JP2024019990A - Tire vulcanization mold and tire manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire vulcanization mold capable of reducing waste and cost, and a tire manufacturing method using the mold.

SOLUTION: A tire vulcanization mold includes: a tire molding surface 1 in contact with an outer surface of the tire; a mounting groove 2 provided on the tire molding surface 1; a marker forming member 3 including a plurality of marker elements arranged in a longitudinal direction of the mounting groove 2; and a fixing member 4 that fixes the marker forming member 3 attached to the mounting groove 2. The marker forming member 3 is formed of a plurality of blocks 5 divided in the longitudinal direction of the mounting groove 2.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a tire vulcanization mold in which a marker forming member is attached to the tire molding surface, and a tire manufacturing method using the same.

A mark is formed on the outer surface of a pneumatic tire, which includes letters and symbols representing the tire size, manufacturer name, year and week of manufacture, etc. As a sign forming member for forming such a sign, a stencil plate (also called a serial plate) made of a thin plate with a thickness of about 0.4 mm is known. The stencil plate is attached to the tire forming surface of the tire curing mold. By pressing an unvulcanized tire against a stencil plate during vulcanization molding, a sign is formed by transfer. Such stencil plates are described, for example, in Patent Documents 1 and 2.

A stencil plate is produced by stamping a sign made up of a plurality of sign elements (for example, characters) arranged in a row onto a single metal plate. When renewing tire markings, stencil plates are replaced and used stencil plates are discarded. Since the label usually includes the year and week of manufacture, the stencil plate must be replaced at least weekly, and the stencil plate must be discarded each time. For this reason, there was a problem of increased waste. Furthermore, it is necessary to produce a number of stencil plates depending on the frequency of updating the sign, which tends to increase costs.

JP2005-88517 JP2014-172360

The present disclosure has been made in view of the above circumstances, and its purpose is to provide a tire vulcanization mold that can reduce waste and costs, and a method for manufacturing tires using the same. There is a particular thing.

The tire vulcanization mold of the present disclosure includes a tire molding surface in contact with the outer surface of the tire, a mounting groove provided on the tire molding surface, and a sign forming mold including a plurality of sign elements arranged in the longitudinal direction of the mounting groove. and a fixing member for fixing the mark forming member mounted in the mounting groove, and the mark forming member is formed of a plurality of blocks divided in the longitudinal direction of the mounting groove.

The tire manufacturing method of the present disclosure includes a step of vulcanizing and molding a tire using the tire vulcanization mold described above.

A vertical cross-sectional view schematically showing an example of a tire vulcanization mold according to the present disclosure Perspective view taken along the X arrow direction in Figure 1 Cross-sectional view taken along line A-A in Figure 2 Cross-sectional view taken along the line B-B in Figure 2 An exploded perspective view of a marker forming member and a fixing member. Perspective view of block

Embodiments of the present disclosure will be described with reference to the drawings.

FIG. 1 shows a cross section of a tire vulcanization mold 10 (hereinafter sometimes simply referred to as "mold 10") along a tire meridian cross section. This mold 10 is in a closed state. The tire T is set with the tire axial 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.

The mold 10 includes a tread mold part 11 for molding the tread part of the tire T, a pair of side mold parts 12 and 13 for molding the sidewall part of the tire T, and a pair of side mold parts 12 and 13 for molding the sidewall part of the tire T. bead rings 14 and 15. The mold 10 includes a tire molding surface 1 that contacts the outer surface of a tire T set in a cavity 16. The tire molding surface 1 includes the inner surface of the tread mold section 11, the inner surfaces of the side mold sections 12 and 13, and the inner surfaces of the bead rings 14 and 15. Although not shown, the inner surface of the tread mold portion 11 is provided with an uneven portion for forming a tread pattern.

An example of the material for the inner surface of the tread mold portion 11 is aluminum. This aluminum material is a concept that includes not only pure aluminum materials but also aluminum alloys, such as Al-Cu, Al-Mg, Al-Mg-Si, Al-Zn-Mg, and Al-Mn. , Al-Si type. Examples of the material for the inner surfaces of the side mold parts 12 and 13 and the inner surfaces of the bead rings 14 and 15 include steel materials such as general structural rolled steel materials (for example, SS400).

The mold 10 includes a tire molding surface 1 in contact with the outer surface of the tire T, a mounting groove 2 provided on the tire molding surface 1, a mark forming member 3 for forming a mark on the outer surface of the tire T, and a mounting groove. A fixing member 4 (not shown in FIG. 1) that fixes the marker forming member 3 attached to the marker forming member 2 is provided. The mounting groove 2 is provided by locally recessing a part of the tire molding surface 1, and the marker forming member 3 is fitted therein. In this embodiment, the mounting groove 2 is provided on the inner surface of the side mold part 12 (an example of the tire molding surface 1).

FIG. 2 is a perspective view taken along the X arrow direction in FIG. 1, and shows a part of the inner surface of the side mold part 12 located on the lower side. A mark forming member 3 is mounted in the mounting groove 2, and the mark forming member 3 is fixed by a fixing member 4. The longitudinal direction LD of the mounting groove 2 corresponds to the tire circumferential direction, and the lateral direction SD of the mounting groove 2 corresponds to the tire radial direction. Further, one side SD1 in the transversal direction SD corresponds to the outer side in the tire radial direction, and the other side SD2 corresponds to the inner side in the tire radial direction. The mounting groove 2 has a horizontally elongated shape in which a length L2 in the tire circumferential direction is larger than a width W2 in the tire radial direction. FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 4 is a sectional view taken along the line BB in FIG.

A recess 31 (not shown in FIGS. 3 and 5) is provided on the front surface of the marker forming member 3 facing the cavity 16. During vulcanization, the outer surface of the unvulcanized tire is pressed against the front of the sign forming member 3, and a convex sign is formed by transfer. Therefore, the recess 31 becomes a mirror image of the mark formed on the tire T when viewed from the front. In this example, the marker is formed by the character string "K6784539." That is, this sign is composed of eight sign elements: "K", "6", "7", "8", "4", "5", "3", and "9". In this way, the marker forming member 3 includes a plurality of (eight in this embodiment) marker elements lined up in the longitudinal direction LD of the mounting groove 2. Note that the sign element is not limited to characters, but may also be a symbol, a figure, or the like.

FIG. 5 is an exploded perspective view of the marker forming member 3 and the fixing member 4. As shown in FIG. In this mold 10, the marker forming member 3 is formed of a plurality of blocks 5 divided in the longitudinal direction LD of the mounting groove 2. In this embodiment, the marker forming member 3 is divided into eight pieces, which is the number of marker elements. The marker forming member 3 is configured by connecting a plurality of mutually independent blocks 5 in the longitudinal direction LD. FIG. 6 is a perspective view showing a single block 5. As shown in FIG. The block 5 is made of a metal material such as stainless steel or aluminum. Each block 5 has the same shape except for the recess 31 provided on the front face 51 thereof.

According to this configuration, when updating the sign of the tire T, it is possible to update the sign of the tire T by replacing only the block 5 including the required sign element. For example, if a sign contains the four-digit number "0712" representing the week and year of manufacture, and when updating it to "0713", block 5 of "2" should be replaced with block 5 of "3". You can replace it with Since the block 5 can be used repeatedly, when it becomes necessary in the future, the removed block 5 can be reused, and as a result, waste can be reduced. Furthermore, since the signs can be changed in various ways depending on the combination of blocks 5, it is not necessary to produce the sign forming members 3 in the number corresponding to the updating frequency of the signs, and it is possible to reduce costs.

In this embodiment, the marker forming member 3 is divided so that one block 5 includes one marker element. That is, the sign forming member 3 is divided into characters (each sign element). This increases the number of combination patterns for blocks 5, making it easier to flexibly respond to variations in signs. However, the present invention is not limited to this, and one block may include a plurality of indicator elements. For example, the manufacturing year/week part, which is frequently updated, may be divided character by character, and the other parts may be integrated. The number of divisions of the marker forming member 3 is preferably three or more, more preferably four or more, but it is even more preferable that it is the number of marker elements as in this embodiment.

As shown in FIG. 6, the block 5 is formed into a rectangular plate shape as a whole. The block 5 has a front face 51 facing the cavity 16, a back face 52 facing the bottom face 21 of the mounting groove 2 (see FIGS. 3 and 4), a side part 53 of one side LD1 in the longitudinal direction LD, and a side part 53 of the other side LD2. , a side portion 55 on one side SD1 in the lateral direction SD, and a side portion 56 on the other side SD2. The back surface 52 is in contact with the bottom surface 21 of the mounting groove 2. The thickness T5 (see FIG. 4) of the block 5 is smaller than the length L5 of the block 5 along the longitudinal direction LD, and smaller than the width W5 of the block 5 along the transverse direction SD.

The thickness T5 of the block 5 is, for example, 1.0 mm or more, and more specifically, 1.0 to 2.0 mm. By having such a thickness T5, the recess 31 can be provided on the front surface 51 of the block 5, for example, by cutting using an NC machine. Therefore, the depth dimension of the recess 31 can be controlled with high precision, which is convenient for forming a convex marker with a required protrusion height. On the other hand, with conventional stencil plates made of thin plates, the recesses are carved by embossing, which can cause wear of the recesses and variations in depth, making it difficult to use convex signs. This may cause problems in forming the required protrusion height.

As shown in FIGS. 3 and 5, the mounting groove 2 is formed between a pair of shallow bottom portions 2S formed at both ends in the longitudinal direction LD, and is deeper than the shallow bottom portions 2S. It has a large deep bottom part 2D. The shallow bottom portion 2S has a relatively small depth, and the deep bottom portion 2D has a relatively large depth. The shallow bottom portion 2S is provided with a female screw hole 23 for attaching a bolt 7, which will be described later. The marker forming member 3 is fitted into the deep bottom portion 2D. Thereby, the marker forming member 3 (each block 5 constituting the marker forming member 3) can be appropriately positioned in the longitudinal direction LD. Furthermore, it is possible to prevent the gap between adjacent blocks 5 from becoming excessively large, thereby suppressing the occurrence of unnecessary rubber burrs.

As shown in FIG. 3, in this mold 10, the side portion 53 on one side and the side portion 54 on the other side of the block 5 in the longitudinal direction LD of the mounting groove 2 have complementary shapes that can be fitted into each other. are doing. According to this configuration, when the blocks 5 are connected in the longitudinal direction LD, the relative positions of the adjacent blocks 5 are stabilized, which is convenient. In this embodiment, the side portions 53 and 54 of the block 5 have a step shape as described below as a complementary shape that can be fitted into each other, but the shape is not limited to this.

In this embodiment, one side (the side part 53) of the side part 53 on one side and the side part 54 on the other side of the block 5 has a stepped shape in which the back side of the block 5 protrudes, and the other side One side (the side portion 54) has a stepped shape in which the front side of the block 5 protrudes. Therefore, the side portion 54 of the adjacent block 5 fits over the side portion 53 of the block 5, and a gap between the adjacent blocks 5 is formed in the shape of a crank (Fig. (See 3). According to this configuration, rubber that has entered the gap between adjacent blocks 5 is blocked midway, so that even if rubber burrs occur, they are hardly noticeable. Furthermore, since the block 5 cannot be fitted upside down, it can also be expected to be effective in preventing looseness.

The height h5 of the stepped surface with respect to the back surface 52 of the block 5 is set to be substantially the same as the height h2S of the shallow bottom portion 2S with respect to the bottom surface 21. Therefore, the stepped surface of the side part 53 from which the back side of the block 5 is projected and the shallow bottom part 2S are substantially flush with each other (see the lower left diagram in FIG. 3), and the connecting part 63 of the frame-like body 6 described later can be placed over the side portions 53. Further, the stepped surface of the side part 54 from which the front side of the block 5 is projected and the shallow bottom part 2S are substantially flush with each other (see the lower right figure in FIG. 3), and the side part 54 is aligned with the edge of the shallow bottom part 2S. It can be covered. As a result, the relative position of the marker forming member 3 (each block 5 constituting the marker forming member 3) with respect to the mounting groove 2 can be better stabilized.

The thickness T5 of the block 5 is preferably 80 to 100%, more preferably 90 to 100% of the depth D2 of the mounting groove 2 (see FIG. 4). The height h5 of the stepped surface is set to It is preferable that the thickness is 40% or more of the thickness T5. Further, from the viewpoint of ensuring the strength of the protruding portion of the side portion 54 of the block 5, the height h5 of the stepped surface is preferably 60% or less of the thickness T5.

As shown in FIGS. 2 to 5, the fixing member 4 includes a frame-shaped body 6 that holds down the periphery of the marker forming member 3, and bolts 7 as fasteners. The frame-shaped body 6 is made of a metal material such as stainless steel, for example. The frame-shaped body 6 is formed of a plate material having a thickness smaller than that of the block 5. The frame-shaped body 6 has a pair of extension parts 61 and 62 extending along the side wall 22 of the mounting groove 2, and a pair of connection parts 63 and 64 that connect them at both ends in the longitudinal direction LD. A window-like opening is formed between the pair of extension parts 61 and 62. A through hole 65 into which the bolt 7 is inserted is formed in the pair of connecting portions 63 and 64. Although the top surface of the bolt 7 protrudes from the tire molding surface 1, it may be arranged at a position recessed from the tire molding surface 1, or may be flush with the tire molding surface 1.

As shown in FIGS. 2 and 4, the frame-shaped body 6 (an extended portion 61 thereof) is mounted on the side portion 55 of the block 5 in the lateral direction SD of the mounting groove 2, recessed from the front surface 51 of the block 5. A mounting surface 55a on which the device is placed is formed. The side portion 55 has a stepped shape in which the back side of the block 5 protrudes, and the frame-like body 6 (of The extension portion 61) is fitted. Although the front surface of the frame-shaped body 6 is arranged at a position recessed from the tire molding surface 1, it may be arranged flush with the tire molding surface 1. Similar to the side part 55, the side part 56 is also formed with a mounting surface 56a on which the frame-shaped body 6 (the extension part 62 thereof) is mounted.

As shown in FIG. 3, the pair of connecting parts 63 and 64 are each placed on the shallow bottom part 2S. The connecting portion 63 of one side LD1 in the longitudinal direction LD protrudes from the wall surface 24 that rises from the bottom surface 21 and reaches the shallow bottom portion 2S toward the deep bottom portion 2D, and covers the side portion 53 of the block 5 adjacent to the shallow bottom portion 2S. It's covered. Further, the connecting portion 64 on the other side LD2 in the longitudinal direction LD is spaced apart from the wall surface 24 in a direction away from the deep bottom portion 2D so as not to prevent the side portion 54 of the block 5 from covering the edge of the shallow bottom portion 2S. There is. In order to avoid unnecessary rubber burrs, the distance between the pair of extended portions 61 and 62 and the distance between the pair of connecting portions 63 and 64 are such that an excessive gap is not formed between the block 5 and the frame body 6, respectively. It is set as follows.

The tire manufacturing method using the tire vulcanization mold 10 includes the step of vulcanizing and molding a tire T using this mold 10, more specifically, setting an unvulcanized tire in the cavity 16, and removing the unvulcanized tire. It includes a step of applying heat and pressure to a vulcanized tire to perform vulcanization molding. The tire expands and deforms due to expansion of the bladder, and its outer surface is pressed against the tire molding surface 1. A mark is formed by the mark forming member 3 on the outer surface of the tire after vulcanization molding.

In this embodiment, an example was shown in which the mounting groove 2 into which the marker forming member 3 is mounted is provided on the inner surface of the side mold part 12 located on the lower side. It may be provided on the inner surface of the side mold part 13 located therein. It is also possible to provide the mounting groove 2 into which the marker forming member 3 is mounted on the inner surface of the tread mold portion 11 or the inner surface of the bead rings 14 and 15.

In this embodiment, a mold structure including a tread mold part 11 and a pair of side mold parts 12 and 13 is illustrated, but the mold structure is not limited to this. It may also be a mold structure.

In the present embodiment, an example has been shown in which the marker forming member 3 (each block 5) is provided with the recessed portion 31 for forming a convex marker on the outer surface of the tire T, but the present invention is not limited to this. Therefore, for example, a convex portion for forming a concave mark on the outer surface of the tire T may be provided on the mark forming member 3 (each block 5).

[1]
As described above, the tire vulcanization mold 10 of the present embodiment includes the tire molding surface 1 in contact with the outer surface of the tire T, the mounting groove 2 provided in the tire molding surface 1, and the longitudinal direction LD of the mounting groove 2. A mark forming member 3 including a plurality of mark elements arranged in a row, and a fixing member 4 for fixing the mark forming member 3 mounted in the mounting groove 2. It is formed of a plurality of blocks 5 divided into.

According to this configuration, when updating the sign of the tire T, it is possible to update the sign of the tire T by replacing only the block 5 including the required sign element. Since the removed block 5 can be reused, waste can be reduced. Furthermore, since the signs can be changed in various ways depending on the combination of blocks 5, it is not necessary to produce the sign forming members 3 in the number corresponding to the updating frequency of the signs, and it is possible to reduce costs.

[2]
In the tire vulcanization mold 10 of [1] above, the lateral portion 53 on one side and the lateral portion 54 on the other side of the block in the longitudinal direction LD of the mounting groove 2 have complementary shapes that can be fitted into each other. is preferred. According to this configuration, when the blocks 5 are connected in the longitudinal direction LD, the relative positions of the adjacent blocks 5 are stabilized, which is convenient.

[3]
In the tire vulcanization mold 10 of [1] or [2] above, one of the lateral parts 53 on one side of the block 5 and the lateral parts 54 on the other side has a step where the back side of the block 5 protrudes. The other side preferably has a stepped shape in which the front side of the block 5 protrudes. According to this configuration, rubber that has entered the gap between adjacent blocks 5 is blocked midway, so that even if rubber burrs occur, they are hardly noticeable.

[4]
In the tire vulcanization mold 10 of any one of the above [1] to [3], the mark forming member 3 is preferably divided so that one block 5 includes one mark element. This increases the number of combination patterns for blocks 5, making it easier to flexibly respond to variations in signs.

[5]
In the tire vulcanization mold 10 of any one of [1] to [4] above, it is preferable that the fixing member 4 has a frame-shaped body 6 that presses the periphery of the marker forming member 3. Thereby, the marker forming member 3 can be held down and fixed in the mounting groove 2 without inhibiting the formation of the marker by the marker forming member 3.

[6]
In the tire vulcanization mold 10 of [5] above, the frame-shaped body 6 is placed on the side part 55 (56) of the block 5 in the transverse direction SD of the mounting groove 2, recessed from the front face 51 of the block 5. It is preferable that a mounting surface 55a (56a) is formed. Such a configuration is convenient for arranging the front surface of the frame-like body 6 at a position recessed from the tire molding surface 1 or flush with the tire molding surface 1.

[7]
In any one of the tire vulcanization molds 10 in [1] to [6] above, the mounting groove 2 is formed between a pair of shallow bottom portions 2S formed at both ends in the longitudinal direction LD and a pair of shallow bottom portions 2S. It is preferable that the marker forming member 3 has a deep bottom portion 2D which is formed and has a deeper depth than the shallow bottom portion 2S, and the marker forming member 3 is fitted into the deep bottom portion 2D. Thereby, the marker forming member 3 (each block 5 constituting the marker forming member 3) can be appropriately positioned in the longitudinal direction LD.

[8]
Further, the tire manufacturing method of the present embodiment includes a step of vulcanization molding the tire T using the tire vulcanization mold 10 of any one of the above [1] to [7]. By using the mold 10 as described above, it is possible to reduce waste and reduce costs.

The tire vulcanization mold of the present disclosure is equivalent to a normal tire vulcanization mold, except that the marker forming member installed in the mounting groove of the tire molding surface is configured as described above, and has a conventionally known shape and shape. Any material, mechanism, etc. can be adopted.

The tire vulcanization mold and tire manufacturing method of the present disclosure are not limited to the embodiments described above, and various improvements and changes can be made without departing from the spirit thereof.

1 Tire molding surface 2 Mounting groove 2D Deep bottom portion 2S Shallow bottom portion 3 Sign forming member 4 Fixing member 5 Block 6 Frame-shaped body 7 Bolt (an example of a fastener)
10 Tire vulcanization mold 16 Cavity 51 Front side of the block 52 Back side of the block 53 Side part of the block in the longitudinal direction 54 Side part of the block in the longitudinal direction 55 Side part of the block in the transversal direction 55a Placement surface 56 Short Side part 56a of the block in the hand direction Placement surface T Tire

Claims (8)

a tire molding surface in contact with the outer surface of the tire;
a mounting groove provided on the tire molding surface;
a marker forming member including a plurality of marker elements arranged in the longitudinal direction of the mounting groove;
a fixing member that fixes the label forming member attached to the attachment groove,
In the tire vulcanization mold, the mark forming member is formed of a plurality of blocks divided in the longitudinal direction of the mounting groove. The tire vulcanization mold according to claim 1, wherein a side portion on one side and a side portion on the other side of the block in the longitudinal direction of the mounting groove have complementary shapes that can fit into each other. One of the lateral parts on one side and the lateral part on the other side of the block has a step shape in which the back side of the block protrudes, and the other has a step shape in which the front side of the block protrudes. The tire vulcanization mold according to claim 2, comprising: The tire vulcanization mold according to claim 1, wherein the mark forming member is divided so that one block includes one mark element. The tire vulcanization mold according to claim 1, wherein the fixing member has a frame-shaped body that presses around the mark forming member. The tire processing device according to claim 5, wherein a mounting surface on which the frame-shaped body is mounted is formed in a side portion of the block in the lateral direction of the mounting groove, the mounting surface being recessed from the front surface of the block and on which the frame-shaped body is mounted. Sulfur mold. The mounting groove has a pair of shallow bottom portions formed at both ends in the longitudinal direction, and a deep bottom portion formed between the pair of shallow bottom portions and having a deeper depth than the shallow bottom portion,
The tire vulcanization mold according to claim 1, wherein the marker forming member is fitted into the deep bottom portion. A method for manufacturing a tire, comprising the step of vulcanization molding a tire using the tire vulcanization mold according to any one of claims 1 to 7.