shown in fig. 2, the form 20 is made of a metal plate having a length L in the tire circumferential direction and a lateral length larger than the width W in the tire radial direction. Specifically, the pattern plate 20 is an elongated strip-like member extending while being bent in the tire circumferential direction. The thickness t1 (see FIG. 3) of the metal plate is not particularly limited, and may be, for example, 0.2 to 0.8mm or 0.4 to 0.7 mm.

As shown in fig. 2 and 3, the die plate 20 includes a mark-forming concave portion 24 formed by embossing and recessed from the surface 20A thereof. That is, a concave portion 24 is provided on a surface 20A of the mold plate 20 facing the tire T side (i.e., facing the cavity), and the concave portion 24 is formed by embossing (bulging processing method) performed from the surface 20A side. The concave portion 24 is configured in a shape in which a logo T5 formed on an outer surface T41 (see fig. 6 and 7) of the sidewall portion T4 is inverted. The symbol T5 includes characters, symbols, or figures indicating the manufacturer, type, size, manufacturing number, year, month, and day of manufacture, and the like of the tire. In the example of fig. 2, the character string of "HLD 5011" is designated as a symbol T5, and the concave portion 24 is formed in an inverted shape. The depth D1 of the concave portion 24 from the surface 20A is not particularly limited, and may be, for example, 0.3 to 1.2 mm.

by forming the concave portions 24, convex portions 26 corresponding to the concave portions 24 are formed on the back surface 20B side of the die plate 20. That is, since the convex portion 26 is a result of the concave portion 24 being viewed from the back surface 20B side of the die plate 20, the protruding height thereof is substantially the same as the depth of the concave portion 24.

As shown in fig. 3, the fitting recess 22 is recessed in the sidewall molding surface 18A, and the mold plate 20 is fitted therein. The mounting recess 22 is a horizontally long groove corresponding to the die plate 20 so as to be fitted with the die plate 20. The depth D2 of the mounting recess 22 is not particularly limited, and may be, for example, 0.8 to 1.8mm or 1.0 to 1.5 mm.

The die plate 20 is fitted or inserted into the mounting recess 22, and is fixed in the mounting recess 22 by the male screw 28, as shown in fig. 4. In this example, the die plate 20 is fixed to the attachment recess 22 at both ends in the longitudinal direction LD thereof by male screws 28.

As shown in fig. 5, the male screw 28 includes a head portion 30 having a tapered (i.e., truncated cone-shaped) support surface 30A and a shaft portion 32 having a thread on an outer peripheral surface thereof. In this example, a countersunk head screw (i.e., a flat head screw) in which the upper surface 30B of the head 30 is formed in a flat planar shape is used, but a round head screw in which the upper surface of the head is circular may be used, for example.

As shown in fig. 4 and 5, the bottom surface 22A of the mounting recess 22 is provided with a mounting hole 34 into which the male screw 28 is screwed. The inner peripheral surface of the mounting hole 34 is provided with a screw thread. A tapered spot facing 36 is provided at an opening of the mounting hole 34 (i.e., a portion that opens into the mounting recess 22). That is, the spot facing 36 is a truncated cone-shaped space portion gradually decreasing in diameter as it goes downward from the bottom surface 22A of the mounting recess 22, and has a tapered spot facing 36A.

the die plate 20 is provided with a bulging portion 38, and the bulging portion 38 is tapered, receives the head portion 30 of the male screw 28, and is fitted into the spot facing portion 36. The bulge portion 38 is formed by being recessed from the front surface 20A by embossing (projecting processing) from the front surface 20A side of the die plate 20, and is provided in a convex shape as viewed from the rear surface 20B, similarly to the concave portion 24. In detail, the bulging portion 38 has a tapered shape (i.e., a truncated cone shape) in which the diameter gradually decreases with distance from the surface 20A. A circular through-hole 40 through which the shaft portion 32 of the male screw 28 passes is provided at a tip (i.e., a lower end) 38A, which is a top portion of the bulging portion 38.

As shown in fig. 2, the through-holes 40 are provided at both ends of the template 20 in the longitudinal direction LD, and the mounting holes 34 are provided at both ends of the mounting recess 22 in the longitudinal direction corresponding to the through-holes 40.

as shown in fig. 5, the projection height D3 of the bulge portion 38 from the back surface 20B of the die plate 20 is set to be greater than the projection height D4 of the concave portion 24 toward the back surface 20B (i.e., the projection height of the convex portion 26). Preferably, the heights D3 and D4 of the rear surface of the concave portion 24 (i.e., the convex portion 26) and the bottom surface 22A of the mounting recess 22 are set so as not to abut (e.g., so as to be slightly raised) in a state where the expanded portion 38 is fitted in the countersink 36.

Further, the inclination angle of the inner peripheral surface 38C of the bulging portion 38 with respect to the axial direction coincides with the inclination angle of the bearing surface 30A of the male screw 28 with respect to the axial direction. Thus, when the head portion 30 of the male screw 28 is accommodated in the bulging portion 38, the clearance between the bearing surface 30A of the male screw 28 and the inner peripheral surface 38C of the bulging portion 38 is eliminated, and the entry of rubber into this portion can be prevented.

The ratio of the large diameter dimension (opening diameter at the upper end where the diameter is largest) d1 to the small diameter dimension (opening diameter at the lower end where the diameter is smallest) d2 of the bulge 38 is not particularly limited, and for example, d1/d2 × 100 may be 120 to 300%.

As shown in fig. 4 and 5, the projection 42 is provided on the bulging portion 38, and the projection 42 projects outward (i.e., radially outward) with respect to the tapered outer peripheral surface 38B of the bulging portion 38 and abuts against the spot facing surface 36A of the spot facing portion 36. The projection 42 is provided at a portion of the expanded portion 38 that enters the spot facing 36, and is provided at a position that abuts against the spot facing 36A of the spot facing 36 when the male screw 28 is fastened.

In this example, the projection 42 is provided so that a part of the tapered outer peripheral surface 38B of the bulging portion 38 bulges outward. That is, the projection 42 is not provided at the tip 38A of the bulging portion 38, but is provided at a position spaced from the tip 38A in the axial direction (i.e., in the vertical direction), and is formed by plastically deforming a part of the side wall of the bulging portion 38 having a tapered shape so as to protrude outward in a convex shape. Specifically, the projection 42 is provided in a ring shape over the entire circumference of the bulging portion 38 at a position substantially at a constant distance from the tip 38A of the bulging portion 38.

The projections 42 may be formed simultaneously with the formation of the bulge portion 38 by embossing (bulging method), or may be formed separately by pressing after the bulge portion 38 is formed by embossing.

The projection height D5 of the projection 42 with respect to the outer peripheral surface 38B of the bulge portion 38 is not particularly limited, and may be, for example, 0.1 to 1.2mm, or 0.3 to 1.0 mm.

When the die plate 20 is mounted to the mounting recess 22, the shaft portion 32 of the male screw 28 is inserted into the through hole 40 and screwed into the mounting hole 34 in a state where the die plate 20 is fitted or inserted into the mounting recess 22 and the expanded portion 38 is fitted into the counter-sunk portion 36 of the mounting hole 34. As a result, as shown in fig. 4, the head portion 30 of the male screw 28 is accommodated inside the expanded portion 38, and the expanded portion 38 is sandwiched between the head portion 30 and the spot facing surface 36A, and the die plate 20 is fixed to the attachment recess 22.

When the pneumatic tire T is manufactured using the curing mold 10 configured as described above, after a green tire (unvulcanized tire) is set in the curing mold 10 and the mold is closed, an unillustrated bladder disposed inside the green tire is inflated, and the green tire is brought into contact with the inner surface of the mold and is held in a heated state. Thereby, the green tire is vulcanized and molded to obtain the pneumatic tire T. The green tire may be molded by a known method.

In the obtained pneumatic tire T, as shown in fig. 6, a logo T5 is formed on an outer surface T41 of a side portion T4 (in the illustrated example, a side portion T2). As shown in fig. 7, the mark T5 has a convex shape protruding from the outer surface T41 of the sidewall T4, and is excellent in visual confirmation.

According to the present embodiment, the projection 42 projecting outward is provided on the projection 38 of the die plate 20 fitted into the spot facing 36 of the mounting recess 22, and abuts against the spot facing surface 36A of the spot facing 36. Thus, when the male screw 28 is used for fastening, the projection 42 abuts against the spot facing surface 36A and is pressed by the spot facing surface 36A, and therefore the bulging portion 38 can be prevented from being drawn downward toward the center of the spot facing portion 36. Therefore, the attachment of the form 20 in a bent state can be suppressed, and molding defects caused thereby can be prevented.

After the fastening by the male screw 28, the bulging portion 38 may be at least the projection 42 in contact with the spot facing surface 36A, but may be deformed by the fastening so that the portion entering into the spot facing portion 36 entirely contacts the spot facing surface 36A. In either case, the bulging portion 38 is locally strongly pressed against the spot facing surface 36A by the projection 42, and thus can be prevented from being drawn in as described above.

According to the present embodiment, since the projection 42 is provided on the entire circumference of the bulging portion, the effect of suppressing the bulging portion 38 from being drawn in can be enhanced.

In the present embodiment, it is preferable that the projection 42 of the bulging portion 38 is brought into contact with the spot facing surface 36A before the concave portion 24 for molding the mark T5 is brought into contact with the bottom surface 22A of the mounting concave portion 22. This can prevent the mark-forming concave portion 24 from coming into contact with the bottom surface 22A of the mounting concave portion 22 and deforming during screwing.

in the above embodiment, the projection 42 is formed annularly over the entire circumference of the bulging portion 38, but a plurality of projections may be provided in the circumferential direction of the bulging portion. For example, in the example shown in fig. 8, dot-shaped protrusions 42A are provided at a plurality of positions in the circumferential direction of the bulging portion 38. The projections 42A are provided in plurality at predetermined intervals in the circumferential direction at positions spaced apart from the tip 38A of the bulging portion 38 in the axial direction by a substantially constant distance, and are formed as hemispherical projections in this example.

The shape of the protrusion 42A is not limited to a hemispherical shape, and various shapes such as an elliptical shape, a polygonal shape such as a triangle or a rectangle in a plan view can be adopted. Further, the projection is not limited to a dot-like projection, and for example, a rib-like projection (i.e., a ridge) extending in the circumferential direction of the expanded portion 38 may be provided intermittently.

The projection 42A may be formed simultaneously with the formation of the bulge portion 38 by embossing, or may be formed by, for example, a punch after the bulge portion 38 is formed by embossing, as in the projection 42 of the above embodiment.

In the above embodiment, the projection 42 is provided separately from the distal end 38A of the bulging portion 38, but the projection may be provided at the distal end of the bulging portion in a curved shape.

for example, in the example shown in fig. 9, the tip 38A of the bulging portion 38 formed in a tapered shape is formed in a shape curved downward, that is, the tip 38A is formed in a short cylindrical shape parallel to the axial direction of the bulging portion 38. Therefore, at the tip end 38A of the bulging portion 38, a protrusion 42B that protrudes outward from the tapered outer peripheral surface 38B is formed over the entire periphery of the bulging portion 38. As shown in the cross-sectional shape in fig. 9, the projection 42B projects outward from the outer peripheral surface 38B because it projects radially outward from an extension 38B1 of the tapered outer peripheral surface 38B. Therefore, the projection 42B abuts the counterbore surface 36A before the outer peripheral surface 38B. Thus, as in the above-described embodiment, when the male screw 28 is used for fastening, the projection 42 comes into contact with the spot facing surface 36A and is pressed by the spot facing surface 36A, and therefore the bulging portion 38 can be prevented from being drawn downward toward the center of the spot facing portion 36.

As shown in fig. 10, the projection 42C may be provided by bending the tip 38A of the bulging portion 38 outward so as to expand in a reverse taper shape. That is, in this example, the tapered bulging portion 38 is once reduced in its tip end portion to form the small diameter portion 38D, and then expanded toward the opening end 38 AE. Therefore, the small diameter portion 38D does not coincide with the opening end 38 AE. By providing the projection 42C by expanding the tip 38A in the reverse taper shape in this way, the projection 42C can be pressed more strongly against the spot facing surface 36A when fastening is performed by the male screw 28. Therefore, the bulging portion 38 can be more effectively suppressed from being drawn downward toward the center of the countersink 36.

The embodiments have been described above, but these embodiments are merely provided as examples and do not limit the scope of the invention. These new embodiments can be implemented in other various ways, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention.